Malaysian Maritime Academy
Correspondence Course
Cargowork
MODULE 1 -TYPES OF CARGO Brief description on types of cargoes carried onboard merchant ships are as follows: -
General Cargo The modern term for these types of cargoes is breakbulk cargoes. It consists of individual items, e.g. pieces of machinery, bags, bales, and and small small quan quantit tities ies of liquid liquids s e.g. e.g. late late in deep deep tanks tanks etc. etc. !eavy !eavy items items may may be lifted lifted onboard using ships gear or shore cranes.
Grain "rain comprises of wheat, corn, rye, barley, oats, rice etc. "rains are liable to heat and#or sweat sweat,, espe especia cially lly if damp damp,, when when they they may may germina germinate te or rot, therefo therefore re requiring requiring careful careful pre-l re-lo oading ing inspe spectio tion, carr carria iag ge and venti ventilat lation ion.. In ma$or ma$or grain grain ports ports,, hand handlin ling g equipment%s are sophisticated, grain elevators being being equippe equipped d to unload unload railway railway wagons, wagons, lorries, barges or coastal craft and to reload from storage silos at high speed into ocean goin going g ship ships. s. &or &or disc discha harg rgin ing g grai grains ns,, the the pneumat pneumatic ic sucker sucker system, system, evacuato evacuators rs and grabs may be utilised.
Timber Incl Includ udes es timb timber er and and its its by prod produc uctt - e.g. e.g. hardwoo hardwood d and softwood softwood logs, sawn timber, wooden products, wood chips wood pulp and paper products. 'here practicable, timber as it is, is carried on deck. The securing and proper stowage of deck timber has the effect of increasing a ships freeboard and because of this timber carrier may be allotted lumber loadlines in addition to the usual load lines. Timbe Timberr load loadlin lines es allow allow ships ships to load load more more cargo as compared to the ordinary load lines as it has the following effects: a. (eserv (eserve e buoyan buoyancy cy of vessel vessel is increa increase sed d by compact compact mass of buoyant buoyant timber timber above above the freeboard deck. b. )ffe )ffect ctiv ive e free freebo boar ard d is incr increa ease sed d with with beneficial effect on the range stability. c. 'eathe 'eatherr deck deck hatch hatches es are prot protec ected ted..
ALAM/July 2002
Coal *oal is a minerali+ed fossil fuel widely utilised as a source of domestic and industrial power. s a sea borne product, it is always carried in bulk. It varies from soft bituminous type to hard anth anthra raci cite te thro throug ugh h to manu manufa fact ctur ured ed coal coal products. espite the carria riage of coal being an established trade, it remains as a difficult and dangerous dangerous cargo to transport due to dangers of gas eplosion, spontaneous spontaneous combustion, and cargo shifting during passage and corrosion to ships hold.
Fertiliser ay be carried in bulk, bags or liquid forms. ost fertili+ers are harmless, especially in bags but a few can be eplosive and#or corrosive. The I/ angero angerous us goods goods *ode *ode should should be consulted when carrying these cargoes.
Cement It may be subd subdivi ivided ded mainly mainly into into bagg bagged ed or bulk cargo in either finished cement or clinkers. It should should be kept kept scrup scrupul ulou ously sly dry dry so as to avoid solidifying. It is often preferred to load bagged cement into the tweendecks of general cargo ships having the facility of reducing the height of stow which in the case of ecessive tier heights in single deck ships may cause splitting of lower stowed bags. The handling of clinker is not so critical as it is normally carried in bulk0 it can however be etremely dusty and is therefore sub$ected to shore-based anti pollution regulations.
Livesto! 1ormally carried on the weatherdeck in tiers of speciall specially y construc constructed ted pens. pens. Include Includes s sheep, sheep, goats goats,, cattle cattle and and buffa buffaloe loes. s. /n this this type type of trade it is not unusual for ships to carry up to 233,3 233,333 33 anima animals ls and and thus thus the provi provisio sion n of adeq adequa uate te of fodde fodderr and and drinki drinking ng water water is a ma$or problem.
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Cargowork
Metals
Li$%i"s
These covers the whole range from raw base materials to metal articles e.g. steel products to scrap metal. ll steel products are liable to shift shift at sea and need need careful careful stowage stowage,, not only only to prevent any movement, movement, but also to avoid seriously damaging the ship.
7ea borne rne liq liquids ids ran range fro from drums rums of products such as bitumen capable of carriage in conventional tween deck ships, to parcels of edible oils transported in specially coated and heated tanks and to huge homogenous cargo of crude mineral oil carried by 89**%s.
(ust will serious seriously ly affect affect the value of steel steel produ products cts and and every every effor effortt shou should ld thus thus be made to avoid its occurrence.
ost of these products are inflammable with a low flash flash point point and and many many are dang dangero erous us in othe otherr ways ways,, eith either er emit emitti ting ng toi toic c gase gases s or possessing corrosive qualities or both.
Unitise" Cargo ny two or more cargo $oined together is said to be unit unitis ised ed - stra strapp ppin ing g toge togeth ther er,, prepreslinging, palletisation, containeri+ation, etc. lthough lthough unitisation unitisation may increase costs to some some ete etent nt 4et 4etra ra pack packag agin ing g cost cost5, 5, it enhances cargo handling operations, reduce pilferages pilferages simplify tallying, reduce the number of peop people le per per gang gang.. In anot anothe herr word words s it contr contribu ibutes tes great greatly ly to a faster faster turn turn aroun around d time for the ship. )ample of unitised cargo is of soft drinks packed on pallet.
Containers *ontainers are basically $ust a bo in which carg cargoe oes s are are plac placed ed and and the the bo bo itse itself lf is trans transpo porte rted. d. a$ori a$ority ty of gene general ral purpo purpose se containers are boes constructed with walls of aluminium or thin steel sheeting, corrugate corrugated d to provide provide strength strength and rigidity, rigidity, reinforced corner posts with double watertight doors at one end. 6sed to carry various types of cargo e.g. tobacco, electronic components, clothing etc.
Ree#er These are mainly concerned with the carriage of fruits fruits and vegetable vegetables s and are seasona seasonal, l, relying on the harvesting of crops around the world. world. /ther /ther reefer reefer cargoes cargoes include include fro+en fro+en fruit $uices, flowers and bulbs, dairy products, meat, poultry and fish, pharmaceuticals, pharmaceuticals, -ray films etc. They are handled either as a break bulk, in pallets or in containers. They require scru scrupu pulo lous usly ly clea clean n and and odor odorle less ss carg cargo o compartments to avoid contamination and the carriage temperature is absolutely critical.
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Gases *onsists *onsists mainly of liquefie liquefied d petroleu petroleum m gas 9" 9" and and lique liquefie fied d natur natural al gas gas - 91". 91". 9" 9" consists mainly of propane and butane and are carr carrie ied d eith either er unde underr pres pressu sure re at ambi ambien entt temperature, fully refrigerated 4-;3 ° to <=°*5 or semi semi refr refrig iger erat ated ed unde underr a comb combin inat atio ion n of pressure pressure and reduced reduced temperat temperature. ure. ny gas that vaporises during handling and carriage will be reliquefied and circulated back to the tanks. 91" is mainly ethane with propane and butane making up the balance. It is carried at or near its its boil boilin ing g poin pointt temp temper erat atur ure e of - 2>< 2>< °* at atmosphe atmospheric ric pressure pressure.. /ne of the particul particular ar features of 91" is that cargo boil off is used as fuel by the ship. !owever, given the high value of natu natura rall gas, gas, the the use use of boil boil off off for for such such purpose is becoming uneconomic and efforts are being made to reduce the daily rate of boil off to below 3.?@A of cargo quantity.
Dangero%s Cargo 6nde 6nderr the the ausp auspic ices es of I/, I/, a ang anger erou ous s "ood "oods s *ode *ode has has evol evolve ved d enco encomp mpas assi sing ng recom recommen menda datio tions ns as to stowa stowage ge,, carri carriag age, e, packaging, documentation and labeling of most dangerous dangerous commodities. Bulk carriers are likely to be affected by the carriage by one homogenous dangerous cargo at a time e.g. sulphur in bulk or a chemical tanker is likely to carry several lots of dangerous bulk liquids at any one time. !owe !oweve ver, r, it is the the gene genera rall carg cargo o ship ships s contai containe nerr ships ships,, which which can be epec epected ted carry several classes of dangerous goods any any one one time, time, the the relati relative ve effect effect of which which
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Cargowork
Metals
Li$%i"s
These covers the whole range from raw base materials to metal articles e.g. steel products to scrap metal. ll steel products are liable to shift shift at sea and need need careful careful stowage stowage,, not only only to prevent any movement, movement, but also to avoid seriously damaging the ship.
7ea borne rne liq liquids ids ran range fro from drums rums of products such as bitumen capable of carriage in conventional tween deck ships, to parcels of edible oils transported in specially coated and heated tanks and to huge homogenous cargo of crude mineral oil carried by 89**%s.
(ust will serious seriously ly affect affect the value of steel steel produ products cts and and every every effor effortt shou should ld thus thus be made to avoid its occurrence.
ost of these products are inflammable with a low flash flash point point and and many many are dang dangero erous us in othe otherr ways ways,, eith either er emit emitti ting ng toi toic c gase gases s or possessing corrosive qualities or both.
Unitise" Cargo ny two or more cargo $oined together is said to be unit unitis ised ed - stra strapp ppin ing g toge togeth ther er,, prepreslinging, palletisation, containeri+ation, etc. lthough lthough unitisation unitisation may increase costs to some some ete etent nt 4et 4etra ra pack packag agin ing g cost cost5, 5, it enhances cargo handling operations, reduce pilferages pilferages simplify tallying, reduce the number of peop people le per per gang gang.. In anot anothe herr word words s it contr contribu ibutes tes great greatly ly to a faster faster turn turn aroun around d time for the ship. )ample of unitised cargo is of soft drinks packed on pallet.
Containers *ontainers are basically $ust a bo in which carg cargoe oes s are are plac placed ed and and the the bo bo itse itself lf is trans transpo porte rted. d. a$ori a$ority ty of gene general ral purpo purpose se containers are boes constructed with walls of aluminium or thin steel sheeting, corrugate corrugated d to provide provide strength strength and rigidity, rigidity, reinforced corner posts with double watertight doors at one end. 6sed to carry various types of cargo e.g. tobacco, electronic components, clothing etc.
Ree#er These are mainly concerned with the carriage of fruits fruits and vegetable vegetables s and are seasona seasonal, l, relying on the harvesting of crops around the world. world. /ther /ther reefer reefer cargoes cargoes include include fro+en fro+en fruit $uices, flowers and bulbs, dairy products, meat, poultry and fish, pharmaceuticals, pharmaceuticals, -ray films etc. They are handled either as a break bulk, in pallets or in containers. They require scru scrupu pulo lous usly ly clea clean n and and odor odorle less ss carg cargo o compartments to avoid contamination and the carriage temperature is absolutely critical.
ALAM/July 2002
Gases *onsists *onsists mainly of liquefie liquefied d petroleu petroleum m gas 9" 9" and and lique liquefie fied d natur natural al gas gas - 91". 91". 9" 9" consists mainly of propane and butane and are carr carrie ied d eith either er unde underr pres pressu sure re at ambi ambien entt temperature, fully refrigerated 4-;3 ° to <=°*5 or semi semi refr refrig iger erat ated ed unde underr a comb combin inat atio ion n of pressure pressure and reduced reduced temperat temperature. ure. ny gas that vaporises during handling and carriage will be reliquefied and circulated back to the tanks. 91" is mainly ethane with propane and butane making up the balance. It is carried at or near its its boil boilin ing g poin pointt temp temper erat atur ure e of - 2>< 2>< °* at atmosphe atmospheric ric pressure pressure.. /ne of the particul particular ar features of 91" is that cargo boil off is used as fuel by the ship. !owever, given the high value of natu natura rall gas, gas, the the use use of boil boil off off for for such such purpose is becoming uneconomic and efforts are being made to reduce the daily rate of boil off to below 3.?@A of cargo quantity.
Dangero%s Cargo 6nde 6nderr the the ausp auspic ices es of I/, I/, a ang anger erou ous s "ood "oods s *ode *ode has has evol evolve ved d enco encomp mpas assi sing ng recom recommen menda datio tions ns as to stowa stowage ge,, carri carriag age, e, packaging, documentation and labeling of most dangerous dangerous commodities. Bulk carriers are likely to be affected by the carriage by one homogenous dangerous cargo at a time e.g. sulphur in bulk or a chemical tanker is likely to carry several lots of dangerous bulk liquids at any one time. !owe !oweve ver, r, it is the the gene genera rall carg cargo o ship ships s contai containe nerr ships ships,, which which can be epec epected ted carry several classes of dangerous goods any any one one time, time, the the relati relative ve effect effect of which which
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relati relation on to stowag stowage e and and reacti reaction on betwe between en cargoes can be somewhat complicated. IMDG IMDG code code covers covers carriage carriage of dangero dangerous us goods in packaged from or in solid form in bulk. The I" code comes in < volumes plus a supplement. nother publication dealing with carriage of dangerous goods in 6 is known as CBlue BookD. NOTE - etail description of specific cargoes will will be give given n in the the subs subseq eque uent nt modu module les s where appropriate.
&ale Ca'ait(
Cargowork
advantage, with due regard to the necessary care and attentio attention n to conditio conditions ns of stowage stowage.. Thus Thus,, the the frei freigh ghtt earn earnin ing g capa capabi bili lity ty of the the vessel is kept at a maimum. To do this it is necessary to know the amount of space, which each each tonn tonne e of a comm commod odit ity y will will occu occupy py.. 7T/'") &*T/( is defined as the volume in cubi cubic c mete meters rs a tonn tonne e of that that carg cargo o will will occupy. The The figu figure re does does not not epr epres ess s the the actu actual al measurement measurement of a tonne of the cargo but takes into consideration the necessary for dunnage and the form and design of the packages. )amples of stowage factors are: *oal 2.2=#2.;; cu.m.#tonne. ai+e 2.;E cu.m.#tonne. (ubber in bales. 2.=2#2.=E cu.m.#tonne
This is the cubic capacity of a cargo compartment when the breadth is taken from the inside of the cargo battens or from the inne innerr edge edges s of the the frames frames,, and and the height height from the tank top to the lower edge of the n intelligent knowledge of the use of stowage factors s is neces necessar sary y to all all cargo cargo offic officers ers in beam beams s and and the the leng length th from from insi inside de of the the factor order order that that they they may may make make econo economic mic use use of bulkhead stiffeners or sparring where fitted. each available space unit.
Grain Ca'ait( This is the total internal volume of a cargo compartment measured from shell plating to shell plating and from tank top to under deck and and an allowa allowance nce is given given for for the volume volume occupied by frames and beams. This space is not only associated with the carriage of grain, as such, such, but but with with any any form form of bulk cargo, cargo, which which would would stow stow simila similarly rly,, that that is to say completely filling the space. It is obvious that a solid cargo can be stowed only up to the limits of the frames and beams where whereas as bulk bulk cargo cargo will will flow flow arou around nd such such membe members. rs. There Therefor fore e when when measu measurin ring g for general cargo, it is the bale capacity, which is taken into consideration. lthough lthough both grain and bale capacities capacities are normally used to show the volume or capacity of a ship ship to carr carry y carg cargo, o, othe otherr unit units s of meas measur urem emen entt are are more more appr approp opri riat ate e for for specific trades, e.g. T)6s for container ships, lane-metres for (o-(o ships, etc.
Sto)age Fator &or successful loading, a vessel must utili+e ever every y cubi cubic c mete meterr of spac space e to the the best best
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&ro!en Sto)age This is defined as that space in a loaded cargo compartment that is not filled with cargo. It is the space space occup occupie ied d by dunn dunnag age, e, the space space between packages and the space that is left over the last tier placed placed in stowage. stowage. Broken Broken stowage is epressed as a percentage of the total space of the compartm rtment. The percentage that has to be allowed varies with the type of cargo and with the space of the compartment. It is greatest when large cases have to be stowed in an end hold due to the shape of the compartment. Broken stowage in an end hold due to the shape of the compa compartm rtmen ent. t. Broke Broken n stowa stowage ge on unifo uniform rm packaged packaged commodities will average about 23A that on general cargo will average about ?@A. &or eample: a5 consign consignmen mentt of apple apples s packed packed in boes boes havin having g stowa stowage ge facto factorr 2.;2c 2.;2cu. u. m#ton m#ton to be loaded in a cargo space having bale capacity equals to 2333cu m. *alculate the total amount in weight that can be loaded. "iven cargo hold space F 2333 cu m cargo stowage factor F 2.;2
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∴
cargo loaded
Correspondence Course
volume
F stowage factor 2333 F 2.;2 F E>;.;> Tons #
Cargowork
is carefully drawn up to show the identification, desc descri ript ptio ion n and and quan quanti tity ty of the the good goods s 4as 4as veri verifi fied ed from from the the ship ship%s %s tall tally y shee sheets ts5. 5. ny ny damage to the cargo noticed before loading on board is entered on the #( and the receipt is then said to be Hclaused%. ll particulars from the #( are transferred to the HBill of 9ading%.
b5 6sing 6sing the the abo above ve que questi stion on 425 425 *alcu *alculat late e the total total amoun amountt of cargo cargo to be ) Bill of Lading (B/L) (B/L) - is properly prepared loaded if 23A broken stowage is allowed. by the ship-owner 4or his agent5 from details in the the ate ate%s %s (ece (eceip ipt, t, and and deli delive vere red d to the the 1ett volume occupied by cargo allowing for ship shippe perr - frei freigh ghtt bein being g usua usuall lly y paid paid at this this 23A broken stowage stage. It is a legal document, which provides 2333 cu m evidence of a Hcontract of carriage% between the F 2.2 shipper and the ship owner 4the carrier5. It also F G3G.3G cu m acts acts as a docu docume ment nt of titl title e to the the good goods s G3G .3G cu m described therein i.e. the holder of the B#9 is ∴ cargo loaded F 2.;2 cu m#ton regarded as the rightful owner of the cargo. F >G;.G> Tons c) Cago Manifest Manifest - is a document containing a deta detail iled ed and and comp comple lete te list list of carg cargo o Has Has Dea")eig*t Cargo loaded%, d%, compi compile led d by the the ship ship owne ownerr 4or his Is cargo on which freight is usually charged loade on its its weig weight ht.. *arg *argoe oes s whic which h meas measur ures es agent5 from the Bill of 9ading. *opies of the manife ifest are delive livere red d to the the shi ship, the the 2.??c 2.??cu.m u.m.#t .#ton onne ne 4s.f5 4s.f5 or less less is classe classed d as man steved stevedore ores s at the discha dischargi rging ng ports ports and and to deadweight cargo. *ustoms authorities at the discharging ports.
Meas%rement Cargo
comprehensive record of all cargo in Is cargo on which freight is usually charged s it is a comprehensive vessel,, it permi permits ts the checki checking ng of cargo cargo on the volume occupied by the cargo and this the vessel discharge thereby avoiding cargo is usually light, bulky cargo having a during over overca carr rria iage ge#s #sho hort rt land landin ing. g. "ove "overn rnme ment nt stowage factor of more than 2.?? uthorities uthorities may use it as material for cu.m.#tonne. compilation of the national trade statistics vi+. the nation%s imports#eports. It has been the custom to set two standards by which which cargo cargo is meas measure ured d and and freigh freightt is !lan - is a plan drawn up by the charged. This is in order to avoid ecessive d) Cago !lan frei freigh ghtt char charge ges, s, whic which h migh mightt be out out of ship%s cargo officer showing the stowage of all prop propor orti tion on to the the spac space e occu occupi pied ed by a cargo on board the vessel. *opies of the plan parti particu cular lar consig consignme nment, nt, and and to prote protect ct the are sent in advance to the discharge ports so that prepa preparat ratio ions ns for for her her unloa unloadin ding g can be ship from loss of freight commensurate with that made before arrival at the port. long with the the amount of space used. summary of the cargo on board, a well drawn up cargo cargo plan plan greatl greatly y assist assists s in facil facilita itatin ting g A" +alorem Cargo discharge and avoidance of overcarraige#short &reight &reight for certain certain epensi epensive ve cargoes, cargoes, e.g. e.g. landing of cargo. precious stones, fold bars, etc. is not levied based on weight or measurement but on the e) Dange Dangeo" o"s s Cago Cago List List - a shipp ipper is value of the cargo. obligated to declare to the aster full details of any dangero dangerous#h us#ha+ar a+ardou dous s cargo cargo shipped shipped by Cargo Do%mentations him him and and cove covere red d unde underr the the CInt CInter erna nati tion onal al a) Mate’s Receipt (M/R) (M/R) - is a document of ari ariti time me angerou rous "oods *ode% 4th 4the receipt given by the ship%s chief officer 4the I... I...". ". *ode *ode5. 5. The aster aster is requir required ed to ate5 for goods actually received on board. It prepare a list of all dangerous#ha+ard dangerous#ha+ardous ous cargo
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shipped on board. It should show the correct technical name of the commodity, its Hclass% as per the I...". *ode, its quantity and weight, position of stowage on board, port of loading and the port of discharge.
Pre'aration O# ,ol" Prior To Loa"ing General Cargo s temporary custodians of the cargo, it is the duty of the ship%s officers to ensure that cargo is delivered in the same condition as it was received on board. Besides ensuring that damage to cargo does not occur during handling 4slinging, lifting by derricks#cranes, working forklifts etc5, it is also important to prevent damage as a result of the condition of the hold itself. 2.3 Cleaning t#e $old 1"1 The method and amount of cleaning required will depend upon the type of cargo previously carried in the hold. "enerally speaking, a hold which is ready to receive cargo should be swept clean, dry, well ventilated and free from odour of the previous cargo4es5.
1"2 The hold should be cleaned prior to loading. The degree of cleanliness required will depend on the nature of the cargo to be loaded. *argoes such as grain, sugar etc. will need a scrupulously clean hold 4and usually surveyed5 before loading can commence, whilst cargoes such as coal, steel etc. may not require the same level of cleanliness. ?.3 Inspecting t#e $old fo da%ages& testing 'ilge and fie sste%s fter cleaning the hold the following inspections#tests are normally carried out:
Cargowork
Hbacklash% does not occur when the bilge pump is stopped. ?.; *hecking the hold fire detection # etinguishing systems - most ships are fitted with the */? etinguishing system and the */? lines to the hold are cleared by passing compressed air. 6sing artificial smoke usually checks the detection system. ?.< *hecking oil#water tightness of the ouble Bottom tank top and its manhole covers - this is done by pressing up the tank to a head of oil#water and checking for leaks. ;.3 Maing t#e $old *e%in fee 8ermin such as rats, cockroaches, silver fish etc, in the holds, can cause etensive damage to cargo on board resulting in huge damage claims from shippers#consignees. It is a requirement by law that every ship must be in possession of a valid erating *ertificate. The ort edical /fficer issues this certificate after fumigation by the burning of sulphur or the release of cyanide gas has been carried out. The certificate is valid for si months, after which a erating )emption certificate will be issued if no diseased rats or a large number of rats are found on board. The rat population may be kept to a minimum by the use of anticoagulant bait, such as sodium fluoracetate. *ockroach bait, pesticides and insecticides may be used to eterminate cockroaches and other insects. *leanliness is the most important factor in keeping a ship vermin free. 'hen certain cargoes such as rice, are loaded, the holds are fumigated after loading to rid the cargo of weevils.
Assignment
lease submit the following assignment to ?.2 Inspection of the hold for internal 9 damages - e.g. pipe guard, ladder rungs, leaking pipes, bilge sounding striker plates, 25 hold, bale capacity ?333 cu m contains, leaking rivets#welding seams etc. 2?33 tonnes of bagged flour, 4stowage factor ?.? Testing the Bilge pumping system - This 2.2@ cu m#tonnes5. *alculate the broken is done if it has not been carried out earlier stowage. during washing of the hold etc. articular ?5 escribe a cargo hold preparation in your attention is paid to ensure that the bilge last ship and state the cargo loaded. 7tate the suction non-return valve is working and preparation of hold prior to load general cargo.
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MODULE - FACTORS TO CO.S/DER FOR GE.ERAL CARGO STO0AGE The following must be borne in mind when loading general cargo: -
turn round% is also dependent on port facilities for clearing the cargo etc.
25 *argoes should be well distributed in all hatches to increase the ort speed. ?5 &oodstuffs and other cargoes liable to tainting - need proper separation #segregation to avoid tainting damage.
General Cargo Sto)age
;5 !eavier cargo should be placed on deck#tank top whilst lighter cargo on top of these cargoes to prevent crushing damage. <5 It is a general rule that fragile and light packages are stowed in tween deck4s5 to avoid the effects of roll and pitch of vessels. @5 )nsure packages stowed evenly 4not tilting5, for eample near turn of bilge, end holds by the proper use of dunnage to achieve compactness of cargo stowage. >5 9ight packages 4cartons, etc.5 stowed away from cargo hold obstructions such as frames, deck beams, stiffeners. E5 8aluable cargo should be stowed in strong rooms or in *hief /fficer%s office. =5 To avoid cargoes being crushed during slinging use proper gears like pallet, spreader. G5 roper securing of cargoes and lashing are essential. )tra pad eyes may have to be welded to have more securing points for lashing cargoes.
Port S'ee"
The following points must be borne in mind when planning loading of "eneral *argo by *hief ate or officer in charge of loading. a5 7afety of the ship stability considerations proper trim#list#draught avoiding structural stresses avoiding physical damage from cargo b5 7afety of the crew and port workers preventing unstable cargo blocks avoiding blocking of escape routes #safety appliances protection from toic fumes#fire ha+ards c5 voiding damage to cargo avoiding condensation#water damage protection from taint # contamination # interaction preventing physical damage to cargo preventing pilferage d5 aimum use of available space on board minimi+ing Hbroken stowage using Hfiller% cargo e5 (apid and systematic discharging and loading providing maimum number of working hatches#even distribution preventing over stowed cargo preventing over carried#short landed cargo 4proper segregation#marking5. enhancing Hport speed%
)ach day that a ship remains unnecessarily in Cargo Plans port results in a reduction of the ship%s cargo plan is a plan showing the disposition earning capacity. n unnecessary delay in and distribution of cargo throughout the vessel, port increase the port dues allied costs and in as much detail as is possible. encroaches on the time that she would have been steaming on her net voyage. cargo plan for a general cargo ship will usually be drawn up at the last port of loading 7hips officers should aim for increasing Hport from information derived from the deck officers speed% by efficient distribution of cargo, cargo workbooks, from mates receipt and from readiness of cargo spaces etc. This Hspeed of
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loading plans produced by shore personnel at the loading ports. *opies of the plan will usually be sent ahead of the ship to the discharge ports. 'hilst the plan is not a scale drawing, it should show with some accuracy the location of specific parcels of cargoes in the locker doors, hatchways so that the order of discharge may be planned 'hilst the format of the plan will vary from company to company, most plans will show the lower holds in elevation 4side view5 and other compartments such as tween decks and deck lockers, in plan view. 'here possible, each parcel of cargo should be identified separately, but this is not always possible when many small parcels are involved 4in which case they are grouped together5. typical entry on the plan could be as follows: 9%//9#1" <33 *7)7 */(1) B))& C7(D ?;t. i.e. <33 cases of corned beef, loaded at 9iverpool for discharge at enang, all cases marked C7(D for identification and the total weight of the parcel is ?; tones. It is usual to colour the plan according to the port of discharge, so that the likelihood of overlooking a parcel of cargo and carrying it to the net port 4i.e. overcarriage5 is reduced. In the case of cargo having optional ports of discharge it is coloured in both port%s colours. 'here there is unused space ad$acent to stowed cargo, it is measured up, and the calculated volume measured, and entered on the plan. 8arious symbols and conventions may be used: - for eample, parcels separated by a diagonal line on a side elevation, are side by side in the hold. In addition to the actual drawing, other useful information is shown in the plan. The name of the ship, master%s name, the voyage number, cargo loaded /1 )*, in masthouses, and in various other etraneous places such as the mate%s office and the draft at the last loading port are shown in the cargo plan. It is good practice to append a statement of dangerous cargo on board for quick
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reference. summary of total tonnages loaded in each hold and other information regarding dead light, as fuel, stores and water0 means of separation used between particular parcels and the total space remaining are also appended to the plan. 1ote: The typical cargo plan of a general cargo ship is shown on the opposite page . The cargo plan has a number of functions: it helps to avert overcarriage and short delivery. the discharge sequence can be planned in advantage. the necessary cargo handling gear can be rigged in advance. discharge time can be estimated. transport arrangement for a particular parcel of cargo can be made. decisions can be made on proper ventilation can be arranged with the aid of the cargo plan. in the event of a fire breaking out in the compartment, the cargo plan is invaluable in fighting the fire, particularly if dangerous cargoes are in the compartment. should any cargo shift while the vessel is at sea, prompt action can be taken with the aid of the plan. the plan, enables the shipowner to assess the position regarding to diverting the vessel enroute to load further parcels of cargo.
Cargo Plan On Tan!ers 9ike the cargo ships, the tanker cargo plan is particularly useful when a number of diverse cargoes are to be loaded. 6nlike the cargo ship, it is only necessary to show the disposition of the tanker cargoes in plan view, at one level. It is sometime the practice to overprint the comparable importance. ost of the functions of the plan are similar to that of the general cargo plan. It is particularly useful to deck officers when loading or discharging to the chief officer for planning tank cleaning and to the chief engineer for maintaining cargo temperature. The cargo plan enables a visual record to be kept of previous cargoes, which is of significant importance to the chief officer when planning the disposition of future cargoes.
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DUT/ES A.D RESPO.S/&/L/T/ES OF CARGO OFF/CERS Cargo O##iers The term H*argo /fficers% implies the person responsible for the safe and efficient handling and stowage of cargo on board. This responsibility also includes the proper preparation of the hold prior to loading, correct supervision during the working of cargoes proper to the preservation of cargo whilst in transit and the co-operation#co-ordination with relevant port authorities whilst in port#harbour. The aster to the senior most deck officer i.e. the *hief /fficer generally delegates the responsibilities of the *argo /fficer. The ?nd and ;rd /fficers, who are called the Hunior *argo /fficers%, assist the *hief /fficer in carrying out these duties.
D%ties An" Res'onsibilities The main duties and responsibilities of the *argo /fficer are listed below: 25 To ensure the proper preparation of all cargo spaces for the types of cargo to be carried. ?5 To inspect the ship%s cargo gear to ensure that it is in good working condition and in accordance with the statutory requirements. ;5 To ensure that all holds, accesses and parts of the ship comply with the requirements of the ock 7afety (egulations. <5 To ensure proper status of guardrails, manhole covers, side ports, stern doors, container fittings etc. @5 To plan and supervise the proper stowage of cargo on board ensuring the safety of life and property, and avoiding ecessive ship stresses whilst having adequate stability during loading and discharging and at all stages of the voyage. >5 To achieve proper stowage of cargo not in such a manner as to prevent correct and speedy discharge, taking into account the
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proper rotation of ports and also ensure that no cargo is over stowed. E5 To undertake measures to prevent the outbreak of fire on board and to ensure that fire fighting equipment is in readiness all the time. =5 To ensure the safe operation of all ship%s cargo handling gears. G5 To avoid damage to the cargo - to ensure the proper handling, slinging, discharging, separation, ventilation, slinging, distribution of cargo. In the case of refrigerated cargoes The proper control of temperature. 235 To take adequate measures to prevent the pilferage of cargo. 225 To maintain a daily check and record of cargo loaded or discharged including the vessel%s draught. 2?5 To make proper and correct entries into the ate%s 9og Book, issue relevant ate%s (eceipts for cargo loaded, drawing up of cargo plans, hatch lists, cargo summaries, dangerous cargo lists etc. To maintain the angerous *argo (egister. 2;5 To attempt a good distribution of cargo at loading and discharge ports, so as to obtain the fastest turn round of the vessel and minimise port stay. 2<5 To ensure that all cargo is properly secured, hatches well battened down and cargo gears secured before the vessel proceeds to sea.
1#) To ensures that proper ventilation of cargo spaces is carried out to prevent cargo damage due to condensation#sweat. To check and record temperatures and */ ? concentrations in refrigerated cargo spaces. 2>5 In the event of bad or adverse weather conditions, to ensure the water tightness of
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compartments, proper trimming of ventilators and the lashings of cargo etc. 2E5 To ensure that all work on board is carried out in accordance with the C*ode of 7afe 'orking racticesD. 2=5 To properly delegate duties to unior *argo /fficers with adequate instructions for the proper loading#discharging and stowage of cargo and the overall safety of the vessel.
Pa!aging O# General Cargo "eneral cargo may be presented for shipment with various forms of packaging, such as: Bags - made from natural fibres like $ute#cotton or from synthetic fibres and paper. 6sed for cement, grain, sugar etc. They are liable to bursting at their seams. Catons - made from cardboard. 6sed for finished goods like condensed milk, shoes, or for carrying fruits etc. They are very fragile and liable to be crushed. C#ests - rectangular#square boes made from plywood. 6sed for carrying tea. They are fragile and liable to be crushed. Cases - rectangular boes made from wooden planks nailed and banded. *an be strong or fragile depending on quality of wood J construction of case. 6sed for heavier goods like spare parts etc. or to protect fragile goods. Cates - rectangular, made from wooden planks with Hgrated% design. 1ot as strong as cases and sides are fragile. 6sed for machinery parts etc. Bales - formed when commodities such as natural fibre, cloth etc. are pressed tightly into a rectangular bundle and then strapped firmly with metal bands or cord. 9ifting by hooking onto bands should be avoided. Baels - made from shaped wooden planks called Hstaves% and held by metal hoops. The weakest part is the rounded middle called the Hbilge% and the strongest is at the quarter hoop%. The opening for filling the contents is called the Hbung%. Ideally placed on wedges, called Hquoins% placed below the quarter hoops keeping the Hbilge off the ground and the Hbung% upwards 4i.e. HBung up and bilge free%5. 6sed for carriage of wine etc. and similar produce.
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Slinging O# General Cargoes 9oading and discharging of cargo is facilitated by the use of proper cargo handling gears namely, derricks#cranes 4the lifting machines5 and slings. 7lings facilitate the Hgrouping% of unit packages of cargo conveniently for connecting to derricks # cranes. 8arious types of slings, for use with different types of general cargo, are available and are designed to minimise damage to the cargo during the lifting process. 7ome of the principle types of slings, available are clearly eplained in various tetbook.
Unitiation2Palletiation To further facilitate quicker dispatch of cargo into#out of the ship, and to allow it to be handled mechanically by machines such as forklift trucks, small packages of cargo 4unit packages5 of uniform si+e are sometimes consolidated into Hunit loads% on Hpallets% 4double-layered wooden platforms of standard dimensions capable of being lifted conveniently by fork lift trucks5. 7pecial Hpallet slings% make the slinging of pallets, onto derrick#cranes, faster and easier. The concept being to assist the process of cargo handling by reducing the number of occasions when a piece of cargo has to be manually handled thereby increasing cargo throughout.
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Can ,oo!s
The hook slips under the lip of the drum or barrel. There are frequently four or five sets of hooks on a ring, which enables drums and barrels to be handled very rapidly. They are not to be recommended for handling heavy barrels as there is a possibility that the staves will be pulled out.
Snotter Hre-slinging% of cargo, where slings are left on after loading so as to facilitate quicker discharge at the other end 4by avoiding the building up of sling loads again5 is a form of uniti+ation and is used on some trades. H*ontainerisationD is a special form uniti+ation and will be discussed later.
of
&AS/C CARGO ,A.DL/.G E3U/PME.T A.D CARE OF CARGO
ay be made of either rope or wire by forming an eye at each end of a 2>mm - ?3mm wire 4?D - ?.@ C5 or @3mm - >3mm rope 4>D - ED5 < to > metres 4?-; fathoms5 in length. It is used for slinging cases, bales, wet hides and timber.
Plate Clam's
C*ain Sling
*onsists of a length of chain with a large ring at one end and a hook on smaller ring at the other end. It is used for lifting heavy logs, bundles of iron and most steel work. *are must always be taken that no kinks are allowed to form in the chain when goods are being lifted.
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There are various type o plate clamps, but the principle is that the plate is gripped when the weight is taken, so that there is no chance of plate slipping as it could do if a chain sling was used.
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Ro'e Sling
This is formed by $oining the ends of a piece of ?@mm - ;3mm rope ;D - ;.@C5 about 23 to 2? metres 4@ to E fathoms5 in length with a short splice. The sling is in very common use. Bags, baled goods, barrels and cases may all be along with this.
&o4es
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This is formed by sewing a piece of canvas between the parts of a rope sling. It is used for bagged grain, rice, coffee and similar cargoes where the contents of the bag are small. ny spillage is retained in the canvas and is not wasted. The stress on the outside bags is spread more evenly and thus the chance of splitting is reduced.
DAMAGE DUE TO /MPROPER USE OF CARGO ,A.DL/.G E3U/PME.T uch cargo damage results from careless or improper handling during the loading and discharging processes, the following being the principal sources of such damage: -
Careless 0in* 0or! 9owering heavy slings or drafts of cargo too fast on to cargo already in stowage not infrequently is responsible for damage which, often goes undetected until discharge.
Cargo ,oo!s 7imilar to the tray by a wooden side is fied around it. 6sed for handling eplosives.
Tra(s
The use of these implements is indispensable in the handling of a large variety of commodities, but with bag cargo, fine bale goods, hides, fire rolls of paper and matting, etc., light packages, liquid containers, crates and like packages whose contents are eposed or unprotected, the use of cargo hooks should be strictly prohibited.
Cro) an" Pin* &ars These also are indispensable to the sound stowage of many classes of heavy packages, but their use should never be permitted when stowing barrels, or other liquid containers, or with any packages which are not substantial enough to withstand damage from their use. ay be square, rectangular or round. They are slung by pieces of rope called legs, attached to the corners. 6sed for small cases and drums.
Canvas Sling
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Cr%s*ing against S*i'5s Si"es !atch coamings, beam sockets, etc., should be safeguarded against by the use of overside skids, the correct plumbing and guying of derricks, and careful winch driving, especially when swinging booms are in use.
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Dragging Cargo ragging *argo by winches along the deck to save trucking, from remote ends and wings of holds and Htween decks instead of making up the CdraftD or CslingD near the hatch, is a prolific source of damage to, and loss of contents of the lighter class of packages, as well as to the cargo in stowage over which such is dragged.
Dro''ing Pa!ages ropping packages from trays, trucks, railway cars, top tiers of lighters, etc., by which their contents are broken or eposed, the packages splintered, deformed or loosened in their fastenings and rendered unfit for the subsequent handling they are sub$ected to. To avoid this, suitable skids should be used for packages, which are too heavy to be handed down.
/m'ro'er A''lianes The use of special appliances tends to be epeditious and economical in handling of cargo, but damage is frequently caused by the improper use of such appliances.
Cargowork
crushing the outside upper packages by compression of the sling. 9ight or fragile packages should not be slung along with heavy packages.
La! o# 0al!ing &oar"s 9ack of 'alking Boards and landing platforms. 'here these are not provided and used, damage is caused to packages, in towage, over which other cargo has to be worked into the position where it is to be stowed. ackages, which are damaged after they are at Cship%s riskD, should be carefully recoopered or repaired before stowing away.
S0EAT A.D +E.T/LAT/O. +) ,E.T a5 C7weatD is condensation, which forms on all surfaces in a cargo compartment due to the inability of the cooled air in the compartment, to hold water vapour in suspension 4warm air can hold much more water vapour than cool air5.
1et slings are most useful with many kinds of small packages, but if used with bagstuff, light cases, etc., a great deal of damage results. 7imilarly chain slings are indispensable for certain types of packages and useful for most classes of iron goods, but the use of such with light cases, sheet iron, coils of lead or copper piping, sawn logs of valuable timber and other goods liable to buckling, fraying or marking by chain is productive of damage and claims. *anvas or web slings should be used for slinging bag flour, coffee and like cargo, while the use of trays for certain classes of goods is much to be preferred to slinging by net or rope.
/m'ro'er Slinging Too much weight in a draft endangers the safety of packages situated at the outside edge of bottom and top tiers into which the sling is liable to be drawn by weight below and compression above. draft composed of many packages should taper off on top to prevent springing or
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b5 7weat may be differentiated as follows:
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i5 7hip%s 7weat - eists when water droplets are deposited onto the ship%s structure in the compartment 4e.g. deckheads, beams, frames, shipside, stringers etc.5 and then fall onto or come in contact with the cargo. It occurs when the dew point of the air in the cargo compartment is more than the temperature of the outside air#structural parts of the compartment.
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removing fumes and odours emanating from cargoes stowed in the compartment to prevent Htaint% or other damage. thus preventing fire.
b5 8entilation may be described as either: )i T#o"g# 0entilation - with the flow of air occurring through the body of the cargo assisted by proper Htrimming% of ventilators and the $udicious use of dunnage.
It is usually found on voyages from warm places to colder places. ii5 *argo 7weat arises when condensation forms directly on the body of cargo itself. It occurs when the temperature of the air in the compartment 4or the cargo itself5 is lower than the dew point of the incoming air. It is likely to be found on voyages from cold to warmer places. c5 revention of amage by 7weat lthough intelligent use of dunnage can minimise damage from sweat, it is more prudent to consider the prevention of damage by the elimination#minimisation of sweat by efficient ventilation. The controlling factor for the formation sweat is the relationship between the temperature and humidity of the air in#outside the compartment. ir having 233A humidity is said to be Csaturated the temperature at which this occurs is called its dew point.
i) 'hen the dew point of the outside air is lower than or equal to the dew point of the air in the compartment - 8)1TI9T). )ii 'hen the dew point of the outside air is greater than the dew point of the air in the compartment - / 1/T 8)1TI9T). ) 0ENTIL.TION a5 8entilation has the main ob$ectives of: preventing moisture damage to cargo originating from condensation 4sweat5 within the cargo compartment.
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)ii ,"face 0entilation - with the flow of air occurring only at the upper surface of the cargo and not being forced into the body of the cargo. c5 8entilation may be provided by two ma$or means: i) Nat"al 0entilation - this is achieved by Htrimming% the ship%s ventilators and obtaining a natural flow of air caused by the vessels movement or outside wind. Trimming the leeward ventilation into the wind and trimming the winward vents away from the wind can effect HThrough natural 8entilation%. The air in the compartment will then move in a direction contrary to the flow of outside air.
ii) Mec#anical o 1oced Da"g#t 0entilation - The simplest of such systems consists of a fan of appropriate si+e and design which delivers outside air into the compartment, and the used air from the compartment is discharged to the atmosphere via the natural ehaust ventilator.
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7ometimes such an arrangement does not prove satisfactory and hence the ehausting is also done mechanically by means of a suitable ehaust fan. The delivery and ehaust is properly balanced to provided good airflow.
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side frames with the distance between the Hbattens% of about ?;3mm 4GD5. *argo battens are sometimes fitted vertically and in such cases the initial epense is generally greater. !owever there tends to be less subsequent damage to the battens and better protection is afforded to the cargo.
The tank top is usually covered with a double layer of non-permanent dunnage called Hportable dunnage%. The bottom layer consists of @3mm @3mm 4?D ?D5 timber spaced about 3.E to 2.3 metre 4?-; feet5 apart and laid athwartships - if the ship has conventional side bilges 4otherwise laid fore-and-aft in case of Hbilge wells%5 to allow free drainage. The upper layer consists of 2@3mm ?@mm 4>D 2D5 boards laid across the lower layer, about ?;3mm 4GD5 apart. 2) D3NN.GE unnage% may be referred to as the wood that is used to protect cargo. It may be in the form of wooden planks, or slats, bamboo, bamboo or rush mats.
In some ships the tank top, in way of the hatch, is protected from impact damage by cargo by a permanent wooden sheating called the Htank top ceiling%. This does not replace dunnage and the portable dunnage should be laid over this and it should also etend over limber boards. 7imilar dunnage arrangements will be found in the tween decks, however the lower layer of portable dunnage may also consist of 2@3mm ?@mm boards 4sometimes only a single layer is used5. articular attention should be paid at the shipside stringer, where a thicker layer of portable dunnage may be prudent, as water tends to accumulate here.
any general cargo ships have permanent dunnage, called Hspar ceiling% or Hcargo battens%, fitted over the side frames in the hold 4and sometimes over the bulkhead stiffeners5. It consists of 2@3mm @3mm 4>D ?D5 timber usually fitted hori+ontally into cleats over the
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Timber used for dunnage should be clean, dry, stain free, odour free and free from nails and large splinters. 1ew timber should be free from resin and the strong smell of new wood.
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'ith some cargoes such as bagged rice etc, the hold pillars should be lagged with bamboo mats. 'hen battens are not fitted on bulkhead stiffeners, a lattice of bamboos may have to be erected as a temporary measure.
These definitions include pump rooms on tankers. There may be special instructions for routine entry into pump rooms on your ship. ake sure you know what they are.
It must be noted that dunnage need not be laid if the cargo does not require ventilation. &or eample, when coal is loaded in bulk, the cargo battens are removed and no portable dunnage is laid.
.N ENCLO,ED ,!.CE ,$O3LD NE0ER BE ENTERED 3NLE,, .3T$ORIT4 $., BEEN GI0EN B4 T$E M.,TER OR . RE,!ON,IBLE O11ICER
The use of dunnage may be summarised as: reventing cargo coming into contact with free moisture#water on the tween deck or tank top. reventing cargo from coming into contact with the steel boundary of the hold thus minimising damage due to Hship%s sweat%. ssisting in providing ventilation, thus preventing # reducing Hsweat%. reventing spontaneous heating by affording good ventilation. iding distribution of weight over a layer of cargo thus minimising crushing damage to cargo. reventing chafage between cargoes. *ertain types can prevent pilferage of cargo. iding in distribution of cargo weight over tank top etc. *an be used to separate cargoes 4this is not considered as a normal practice5.
Entr( /nto Enlose" S'aes There are many enclosed spaces on a ship - if in doubt about any space you may have to enter *!)* &I(7T with *hief /fficer.
An Enlose" S'ae /s any space or compartment that has been closed or unventilated for some time. any space or compartment that may, because of the cargo carried, contain noious, flammable or harmful gases. any space or compartment which may be contaminated by cargo or gases leaking through a bulkhead or pipeline. any storeroom or space containing noious or harmful materials any space or compartment which may be deficient in oygen.
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The atmosphere in any enclosed space may be incapable of supporting human life. It may contain flammable or toic gases or not enough oygen. This is why it is essential that the aster or officer in charge, who will ensure that all the necessary safety precautions have been taken before anyone is allowed to enter an enclosed space, must give instructions or permission.
Prea%tions &e#ore Entering Tan!s Or Con#ine" S'aes 25 rior to entry into enclosed space it is essential to obtain permission first. ?5 Test on tank atmosphere - should be checked by using eplosimeter and oygen analyser where appropriate for safe entry. ;5 8entilate space prior to entry and continuously during the operation so as to ensure the environment is safe. <5 )ntry should be restricted to the minimum number of personnel required for the $ob and a record is made on the number of personnel. @5 dequate lighting to be provided for the entry. >5 roperly attired and safety gear should be observed by all personnel involved in the entry into enclosed spaces. E5 6se only intrinsically safe equipment when the enclosed space was used to store or carry flammable cargoes prior to the entry. =5 ost signs at entrance and one competent man on standby to monitor the operation. G5 roper and effective communication established between all parties involved in the entry. 235 )mergency procedures and evacuation should be briefed and well understood to all personnel involved.
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?5 escribe ship sweat and cargo sweat and the factor affecting sweat.
Assignment lease complete the assignment and return to 9 25 7tate the functions of a cargo plan in a bulk carrier.
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MODULE 6 - CO.+E.T/O.AL DERR/C7 R/GS T*e Single S)inging Derri!
The single derrick rig is basically a boom supported at its base 4heel5 by a special pivotal arrangement called the Hgoose neck%, which allows it to be raised or lowered by means of a Htopping lift span% and to be swung from side to side by means of Hslewing guys%. 1ear the head of the derrick boom is the Hspider band% onto which are attached the Hderrick head span block%, the Hslewing guy pendants% and the Hcargo head block%.
The Hcargo runner% downhaul is led from the Hcargo head block% to the cargo winch via the Hderrick heel block% and usually passes through a Hrunner guide% on the boom, which prevents the runner from sagging. The slewing guys 4fitted on each side of the boom5 which have their wire pendants shackled to the spider band at the derrick head have their lower parts consisting of a cordage tackle for hauling on. The single derrick rig can be used to lift loads to the full etent of it%s 7'9 4safe working load5, which is marked near the heel of the boom, provided the cargo runner 4or cargo purchase5 is also rated to that 7'9.
The topping lift span, downhaul 4the hauling part5 is led via the Hmast head span block% on to a Hdolly winch% usually fitted with its own motor for the sole purpose of raising#lowering the derrick boom 4in order ships the daily NOTE: When a single derrick is used in the winch may have no motive power of it%s own Union Purchase rig, a ‘preventer guy’ is and is turned by using a Hbull wire% onto the passed over its head on the outoard side. side drum of the cargo winch. safety device in the form of a Hpawl% is fitted to the dolly single swinging derrick which converts a winch to prevent the accidental lowering of the single whip to a double whip and creates a mechanical advantage. 6sed to lift load derrick boom. double of the 7'9 of the cargo runner 4The derrick must be rated higher5.
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YO-YO Gear )mployed using two or four single derricks. 6sed for loads heavier than those, which can be handled by the union purchase or single swinging derrick.
T)o Derri!s The two inshore derricks are rigged with a gun tackle and their moving blocks are $oined by a heavy strop supporting a floating block 4K/K/5 with the cargo hook attached. /peration is carried out by swinging both derricks towards the hatch#quayside, keeping both derricks heads as close together as possible.
Fo%r Derri!s Two pairs of derricks are rigged similar to the union purchase. The two cargo runners of the inboard derricks are passed through a floating block and shackled together0 similarly the outboard derrick runners are passed through another floating block and shackled together. The floating blocks are then shackled together to form the union with the cargo hook secured below them.
DERR/C7 R/GS Union P%r*ase S(stem
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a union hook and worked in con$unction with each other. Refe to fig5 .. )ach cargo boom is $oined to the vertical mast or post by a swivel fitting known as a goose neck 4so named because of the shape of the fitting5. Then up and down, or luffing, movement as the boom is carried out by a topping lift#span tackle, and the hori+ontal or athwartships movement is controlled by a slewing guy attached to the outboard side of the boom head. The two booms are linked by a schooner guy which runs from the inboard side of one boom head to the other and thence to the deck via a lead block on the mast. Inboard slewing guys sometimes replace the schooner guy but the latter tend to interfere with the cargo-working operation. The schooner guy is always well clear of the cargo working area. The guys and tackles position the derricks. /ne boom is positioned over the hatch and the other boom is positioned over the ship%s side. 'hen the booms are set up in position the preventer guys are set up tight. These are single lengths of wire which lead from the outboard side of the boom to the deck and which have the function of taking the guy load during the cargo-handling operation. The preventer guy is sometimes called the standing guy as it has no moving parts whereas the slewing guy consists of a tackle 4usually the only tackle on board ship rigged to advantage5. cargo wire, or runner, from each boom is $oined by a three-way swivel which is known as a union hook. In the unloading process the boom centred over the hold lifts the load by its runner. /nce the loadline has been lifted to a sufficient height to clear deck obstructions, the cargo runner from the other derrick is used to move the load over the ship%s side and on the quay or into a lighter.
&ig. - 6nion purchase rig !sle"ing guys not sho"n# This is probably the most common derrick system in use on general cargo vessels. Two derricks are CcoupledD, CmarriedD, or $oined by
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load, by the topping lift span led to a separate winch, and it can be swung from side to side 4slewed5 by Hsiean guys% or either side led to separate winches. In view of the greater 7'9, the topping lift span0 the cargo fall and the steam guys are all multiple-fold purchases. &urther the cargo purchase and the topping lift purchase are rigged advantage 4by use or additional Hlead% sheaves5. In view of the heavy loads involved and the si+e of the rig, great care is required for setting it up 4which may take up to ? - ; hours5.
PATE.T DERR/C7S &asi C*arateristis Prea%tions The following criteria must be complied with at all times: 5a The minimum operating angle of either derrick should be not less than 2@L to the hori+ontal, and it is recommended that the angle be not less than ;3L0 5b The maimum included angle between the cargo runners must not eceed 2?3L0 5c The outreach beyond the midship breadth of the ship should not less than
Disa"vantages a5 It can only be used for light loads, an average of approimately 2.@ - ? tonnes per load. b5 The winchmen must be highly skilled and eperienced. c5 The derricks cannot be used for Cspot loadingD. d5 (e-positioning the derricks is timeconsuming.
i5 The twin topping lift#slewing guy principle is used which gives good control of a single derrick. ii5 The capability of handling heavier loads than the union purchase system. iii5 *ombined slewing and topping 4luffing5 tackles. iv5 8ery good spot loading facilities. i.e. the load can be set down in most positions within the hatch area. v5 high degree of centrali+ed control with the operation being conducted by one man. vi5 The derrick is rigged at all times and can quickly be brought into operation. vii5 The use of new technology reduces the stresses encountered with the union purchase system. There are many patent derrick systems used on board ship but the best known are probably C!allenD and C8elleD for the handling of general cargoes and C7tuelckenD for heavy lifts.
T*e 8%mbo Derri! This is basically a single swinging derrick with a much greater 7'9 4about ;3 - @3 tonnes5. The boom can be raised or lowered, with the
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,allen Derri!
The !allen swinging derrick employs the twin topping principle which allows good control of a single derrick. This derrick was originally designed for loads of @ - = tonnes but loads of over 233 tonnes are now uneceptional. The derrick can be mounted on all types of mast or derrick post and can make a traverse from port to starboard of 2>3 - 2=3L.
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when swung out over the ship%s side to an angle of =3L from the fore and aft line. The frame also helped to keep the derrick stable in all positions, even when the vessel had a list. !owever, under some operational conditions there were disadvantages when using the frame: 25 'hen the derrick was swung outboard, the sharp angle created by the contact of the topping lift guy pennant with the frame caused ecessive strain in the topping lift. ?5 There was a tendency fro the single-wire pennant on the topping lift to slip above or below the frame when working at CdifficultD angles, once again putting ecessive strain on the topping lift. ;5 The contact with the frame caused chafing on the pennant. This was reduced by fitting rollers to the frame or by protecting the wire. The frame has been largely replaced by outrigger rods. 4fig. ;5 which are pivoted, and are stayed on the outboard side only so that the rod nearest the discharging side can swing towards the ship%s side, thus ensuring a wide separation angle of the topping lifts. s with other patent derricks, such as 8elle and 7tuelcken, the 8-shape arrangement of the topping lifts gives a broad base which is necessary for lateral holding and guiding of the derrick. In figure ; the broad base between the topping lifts is provided by a cross-tree at the mast head. It could also be provided by derrick posts, gate masts, or 8 masts. In the !allen system each topping lifts runs to its own winch. !auling on both winches tops the derrick, and if one winch hauls in while the others pay out, the derrick slews to the side of the ship on which the hauling winch is located. a third winch is used for hoisting and lowering the cargo. The derrick is controlled by two levers. /ne lever operates the cargo, purchase and the other lever has a multiposition control for the topping and slewing operation.
In the original design a fied frame CoutriggerD was fitted to the mast 4as in fig. B5 which was commonly known as a CD frame. This had the effect of keeping the topping lifts at a sufficiently wide angle to one another to ensure the derrick remaining steady even
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+elle Derri! The 8elle swinging derrick also uses three winches. The cargo purchase is operated by a standard type winch but the topping lifts are arranged so that one of the other two winches
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controls the luffing while the third winch is used solely for slewing. )ach of the topping lift winches has a split or divided barrel on to which the ends of falls are secured. /n the luffing winch the falls are laid on to the split barrels in the same direction. Thus both falls will hoist or lower the derrick simultaneously. /n the slewing winch the falls are laid on to the split barrels in opposite directions. Thus when the barrels rotate, one fall pays out while the other heaves in and the derricks slews to port or starboard. The topping lift luffing and slewing winches are operated by a multiposition control lever which is positioned ad$acent to the cargo purchase control lever. The operator stands between the levers and operates the cargo purchase with his left hand and controls the derrick movements with his right hand. &igure * shows a plan view of an early version of the 8elle derrick in which a bridle bar was used to spread the topping lift spans at the derrick head. The bridle bar evolved into the CTD- shaped derrick head shown in &igure @. Both arrangements make very wide slewing angles possible due to the good lateral stability achieved by the spread of the spans at the derrick head. The derrick can be swung outboard until it is almost perpendicular to the ship%s side, even with an adverse list. endulous swinging of the load has been a ma$or problem with derricks in which the load hangs a Csingle pointsD. "ood load stabili+ation is achieved with the T-shaped derrick head as the spread of the cargo runner reduces pendulous swinging and load rotation. The 8elle derrick is noted for its comparatively simple design, reliability, and versatility. The standard designs operate up to a capacity of approimately ;@ tonnes but heavy-duty designs are capable of lifting approimately 233 tonnes.
Disa"vantages o# 9D5 #rame 25 'hen swung outboard, sharp angles created by topping guy with frame cause ecess strain in topping guy. ?5 t difficult angles single topping pennant to slip above or below CD frame - ecessive strain.
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;5 *ontact with frame cause chafing. (educe by fitting rollers.
T)o Levers 25 /ne operates the cargo. ?5 /ther 4multi-position5 for topping J slewing position.
S,/PS CARGO DEC7 CRA.ES 7ome modern ships are fitted with cranes instead of derricks. Basically they are provided with individual electrical driven motors to permit lifting of the HIB%, slewing of the $ib and the working of the cargo hoist. The HIB% is a pro$ecting hinged arm and is usually of the luffing type which allows it to ensures hat the hook carrying the weight remains at the same level. The lifting wire rope is rigged usually as a single whip. It leads over a sheave at the head of the $ib and is called the purchase. Between the purchase and the hook is a weight called the Hponder ball%. Its function is to help the purchase to over-haul when there is no load. The crane may be set to move on rails the ship or along the ship or may be fied centrally with a large reach and angle of slew. *ranes offer the following advantages: greater Hspotting area% particularly when installed on the vessel centre line, providing greater fleibility. faster loading#discharging rate. less time in preparing for operations. decks clear of guys, stays and other standing#running riggings. self contained and easier to operate. The main disadvantages of the crane are its higher initial cost and the possible pendulous swinging of the load when slewing is done in a fast manner.
Derri! Testing 7hip%s derricks are initially tested 4initial test5 with the boom at an angle of not more than 2@L to the hori+ontal or, if this is impracticable, ;3L.
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uring its working life, it is recommended that the derrick be retested after any repair to the derrick or permanent fittings, or after any alteration of the rig is not covered by the ship%s plan. 'hen carrying out a test, the ecks (egulations, form GG should be consulted, to ascertain whether the accessory gear complies with the statutory requirements. If all is in order, the test may be carried out0 otherwise, all loose gear, blocks, shackles, etc., should be sent to works for the necessary treatment in accordance with the statutory requirements laid down in form GG. The safe working load of the derrick Has rigged% should be checked by reference to the individual safe working loads of the blocks and shackles in the rig, either by direct calculation, or by the preparation of load diagrams. The strength of the wire ropes in the cargo and span purchases should also the checked for the required factor of safety. If any items of gear are found to be of insufficient strength, either they should be replaced by gear of the appropriate si+e and strength, or the safe working load of the derrick reduced. Tests are generally carried out by the use of loads 4known as a Hdead load test%50 or by the use of a dynamometer 4test clock5. It is preferable that the Hinitial test% be carried out by Hdead load%. If no particular derrick a single whip is normally used but the derrick boom and span gear are capable of supporting a cargo load greater than that which may be lifted by a single whip, a proof load may be applied with the cargo runner double up at the derrick head, provided that the ship%s blocks and shackles are used for the test. 'here it is found necessary to use the doubling-up method 4i.e. a gun-tackle rig5, this should be stated on the certificate of test, also the safe working load that may be lifted on a single whip. 'hen a derrick is rigged with a cargo purchase, and the hauling part of the purchase
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is parallel to the boom, the safe working load marked on the upper block in the purchase should be greater than that marked on the lower block. This takes into account the increased resultant load due to the tension in the hauling part of the purchase. Before applying a proof load to the derrick, all permanent attachments on the mast and derrick should be carefully eamined. It is also good practice to rig an adequate preventer span wire rope as a precautionary measure against any part of the span gear Hcarrying away%. This additional span wire rope should not take the mass of the mass of the derrick during test. 'hen proceeding with the test, the proof load should be applied steadily, and all fittings should be carefully watched for any indication of failure. part from watching, it is also desirable to Hlisten% for any signs of failure. 'hen testing heavy-lift derricks, care should be taken to ensure that the anchorage for the test clock is of adequate strength, avoiding any risk of structural damage to the ship. &or derricks of ;3 t safe working load and over, it is advisable to lift moving loads or use a specially designed anchorage on the vessel, and to ensure that there is sufficient stability to avoid ecessive list under test. It is also important that shrouds and preventers are properly set up to give adequate support to the mast. &urthermore, slewing guys should be so placed that the angle they make with the derrick boom is not unduly narrow, so that when the vessel heels over under load, they will control the derrick without developing ecessive tension. /n completion of the test, a final visual eamination of all parts of the derrick rig, and of all permanent attachments on the mast and derrick, should be made before issuing the certificate of test and eamination. In all cases the winches should be carefully eamined to ensure that they are in good working order, and that the controls act effectively. Information to this effect should be noted on the certificate of test and eamination.
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)very derrick boom should be clearly marked ll beams used for hatch covering to have with its safe working load. certificate of test suitable gear for lifting on#off without persons for this safe working load is required for the having to go upon them to ad$ust. ll hatch derrick Has rigged%, and further certificates of covers to be marked to indicate deck, hatch test are required for the individual blocks and and position unless covers are shackles in the rig, including such items as interchangeable. guy blocks, chain stoppers, etc. The dequate handgrips on hatchcovers. appropriate statutory forms should be used. In 'orking space around hatch at least ? ft. the case of wire ropes, a breaking load test 4form =E5 is required. Part 6: Tests Et: O# Li#ting copy of the ocks (egulations, form GG, containing all the prescribed particulars, together with copies of all the appropriate certificates should be kept on board.
DOC7 REGULAT/O.S S%mmar( pply to the process of loading, unloading, moving and handling goods on any wharf, quay or ship.
Part 1: Sa#et( Meas%res At Do!; 0*ar# An" 3%a(s 25 &encing. !eight of fence not less than ?% 3>D 43.E>m5. ?5 97 in readiness at wharf or quay. ;5 )fficient lighting. <5 &irst aid boes, ambulance facilities whereabouts indicated by notices.
Part : Aess To An" From S*i' An" Part O# T*e S*i's longside quay: ccommodation ladder properly secured ??D wide, fence each side to height of ?% 3GD. longside other ship 7afe means of access, provided by vessel with the higher freeboard. ccess to holds etc pplies where hold depth eceeds @ ft. 9adders in line 9adders provide foothold to depth of not less than
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Ma*iner( ll lifting machinery to be tested before being brought into use and eamined by a competent person. ll derricks and attachments to masts and deck must be inspected every 2? month and thoroughly eamined every < years. /ther lifting machinery thoroughly eamined at least every 2? months. 4Through eamination F visual eamination and hammer test or similar dismantling if necessary5. *hains, rings, hooks, shackles, swivels and pulley blocks used in lifting and lowering must be tested and eamined before being brought into use. nnealing or similar treatment - M C or smaller at least every > months, other at least every 2? months.4Thorough eamination F visual eamination and hammer test or similar dismantling if necessary5. "ears to be inspected before use, unless previously inspected within last ; months. (opes to be of suitable quality and free from obvious defect. 'ire rope to be tested before being brought into use, inspected every ; months and if any wire in the rope is broken, every month. If number of broken wires in a length of = diameters eceeds 23A of total wire in the rope, it must not be used, nor if it shows signs of ecessive wear or corrosion. 7'9 to be marked on blocks and on ring attached to chain sling. *hain#'ire slings not to be shortened by tying knots in them. achinery to be securely fenced. 7afe access and fencing to crane cabs and driver%s platform. 7'9 is to be marked on derricks and cranes. )haust steam not to obscure any part of deck or access.
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ethod of preventing foot of derrick being lifted out of socket.
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Part <: Misellaneo%s R%les eans of escape from hold or tween deck where coal or bulk cargo is being worked. 1o winch drivers or signalmen under 2> allowed. 'alking space around cargo stacked on quay. If hold depth eceeds @ ft. it must be fenced to height of ;ft unless coaming is ?% 3>D. If working cargo in T# at least one section of hatches to be in place. 7ignaller to be employed.
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Part = 1o person to interfere with gear, etc. unless authorised. /nly authorised access to be used. 1o person to go upon beams to ad$ust them.
Part > If shipowner fails to comply with safe access regulations the duty to do so falls on employer of the persons employed. to be kept available for (egister inspection.
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DOC7 REGULAT/O.S - TESTS A.D E?AM/.AT/O.S Ever( )in* an" all aessories t*ereto Test - roof load in ecess of 7'9 as follows: 7'9 less then ?3 Tons - ?@A in ecess 7'9 ?3 - @3 Tons - 7'9 N @ Tons 7'9 over @3 Tons - 23A in ecess ethod - )ither weights or spring#hydraulic balance. 4K1/)T)(5.
Ever( rane2"erri! an" all aessories t*ereto Test - s above ethod - 'eights swung as far as possible each way and for crane with variable $ib at maimum and minimum radii as well. erricks to be positioned at lowest working angle.
Loose Gear 0*et*er Aessor( Or .ot Test - roof load as follows: *hain, ring, hook, shackle or shivel - ? 7'9 7ingle sheave blocks - < 7'9 ultiple sheave blocks: 7'9 less than ?3 Tons - ? 7'9 7'9 ?3 - <3 Tons - 7'9 N ?3 Tons 7'9 over <3 tons - 2M 7'9 )amination - fter test of all gear, including dismantling of blocks to see that no damage or deformation has occurred.
0ire Ro'es Test - 7ample tested to destruction. 7'9 not to eceed 2#@th of breaking load.
STRESSES /. DERR/C7 R/GS To avoid the possibility of accidental failure 4breakdown5 of derrick rigs, due to overloading, it is essential to know the stresses likely to be eperienced by the various parts of the rig when lifting a load.
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)stimates of the stresses involved may be made by resolution of Hparallelograms of forces% and in some cases by use of empirical formulae. +) In t#e ,ingle ,6inging Deic The main areas of stresses, when lifting a load by a single derrick would be: a5 the stress on the hauling part of the cargo runner#tackle. b5 the resultant load on the cargo head block. c5 the tension in the topping lift span. d5 the resultant thrust on the derrick. e5 the resultant load on the heel block. f5 the resultant load on the mast head span block. 8arious factors are considered when making estimates of derrick stresses, and for a basic understanding, an eample is eplained with the rig parameters given below: C single swinging derrick boom, 2>m long and weighing 2 tonne, makes an angle of >3 ° to the hori+ontal when suspended by a single span topping lift with the mast head span block secured 2;m above the heel. load of @ tonnes is to be lifted using a guntackle rigged to disadvantage, secured at the derrick head, with its hauling part led parallel to the derrick to the winch via a heel block. The heel of the derrick is ;m above the deck, and the winch point is ;m from the mast and ?m above the deck. The lifting gun tackle itself weighs 3.? tonnesD. a) Esti%ating t#e ,tess on t#e $a"ling pat of t#e Lifting Tacle This is obtained using the formula: n' '+ 7F 23 : 'here 7 F stress on the hauling part ' F load to be lifted
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n F number of sheaves in the system including lead sheaves F theoretical ower "ained 4..5 4a Hfrictional allowance% of 2#23 of the load, for n' every sheave, is normally used hence 23 Therefore in the eample: 4? × @5 @+ 7F 23 ? .. of "untackle F ? 4disadvantage5 >3 2 × 23 ? 1o. of 7heaves F ? F ; tonnes
F
NOTE7 If a single cago "nne (single 6#ip) 6as "sed fo lifting& instead of t#e g"n-tacle& t#e stess on t#e #a"ling pat 6o"ld #a*e 'een +/+8 of t#e load %oe t#an t#e load itself - allo6ing fo fiction in t#e cago #ead 'loc5 ') Esti%ating t#e Res"ltant Load on t#e Cago $ead Bloc The final load on the cargo head block is a result of: the forces eerted by the suspended load, and the stress on the hauling part of the cargo runner#tackle. In the figure, the Hparallelogram of forces% B* is resolved using the scaled values of the load B 4@ tonnes in this case5 and the calculated stress on the hauling part 4; tonnes as determined by the formula5. The resultant force at H% represented by the scaled value of *, is the resultant load on the cargo head block 4equals E.= tonnes in this eample5. c) Esti%ating t#e Tension in t#e Topping Lift ,pan The tension in the topping lift span results from the combined effects of: weight of the load being lifted
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the weight of the lifting tackle suspended from the derrick head part of the weight of the derrick boom 4it is usual to take this as M the weight of the boom5.
s given in the figure, this is resolved by etending the vector * 4representing the load to be lifted5 by a scaled amount *) equal to the sum of the weight of the lifting tackle and M the boom weight 43.? N 3.@ F 3.E tonnes in this eample5 and drawing )& parallel to the topping lift span 4parallelogram )&"5. The tension in the topping lift span is then represented by the scale value &) 4;.< tonnes in this case5. d) Esti%ating t#e T#"st on t#e Deic The forces which produce the thrust on the derrick boom are: the tension in the topping lift span the resultant load on the cargo head block This is represented by the scaled value of &, which is equal to N & 423 tonnes in the case5. e) Esti%ating t#e Res"ltant Load on t#e $eel Bloc The final load on the heel block results from the stresses in: the cargo runner, acting in the direction of the cargo head block, and the cargo runner, acting in the direction of the winch In the eample, the stress in the direction of the cargo head block is ; tonnes 4as determined in para 24a55 whilst the stress in the direction of the winch would be ;.; tonnes 4allowing for 2#23 of the load for friction in the heel block - using the empirical formula for stress on the hauling part with three sheaves5. The forces are then resolved using the Hparallelogram of forces% 'OKP, where OK F scaled value of stress towards the derrick head and O' F scaled value of stress towards the winch.
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The resultant load on the heel block is represented by the scaled value of OP.
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Assignment
f) Esti%ating t#e Res"ltant Load on t#e lease complete the assignment and return to Mast $ead ,pan Bloc 9 The final load on the mast head span block results from: 25 )plain the advantages and disadvantages the tension in the topping lift span and of a union purchase in cargo operation. the stress on the hauling part of the topping lift towards the dolly winch ?5 derrick ?< m long is supported by a span 2? m long. ttached to a point on the mast ?3 In the eample, the tension in the topping lift m vertically above the heel of the derrick a span is ;.< tonnes 4as determined in para guntackle is rove to disadvantage is used to lift 24c55 whilst the stress on the hauling part of a weight of 23 tonnes. 7pan tackle also a the topping lift towards the dolly winch would guntackle is rove to disadvantage. The mass be ;.E< tonnes 4allowing for 2#23 of the of the boom is ? tonnes and the mass of cargo topping lift tension for friction in the mast head gear is 3.@ tonnes. &ind the stress on: span block5. The forces are resolved using the Hparallelogram of forces% 1/, where 1 F the scaled valve of tension in the topping liftspan and F the scaled value of stress in the hauling part of the topping lift, towards the dolly winch. The resultant load on the mast head span block is represented by the scale value of /.
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i5 errick head purchase block shackle. ii5 errick heel block shackle iii5 The load on the mast head span block shackle iv5 The thrust on the derrick 4fter leaving the heel block runner makes an angle of >3 3 with mast5
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MODULE < - ROLL O.2ROLL OFF SYSTEMS (o#(o vessels promote wide and comprehensive forms of unit carriage, from palleti+ation on basic form to heavy vehicular traffic, including containers. echani+ation is highly developed with mobile forms of handling continually increasing in adaptability, and ship design forms provide for entry and eit of cargoes in a variety of fashions. /ne of the most important economical aspects of these types of vessels is the quick turn around. (o#(o vessels now operate with either or a combination of bow, stern, quarter or slewing ramps, which increase their versatility. (elated to these forms of ship construction are interesting facts concerning the ship to shore interface. !eights, slope, inclination and overall dimensions also take into account the types of cargoes likely to be handled. There are some ramps 4link spans5 which can service double decks.
Sto)age any (o-(o vessels have a predominance of the weight 4e.g. ramp systems5 aft. This may require that tanks are used to maintain an acceptable trim during loading operations, and may also require that cargo is first in and last out - to the forward lower decks. *argo may be taken on board the (o-(o vessel in one or more of the following ways: a5 road vehicles with integral haulage power which will also remain with the vessel. b5 road trailers which will remain with the ship throughout the sea transport leg. c5 roll trailers which are not suitable for road haulage but which will remain with the ship during sea transport. d5 cargo towed on board using roll trailers, and then cargo removed and stowed without its wheels. e5 cargo secured on flats and carried on board wither using roll trailers or by other mechanical handling equipment0 both the flat and its cargo being stowed as a unit. f5 pallets either singly or in groups carried on board using roll trailers or fork lifts trucks. g5 individual items of cargo brought on board by fork lift trucks.
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8ehicles are usually close parked in lanes of about ; metres wide. This should allow access for lashing gangs to secure each vehicle properly. *ontainers may be stowed fore and aft or athwartships, but care must be taken to ensure that suitable strengthened areas of the deck are in the way of the corner castings. Trailers may be backed up the ramp and positioned so that at the port of discharge towing vehicles may have direct access to the coupling point of each trailer, and be able to tow straight off the vessel without the need to turn around. It is important that different types of cargo e.g. containers and pallets, are properly separated to prevent the one causing damage to the other. This separation, which in many cases also provides restraint, may be by means of timber dunnages, dunnage bags, sheets of plywood or hard board, and other cargo e.g. tyres etc. 'here containers with air cooled integral refrigeration units are stowed below decks, it must be ensured that adequate ventilation can reach these containers to allow proper air cooling to take place, as well as sufficient space, in way of the equipment end of the container, so that maintenance may be carried out and temperatures monitored. ppropriate angerous "oods regulations apply to all dangerous goods cargo. These should be segregated from other vulnerable cargoes and closely available to fire fighting provisions.
Se%ring 7ecuring of vehicles on board (o-(o vessels must be in accordance with an approved system, making full use of trestles, pedestals, deck securing points, as are recommended by the builders. 7ecuring points and appropriate trestles etc., should be used to by-pass the springing system of vehicles in order to secure them. *ontainers should be lashed and secured in accordance with an approved system, preferably to locating cones and securing pins, wire, chains, hooks and levers must be set up so as not to take undue strain and there by rack or distort the container.
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d5 ll lashings should have efficient tightening devices.
There should be a sufficient number of men who have been trained in the use of the securing equipment and in the most effective methods of securing various types of vehicles 4cargo units, so that proper lashing operations are completed before the vessel proceeds to sea. The following precautions should be taken. a5 ll vehicles should, as far as is possible, be stowed in a fore and aft direction with the hand brakes on and the engines in gear. ny vehicle stowed athwartships must be securely lashed. b5 The suspension units of heavy vehicles or trailers should, wherever practicable be relieved by the use of $acks, after which the vehicles and trailers should be securely lashed in their stowed position. c5 )very stowed vehicle having a road laden weight in ecess of ? tonnes which is not fully balanced, should be supported at one end by $acks, rests, trestles or table laid on friction pads and then secured by lashings at both ends and at the sides as necessary.
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There are several variable factors which affect the number and strength of lashings needed. 7ome of them are as under: 25 The weather conditions and duration of voyage. ?5 The si+e and weight of the vehicle of cargo unit and the position of its centre of gravity. ;5 The positions of the wheels, or trestles, in relation to the cargo load, as this affects the fulcrum position and hence the tipping moment. <5 The position and angle at which the lashings are inclined. @5 The coefficient of friction between the various bearing surfaces. >5 The safe working load of the lashing equipment. robably the most effective method of dealing with this comple problem is to rely on eperience and past practice Q i.e. to employ lashing arrangements which have proved successful at times when very severe weather conditions have been encountered. 'here such proven lashing arrangements are available, they should be displayed, either diagrammatically or in a tabular fashion on specially prepared notice boards posted in the vehicle spaces.
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CO.TA/.ER/SAT/O. It is a practice of grouping loads of cargo together and stowing them in /1) container to protect and preserve them and to ensure their efficient distribution. *ontainers are C!K7I*9 *769)7D, made of steel, aluminium, plastic or wood to hold a large member of individual units for shipment. In short, they are boes usually of metal with doors and lifting points.
Its rigid in construction and its components are permanently assembled. ) Collapsi'le 1eig#t Containe It can easily be dismantled and parts of which easily folded and then fitted together again. 2) ,ide Loade It is also of standard si+e, having one or more openings on its sides.
The use of containers is international along 9) Open Top with their construction. !ence, variations in lso of standard si+e, having no roof. design and applications can be epected. To standardi+ed the equipment for international :) $alf $eig#t Containe use, a body known as HI1T)(1TI/19 It is a container having standard si+e ecept 7T1(7 /("1I7TI/1 4I7/5% has for height which is only < feet. It is used for been formed. This organisation is mainly cargoes of low stowage factor, and heavy responsible for setting standards in respect of weights like steel plates and machinery plates. construction, durability, fitures and The sides can be completely opened by attachments and for methods of handling, unhinging them. The roof is generally soft, that lifting and slinging of containers. The *odes is covered only by a canvas or plywood. It has and ractices of the I7/ are issued in a a capacity of about <33 cubic feet. publication on I7/ container standards and recommendations, which should be read and ;) Ins"lated Containe understood by all officers serving on container It is of standard si+e but with internal insulation vessels. of polyurethane type fitted between a plywood lining and the outer skin.
Freig*t Container ccording to I7/, a freight container is an article of transport equipment: 25 of a permanent character and accordingly strong enough to be suitable for repeated use0 ?5 specially designed to facilitate the carriage of goods, by one or more modes of transport, without intermediate reloading0 ;5 fitted with devices permitting its ready handling, particularly its transfer from one mode of transport to another0 <5 so designed as to be easy to fill and empty0 @5 having an internal volume of 2 cubic metres 4;@.; cubic feet5 or more. There are many types of containers in use throughout the world today, some of them are as shown below: +) Non-Collapsi'le 1eig#t Containe
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<) Refigeated These are standard si+e containers carrying refrigerated cargoes and having their own machinery for cooling. =) ,peciali>ed Containes There are so many special types of containers, used for dry bulk cargoes and chemicals in powder form. 9iquids can also be carried in these pressuri+ed tanks or liquid containers.
Stan"ar" Sie O# A Container *ontainers used in international trade constructed according to the specifications of International /rganisationsR 4I7/5. &ollowing are the standard si+es of containers: +) T6ent 1eet 3nit (8 1eet ? = 1eet ? = 1eet)
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This is the si+e most commonly used in the world container traffic, to facilitate carriage by sea, road or air having standard points for lashing, scurrying and lifting. *ontainers are made of steel having a capacity of about 2333 cubic feet. )ach container weighs about ? tons and can handle cargo of about ?3 tons.
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;@3 T)6 will carry ;@3 number of standard twenty feet containers.
A"vantages Using Containers 25 7peed and economy in handling, particularly at the ports. /ne gang of twelve or thirteen men can discharge and load a fully loaded container ship in three to four days instead of a hundred men taking three to four weeks. ?5 7afety, both as regards breakages and pilferage, especially when transporting sophisticated electrical goods like radios, T8s, 8*(s etc. ;5 acking can be reduced. <5 real door-to-door service can be offered.
Disa"vantages ) T6o TE3s (98 1eet ? = 1eet ? = 1eet) 'eight of container F ;.@ tons *("/ *((KI1" **ITK F ;3 to ;@ tons
2) ,%all ,i>e (+8 1eet ? = 1eet ? = 1eet)
4) Medi"% ,i>e (28 1eet ? 2 1eet ? = 1eet)
25 &inancial: assive capital outlay for the ship which is more epensive than a conventional general cargo ship. ?5 )ach ship needs three sets of containers, that is one at loading terminal, one on the ship and one at the discharging terminal. n ordinary container is a very epensive item of equipment. ;5 (epairs and maintenance of containers being very epensive. (eefer containers are even more epensive to get, repair and maintain. <5 7pecial terminals will have to be constructed with epensive high speed cranes capable of lifting forty tons and more weights. @5 )pensive machines must also procured to move the containers around the terminal. >5 6nprofitable movement of empty containers produces a problem of an imbalance of trace. E5 In certain countries there are customs, documentation and legal difficulties.
Design O# A Container
*ontainer is designed and constructed as per Carr(ing Ca'ait( O# A S*i' the recommendations and specifications of the The container carrying capacity of a ship is I7/. In order to make sure that a container indicated by how many twenty feet containers has been produced up to the standards, it has a vessel is constructed and classified to carry. to be proved that its structural calculations are It is denoted by the term T')1TK &))T correct and that it can withstand strength )S6I89)1T 61IT 4T)65. !ence, one <3 testing. &or that reason, such organisations as feet container is ? T)6s. container vessel of 9loyd%s (egister, Bureau 8eritas and the merican Bureau of 7hipping, engaged in the
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certification of containers granted on the basis of conformity to an approved type, have established regulations and procedures of a rigorous nature, mostly based on I7/ recommendations.
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!) DOOR,7 oors may be at the ends or sides, which can be opened fully to give complete access to the cargo. (ubber strips around each door and strong bolting system ensures that the container is watertight. The frame of the door is also made of steel for strength and rigidity. &or security reasons, the bolts of the doors are sealed.
Material Use" 7teel seems to be the best basic material. It is superior in yield, tensile and sheer strength and at the same time its elasticity is of a high rank. 7teel is also cheaper. 7ome containers are of mied construction with frames and castings of steel and sides and walls of aluminium. 7ome countries are using wooden, plywood and plastic containers. &ibreglass reinforced plastic overlaid plywood containers are successfully produced. 7tainless steel containers are used for transporting specialised cargoes, like foodstuff, chemicals, liquor, wines etc. The main parts of a container are: 1) .LL,7 The container walls are not load bearing, they merely provide weather protection and security to the cargo within the container. "lass reinforced plastic, aluminium and even plywood can be used, but for a longer life of a container and to give strength and rigidity 7T))9 is the material used.
2) CORNER !O,T,7 ain strength of a container lies in its corner posts. *ontainers are stacked si high, thus, corner posts should be strong enough to withstand these stresses. 3) CORNER C.,TING,7 These are built into the top and bottom of each corner post and provide means of lifting and lashing a container. The top of the casting has an elongated hole for twistlocks of lifting machinery and the sides have smaller holes for lifting hooks of conventional cranes and for lashing.
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Testing An" .%mbering *ontainers must be eamined and tested every ?M years by *lassification 7ociety 7urveyors and a certificate issued. small plate is also fied onto the container indicating the date of such survey. &or identification purposes, containers carry the letters of their owners, like /*9 4/cean *ontainer 9ines5, 1/9 41eptune /rient 9ines5, I7* 4alaysian International 7hipping *orp.5 etc. series of figures also follow these letters, which indicate the type of a container.
FCL 'hen a container is completely filled with the goods from a shipper to a consignee, the container is being used as a &699 */1TI1)( 9/.
LCL 'hen a container is being used by a shipper to transport goods belonging to various
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consignees, only part of a container is being utili+ed for each and every consignee in a same /(T, the container is than said to be used as 9)77 T!1 */1TI1)( 9/.
CO.TA/.ER +ESSEL DES/G. The main ob$ect in the design of container ships is to carry the maimum number of containers within the designed length and breadth having regard to the form and structural arrangement. dequate structural strength must therefore, be provided.
Framing 9/1"IT6I19 framing throughout the main body of the vessel. T(178)(7) framing in the forepart and afterpart of the vessel.
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De! *ontainers are also carried on deck resulting in high deck loading. Thus, the deck and hatch covers must be strengthened to withstand this etra loading.
G%i"es The container guides and ad$acent structures are designed to withstand dynamic forces due to rolling, pitching and heaving. The guides consist of angle bars approimately 2@3 mm 2@3 mm 2< mm connected to the vertical webs and ad$oining structure and are spaced ?.>3 metres apart. The bottom of the guides are bolted to brackets and welded to the tank top and beams. These brackets are welded to doubling plates about 2@ mm thick which are welded to the tank top.
Gir"ers *ontainer vessels are built having *)9969( construction at the sides, strong longitudinal bo girders are formed, port and starboard side, by the upper deck, second deck, top of shell plating and top of the longitudinal bulkheads. !igh tensile steels are used in the upper deck and strake to form a strong bo girder. These bo girders in addition to providing longitudinal strength provide stiffness against racking stresses as well as being useful tank spaces.
,at*)a( !atchway is divided into three sections and two long hatch girders are fitted. These girders are continuous, so that the longitudinal bending strength is shared throughout the length of the girders and also provide additional section modulus.
,at*es !atches or container spaces are suited for the standard si+e of container 4?3 feet or <3 feet units5. form of bulkhead is fitted at interclass of 2<.E3 metres 4<=.? feet5, center to center with watertight bulkheads as per the *lassification 7ociety (ules and 7pecifications. These bulkheads resist racking stresses, giving support to the double bottom structure.
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Container Cells The individual container cell is formed by four vertical guides located at each corner of the container stack running from the hatch coming down to the tank top. The guides have three related functions which are as follows: a5 To guide the containers down to their stowed position even though the vessel may be listing or the crane not perfectly centered over the cell. b5 To land any container on top of the container below it within prescribed tolerances so that the superimposed loads on these lower containers do not eceed the peculiarities for which they are designed. c5 To hold the containers in their stacked position and absorb the hori+ontal forces
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imposed on them by the containers due to the motion motion of the vessel vessel in the the sea. *ontain *ontainers ers are $ust 9I&T)-/1 and#or 9I&T)-/&&.
TYPES OF CO.TA/.ER S,/PS *ontainer ships can be divided into following categories: -
+) 1"ll 1"ll Con Conta tain ine e ,#i ,#ips ps These These are ships ships with with speci special al featu features res and and arrange arrangement ments s to carry carry only only contain containers ers in all availab available le spaces. spaces. !ence, !ence, they are general generally ly 7I1" 7I1"9) 9)- -6( 6(/ /7) 7) ship ships. s. Thes These e sing single le-purpose ships only move containers, stacked on top of each other in vertical stacks on deck. 9oading is achieved by lowering the container into into a cell cell or stack, stack, vertica vertically lly to its stowed stowed positio ition n with ithout furth rther shi shiftin fting g in the the hori hori+o +ont ntal al plan plane. e. uri uring ng disc discha harg rge, e, the the reverse procedure is followed. The containers can be stacked on deck up to four high. This etends the carrying ability of a ship beyond the confines of the hull and lessen the cubic losse losses s susta sustaine ined d by the squa squarin ring g off off of the ship%s hold. The limiting forces here are the ship ship%s %s stab stabil ilit ity y and and sati satisf sfac acto tory ry mean means s of securing the containers in place. The The bigge biggest st and and fastes fastestt and and also also the most epe epensi nsive ve conta containe inerr ships ships are those those of the 7)-91 E7 *977. They have a capacity of 23G> 23G> cont contai aine ners rs of ;@ and and <3 feet feet,, a maimum speed of ;; knots and cross the T91TI* T91TI* from 1ew Kork to (otterdam (otterdam in four and a half days.
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/ther well known 7hipping *ompanies which operate all container vessels are: a5 9K7I1 I1T)(1TI/19 7!II1" */(/(TI/1 4I7*5 b5 1)T 1)T61 61) ) /(I /(I)1 )1T T 9I1 9I1)7 )7 41/9 41/955 c5 )( )(I* I*1 1 () ()7I 7I) )1T 1T 9I1 9I1)7 )7 4 495 95 d5 67T 67T( (9I 9I1 1 1T 1TI/1 I/19 9 9I1)7 9I1)7 4195 4195 e5 /*) /*)1 1 */1T */1TI I1) 1)( ( 9I1 9I1)7 )7 4/*9 4/*955 f5 ' '7 7I I I7) I7)1 1 I I7! 7! 44-9I 9I1) 1)75 75 g5 7*1 6T*! 9I1)7 J )(I*1 )O/(T I7B(1I7)1 9I1)7 h5 7ea 7ea 9and 9and,, 7ea 7ea Trai Train, n, 7no 7now w 7hip 7hippin ping g and and 6nited 7tates 9ines. ) !ati !atial al Contai Containe ne ,#ips ,#ips In thes these e ship ships s /19K /19K part part of the the vess vessel el%s %s capacity is especially designed for containers. The The vesse vessels ls of tla tlanti ntic c *onta *ontain iner er 9ine 9ine and and *are 9ine belong to this category as they carry not not only only conta containe iners, rs, but but also also every every type type of general cargo on its own wheels or tracks or on trailers. The containers are lifted-on#liftedoff, while the trailers and other rollable cargo including cars are rolled-on#rolled-off over the stern ramp and through the stern door. These multi-purpose ships employ a combination of different cargo handling systems. The ships of this category vary in si+e from 2>,@33 to less than @33 gross gross tonnes. tonnes. The apane apanese se 1K
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9ine pro$ected a big ship, 2<,333 dwt for the apan to ustralia rotate.
unitised as well as bulk, liquid, commodities commodities or even heavy lift items.
a) Con*e Con*eti ti'le 'le Cont Contain aine e ,#ip ,#ips s In thes these e ship ships s part part or whol whole e the the vess vessel el%s %s capacity may be used for either containers or other cargoes and embodying special features which permit their convertibility on a voyage to voya voyage ge base bases. s. Thes These e ship ships s are are used used to tran transp spor ortt cont contai aine ners rs and and cars cars from from say say Kokohama 4apan5 to !awaii, while returning with containers, sugar and molasses in bulk.
These floating units can be towed or pushed in ports ports and on inland inland waterway waterways s and hoisted aboard the mothership for transport by sea. Besides fleibility, their advantage is that they can can bypa bypass ss trad tradit itio iona nall bert berth h faci facili liti ties es in congest congested ed ports, ports, releasin releasing g the door-to door-to-doo -doorr wate waterr tran transp spor ort, t, furt furthe herr redu reduci cing ng carg cargo o handling, handling, warehousing, warehousing, inventory costs, risks of loss and damages.
') Li%ite Li%ited d Conta Containe ine ,#ip ,#ips s These are ships of limited container-carrying capacity in which some container handling and securing devices are installed, but otherwise they they are are of norm normal al cons constr truc ucti tion on carr carryi ying ng general, bulk and liquid cargoes.
articulars of a typical 97! ship are: *((KI1" **ITK F >2 to E; lighters 9I"!T)( 7IP) 4each5 F >2 ft. > in. ;2 ft. ? in 2; ft. ')I"!T of each lighter F <33 tonnes appro. "(/77 T/11") F ?><33 to ;G333 tonnes 9)1"T! F =2< feet B) F 233 feet 7)) F 2G to ??.@ knots
c) Con* Con*en enti tion onal al ,#i ,#ips ps These are ships without special containers stowing or or handling handling devices. devices. /n these these ships, container is merely treated as a larger than usual piece of cargo. It is secured and stowed by conve conventi ntion onal al mean means. s. 7uch 7uch ships ships could could conventional general cargo ships and roll on, roll-off vessels with four steel decks below the wate waterr deck deck,, all all link linked ed by slop slopin ing g ramp ramps. s. *ont *ontai aine ners rs are are hand handle led d with with ship shipbo born rne e equipment equipment like forklifts with a side lift frame for ?3 feet containers and forks for boes, pallets and and case cases. s. Thes These e ship ships s norm normal ally ly have have a capacity of ?2,E33 dwt and 2,G23,333 cubic feet bale capa capacity city.. (emarkab (emarkable le ramps ramps are mounted aft on starboard side, 23@ feet long, weighting 2@3 tonnes and can bear loads up to 23@ metres or less space on the quay. This hinged angled stern ramp can be continuously ad$usted to tide and draught.
SPEC/AL TYPES OF S,/PS +) Bag Bage e Ca Caie ies s There are two such specially designed ships which carry barges or lighters: a) L.,$ It stan stands ds for for H9I" H9I"!T !T)( )( B/ B/( ( 7!I 7!I%. %. 9ighter or barges are independently floating, universal units without the propulsive power, and loaded with cargo of very different kinds,
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9igh ighters or barge rges are constru struct cte ed of fiberglass to boost the payload and facilitate handlin handling, g, as well well as reducing reducing maintena maintenance nce.. The ship can also be loaded with containers, as many as 2?33 units of ?3 feet. lash ship can be filled within ?< hours with
containers by means of a travelling ship shipbo boar ard d cran crane e of @33 @33 tonn tonnes es capa capaci city ty,, supplem supplemente ented d by a gantry gantry capable capable of lifting lifting upto ;@ tonnes. &eeder vessels are now in use. The 1*T 4B(")7 B/( *T(15 are merely floats or rafts formed of a number of logs tied side by side some distance apart. They ferry ferry lighters lighters to the mother mother ship, ship, which which operate operates s only only a limite limited d numbe numberr of ma$or ma$or ports ports-of -of-ca -callll and reduces port turnaround times. ') ,E.BEE 9ykes 9ykes 9ines 9ines is a ma$or ma$or shipp shipping ing compa company ny,, owning a fleet of 7)B)) ships. 7eabees 7eabees are an impressive improvement on the theme of carrying standard barges barges on a large sea going vessel. 7eabee is a ship operating solely as a deep deep sea sea tran transp spor ortt of prepre-lo load aded ed barg barges es havin having g real real eten etensio sions ns to provid provide e servi service ce dire direct ctly ly to the the port ports s and and othe otherr wate waters rsid ide e loading locations. 7eabee permits all types of cargoes cargoes whether whether unitised unitised,, bulk, bulk, break-bu break-bulk, lk,
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palletised, palletised, containerised, containerised, and heavy heavy lifts. 7he can can also also be conve converte rted d into into a roll-o roll-on# n#rol roll-o l-off ff vessel and can eclusively move containers. The The barg barges es whic which h carry carry carg cargoe oes, s, are are the the etensions etensions of mothership allowing the 7eabee herself to avoid the risk run by any big ship going into port and to develop the technique of discharging offshore. articulars of a typical 7eabee are: *((K *((KI1" I1" * **IT *ITK K F 2,@33 2,@33 tonn tonnes es to 2,=33 2,=33 conta containe iners rs of stand standard ard ?3 feet. feet. lus lus 2@,333 tonnes of liquid in deep tanks. 7 (/99-/1#(/99-/&& (/99-/1#(/99-/&& F @ kilometres of 99)K7 99)K7 with a width width of ?.= metres. metres. 9)1"T! F ?E> metres B) F ;?.@ metres )')I"!T F ?E333 tonnes appro. 7)) F ?3 knots B(")7 7IP) F ?G.2 metres 23.E metres 1/. /& B(")7 F ;= each weighing =33 tonnes B9) **ITK F ;G,333 cubic feet They They also also have have a heav heavy y lift lift subv subver ersi sive ve elevator at their stern with a capacity of ?333 tonnes to load and discharge two barges at the same same time. time. Theore Theoretic ticall ally, y, the compl complete ete loading or discharging operation takes about 2; hours. &rom the elevators, power operated transporters transporters bring the lighters to and from their storage location. The main differenc difference e between between the 9ash and 7eab 7eabee ee is the numbe numberr and and capa capacit city y of the barges each can transport. 9ash carries upto E; barges with a capacity of <33 tonnes each and bale space of 2@,G33 cubic feet, whereas the 7eabee carries ;> with =33 tonnes each and bale space ;G,333 cubic feet. &urth rthermo rmore, re, 97! uses a shipb ipboard travelli travelling ng crane, crane, whereas whereas 7eabee 7eabee employs employs and elevator for the mechanical handling of these lighters.
CO.TA/.ER ,A.DL/.G E3U/PME.T ifferent types of container cranes are used to load load and and unlo unload ad cont contai aine nerr ship ships. s. any any shipping shipping compan companies ies started started their their contain container er opera operatio tions ns using using shipb shipboa oard rd gantr gantry y crane cranes. s. The advan vantag tage of ship shipb board handlin ling
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equipment is that ships can call at ports which have have no costly costly custom-b custom-built uilt installa installation tions s like gantry cranes etc.
Cranes In the the ma$o ma$orr port ports s of the the worl world d ther there e are are speci special al */1T */1TI1) I1)( ( B)(T B)(T!7 !7,, where where two kinds of cranes are used: a) !ota taine ine Cane ane This is a gantry with usually /1) boom, which merely moves the containers from the ship%s hold onto flat beds of lorries and forklift trucks on the quay. This crane is employed in ma$or contain container er ports, ports, where where large large containe containerr ships ships arrive regularly and where storage space and marsh marshal allin ling g yards yards are conse consequ quen ently tly big or situated near the quay. ') Tan Tanst stai aine ne Can Cane e It is a crane of the overhead travelling type, which spans a storage place or marshalling yard. yard. It is multi multipu purpo rpose se crane, crane, capab capable le of unloadi unloading ng ships, ships, moving moving contain containers ers to their their storage place, loading trucks and trains and, betw betwee een n the the arri arriva vals ls of vess vessel el it can can be employed for marshalling. Its speed is low in comparison with portainer portainer crane. This crane is perfe perfectl ctly y suita suitable ble for for ports ports with with mode moderat rate e output.
S'rea"ers )ver )very y cont contai aine nerr cran crane e has has a rect rectan angu gula larr sprea spreade derr frame frame with with couple couplerr latche latches s in the corners. These twist locks enter into the top holes holes of a conta containe inerr corne cornerr castin castings gs as the the spre spread ader er is lowe lowere red d onto onto the the cont contai aine ner. r. 9atches are locked and unlocked electrically, hydraul hydraulical ically ly or pneumat pneumatical ically. ly. (etracta (etractable ble alig lignmen ment arms kee keeps the the sprea reader in posit position ion.. I7/ I7/ (ecom (ecomme mend ndati ation ons s gives gives the speci specific ficati ation ons s of corne cornerr fittin fittings gs for freig freight ht containers.
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For! Li#ts &ront loading or side loading fork lifts are in common use as container handling equipment.
SECUR/.G CO.TA/.ERS 'hen loading containers on deck of the full container and roll-on#roll-off vessels, separate lashing arrangements would have to be made. The The prob proble lem m of lash lashin ing g diff differ eren entt si+e si+es s of contain containers ers is further further aggrava aggravated ted by differe different nt contain container er heights heights and maimum maimum permissi permissible ble gross weights of various types of boes. )ach ship ship carri carries es a large large stock stock of fittin fittings, gs, wires, wires, bott bottle le scre screws ws,, turn turnbu buck ckle les s and and ratc ratche hets ts.. !ooks !ooks and chain chain tension tensioning ing devices devices secure secure the vehicles to an elephants% foot located in a deck flush fitting with four slots in the form of a cross, radiating from a central hole. &irst tier of container is lowered over removable stud on the hatch covers and decks and a safety metal pin pin inse insert rted ed thro throug ugh h corn corner er cast castin ings gs and and studs. The second tier is fied into the first tier by inserting single or double bridging pieces into the corner castings, or both the tiers. Inside Inside the holds holds the conta containe iners rs are held held in place by the cell guides.
(n deck urt*er las*ings o wire+ c*ains and rods are pro,ided+ tig*tened y ottle screws and and turn turnu uckl ckles es"" (n some some ,ess ,essel elss las* las*in ing g ridges are constructed"
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DEC7 CARGOES The carriage of deck cargo - governed by 7tatutory Instrument 2G>= 1o. 23=G. 25 The vessel must have adequate stability at all stages of the voyage. *argoes such as coke and timber can absorb upto about a third of their own weight of water. 9osses of weight such as those due to consumption of fuel, water and stores must also be considered. 6psetting moments - wind taken into account.
<5 'here the cargo is stowed on the hatches - properly battened down, sufficient strength to take the intended cargo. @5 eck - sufficient strength for the intended cargo. If necessary strengthened by tomming or shoring underneath. >5 eck cargo - well secured, protected from weather. 1ot so high as to interfere with the navigation of the ship.
?5 dequate provision for safety of crew when passing from one part of the vessel to another - a walkway has to be provided over the cargo. 'alkway not less than 2 metre in width, not less ; courses of guard rails or wires supported by stanchions intervals not more than 2.@m. The vertical opening between lowest rails or wires not to eceed ?;3mm and no opening above that shall eceed ;=3mm. ;5 7teering arrangements effectively protected from damage. Breakdown in the main steering arrangements - emergency gear.
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REFR/GERATED CARGOES De#inition ny cargo that has to be loaded, maintained and#or carried at a certain temperature in order for it to reach its destination without deterioration is classed as refrigerated cargo. This includes meat, fish, poultry products, dairy products, drugs and eperimental samples.
T('es O# Re#rigerate" Cargoes 25 "oods carried in fro+en state i.e. meats, fish and butter0 ?5 "oods carried in chilled state i.e. beef, vegetables, cheese and eggs0 ;5 "oods carried in air cooled condition i.e. fruit. 1ote: rugs and eperimental samples may be fro+en or chilled.
Pro'erties O# Re#rigerate" Cargoes 25 (apid deterioration if proper temperatures are not maintained during loading, voyage and discharging. ?5 7usceptible to tainting and moisture contact damage. 3) )ffected by presence of */ ?.
Re$%irements For Sa#e Trans'ort a5 )fficient refrigeration machinery and good insulation of the compartment. b5 *areful preparation of the compartment including cleaning, dunnaging and precooling. c5 )ffective system for monitoring and maintaining specified temperature during loading, transportation and discharging. d5 7egregation of cargo. e) onitoring and control of */ ? concentration in the compartment, and good ventilation.
Prea%tions Relating To Trans'ortation O# Re#rigeration Cargoes ALAM/July 2002
.) Refigeation Mac#ine 25 (efrigeration machinery should be checked and tested. Brine pipes should be tested to a pressure 2M times their normal working pressure to check for any possible leaks. close inspection must also be made of all insulation and defects rectified. Insulated ventilator plugs must be closely fitted in place and sealed with saw dust. ?5 7cuppers and other water drainage system around and near refrigeration machinery must be checked to ensure that moisture will have an easy and free access to the bilges. 3) Test */? etraction, generation and in$ection equipment. B) !epaation Of Co%pat%ent 25 7weep and clean thoroughly with particular attention to brine pipes, insulation, bins, gratings, air ducts in order to remove all traces, stains and odour of previous cargo. fter cleaning these should be wiped down with a disinfectant fluid to prevent formation of mould there on. ?5 Bilges should be made dry, cleaned and ventilated in order to remove foreign matter and odour. Brine traps should be checked and topped up to prevent cold air from entering the bilges and free+ing them or odour from reaching the refrigerated compartment. ;5 7trum boes should be cleared and bilge suction tested. <5 *lean dunnage, likely to be used, meat hooks, bars chains or any other equipment or appliances to be used for loading or stowage of cargo should be placed in the compartment after they have been cleaned and sterilised. @5 Thermometers should be tested and kept ready and thermometer pipes, if removed, should be fitted, or etended to enable recording of temperatures at the top, middle and lower levels of the compartments. >5 ortable trunks in holds of battery compartments must be assembled in place. E5 The compartment should be pre-cooled to a temperature lower than the normal carrying temperature, to allow for fluctuations during loading, ?<#<= hours before commencement of loading.
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&) If lead, copper or tin ingots are also loaded in refrigerated compartments, additional precooling is necessary. *hilled compartments should be maintained at their transit temperature and fro+en compartments at 2< o& for > hours for each floor tier of ingots. G5 pproimate pre-cooling temperatures: &ro+en compartments 23 o& *hilled compartments ?? o& pples, pears, peaches and grapes ?= o& /ranges, lemon, grape fruit ;> o& *heese <3 o& 235 The pre-cooled compartment should be inspected by the appointed surveyor and certified Hfit to load% before loading can commence. C) Loading& Disc#aging& $andling 25 unnaging should be so arranged so as to: a5 provide adequate support to the cargo, b5 ensure sufficient clearance from deck and sides to prevent contact between cargo and the cooling pipes, air ducts, baffle plates and any water likely to condense in the compartment, c5 in the event of different temperatures being maintained in ad$oining compartments liberal use should be made of saw dust on deck dunnage on the sides and drip trays under deck head to prevent water contamination in the warmer compartment, d5 to prevent damage to bottom tiers by over stowed cargo, e5 to permit unobstructed circulation of cooled air below, around and through the cargo including dunnaging at intermediate tiers for cargo of tight block stow type so that uniform temperature can be maintained throughout the compartment. ?5 *argo tendered for shipment should be inspected thoroughly: a5 fro+en cargo should be hard fro+en and free of spots or mould. There should be no blood stains on the wrappings, b5 fruit should not be in advanced stated of ripeness, skin should not be discoloured and should not be brown on the inside. (andom samples should be taken and cut open. ;5 *ooling in compartment opened for loading should be stopped to prevent frosting of grid pipes which will not only reduce cooling
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efficiency but on melting will result in water accumulation in the compartment and possible damage to cargo there in. ny snow formation on pipes should be carefully swept off. <5 *ompartments not being worked should be kept closed. If necessary to keep them open to permit loading in ad$oining hold or space, escape of cold air should be prevented by rigging tarpaulin screens or some similar device. ir screens may be fitted on some ships. @5 onitor temperature in the compartment during loading and should it rise above the specified level, close the compartment and recool it. >5 1o walling should be permitted on cases of fruit, eggs or cheese as they are fragile /ver other fro+en cargo, shoes should be covered with clean gunny sacking or similar material. E5 *argo should not be dragged, pushed or thrown. 7lings should be made in the hatch square. =5 roper cargo gear should be used e.g. canvas nets for meat and trays for crates#cases of cheese, butter, eggs and fruit. G5 !eavy meat should not be stowed over light meat. 235 Taintable cargo should not be stowed with fruit nor loaded in a compartment which has carried fruit unless it has been de-odourised. 225 Thick paper should be pasted over $oints to prevent air leak. D) D"ing 0oage 25 onitor and record temperature in all compartments and ensure that it is maintained at the desired level. 2) onitor */? concentration in compartments carrying fruit and arrange etraction to ensure that it does not eceed @A. 3) In compartments containing meat */ ? may be in$ected upto > kg per 2333 cubic feet to help pressure it for a longer time. <5 &or chilled meat ventilation should be arranged to achieve complete air change ?3?@ times every hour.
CO Control 1) (ipening of fruit generates heat and */ ? which must be removed to preserve the cargo. aimum permitted concentration is @A.
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2) resence of */ ? helps preserve meat for a longer time and */ ? should be in$ected into the compartment loaded with meat, if necessary, upto 23A concentration. 3) */? concentration should be checked and recorded at least once daily, but preferably once every watch at sea. !) In the past litmus paper cartridge was used to determine */ ? concentration by lowering it into the hold. Its degree of discolouration indicated */ ? concentration. #) odern method is thermoscope in which a sample of air is drawn from the hold and allowed to mi with caustic soda. This generates heat which, when measured, indicates */? concentration.
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thus becomes very cold. It then passes through the evaporator, containing brine, before being drawn back into the compressor. *ooled brine is circulated through grids or batteries and thus cools the refrigerated compartment directly or indirectly.
Containers considerable amount of refrigerated cargo is carried in containers. These are of two types: -
Gri" S(stem Or Diret Cooling
Ree#ers
"rids of ?D pipes are fitted around the compartment through which cooled brine is circulated. "rids are so arranged that damage to one section can be compensated by etra cooling of other sections.
containers with an independent electrical or diesel driven refrigeration system. portholes which depend on eternal source for cooling.
A"vantages o# %sing ontainers are no contamination or tainting no stacking damage no condensation damage no insulation required in ships% cargo space.
&atter( S(stem Or /n"iret Cooling ir is blown over a battery of pipes through which cooled brine is being circulated. This cooled air is then blown into the compartment through an arrangement of air ducts. 'arm air is etracted and again blown over the battery of brine pipes.
Re#rigeration S(stems basic refrigeration system consists of compressor, condenser, epansion valve and evaporator. The coolant, freon gas, is compressed in the compressor, cooled and condensed into a liquid in the condenser and passed through the epansion valve where it epands and
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SAFETY PRECAUT/O.S O. FERR/ES; RO2RO CARR/ERS A.D CAR CARR/ERS GE.ERAL 25 7eaman working on vehicle decks and in close proimity to moving vehicles should wear safety helmets and clothing of high visibility, such as fluorescent Hslip-overs%. ?5 7uitable footwear should be worn to avoid risk of in$ury from securing gear. ;5 'here no other means of access is provided, care should be taken by personnel using loading ramps for access while vehicles are moving on or off the ship. <5 acks, trestles and lashing equipment should not obstruct walkways, doorways or emergency escapes. @5 7hip%s stores should not be stowed on any part of the parking area for vehicles. >5 lifebuoy with self-activating light and line of suitable length should be available close to the vehicle deck access doors. E5 ll decks should be kept free of water, oil and any other substance which might be conducive to a vehicle or cargo unit sliding. =5 ny spillage of petrol, oil or cargo should be cleaned immediately0 sand boes, drip trays and equipment should be provided for such use on each vehicle deck. G5 There should be no smoking or use of naked lights on vehicle decks. 235 1otices setting out the precautions to be observed in handling and stowing vehicles should be prominently displayed in all vehicle spaces. 225 ny damage to electric lights and fittings should be repaired as soon as practicable. 2?5 very high standard of crew fire drill is essential. patrol should be maintained on vehicle decks during the passage.
Sto)age O# +e*iles 25 ll vehicles should be stowed in a fore and aft direction as far as practicable. ?5 ny vehicle stowed athwartships should be securely lashed. ;5 8ehicles should not be stowed across a water spray fire curtain. <5 7pecial care should be taken in positioning and securing a vehicle or cargo unit when
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decks are sparsely loaded to minimi+e the damage which would be caused by the vehicle breaking free into unrestricted space. @5 8ehicles containing dangerous cargoes should be handled in accordance with the code for portable tanks and road tank vehicles for the carriage of liquid dangerous goods in ships or otherwise as directed in the HBlue Book% and the International aritime angerous "oods *ode 4I" *ode5. If tanks are found to be leaking or having evidence of possible leakage or otherwise significantly damaged so as to possibly affect the integrity of the tank, the vehicle should not be accepted for shipment. 'hen the vehicle carries a transport emergency card 4tremcard5 for its load, the card should be lodged with the aster for reference in case leaks should develop during the voyage. >5 ny vehicle carrying dangerous goods should be segregated from other cargo, accommodation, machinery openings and animals, in accordance with the HBlue Book%. It should be readily accessible to an emergency party and, whenever practicable, located in a position convenient to fire fighting services and drainage scuppers. E5 ersonnel should not stand behind or between vehicles when these are manoeuvering. =5 ersonnel should not attempt to secure a vehicle until the brakes have been applied and the engine switched on. G5 9ashing and securing of vehicles and cargo units should be carried out by men trained and eperienced in the task. 235 There should be an adequate supply of efficient securing and lashing equipment which should be properly maintained and regularly inspected. 225 ll lashings should have suitable tightening arrangements. 2?5 9ashings should be tightened to ensure that they are secure but not over tightened so that unnecessary strain is thrown upon the lashing. *are should be taken to equali+e as far as practicable the tensions of the several lashings of a vehicle etc.
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2;5 ersonnel should not remain on internal $amming occur, care should be taken in case deck ramps which are being raised or lowered. of sudden release of the $am. ;5 ortable stanchions and hand rails should always be in position when portable decks are +entilation 25 8entilation systems serving the vehicle in use. decks should be in operation during loading <5 *are should be taken to ensure that and unloading and as many be necessary on portable decks are properly stowed and passage to avoid the accumulation of secured when not in use. @5 'hen portable decks are in the stowed flammable and toic vapors. ?5 *onnecting doors between car-decks and position, access doors should be secured. machinery, service and accommodation spaces should be kept closed while the ship is at sea. ;5 *onspicuous notices should be posted warning against the starting of vehicle engines before doors leading to ramps are opened and before the vehicle is required to move. <5 ny refrigerated vehicle needing to run its refrigeration plant during the voyage should utili+e the ship%s electrical supply where practicable, in preference to running its engine.
Portable Car De!s 25 &requent inspections should be made of the equipment and associated gear used for raising, lowering and suspending portable decks. ?5 7eamen should stand clear while portable decks are being raised or lowered. 7hould
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T/M&ER CARGOES In many trades timber is carried in large quantities and may be loose or packaged. 9oose timber can be individual planks, cubic units, pit props or logs but the carriage of loose timber is mostly taken over by packaged timber mainly because packaged timber is much less cumbersome, more easily transportable, easily handled by mechanical means and therefore more economical.
Loose Timber But the carriage of logs is still a common trade although is usually done by vessels which are specially constructed for the purpose, and have their own suitable gear. In many frican countries from which timber is eported, logs are kept in floating ponds and are towed to the vessel by tugs. In some ports of discharge the timber is similarly discharged into the water and then transported by tug towage inland through canals and waterways. 9oose timber carriage involves high costs and a waste of labour. uch time and many has to be spent on handling and sorting out and the operation of loading or unloading loose timber cannot be carried out with speed. This is more the case with conventional ships which are not specially constructed for the carriage of timber.
Pa!age" Timber Being packaged this form of timber carriage is much more speedy and economical, and can be easily and quickly handled by fork lifts and mechanical means. ackaged timber is presently increasingly carried in unit loads of uniform si+e, and speciali+ed vessels having suitable gear for unit loads are increasing in number. 7everal ports have separate terminals marked off for the working of such unit loads and the saving in terms of port stay and turnaround are great. /verall, the advantages of packaged timber are increased efficiency of handling, use of less manpower at both the loading ends, faster turnaround of the vessel, and lesser damage and breakage.
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Timber De! Cargo Timber is not only carried in holds but also on deck. 'hen timber is carried on deck there are great chances of its shifting, and with it not only the less of the cargo but damage to the vessel itself. It should therefore always be compactly, stowed and secured with adequate lashings. 7ome of the important procedures that must be observed when loading such cargoes are as follows: a5 The packages should be securely bound and in solid form. b5 /ne tier of dunnage should be laid with the planks close up on each other and placed athwartships. This helps to spread the weight of the cargo over the deck. c5 fter every tier of cargo all loose space should be properly filled in or checked, to minimi+e the chances of shifting. d5 The packages should be stowed such that the lashing arrangements are not blocked or obscured. e5 ackages of different weight and si+e are to be stowed separately or with suitable separation if stowed together, so as to prevent chances of damage. f5 s far as possible the packages should be stowed in a fore-and-aft direction so as to prevent shifting, also so as to enable proper lashings to be taken. g5 1ecessary arrangements should be made to tighten the lashings during the voyage, as this might be necessary due to vibrations or movement of the vessel. h5 s far as possible only uniform si+ed packages should be loaded on deck and irregular packages stowed 4in holds5, so that
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lashing and securing of the cargo on deck end be easier. 'henever timber is stowed on deck it must comply with the regulations of the I/ code of safe practice for ships carrying timber deck cargoes. This code applied to all vessels of ?< metres 4EG feet5 or more in length and deals with following:
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event of an emergency. The lashings should be of 2Gmm chain or wire rope of equal strength and should be eamined at least once in 2? months. If wire lashings are used they must be provided with a short length of chain so that their lengths can be regulated. The lashing spacing as shown in &igure 2.
2) Co%pactness The stow should be as compact and tight as possible, with each tier properly chocked before loading the net tier. ll spaces in the wells of vessels should be stowed as solidly as possible, this is more so in the case of vessels assigned timber loadlines, where the deckline is virtually raised to the level of the superstructure deck. +) ,to6age The cargo should be compactly stowed and should not interfere with the navigation of the vessel, and with any arrangements that may be necessary for temporary steering of the vessel. The stow should also permit free access to accommodation and machinery spaces and should not endanger the safety of the crew in their normal duties. If the stow requires uprights these should be placed not more than ; metres apart, and must etend to above the outboard top edge of the cargo. The uprights must be properly secured at their base and arranged such that each pair end be secured with athwartship lashings. 'here practicable permanent ports of the ships structure can also be used as uprights. ) Las#ings The entire deck stow should be provided with lashings which can be taken athwartships and secured to permanent eye pads or similar structures. )very lashing should be independent and should be provided by arrangements for shortening or lengthening ad$ustments turnbuckles as required during the course of the voyage. They should also be provided with sliphooks for releasing in the
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9) Logs& !it !ops .nd ood !"lp 9ogs should be stowed as compact as possible in a fore and aft direction and should be interlocked. They should be stowed to facilitate the rigging of lashings and uprights as in the cease of packaged timber. it props and wood pulp, although must meet the same stowage requirements, are usually loaded as per local practice. :) $eig#t Of Dec ,to6 The height of cargo on deck would depend mainly upon the load bearing capacity of the deck. But in any case the height of the timber deck stow should not interfere with the navigation of the vessel. If the vessel is loading in a seasonal winter +one during winter or is epected to unload or pass through such a +one during the course of the voyage, the height of cargo on deck should not eceed the etreme breadth of the vessel. ;) ,afet Of Ce6 7afe access to crew accommodation should be provided by way of walk-ways with guard rails of 2 m height. lso an additional lifeline, along the centreline of the vessel, should be provided.
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Stabilit( *areful attention is to be paid to the stability of the vessel when loading timber cargoes. It should be remembered that during the voyage timber deck cargo would absorb considerable moisture by way of rain, ice or snow. ue allowance must be given to this and the vessel should have adequate initial " to allow for this factor. It would therefore be seen that the amount of timber carried on deck would have an important bearing on the ultimate safety of the ship. It is felt that as a general rule, on vessels fully loaded with timber, not more than of the weight of timber carried should be stowed on the open deck.
mong the stability information carried on ships the aster and /fficers are also to have suitable information to enable them to foresee the stability characteristics of the vessel in relation to the deck loads, under all conditions of the intended voyage. In planning the loading and voyage with timber deck cargo the guidance information contained in the vessels stability booklet must be observed.
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MODULE = - &UL7 CARGOES ,aar"s In general, the ha+ards may be considered to fall into three categories: 25 Improper weight distribution resulting in structural damage a5 )cessive concentration of weight on deck or inner bottom. b5 Improper distribution of weights between holds.
DEF/./T/O.S &%l! Cargo cargo consisting of solids in particle or granular form, with or without entrained moisture, generally homogeneous as to composition and loaded directly into a vessels cargo spaces without bagging or packaging.
Conentrate
That material obtained when a natural ore has ?5 Improper stability or reduction in stability a5 Too stiff a vessel resulting in violent rolling undergone some form of purification by a and possible cargo shifts and structural physical separation of undesired ingredients. In contrast to natural ores which contain a damage. considerable percentage of large particles and b5 reduction in stability as a result of:i5 transverse shift of the cargo surface lumps, concentrates ordinarily consist of a as in the case of C(KD cargoes and cargoes miture of small particles. which do not become fluid when wet. ii5 transverse shift of C')TD cargoes Angle o# Re'ose which become fluid and give rise to free ngle of repose is between a hori+ontal plane surface effects. and the cone slope obtained when bulk cargo is emptied on to this plane. low angle of ;5 *hemical (eaction: few cargoes like fine repose characteri+es a bulk cargo which is copper ore, etal turnings and borings are particularly liable to dry surface movement sub$ect to spontaneous heating. aboard ship. C(KD bulk cargoes include Cores and similar bulk cargoesD
GE.ERAL PRECAUT/O.S 0/T, &UL7 CARGOES
C')TD bulk cargoes come under the heading of C/re *oncentratesD
25 stability booklet should be provided. ll relevant information in connection with loading, precautions and any necessary data should be supplied to the aster. rior to sailing, the aster should calculate the stability for the anticipated worst conditions during the voyage as well as that on departure and ensure they are satisfactory.
rovisions of the code apply when bulk cargoes from a considerable part of the total cargo for the voyage. 'hen bulk cargoes ecept ore concentrates, make up less than /1)-T!I( of the cargo deadweight of the vessel, the aster at his discretion may depart from the portions of the *ode that are not considered to apply. In the case of small part cargoes of concentrates carried in general cargo vessel it may not be necessary to comply fully with these provisions.
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?5 n ecessively stiff ship may roll very violently, resulting in damage to the ship. !owever, a vessel with a relatively large " is better able to resist the tendency to list, if a shift of cargo should occur. &or this reasons, no concern should be felt about operating a bulk laden vessel with a large " where eperience has shown that the resulting motion is not too severe.
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;5 'hen loading a high density bulk cargo with a 7.&. of about ?3 cu. ft. per ton 43.@> m@#ton5 or lower, the loaded conditions are different from normal and particular attention should be paid to the distribution of weights to avoid ecessive stresses. general cargo vessel is normally constructed to carry cargoes of about @3 - >3 cu. ft.#ton 42.;G to 2.>E m;#ton5 when loaded to full bale and deadweight capacity. In such cases, the shipmaster should be provided with comprehensive loading information so that the ship may not be overstressed. <5 'here such information is not available, the following precautions should be observed: a5 The general fore and aft distribution of cargo by weight should not differ appreciably from that found satisfactory for general cargoes. b5 The maimum member of tons of cargo loaded in any hold should not eceed 3.G 9B metric tons where 9 - 9ength of hold, B F average breadth of hold and F summer load draught 4all in metres5. c5 'here cargo is untrimmed or only partially trimmed the height of the cargo pile peak above the hold floor should not eceed. 2.2 7towage factor 47.&. in m;#ton5 d5 If the cargo is trimmed entirely level, the maimum load in the lower hold may be increased by ?3A sub$ect to compliance with 4a5 above. e5 In holds with a shaft tunnel, lower holds may be loaded to 23A in ecess of the trimmed or untrimmed values sub$ect to compliance with 4a5 above. shaft tunnel has an etra stiffening effect. @5 recautions should be taken to prevent dust from coming into contact with deck machinery. 8entilation systems to accommodation spaces should be screened or shut down.
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&%l! Cargoes ,aving An Angle O# Re'ose Greater T*an 6= 25 !igh density cargoes should be loaded entirely in the lower holds unless this results in the ship being Ctoo stiffD or if cargo weight on bottom structure is ecessive. ?5 *argo should be trimmed sufficiently to cover the tank top. This trimming can be accomplished by leaving within the hatch square so that the slope is uniform towards the ships sides and substantially so, to the end bulkheads. The importance of trimming to prevent a shift of cargo is stressed. This advice applies especially to smaller vessels i.e. 233 metres or less in length. ;5 'hen cargo is carried in tween decks to reduce stiffness, it should be the least amount necessary to do so. <5 If cargo is loaded in tween decks, hatches should be closed and cargo trimmed reasonably level. If cargo does not etend side to side and bulkhead to bulkhead then it should be stowed in bins.
&%l! Cargoes ,aving An Angle O# Re'ose Less T*an 6= These cargoes are more liable to shift in a seaway. Thus they require more trimming. 7paces in which they are loaded should be preferably filled without overstressing the vessel. In tween decks they should be loaded in bales or be fitted with shifting boards similar to grain cargoes. 7i+es of shifting boards should be adequate for the density of the cargo.
>5 !olds should be thoroughly inspected prior to loading. Bilge wells and strainer plates should be prepared to facilitate drainage. Bilges should be frequently sounded during and after loading.
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CARR/AGE OF COAL The main consideration to keep in mind with coal is that it emits methane, an odorless, flammable gas which is less dense than air. This gas is emitted particularly if the coal has been freshly mined or if it is dropped into the hold when loading, causing it to break up. Thus a risk of fire and eplosion is always present on a ship carrying coal. ethane levels of between @A and 2@A in air constitute an atmosphere which can be r eadily ignited and eplode. any classes of coal, including anthracite, are liable to spontaneous combustion if allowed to heat ecessively. 7paces in which coal is to be stowed should be carefully cleaned, ensuring that all traces of oil or grease and of previous coal cargoes are removed. Bilges and scuppers must be tested and in working order and electrical wiring in the compartment disconnected or sheeted in heavy gauge screwed steel conduit.
Bulkheads between coal carrying compartments and accommodation or machinery spaces must be gas tight. eck houses and other compartments on deck may collect methane and must be well ventilated at all times. 1o naked lights or smoking must be allowed in or near a coal-carrying compartment. *are must be taken not to create sparks as a result of impacts of steel on steel. The absorption of oygen from the air by the coal loads to oidation and the evaluation of more methane and heat generation. The cargo must therefore not receive through ventilation, but generous surface ventilation must be provided to quickly remove any evolved gas and keep the cargo cool. !atch covers may be opened during suitable weather to assist this. If the temperature of the coal is found to rise too much, it may be necessary to cool the ad$acent bulkhead by directing hoses at it and removing the water via the bilge pumps.
&ire fighting, life saving and smoke detection equipment must be carefully eamined and tested. The fire fighting equipment should be methanometer being carried on board to test available for immediate use at all times when for the presence of methane around the loading and on passage. The smoke detection vessel. equipment must be continuously operated and monitored regularly. /nly intrinsically safe torches and other equipment may be used in or near coal rrangements should be made before loading compartments. to enable temperatures to be taken at the ends of compartments and in the bottom of the *oal must be segregated from any other cargo stow via suitable pipes from the deck, to liable to spontaneous heating and must be ensure rapid detection of a temperature rise. kept clear of warm bulkheads. 'hen loading in the hatch square using chutes, etra boards should be provided in the hold to prevent damage to the tank top plating. The arrangements for carrying a coal may, if the master so requires, be eamined by a arine epartment 7urveyor to ensure that the vessel is in all respects satisfactory.
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It must also be stowed away from cargoes liable to damage from coal dust. If necessary, other cargo in the same compartment may be completely covered with tarpaulins or other dust-proof materials. 'hen loading small coal, shifting boards may be necessary to prevent the movement of cargo on passage. uring loading, the coal should be carefully trimmed into the winds and ends of compartment to achieve a level stow, preventing any shifting and also the
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accumulation of pockets of methane above the stow. If a coal fire breaks out when on passage, steam in$ection must not be used to etinguish the fire, and it should be controlled using */?, inert gas or high epansion foam, which should be in$ected into the compartment. The vessel should head for the nearest port and keep the hatches sealed until specialist advice is obtained. )ntry into a coal compartment must only be attempted by personnel wearing breathing apparatus and having adequate back-up personnel to render assistance standing by on deck. Through ventilation of the space must be provided before entry is attempted and during the time that crew members are in the space.
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GRA/. 0*at /s Grain ll cereals e.g. wheat, rice, barely, oats pulses, seeds, corn and rye, in processed and unprocessed forms, are classified as grain in so far as their transportation by sea is concerned. It can be carried in bags or in bulk.
Pro'erties O# Grain a5 It is easily taintable b5 It is sub$ect to heating and condensation particularly if it is shipped at the beginning of the season. It readily absorbs moisture. c5 It is likely to move if tilted beyond its angle of repose.
Prea%tions Relating To Carriage O# Grain +) Cleanliness a5 *ompartment where grain is to be loaded should be perfectly clean and free of any odour. b5 The bilges should be free and clean particular attention being given to the strum bo. coating of lime and cement wash is advisable. c5 The limber boards should be in good condition and repair, seams caulked. Burlap should be laid over the limber boards and nailed down to prevent grain from entering the bilges and bilge well. d5 The tank-top ceiling, if fitted, should be clean, dry and free from any stains and with seams properly caulked. If ceiling is damp and stained, sprinkle lime all over, leave for a while and then sweep it away. e5 The entire compartment including bilges, limber boards, spar ceiling, side battens, pipe guards, fittings and all spaces including those over the top of deck hold beams and frames should be free of infestation of any kind. ) 0entilation a) #en Caied In Bags The air intakes are to be at the bottom layers of cargo while the air etractors are to be aimed at the top layers.
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') #en Caied In B"l Both air intake and etractors are to be directed at the surface. 2) ,#ifting Boads "rain in bulk, when tilted beyond its angle of repose will shift and will not return readily to its original position. This will cause a corresponding shift in the position of centre of gravity H"% of the ship and thus influence righting moments and endanger the ship%s stability. Therefore, measures have to be taken to ensure that shift of grain due to hauling movements of the ship is restricted to the minimum. These comprise of: a5 )recting of shifting boards0 b5 /ver stowing bulk grain with bagged cargo or other suitably packed cargo or strapping it down. c5 *onstruction of feeders to fill void spaces resulting from settling of cargo during the voyage.
etailed specifications of shifting boards, feeders and other methods for securing grain cargoes are given in I/ "(I1 (69)7
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which also specify stability requirements of ships used for carriage of grain in bulk..
reduce the effect of grain shifting depends upon the stability of the vessel.
/MO Grain R%les
9ongitudinal divisions or shifting boards, which must be grain tight, may be fitted in both filled and partly filled compartments. In filled compartments they must etend downwards from the underside off deck to a dist below the deckline of at least 2#=th the breadth of the compartment, or at least 3.>m below the surface of the grain after it has been assumed to shift through an angle of 2@ °. In a partly filled compartment the division should etend both above and below the level of the grain, to a distance of 2#=th the breadth of the compartment.
These rules must be complied with in all respects when carrying bulk grain. "rain is defined as 'heat, (ice, *orn, (ye, /ats, barley, pulses, seeds and their processed forms. The rules are in three parts. art deals with definitions, shifting boards, stability requirements and information, maimum permissible heeling moments, loading instructions and a worked stability and loading eample. art B deals with the affect on the stability of the vessel caused by a shift of grain. art * deals with the specifications of shifting boards, saucering and building of grin and securing the cargo in a partly filled compartment.
Stabilit( The main criteria in connection with bulk grain loading is the stability of the vessel and this must be kept foremost in all loading procedures. The I/ grain rule outline the minimum stability requirements of a vessel loading bulk grain and these are as follow: 1) The angle of heel due a shift of grain should not eceed 2? ° ?5 The initial ", after correction for any free surface effect, should not be less than 3.;3m. 3) The remaining area between the original curve of righting levers and heeling arms upto <3° heel must not be less than 3.3E@ metreradians. 4If openings in the vessel which cannot be made watertight immerse at a smaller angle then such an angle5.
Grain Fittings In any compartment filled with grain there will remain a void space between the top of the cargo and the deck head of the compartment and it is to be ensured that the free surface effect and the heeling moments of a vessel so loaded do not adversely affect the grain behaviour in the void spaces and that the vessel is at all times left with adequate stability. The need to provide shifting boards or other temporary grain fittings in order to
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25 ll timber used for grain fittings shall be of sound quality and proven satisfactory for the purpose for which it is intended. 7uitably grained and bonded plywood can be acceptable provided its strength is equivalent to solid timber. ?5 6prights must be of sound construction and adequately secured against displacement from their end sockets. 'here there is no securing at the top, then the upper most shore or stay must be fitted as near there to as possible. ;5 7hifting boards should have a thickness of not less than @3mm, be grain tight and where necessary, supported by uprights.
&agging In partly filled compartments the grain tight can be topped off by loading bagged grain or other suitable cargo. In this case the surface should be properly levelled off, over which should be spread separation cloth 4gunny sacks5. platform made by spreading wooden boards on wooden bearers can be used instead of separation cloth. The bulk cargo should now be over stowed with sound, well filled bags to a height of 2#2>th the maimum breadth of the free grain surface, or to a height of 2.? metres, whichever is greater.
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Stra''ing or Las*ing The surface of the grain in partly filled compartment may also be secured by strapping or lashing. In this case the surface of the grain is levelled, but slightly crowned. The surface is then covered with separation cloth or tarpaulin, whose $oints overlap at least 2.=m. /ver this two solid floors of ?@mm timber should be laid. The first tier athwartships and the top tier for-and-aft. These floors are lashed down with double steel strapping, wires or chain with a breaking strength of at least @333 kg. and their ends attached to shackle or beam attachments at a point appro <@3mm below the final grain surface. The lashings should not be placed more than ?.< metres apart. The lashings must have tensioning arrangements and these must be checked and ad$usted regularly during the voyage.
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CARR/AGE OF DA.GEROUS GOODS /. PAC7AGED FORM OR /. SOL/D FORM /. &UL7 goods which shall include the precautions necessary in relation to other cargo.
Reg%lation 1 - A''liation 25 6nless epressly provided otherwise, this part applies to dangerous goods classified under regulation ? which are carried in packaged form or in solid form in bulk 4hereinafter referred to as Hdangerous goods%5, in all ships to which the present regulations apply and in cargo ships of less than @33 tons gross tonnage. ?5 The provisions of this part do not apply to ships% stores and equipment. ;5 The carriage of dangerous goods is prohibited ecept in accordance with the provisions of this part. <5 To supplement the provisions of this part, each *ontracting "overnment shall issue, or cause to be issued, detailed instructions on safe packaging and stowage of dangerous
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Reg%lation - Classi#iation angerous goods shall be divided into the following classes: Class + )plosive. Class "ases: compressed, liquefied or dissolved under pressure. Class 2 &lammable liquids. Class 95+ &lammable solids. Class 95 7ubstances liable to spontaneous combustion. Class 952 7ubstances which, in contact with water, emit flammable gases.
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Class :5+ /idi+ing substances. Class :5 /rganic peroides. Class ;5+ oisonous 4toic5 substances. Class ;5 Infectious substances. Class < (adioactive materials. Class = *orrosives. Class @ iscellaneous dangerous substances, that is any other substance which eperience has shown, or may show, to be of such a dangerous character that the provisions of this part shall apply to it.
Reg%lations 6 - Pa!aging 25 The packaging of dangerous goods shall be: 2.25 well made and in good condition0 2.?5 of such character that any interior surface with which the contents may come in contact is not dangerously affected by the substance being conveyed0 and 2.;5 capable of withstanding the ordinary risks of handling and carriage by sea. ?5 'here the use of absorbent or cushioning material is customary in the packaging of liquids in receptacles, that material shall be: ?.25 capable of minimi+ing the dangers to which the liquid may give rise0 ?.?5 so disposed as to prevent movement and ensure that the receptacle remains surrounded0 and ?.;5 where reasonably possible, of sufficient quantity to absorb the liquid in the event of breakage of the receptacle. ;5 (eceptacles containing dangerous liquids shall have an ullage at the filling temperatures sufficient to allow for the highest temperatures during the course of normal carriage. <5 *ylinders or receptacles for gases under pressure shall be adequately constructed, tested, maintained and correctly filled.
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@5 )mpty uncleaned receptacles which have been used previously for he carriage of dangerous goods shall be sub$ect to the provisions of this part for filled receptacles, unless adequate measures has been taken to nullify any ha+ard.
Reg%lation < - Mar!ing; Labelling An" Plaar"ing 25 ackages containing dangerous goods shall be durably marked with the correct technical name0 trade names alone shall not be used. ?5 ackages containing dangerous goods shall be provided with distinctive labels or stencils of the labels, or placards, as appropriate, so as to make clear the dangerous properties of the goods contained therein. ;5 The method of marking the correct technical name and affiing labels or apply stencils of labels, or of affiing placards on packages containing dangerous goods, shall be such that this information will still be identifiable on packages surviving at least three months% immersion in the sea. In considering suitable marking, labelling and placarding methods, account shall be taken of the durability of the materials used and of the surface of the package. <5 ackages containing dangerous goods shall be so marked and labelled ecept that: <.25 packages containing dangerous goods of a low degree of ha+ard or packed in limited quantities0 or <.?5 when special circumstances permit, packages that are stowed and handled in units that are identified by labels or placards0 may be eempted from labelling requirements.
Reg%lation = - Do%ments 25 In all documents relating to the carriage of dangerous goods by sea where the goods are named, the correct technical name of the goods shall be used 4trade names alone shall not be used5 and the correct description give in accordance with the classification set out in regulation ?.
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?5 The shipping documents prepared by the shipper shall include, or be accompanied by, a signed certificate or declaration that the shipment offered for carriage is properly packaged and marked, labelled or placarded, as appropriate, and in proper condition for carriage. ;5 )ach ship carrying dangerous goods shall have a special list or manifest setting forth, in accordance with the classification set out in regulation ?, the dangerous goods on board and the location thereof. detailed stowage plan which identifies by class and sets out the location of all dangerous goods on board may be used in place of such special list or manifest.
Reg%lation > - Sto)age Re$%irements 25 angerous goods shall be stowed safely and appropriately in accordance with the nature of the goods. Incompatible goods shall be segregated from one another. ?5 )plosives 4ecept ammunition5 which present a serious risk shall be stowed in a maga+ine which shall be kept securely closed while at sea. 7uch eplosives shall be segregated from detonators. )lectrical apparatus and cables in any compartment in which eplosives are carried shall be so designed and used as to minimi+e the risk of fire or eplosion. ;5 angerous goods in packaged form which give off dangerous vapours shall be stowed in a mechanically ventilated space or on deck. angerous good in solid form in bulk which give off dangerous vapours shall be stowed in a well ventilated space. <5 In ships carrying flammable liquids or gases, special precautions shall be taken where necessary against fire or eplosion. @5 7ubstances which are liable to spontaneous heating or combustion shall not be carried unless adequate precautions have been taken to minimi+e the likelihood of the outbreak of fire.
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Reg%lation @ - E4'losives /n Passenger S*i's 25 In passenger ships the following eplosives only may be carried: 2.25 safety cartridges and safety fuses0 2.?5 small quantities of eplosives not eceeding 23kg total net mass0 2.;5 distress signals for use in ships or aircraft, if the total mass of such signals does not eceed 2,333kg0 2.<5 ecept in ships carrying unberthed passengers, fireworks which are unlikely to eplode violently. ?5 1otwithstanding the provisions of paragraph 2, additional quantities or types of eplosives may be carried in passenger ships in which special safety measures approved by the dministration are taken.
Carriage O# Dangero%s Goo"s The term dangerous goods is commonly applied to a wide range of non-bulk cargoes which for one reason or another are considered to be potentially dangerous. Because of this, the carriage of dangerous goods is governed by a set of regulations, compiled in accordance with 7/97 2GE< *hapter 8II 4*arriage of angerous "oods5. art of this chapter applies to dangerous goods carried in packaged form or in solid form in bulk, in all ships and in cargo ships of less than @33 tons gross tonnage. art B and * of this chapter - *onstruction and )quipment of ships carrying dangerous liquids chemicals in bulk and liquefied gas in bulk respectively. The packaging and labelling of dangerous goods shall be in accordance to the class of the dangerous goods and requirements of I" *ode. The regulations state that the shipper must supply the following information on the package to be shipped: -
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the correct shipping name 4technical name5 for each dangerous goods 4trade names are not acceptable5. the 61 number of the dangerous goods. appropriate class and subsidiary risk labels, or of affiing placards. other additional markings as required.
In addition the shipping documents prepared by the shipper shall include or accompanied by, a signed certificate or declaration that the dangerous goods is properly packaged and marked and safe for carriage. The dangerous goods shall be stowed safely and be segregated in compliance with the I" *ode.
Marine Poll%tant These classes each have a distinctive label, diamond in shape with the ha+ard type printed on it as well as the class 1umber, in addition the colour coding gives some indication as to the danger.
/:M:D:G /nternational Maritime Dangero%s Goo"sB Co"e I" *ode consists of four 8olumes and 7upplements, namely 8olume I, 8olume II, 8olume III, 8olume I8 and 7upplement *ode. The "eneral Table of *ontents of these volumes and supplement are as follows: -
General Table O# Contents +ol%me /
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*lass ; - &lammable liquids
+ol%me /// 9ist of abbreviated units *lass < - &lammable solids 7ubstances liable to spontaneous combustion 7ubstances which, in contact with water, emit flammable gases *lass <.2 - &lammable solids <.? - 7ubstances liable to *lass spontaneous combustion *lass <.; - 7ubstances which, in contact with water, emit flammable gases - /idi+ing substances and *lass @ organic peroides *lass @.2 - /idi+ing substances *lass @.? - /rganic peroides
+ol%me /+ 9ist of abbreviated units *lass > - oisonous 4toic5 and infectious substances *lass >.2 - oisonous 4toic5 substances *lass >.? - Infectious substances *lass E - (adioactive materials *lass = - *orrosives G - iscellaneous dangerous *lass substances and articles
S%''lement 9ist of abbreviated units )mergency rocedures 4)m75 edical &irst id "uide 4&"5 7olid *hemical in Bulk 47B *oce5 rocedures acking (eporting transport 4pcs5 6se of pesticides in ships
cargo
9ist of abbreviated units "eneral Introduction to the *ode nne I - acking recommendations Assignment "eneral inde 4alphabetical5 of dangerous lease complete the assignment and return to goods 9 1umerical inde 4table of 61 numbers with corresponding I" *ode page numbers, 25 7tate the ma$or ha+ards in the carriage of )7 numbers and &" table numbers5 dry bulk cargoes on ships. 9ist of definitions
+ol%me // 9ist of abbreviated units *lass 2 - )plosives - "ases: compressed, liquefied *lass ? or dissolved under pressure
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?5 7tate the classes as mentioned in the I" code, also state the information required to be supplied by the shipper to the aster of the 8essel.
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MODULE > - TA.7ERS Tankers vary in si+e, type and design depending upon the trade that they may be engaged in. The construction of tankers, although changed greatly and advanced with the various types of cargoes, is basically the same for all types. The operation of tankers must comply with many local and International rules, some of them being I/ rules regarding oil pollution, personal safety, maritime safety and loading constraints. lso at national level tankers have to comply with the /T regulations, TI of 6.., *oast "uard regulations of the 67, aritime 7afety gency regulations of apan, etc. /il cargoes are generally divided into two classes: 9ight oil which include various spirits such as gasoline white spirit, alcohol, kerosene, light gas oil, etc. and !eavy oils which include crude oils, asphalt, fuel oils, heavy gas oils, diesel oil, lubrication oils, etc. The discharge of oil is carried out by suction pipes from the tanks via the pumprooms to the manifold on either side of the deck or even at the stern. aster valves permit and regulates the discharge. 8entilator piping is provided on deck so as to release ecess gasses into the atmosphere through #8 valves or mast risers. ost tankers are loaded and discharged in the same manner ecept that more stringent measures are necessary with cargoes having low flash points.
Pi'eline La(o%t )ach ship owner may have his preference of pipeline layout depending upon the trade that the vessel may be engaged in. The most common types are as follows: 1) 1ee flo6 sste% - is generally used on large crude carriers employed on fied routes. This system is very simple0 pipelines are generally of high capacity and therefore capable of trimming the vessel as the loading progresses. There is a sluice v#v at each bulkhead to allow oil flow from every tank simultaneously as required.
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2) Diect line sste% - this allows the fleibility of isolating tanks in the event of different grades of oil being carried. In this system there can be three or more independent lines, which can be used when different grades are carried. )ach line serves approimately one third or one-fourth the number of tanks. But if only one grade is carried these lines can be linked together by means of cross overs.
3) Ring %ain sste% - lines run from the pumproom in a ring fashion serving all the tanks. The rings end can be made common by opening the cross over v#vs.
Terms Use" /n Oil Carriage Ullage The space height left in a tank between the surface of the oil and the tank top for any epansion of the cargo, it is usually about ?A of the tank capacity in loaded condition.
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Flas*'oint
Eart*ing Or Gro%n"ing
The temperature at which the oil gives off sufficient vapour at such concentrations, which will catch fire or eplode if mied with air and eposed to naked light#incendive spark.
The electrical connection of equipment to main body of the earth. /n board shop the connection is made to the main metallic structure of the ship, which is at earth potential because of the conductivity of the sea.
Dangero%s Oils /ils having flash points less than E; ° & or ?; ° 4*5.
Or"inar( Oils /ils having flashpoints between E; °& and 2@3°& or over ?; °4c5 and >@.@ ° 4c5.
/gnition Point The temperature at which the oil gives off vapour at a rate, which allows continuous burning when a flame is applied.
Gas Free 'hen sufficient fresh air is introduced into a tank or compartment lower the levels of any flammables, toic or inert gases to those required for specific purpose, e.g. main entry, hot work, etc.
/nert Gas gas such as nitrogen, */?, or mitures of gasses such as flue gas containing insufficient oygen to support the combustion of hydrocarbons. 4I/ ()ST - B)9/' =A5
+isosit( The quality of liquids whereby they resist internal flow.
&a!'ress%re The pressure that a pump might have to counter due to oil already contained in a length of pipeline, frictional resistance, or bends in the line. The pump has to overcome this pressure, which is registered on the pressure gauge as soon as the pump is started.
Sam'ling 7mall quantities of oil are taken from the ship%s tanks into bottles after the completion of loading. These are tested in the laboratory for quality and grade and on satisfactory testing one sample is kept with the loading terminal while another is sealed and sent back to the ship for delivery at the discharge port where the sealed sample is compared again with fresh samples taken from the tanks prior to discharge.
/nert Con"ition 'hen a tank or compartment has its oygen content reduced to below =A by volume by the addition of inert gas.
Stati Eletriit(
&on"ing
The electricity produced on dissimilar materials through physical contact and separation.
The connecting together of metal parts to ensure electrical continuity
Stri''ing The final operation in pumping out of liquids 4the last quantity5 from a tank or pipeline.
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+olatilit( The tendency of a liquid to produce gas vapour by evaporation.
Tan! Cleaning The amount of cleaning that a tank requires would depend upon the nature or grade of oil to be carried. *lean oils e.g. naphtha, aviation spirit, lubrication oils, etc. require a high standard of cleaning, black oils such as fuel oil do not require such high standards of cleanliness although with the technique known as crude oil washing, crude oil tanks do reach high standards.
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The main advantages of this system are: The cleaning equipment is inside the tanks there is no need to keep the tank ports open, which result in the escape of hydrocarbon vapours. The sediment is discharged along with cargo as it dissolves in crude oil. The sludge remaining in the tanks is minimal hence more of net cargo can be loaded. Because of much less sludge retention in tanks the cargo out turn is better. It is much faster than conventional water washing and saves manpower required for manual desludging.
*onventional tank cleaning uses high speed Loa" On To' Proe"%res steam in$ection into tanks for about > - = hours followed by hose washing using Butterworth This technique was introduced on tankers in machines and adequate ventilation. !ot water the early 2G>3s, and is a common practice on is used for hose washing so that the residue is crude oil carries and even on some product more easily removed. If necessary a further carriers, it is as follows: steaming for ? - < hours is carried out followed tanker begins her passage with dirty ballast. by the final washing down. uring the passage tanks to be filled with clean ballast are cleaned, then filled with Cr%"e Oil 0as*ing seawater ballast. The bottom portion of the *rude oil washing is the procedure where by dirty ballast is then carefully pumped over the washing of the tanks is done by crude oil board. rovided that it has settled for a few itself when the discharge is in progress. The days. This bottom water should be clean, free system has the fied cleaning machines fitted oil having floated to the surface. It should still inside the tank itself, and before the cleaning be discharged outside prohibited +ones since is started the atmosphere inside the tank is it is bound to contain a small amount of oil. made safe by in$ecting inert gas so as to lower the oygen level of the tank to below =A. t this point in the procedure each dirty ballast tank contains several feet of residues, which should be stripped into a single slop tank. The resultant oil and water miture is allowed to settle in the slop tanks for a few days, after which the clean bottom portion is pumped over board the remaining slops are retained and mied with the net cargo. In this manner a tanker enters he prohibited +one at the end of her ballast voyage with clean ballast in her tanks and small quantity of slops.
Meas%rement O# T*e Cargo The following considerations are taken into account when arriving at the quantity of cargo in a tank: -
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the accurate measurement of ullage, which measures the height remaining in the tank above the top of the oil. the quantity of water if any is determined by the use of a dip rod at the end of which is applied water finding litmus paste, which changes colour when in contact with water. temperature of the cargo at three levels should be taken to arrive at a mean temperature. *hanges in temperature affect the volume of a liquid, causing epansion or contraction. rise in temperature causes a decrease in 7" and an increase in volume and vice versa with a fall in temperature.
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225 *argo 91 - check this for the following information: a5 roducts to be loaded in each tank b5 &inal ullage for each tank c5 7" and appro. temperature of each product d5 Total weight or quantity in barrels of each product e5 &inal draft and trim 2?5 7tart loading slowly and ensure that cargo is flowing into the desired tanks.
The amount by which the 7" changes per degree of temperature is known as the 7" correction coefficient. These coefficients vary with the grade of oil0 oil is shipped at some agreed temperature, so any difference of temperature necessitates a correction to be applied. 7" correction coefficient tables are also available for quick working.
&e#ore Loa"ing Or Dis*arge The following are some of the precautions that are to be taken before commencing loading: 25 7cupper plugs - ensure that all deck scuppers have been plugged and cemented. ?5 7ea suctions - all sea v#vs to be lashed on closed position. ;5 !ose connections - check for tightness, keep empty drip tray under each. <5 HB% flag and red light - to be displayed prominently. @5 *argo pipeline lineup - checked by two officers preferably. >5 *argo tanks and tank v#vs - tanks to be T, v#vs ready for opening. E5 ump suction and discharge valves to be open. =5 Terminal information: a5 7equence b5 9oading rate c5 1o. /f shore pumps to be used d5 1otice prior to topping up or closing e5 7ignals for shutting down G5 ark hose, with chalk. 235 eclaration on inspection - all tanker officers and terminal representative are required to carry out checks and inspection of various procedures and safety precautions and sign the declaration or check list.
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Tan!er Sa#et( C*e!list 25 Is the ship securely mooredU ?5 re emergency towing wires correctly positionedU ;5 Is there a safe access between ship and shoreU <5 Is the ship ready to move under its own powerU @5 Is there an adequate deck watch onboard and adequate supervision on the terminalU >5 Is the agreed ship#shore communication system operativeU E5 !ave the procedures for cargo, ballasting and bunkering been agreedU =5 !as the emergency shut down procedures been agreedU G5 re cargo and bunker hoses or arms in good condition and properly connectedU 235 re fire hoses and && onboard and ashore ready for immediate useU
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225 re scuppers effectively plugged, and drip trays in position both onboard and ashoreU 2?5 re unused cargo and bunker connections, including stern discharge line if fitted are blankedU 2;5 !ave sea and overboard discharge v#vs, when not in use, closed and lashedU 2<5 re all cargo and bunker tank lids closedU 2@5 Is the agreed venting system being usedU 2>5 re hand torches of an approved typeU 2E5 re portable 8!!& transceivers of an approved typeU 2=5 re the ships main radio transmitter aerials earthedU 2G5 re electrical cables to portable electrical equipment disconnected from powerU ?35 re all eternal doors and ports in the midships accommodation closedU ?25 re all doors and ports in the after accommodation leading to or over looking the tank deck closedU ??5 re air conditioning intakes, which may permit the entry of petroleum gas, closedU ?;5 re window type air conditioning units disconnectedU ?<5 re smoking requirements being observedU ?@5 re the requirements for the use of galley and other cooking appliances being observedU ?>5 re naked lights requirements being observedU 4To be signed on behalf of the ship and also on behalf of the terminal5
Tan! 0as*ing 0it* Cr%"e Oil *rude oil washing has been practiced by ma$or tanker operators for several years. )perience gained suggests that it is in the interests of the industry and community as a whole to adopt crude oil washing on all suitably equipped vessels.
A#ter Dis*arge O# Cr%"e Oil fter discharge of cargo, ship%s tanks, which have held crude oil, usually contain deposits of sediment on the tank bottoms and other hori+ontal surfaces of the tanks structures. This sediment, which has settled from the cargo on passage, consists mainly of way and asphaltic substances. If allowed to remain it will build up after several voyages and impede draining and also reduce cargo-
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carrying capacity. ll oil and sediment be removed from cargo tanks, which are to be used for clean ballast.
0*( Cr%"e Oil An" 0*( .ot 0ater Traditionally, tanks have been cleaned by washing with $ets of water, but such method of washing produces a large amount of oily water, which must be separated. The separation process is complicated by the oil and water emulsions which are produced during washing. This has led to the retention on board of large quantities of water along with the slop oil, recovered by the load-on-top procedure. 6nder the load-on-top procedure, cargo is subsequently mied with the oil and#or water and is discharged as part of the cargo at the receiving port. *rude oil washing is a process whereby part of the cargo is circulated through the fied tank cleaning equipment to remove the way asphaltic deposits. This is normally carried out during discharge. *rude oil washing has proved to be more effective than water washing for this purpose because the crude oil acts to disperse and suspend the sediments and tends to restore the cargo to its as loaded condition. If the tank is required for clean ballast or for entering into it for survey, repairs etc, after crude oil washing, water washing will become necessary.
,istorial &a!gro%n" In the past it has been recogni+ed that crude oil itself might be the most effective medium for removing crude oil sediments from tanks. Then came the invention of tank cleaning apparatus fitted within the tanks and served by permanent piping, which made it possible for cargo to be circulated through the tank cleaning system without risk of escape from hose connections or deck openings. Inert gas was then introduced, which provided a means of controlling the tank atmosphere and keeping it outside the flammable range.
A"vantages O# Cr%"e Oil 0as*ing +5
Cago O"tt"n
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The most important advantage, and the one from which the other advantages come to the limelight, is that substantially the whole of the sediment can be discharged with the bulk of the cargo. This is refinable material, which is part of and entirely suitable for discharge with, the remainder of the cargo. fter crude oil washing only small quantities of cargo will remain in the tanks, pumps and pipelines. The comparative figures for oil remaining in the cargo system of a ?2@,333-dwt ship after discharge are: fter crude oil wash ;33 tonnes appro fter conventional 2333#?333 tonnes discharge appro 5 !oll"tion .*oidance The load-on-top procedure is established as an acceptable method of controlling oil pollution of the sea. Its principle feature is the separation and retention aboard of the oil content of the oil#water mitures generated by the ballasting and water washing of oil tanks. 'ithout crude oil washing, large quantities of water are needed to clean crude oil tanks and the resulting mitures and emulsions, together with dirty ballast mitures, must be retained on board until they have been settled and separated. This process is much simplified when tanks have first been crude oil washed. The oil content of dirty ballast is greatly reduced. *argo tanks, which are to be used for clean ballast, need only a short rinse with water after oil washing, but pumps and lines will need to be thoroughly flushed with water. Tanks, which are not required for ballast, need not be water, washed, because the sediment is kept under control by crude oil washing. !ence, not only is the quantity of residue in the ship greatly reduced, but also tank washing is much smaller. These factors reduce the pollution. 25 C.RGO CONT.MIN.TION The salt-water content of crude oil cargoes poses a continuing problem for oil refineries. *rude oil washing reduces salt-water contamination of the cargoes, due to the elimination of water from tanks and reduction in the quantity of slops. 95
Inceased Caing Capacit
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In the 9/-/1-T/ procedures, the ship%s capacity to load new cargo is reduced by the weight of retained slops and sediments on board. *rude oil washing increases the effective cargo capacity of a vessel. Typical oil#water quantity for a ?2@,333-dwt tanker in the tanks as retained sediment is: fter water 2?33#2;33 tonnes appro. washing fter crude ;>3 tonnes appro oil washing :5 ORA LO.D *rude oil washing generates its own load and this usually occurs when personnel are occupied with cargo discharge. The overall time and effort applied to tank cleaning is much reduced, benefiting the ship%s personnel, thereby reducing to risks of pollution due to human error. ;5 CORRO,ION *rude oil washing reduces corrosion.
SAFETY PROCEDURES uring the process of crude oil washing, following safety measures should be strictly adhered to: 25 To prevent the escape of oil or vapour. ?5 To maintain the tank atmosphere within 1/1-&9B9) 9IIT7. ;5 To prevent the development of a source of ignition. <5 /il to be introduced into the tank for crude oil washing at a point outside the engine room. @5 ersonnel to be well trained and familiar with the crude oil washing, and possess thorough understanding of the entire operation. >5 6sually crude oil washing should be carried out in a port while the cargo is being pumped ashore. E5 7tage by stage cleaning of tanks must be programmed. =5 Before clean ballast is loaded, tanks should be water-washed and the pumps and lines flushed with water. G5 *ontrol of atmospheric emissions is necessary by preventing ventilation of tanks. !ydrocarbons from tanks are not allowed to escape out into the atmosphere, nor is air allowed to enter from outside into the tanks. 235 ll crude oil washing operations must be entered in the /I9 ()*/( B//.
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225 fter crude oil washing, tanks must be washed with water and fully ventilated before being considered gas free and suitable for entry. 2?5 *autionary notes regarding non-opening of valves, no smoking and other safety measures, to be posted on board.
C,EC7L/ST 2 ? ; < @ > E
BE1ORE .RRI0.L .T T$E DI,C$.RGING !ORT !as terminal been notifiedU Is /ygen analy+ing equipment tested and working satisfactoryU re tanks pressuri+ed with good quality Inert "asU 4aimum =A /OK")15U Is tank washing pipelines system isolated from water heater and engine roomU re all hydrant valves on tank washing line securely shutU re all valves to fied tank washing machines shutU !ave tank-cleaning lines been pressuri+ed and leakages made goodU
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IN !ORT Is quality of inert gas in tanks satisfactory 4maimum =A oygen5U Is Inert "as pressure satisfactoryU
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BE1ORE .,$ING re valves open to machines on selected tanksU re responsible persons positioned around the deck to watch for leaksU re tanks ullage gauge floats lifted on tanks to be washedU Is Inert "as system operatingU re all tanks closed to outside atmosphereU !ave tanks positive Inert "as pressureU
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D3RING .,$ING 2 ? ; <
re all lines oil tightU re tanks washing machines functioning correctlyU Is quality of Inert "as in tanks satisfactory 4maimum =A /OK")15U Is positive pressure available on Inert gas systemU
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.1TER .,$ING re all valves between discharge line and tank washing line shut downU !as the tank washing main pressure been equali+ed and line drainedU re all tank washing machine valves shutU
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2 ?
.1TER ,.ILING !ave any tanks to be inspected been purged to below the *ritical ilution 9evel prior to introducing fresh airU !as oil been drained from tank washing lines before opening hydrants to deckU
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/.ERT GAS SYSTEMS Inert gas is used to blanket some cargoes. *argoes, which react with air or water vapour in the atmosphere, must be loaded into a tank, which has been purged with I1)(T "7, and the tank must remain inerted until the tank cleaning has been completed. 7ome other cargoes have the ullage space inerted either as a fire precaution or to prevent reactions. !ydrocarbon gas normally containing encountered is petroleum tankers cannot burn in an atmosphere containing less than 22A of /OK")1 by volume. Thus, one way to provide protection against fire or eplosion in the vapour space of cargo tanks is to keep the /OK")1 content below =A by volume, which gives an adequate safety margin. means of achieving this is by using a fied inert gas system connected by piping to each tank, which reduces the air content of the tank and makes the atmosphere in the tank nonflammable. 7uch an atmosphere is deemed to be CI1)(TD. !ence, introduction of inert gas into the cargo and surrounding void spaces, at all times, minimi+es the risk of eplosion or fire.
produced when carbon dioide is dissolved in water. Thus, the modern tankers avoid using carbon dioide and nitrogen for inerting the tanks, keeping in view the dangers and cost element. ;5 1L3E - G., The products of combustion of fossil fuels, provided that these are processed into an acceptable condition, are mainly used as inert gas. 7ources of such combustion gases are: a) Internal combustion )ngines like gas turbines and diesel engines. The products of combustion from such engines are not suitable due to ecessive oygen content. This problem can be overcome by employing an C&T)( B6(1)(D b5 Boilers c) Inert gas generators: These employ heavy fuel oil or diesel oil.
Pro"%tion O# /nert Gas
odern tankers employ the following two main processes for the production of inert gas: 25 7hips with main or auiliary boilers normally use the &96) "7, which contains only ?A to
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The design of any inert gas system must embody the following safety precautions: a5 revent the passage of hot, unwashed and wet gases to the deck main. b5 revent the return of hydrocarbon vapours and gases to the CsafeD +one.
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c5 The system must be capable of maintaining a positive pressure in the cargo tanks at all times, regardless of the cargo or ballast discharge rate. d) The cargo tanks must 1/T be capable of being /8)( ()776(IP) by the inert gas or by cargo vapours.
T*e &asi /nert Gas S(stems The basic inert gas system will consist of the following: 25 n inert gas source, that is, boiler flue gas or an inert gas generator. ?5 boiler flue gas valve at the uptake. ;5 scrubbing tower, which normally acts as a cooler. <5 demister unit. @5 Two electric motor or steam turbine driven inert gas blowers complete with isolating valves. >5 n inert gas pressure-regulating valve. E5 means of stabili+ing the plant on startup, which also serves the purpose of maintaining a minimum inert gas flow through the scrubber and blowers. This may be either a gas =5 recirculating line or a bleed-off line at atmosphere, which incorporates, some form of control valve. G5 liquid non-return device, 4deck seal5, in the inert gas main, The deck seal and seal water supply line are to be fitted with means to prevent free+ing of the water. 235 mechanical non-return device in the inert gas main. 225 deck main with branch lines for delivery of inert gas to the various cargo tanks. )ach cargo tank will be capable of being isolated from the deck main. The deck main is to be fitted with isolating valves if the mechanical non-return valve is not of the positive closing type. The deck main is also fitted with drain valves sited at suitable points. vent line and valve is fitted in the main at some point between the gas regulating valve is open when the inert gas plant is not in use. 2?5 means to prevent ecessive pressure or vacuum building up in the deck main and individual cargo tanks, that is, #8 breather valves and #8 breaker. 2;5 C6D seals and siphon breakers are fitted to the scrubber tower effluent line deck seal drain line, deck seal water supply line. nd line
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4other than the inert gas main5, which passes through the safety barrier and through which hydrocarbons could pass, are also fitted with C6D seals.
9Poll%tion &( S*i's5 O'erational An" Ai"ental In the lat one hundred years, in the so-called Hage of oil%, escapes of oil into the environment has increased in quantity and has become ob$ectionable, and so, Hoil pollution% has arrived. In 2GEG the oil production was ;333 million tons. t every stage of its transportation, oil can escape into the sea from ships. The two main causes of sea pollution by tankers are: ccidental pollution /perational pollution
Ai"ental Poll%tion uring a voyage of an oil tanker while conveying the oil to the refineries, accident can occur, such as collision between two tankers or grounding of a tanker due to a 1avigational error. Both these can result in seepage of oil into the sea. The two important incidents that resulted in etensive sea pollution are the grounding of the HTorrey *anyon% and the Hmoco *adi+%. The effect on the environment due to these accidents has been catastrophic and the cost for cleaning up was huge. G;A of oil over @333 bbl is a result of grounding or collision.
O'eration Poll%tion But by far the highest percentages of spills are caused due to operational reasons, associated with: a5 Tank cleaning with water b5 9oading and discharging c5 Ballasting and deballasting Thus, in complete round trip of a tanker oil can enter the sea due to a number of operational reasons. In the following pages some of causes of the operational pollution are highlighted and eplained.
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Mis%"ging T*e Filling Rate any tank overflows occur simply because ships% personnel mid$udge the filling rate 4i.e., the rate at which the tank ullages change5 but not infrequently this mis$udgment is associated with an unepected change in the filling rate. These changes can arise from operational changes on shore - for eample, changing from low to high level tanks or from a for the a near tank, both of which can result in an increased loading rate. They can also arise from aboard activities such as closing down tanks as they top off or transferring from loading a large tank to loading a small tank. 7ome authorities seek to overcome this problem by recommending loading all tanks initially to ullage short of the final ullage and thereafter topping off each tank individually at reduced loading rate. !owever, this is Hhaving two bites at the cherry% and does not guarantee against overflows during the initial loading phase. n alternative, practiced by many eperienced tanker men, is to open up as many tanks as possible consistent with stability and stress as by so doing the filling rates of individual tanks, and thereby the effect of changes in loading rate, are minimi+ed. The filling rates to individual tanks are so arranged that tanks reach completion ullage in sequence and the time interval between completion of one tank and completion of the net is sufficient to allow a check that follow into the tank $ust completed has ceased. 1ormally trim plus the varying lengths of line serving the tanks effects the stepping of levels automatically but if the difference in levels is considered in adequate it is increased by partly closing selected tank valves. s the first group of tanks fill and are shut off other tanks in the net group are opened in order to maintain an acceptable filling rate. The rate into the final group is ad$usted by bleeding off to one or emptier tanks, which are reserved for that purpose and used finally as balance, or completion tanks. 6sing these techniques product vessels have repeatedly loaded three and four grades concurrently at
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widely different loading rates without incident and without any sense of urgency.
F%el Oil Loa"ing !eavy fuel oil presents a special case with regard to varying loading rates, for if the contents of the shore lines are inadequately heated, or in particular, if failure of a section of steam trace leads to the formation of a Hcold plug% the initial loading rate will be etremely low until the relatively cold oil is displaced from the line, where upon the rate will increase dramatically. This sudden increase can catch ships% staff off guard and is particularly serious when loading bunkers to capacity, which operation involves filling double bottom and deep tanks. The best way to guard against mishaps under these circumstances is to ascertain the capacity of the shore line in advance and direct the contents of the line into one of the main tanks before embarking upon topping off the smaller and more difficult tanks.
Lea!s From Mani#ol" Flanges 9eakage of oil from manifold $oints is not only common but can be etremely messy should the $oint fall completely under pressure, for the oil is then sprayed into the air and spreads over a wide area of the deck and superstructure. There are two kinds of failure failure of a blank securing a manifold not in use, and failure of the $oint between hose or flow boom and manifold flange.
Over#illing Slo' Tan!s The possibility of overflowing slop tanks through valves left open to the main line has been mentioned already, but these tanks can also overflow from the oil introduced during stripping and operations. The introduction of eductors for stripping and crude washing has added a new dimension to this problem. In the older type of system, based on positive displacement pumps, only the oil from the tank being stripped entered the slop tank and it was usually sufficient precaution to lower the level to half tank before commencing stripping
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operations. 'ith eductors the drive liquid as well as the stripping liquid enters the slop tank and the drive liquid continues even when the cargo tank being stripped is empty. *rude washing adds a further complication because the oil used for washing plus the oil used to drive the eductor is discharged to the slop tank. The situation can be alleviated by lining up the cargo pump supplying drive and washing liquid to take suction only from the slop tank, in which case the net input to the slop tank will be the normal stripping from the tank being washed. This technique, however, is not always feasible. n alternative is to discharge the slop tank to a low level prior to start of stripping and then, when the eductor discharge has stabili+ed, crack open the slop tank suction until the tank level remains constant or falls slowly. !owever, even with this technique there can be no guarantee that the tank will not gain liquid as the discharge progresses and the only way to prevent an overflow is to keep the tank under constant observation.
Containment O# Oil On De! /il escaping on to the decks, from whatever source, does not become polluted until such time as it flows overboard on to the water alongside. ost regulations recogni+ed this fact and seek to confine the oil onboard, pending its removal, by calling for deck scuppers to be securely plugged throughout the vessel%s time alongside. !owever, for this regulation to be effective there must be a sufficiently high up stand at the ship%s side to contain the oil and this is by no means always the case. It will be appreciated that many modern vessels, including 89**s, have similar small up stands. 1or is the regulation effective if the decks become waterlogged from heavy rain, which carries the oil over the top of the up stand. This fact is also recogni+ed by the regulation which call for a crew member to be stationed at the aftermost scuppers in order to periodically drain off the water, but again the
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regulation is only partly effective for there have been several instances of oil escaping overboard before the scuppers would be resealed and others in which rain has subsequently waterlogged the decks and carried the oil overboard.
Terminal Sta## In this matter terminal staff can play a useful role by recogni+ing that strangers to the terminal pose a potential pollution risk, which requires special attention on their part. They must be prepared to allow such vessels etra time to double check line-up before embarking upon cargo operations and, in so far as they are able, back up the ship%s staff by carrying out their own check. bove all they must recogni+e that such vessels cannot be epected to perform safely as efficiently as regular traders and take care that they do not inadvertently pressuri+e the vessels into embarking upon operations beyond their capabilities. !owever, regardless of caliber and eperience, no vessel can claim immunity from the possibility of a mishap during cargo operations and if the consequences of such mishaps are to be minimi+ed careful attention must be paid to emergency procedures and contingency plans must be introduced to deal with any spillages which may arise.
Emergen( Proe"%res To be effective, emergency procedures must involve the whole crew regardless of rank or rating and, in the absence of a responsible officer, individual crew member, must be vested with the authority to order an emergency stop should they have reason to suspect that all is not well. They should, if necessary, to be permitted to actuate the onboard main pump emergency stops and stripping pump controls themselves. !owever, in order that crewmembers not normally involved in cargo operations are in a position to $udge between the normal and the abnormal, and thereby act responsibly, they should be instructed in basic cargo handling techniques.
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They should also be shown the locations of the pump emergency stops and steam pump controls and told how to coach instructions to the shore in such a way that there can be no misunderstanding between their request for an emergency stop and a normal request for stopping cargo. It is essential that these on-board procedures are communicated in writing to the shore staff prior to the start of cargo operations and they should be advised that in the matter of emergency stops they have the master%s authority to act on the instructions of anyone on board ship. t the same time it should be made clear that the procedure relates only to emergency stops and that only the officer of the watch or other designated crew member has the authority to start cargo operations. To avoid possible confusion the //' or designated crewmember should identify himself personally to the shore staff where taking over the cargo watch.
Contingen( Plans *ontingency plans should be based primarily upon the need to clean up a spillage on deck with the utmost dispatch in order to prevent the oil escaping overboard and creating pollution. They should, also provide contingencies for emergencies such as cargo valves failing to close correctly when topping off tanks, etc.
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Some O# T*e Proe"%res A"o'te" To Prevent O'erational Poll%tion 25 9oad on top system ?5 edicated 4*BT5
clean
ballast
tank
system
;5 7egregated clean Ballast tank system 47BT5 <5 *rude oil washing system @5 7hore reception facilities for receiving oily# water moistures >5 /il content monitors#control system, oily water separators
Some O# T*e Re$%irements To Prevent Ai"ental Poll%tion; Aboar" Tan!ers 25 utomatic radar plotting aids 4(5 ?5 dditional radar on certain si+e of tankers ;5 7pecial steering gear arrangements
They should also incorporate on-board training programmed whereby the ship%s personal receive practical instruction and the effectiveness, of the laid-down procedures is tested. These procedures should not be considered sacrosanct and if they are found to have outlived their usefulness in their present from they must be changed or discarded.
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A.T/-POLLUT/O. OPERAT/O.S SE3UE.CE - /. PORT IT)7
()(TI/1
7hip Board lanning ersonnel Transfer Terminal
*heck repare equipment
*ommunication )mergency rocedure *ontainment shore 7pill containment persons in-charge onitoring $etty
7hips moorings 7cuppers rip trays
dequate
7ea valves !ose arms
7ecured "ood condition &irmly secured
*argo system
lugged In position
*hecked
*argo tanks rrival #ort
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6(I1" *("/ T(17&)( 'atch eeping /perational *hecks
roperly lined up for transfer 6llages monitored *ommence Transfer *heck lists
*/9)TI/1# 7)*6(I1" *learing ecks eparture 7tow !oses
dequate for tide weather )cess water draining 6nplugged eans available for rained draining ecess water Ballast 7ufficient length rained isconnected Blanked 7hut down anifolds blanked 7ailing
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STAT/C ELECTR/C/TY A.D STRAY CURRE.TS 7ettling of droplets of one liquid through In special conditions, which favor the another, e.g. water droplets separating out in a generation of electrostatic charges and their tank containing petroleum liquid, collection on some ob$ects, the discharge of Breaking up of liquid in free fall, e.g. during the accumulated charge as a spark can ignite overhead filling of tanks0 flammable vapour. These conditions can arise 7praying and splashing by the break-up of in tanker operations and steps have therefore $ets or bubbles, e.g. during splash filling of to be taken to minimi+e the generation of static tanks and high speed e$ection of liquids from and to avoid accumulation of static charges on no++les0 any ob$ect within a flammable atmosphere. impingement of solids on solids, ).g. brief eplanation of the mechanism of charge during sand blasting. generation, and of static discharge, and the ignition of flammable atmospheres by static is *ompared with the electric currents carried in electrical equipment, the therefore given so that the reasons for the conventional operational safety procedures in the various quantities of electric charge transferred in stages of petroleum liquids handling may be electrostatic generation are very small indeed, but they can give rise to very high voltages better understood. when they accumulate on electrically insulated bodies.
/ntro"%tion
Stati Generation
'henever unlike materials are in contact, some transfer of electric charges takes place across the interface or there is some accumulation of electric charges at the interface0 this occurs for solid#solid, liquid#liquid, solid# liquid and liquid#gas interfaces, and is of no practical significance until the surfaces are separated from each other. )lectric charges are then carried away by the separating materials and become evident as static electricity, positive charge being carried away by one of the materials and an equal amount of negative charge by the other. The word Hstatic% is used to differentiate between this kind of electric charge and the more familiar form, in which a continuous supply of electricity flows steadily in a conductor. )amples of separation processes causing electrostatic generation are: assage of liquid through pipes and filters, e.g. during fueling of vehicles and loading of tanks. 7ettling of solid particles0 in liquids, as when rust and sludge particles settle in a tank0
Because of this high voltage and the small quantity of charge involved, static electricity quickly leaks away unless prevented by very high electrical resistances 4of at least 23= ohms5. The strength of the electrostatic voltage therefore depends on the electrical conductivity of the materials involved and is the net result of the rates at which charges are generated and are able to leak away. If the material has a high conductivity, e.g. crude oils and residue fuels, the charges leak away as quickly as they are formed, whereas refined distillate products, which in general have relatively low conductivities, can accumulate considerable amounts of static charge.
C*arges Can A%m%late /n insulated conductors0 In low conductivity petroleum passing through pipes and filters0 In mists and sprays of conducting or nonconducting liquids where the charged droplets are insulated by air.
Stati Dis*arge If a conducting body, e.g. a metal storage tank or metal pipe is in contact with the ground or
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connected electrically to earth, static charges are conducted harmless to earth and therefore cannot accumulated on the body. Because most refined petroleum liquids are poor electrical conductors any accumulated electrostatic charge on such liquids cannot be quickly discharged by having the tank containing them connected to earth. The charge on the liquid will either gradually leak away to earth or recombine with the charge of opposite sign from which it was separated in the static generating process. In a static generating process, e.g. filling an unearthed metal tank with a refined petroleum liquid through an unearthed metal pipe which is not in contact with the tank, any possibility of accumulation of opposing electric charges, i.e. charges of opposite sign, on the surfaces of the fill-pipe and the tank can be avoided by making an electrical connecting between them, i.e. bonding them together, so that the separated charges are re-united through the bond as fast as they appear. Bonding, however, does not reduce the charging of the liquid itself and if there is a heavy charge accumulation within the liquid a static discharge might possibly occur between the liquid surface and any conducting ob$ect near it.
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ischarged harmlessly to earth0 1eutrali+ed by recombination through a bonding connection0 as a spark through the ischarged medium surrounding the charged body, when the electric field strength eceeds the breakdown value of the medium.
/gnition O# Flammable Atmos'*eres Before a spark can ignite a flammable petroleum vapour#air miture it must release sufficient energy 4at least 3.? mill $oules5 but if ignition does occur within a restricted space containing petroleum a serious eplosion can result. The infrequency of such eplosions in the course of handling petroleum liquids suggests that: 7tatic sparking is relatively rare0 any static sparks are of low energy0 t the time and place of discharge of a static spark capable of igniting the surrounding atmosphere there was no flammable petroleum#air miture being either too weak or too high.
TA.7ER OPERAT/O.S Loa"ing an" Dis*arging
The charges, which accumulate on insulated conductors or insulating materials, such as poorly conducting liquids, may set up high electrostatic voltages. If these voltages eceed the appropriate critical value for the surrounding medium, the electrical resistance of the insulating medium breaks down, and there is a rapid discharge of electricity in the form of a spark. 6sually the discharge takes place in air or, when petroleum liquids are being handled, in the vapour space above the liquid, but static discharges also occur within liquids, mists and stream clouds. In air, the critical breakdown value is about ;,333 kilovolts per meter0 up to this value, air is an effective insulator. )lectric charges, which accumulate on a body, may therefore be:
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The flow of electrostatic charge during loading of a tanker is shown diagrammatically in &igure 2. s the oil flows along the shoreline electrical charge of one sign 4say negative5 separated from it and accumulates on the pipe, which would therefore become negatively charged if it were not connected to earth. s it is earthed, this negative charge, indicated by a bracketed 4-5 sign, in fact flows to earth and, for practical purposes is lost. The liquid, which was originally electrically neutral, now carries a positive charge into the ship. The hull of the ship collects positive charge from the liquid but, the ship is floating in water, which whether it is fresh or salt, readily conducts static charges, the positive charge, denoted by 4N5 in the diagram, travels through the water to earth where it too is lost. Both ship and shore are therefore at earth potential 4apart from any cathodic protection
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voltage5. nd no electrostatic between the ship and the $etty.
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edge of the opening, i.e. earthed, a spark could occur between the bob and the surface of the liquid. I the tape is held clear of the opening 4i.e. not earthed5 until the bob is immersed in the product, the charge collected from holding the tape or, if he is insulated from the deck, discharge as a spark between the tape and the tank opening. 7imilarly a metal sampling CcanD could collect charge when immersed in the product and create by discharging to the tank structure inside the tank or to the rim of the tank opening as it is withdrawn.
The length of time the charge is retained by the liquid depends on its electrical conductivity but even with light petroleum distillates, which in general have relatively low conductivities, the time required is usually of the order of a minute or less. )ceptions are, highly purified hydrocarbons and also where high concentrations of water are dispersed within cargoes of light petroleum distillates. Then, a significant voltage may be observed for up to ;3 minutes sue to settling of water through the oil. s any isolated metal ob$ect can act as a charge collector, particular care should be The normal precaution taken to keep taken after a dry-dock period to ensure that electrostatic generation down to an acceptable ob$ects, such as tins, which might float about level is to keep the linear rate of flow of liquid in the cargo, are removed. below a specified value, which is frequently taken as E meters#second. This level is, ,ose &on"ing however, considered to be too high when The accumulation of electrostatic charges on there is a large amount of free water mied metal hose couplings is normally prevented by with the oil, as the presence of water droplets connecting the couplings to earth through the increases charge separation in flow through internal bonding wire in the hose. 'ithout this pipelines and pumps as well as settling of the bonding wire, intermediate coupling in a hose water through the oil in the tank. In the initial string could be isolated from earth, even stages of loading when water that may have although the end couplings are earthed, and collected in pipelines or at the bottom of a tank could therefore collect electrical charge from may be disturbed the linear rate of flow is the liquid flowing in the hose. 7uch isolated generally restricted to 2 meter#second until the couplings might acquire a high static voltage bottom girders of the tank are covered. This and provide a spark by discharging to any also helps to reduce splashing and spray nearby earthed conductor. formation, which is another charge separation process.
Tan! Cleaning
Ullaging an" Sam'ling 'hen loading clean products it should be assumed that static electricity could be generated. 7afety regulations therefore require that no conducting ob$ect be introduced into a tank, which loading is in progress and a ;3-minute delay period is necessary on completion to allow for the dissipation of any static electricity. To obviate this, clean product vessels are supplied with linen tapes to be used in con$unction with a circular wooden float, to enable bilges to be taken when the level of liquid is below convenient gauging by a wooden ullage stick. If a conducting metal dip tape is lowered through a deck opening into a tank containing a charged product so that it is contact with the
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The precaution of not introducing an isolated conductor into a tank applied to tank washing machines0 the machine itself and all metal couplings on the hose are bonded together and earthed through the integral bonding wire in the hose. uring water washing the machine is in fact earthed via the seawater slowing through the hose. The amount of static produced by water washing is very small. 7teaming tanks is potentially dangerous as an electrostatic charged mist may be produced and where steaming out is necessary the steam should be introduced at low velocity to lessen the charge separation.
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1o tank washing machine or other earthed conductor should be permitted in a tank when steam is present, as a spark discharge may occur between the steam cloud and the machine. s any in earthed conductor might accumulate a dangerous static charge, unearthed conductors should be banned if steam is present.
Loa"ing Overall 9oading overall of volatile petroleum is not permitted because of the possibility of electrostatic charging occurring in the presence of flammable gas. 9ikewise, nonvolatile products may be loaded overall only if the tanks are gas-free and provided there can be no contamination with volatile petroleum, which would give a flammable atmosphere in the tanks. The ha+ard is similar to that of a steam cloud in that charges mist may be produced, not only with the clean products normally regarded as static procedures, but with other kinds of petroleum as well. 'ater should not be loaded into a tank which has contained volatile clean oil until after the tank has been stripped because large static voltages could be generated by water droplet settling through the oil layer, if this is of any depth, and the tank could be in a flammable state.
STRAY CURRE.TS Cat*o"i Protetion C%rrents In order to prevent corrosion, $etties of metallic construction are provided with a cathodic protection system, which maintains the $etties at an electrical potential slightly negative to the water in which they are immersed. This is done by making the $etty one electrode 4the cathode5 in large electrolytic cell, as illustrated in &igure ?a. The other electrode 4the anode5 may be a mass of a suitable dissimilar metal, such as magnesium, which maintains a voltage difference between itself and the $etty by electrochemical means, and is itself consumed in the process. lternatively, the required driving voltage may be provided from a suitable eternal power source through an electrode, which may or may not be consumed
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according to its material of construction. In either case, the voltage in the system is quite small, of the order of a volt, but the current transferred can amount to many amperes. 'hen a ship alongside the $etty and hoses are rigged for the transfer of cargo, the cathodic protection current automatically etends to the shipside it is electrically connected to the $etty by the built-in bonding wire in the fleible hoses. This is illustrated in figure ?b, which shows that the internal bonding wire must carry on its return $ourney to the source of voltage, the current that has traveled from the anode to the ship. The current in the internal bonding wire may amount to as much as @3 amps or even more and when such a circuit is made or broken heavy sparking will result. If therefore introduces and ignition ha+ard through arcing when the hose connection is made or broken at the ship%s manifold in the presence of hydrocarbon gas. 7imilarly, electrical currents may result from ship%s eternal cathodic protection system, which protects the ship%s hull from corrosion. nother source may be current leakage from electrical installations ashore. The solution to the problem of stray currents is to block their passage completely by means of an insulating flange in the loading line, as illustrated in &igure ;. 7ince no current can now flow in the internal bonding wire, hose connections can be made and broken at the ships manifold without any risk or arcing. The same result could be achieved by using hoses without an internal bonding wire but where more than one length is used0 the risk from static charges on isolated intermediate hose couplings again arises. This however becomes a problem only when the hoses are used for pumping clean oils. It should be noted that when an insulating flange in the loading line all parts of the hoses system remain securely earthed, either from the flange shoreward or from the flange in the opposite direction to the ship.
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&ull protection against strays current without detriment to precautions against static electricity, is therefore provided by a single insulating flange in the loading line.
Se'arate &on"ing 0ire The use of a separate bonding wire between ship and $etty, formerly required at most installation, is now being discontinued as investigation of its effectiveness has shown that it serves no useful purpose.
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7o far as static electricity is concerned, the separate bonding wire plays no part as no electrostatic potential eists between the ship%s hull and the $etty because both are in contact with the water. The separate bonding wire therefore serves no useful purpose either in dissipating static electricity on the $etty or the ship or in preventing stray current from flowing through the internal bonding wire in the loading line.
The intended purpose of the wire was to shortcircuit any stray current flowing between ship and shore so that the loading line could be connected and disconnected safely without risk of arcing. To be effective the total resistance of the wire and the contact resistance of the flameproof switch and connecting clamp need to be of the order of 3.332 ohm. This would require a wire of a very large diameter, even if contact resistance could be reduced sufficiently, and indicates that the separate wire as normally used cannot be relied upon to perform this function. 'here installations still insist on the use of the separate bonding wire the proper procedure must be followed in connecting and disconnecting so that arcing does not occur at the ship%s side but within the flameproof switch. It should be the first electrical connection made between the $etty and the ship, and the last one broken, the circuit being completed at the flameproof switch so that the resultant spark cannot ignite any flammable vapour that may be present and so propagate an eplosion.
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C,EM/CAL CARR/ERS E4trat o# /MO Co"e #or t*e Constr%tion an" E$%i'ment o# S*i's arr(ing Dangero%s C*emials in &%l! 1
?5 ;5 <5 @5
!ealth ha+ard 'ater pollution ha+ard ir pollution ha+ard (eactivity ha+ard
*hemical cargoes carried onboard tankers chemical tanker may be damaged as the today include solvents, heavy chemicals, result of a collision, stranding or from some acids, alkalis, alcohols, additives, vegetable other circumstances, which may lead to an uncontrollable release of cargo. *onsequently and animal oils and molasses. to afford the cargo containment system some from eternal damage, These cargoes may possess one or more of protection the following properties, which influence the consideration must be paid to the sitting of the cargo tanks in relation to the ship%s sides and design of the ship: bottom. In order to determine the criteria for 25 !igh 7pecific "ravity up to ?.? cargo tank sittings and ship stability, it is ?5 !igh viscosity necessary to define the assumed damages ;5 !ighly corrosive and to state the conditions of survival and of <5 oisonous cargo containment. @5 &lammability >5 7elf-reactive E5 !eat sensitive DAMAGE ASSUMPT/O.S =5 !igh heat required to prevent solidification G5 !ighly sensitive to impurities because of 25 Collision Da%age possible reaction or cargo impairment. 9ongitudinal etent 2#; 9 or 2<.@ m whichever is less The I/ code applies to bulk cargoes having Transverse etent B#@ or 22.@ m fire ha+ards in ecess of petroleum, or having whichever is less significant ha+ards other then flammability. 8ertical etent &rom baseline upwards without The purpose of the *ode is to recommend limit. suitable design criteria, constructional standards and other safety measures, for ?5 ,tanding Da%age ships used in transporting dangerous 9ongitudinal 9#23 for 3.;9 from the forward chemicals in bulk so as to minimi+e the risk to etent perpendicular0 and 9#23 or @ the ship, its crew and to the neighborhood. m 4whichever is less5 over The *ode provides for three types of ships, any other part of the ship Type I, II and III, corresponding to three Transverse B#> or 23 m 4whichever is classes of ha+ardous chemicals. etent less5 for 3.; 9 from the forward perpendicular0 and @ Type I is the %ost ha+ardous m over any other part of the Type II is the %odeate ha+ard ship. Type III is the least ha+ardous 8ertical &rom baseline upward ;#2@ etent or > m whichever is less. The ship type classification is based on the ship%s ability to survive specific etents of ;5 Mino Da%age damage, and to prevent or limit the cargo This is damage, which may occur during release and also is influenced by the ha+ards harbor maneuvers due to tugs, piers, etc. associated with the release of a particular The transverse etent, inboard from the sip%s cargo: side, at right angles to the center line, at the 25 &ire ha+ard
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level of the deepest load line is taken as E>3m.
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Cargowork
TA.7 TYPES /ntegral Tan!
cargo containment envelope, which forms Is designed to transport products, which part of the ship%s hull, and may be stressed in require maimum preventive measures to the same manner and by the same loads, preclude the escape of the cargo. The ship which stress the contiguous hull structure. n should be capable of sustaining or stranding integral tank is essential to the structural damage anywhere along her length. Tanks completeness of the ship%s hull. designed for cargoes in this type of ship must lie outside the etent of damage specified0 in /n"e'en"ent Tan! collision damage - transverse etent, and cargo containment envelope, which is not a stranding damage - vertical etent, and must contiguous part of the hull structure. n not be closer to the ship%s shell than E>3 mm. independent tank is built and installed so as to eliminate whenever possible 4or in an event, to S*i' T('e // minimi+e5, its stressing as a result of stressing It is designed to transport products, which or motion of the ad$acent hull structure. n require significant preventative measures to independent tank is not essential to the preclude the escape of the cargo carried. completeness of its ship%s hull. 4Hcontiguous% means Htouching% or ad$oining5 ship of 2@3 m or less in length, should be capable of sustaining damage anywhere in her Gravit( Tan! length, ecept involving either of the Tank having a design pressure of not greater bulkheads bounding a machinery space than 3.E p#cm ? at the top of the tank. ay be located aft, and surviving as specified. integral or independent. ship or more than 2@3 m in length should be S,/P ARRA.GEME.TS capable of sustaining collision or stranding damage anywhere along her length and Cargo Segregation surviving as specified. cargo sub$ect to the *ode shall be The tanks containing cargo should be located segregated from machinery and boiler spaces, outside the etent of damage specified0 in accommodation and service spaces, drinking stranding damage - vertical etent, and minor water and stores for human consumption0 by side damage. means of cofferdam, void space, cargo pump room, empty tank fuel tank or other similar spaces, ecept where otherwise ecluded by S*i' T('e /// Is designed to carry products having sufficient the *ode. ha+ards to require a moderate degree of containment, to increase survival in a *argoes, which react in a ha+ardous manner with other cargoes should: damaged condition. a5 Be segregated from such other cargoes by ship of 2?@ m and over in length, should be means of a cofferdam, void space, cargo capable of sustaining stranding damage pumproom, empty tank or mutually compatible anywhere along her length, ecept inclosing cargo0 as specific. ship of less than 2?@ m in b5 !ave separate pumping and piping length, should be capable of sustaining systems, which should not pass through any collision or grounding damage anywhere along other cargo tanks containing such cargoes, her length and ecept for damage in way of unless encased in a tunnel0 and c5 !ave separate tank vent systems. machinery space, survive as specified. There are no special requirements for cargo tank location in Type III ships.
ALAM/July 2002
*argo piping should not pass through any accommodation or machinery space other than cargo pumprooms.
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Correspondence Course
cargo sub$ect to the provisions of the *ode should not be stowed in the fore and after peaks.
Aess To +oi" S'aes Cargo Tan!s An" Ot*er S'aes /n T*e Cargo Tan! Area rrangements for void spaces, cargo tanks and other spaces in the cargo tank area, should be such as to ensure adequate access for complete inspection. ccess to the cargo tanks should be direct from the open deck. &or access through hori+ontal openings dimensions to be such as to permit passage of person wearing breathing apparatus, and allow the hoisting of an in$ured person from the bottom of the space. inimum clear opening to be >33 mm >33 mm. &or access through vertical openings, providing passage through length and breadth of the space, the minimum clear opening shall be >33 mm =33 mm, at a height not more than >33 mm from the bottom shall be plating, unless gratings or other footholds are provided.
Tan! +ent S(stems ll cargo tanks should be provided with a venting system appropriate to the cargo being carried. 7ystems to be so designed as to minimi+e the possibility of cargo vapour accumulating about the decks, entering accommodation and machinery spaces, and in the case of flammable vapours, other spaces containing sources of ignition. They should also be designed to minimi+e possible spraying on deck. Tank vent outlets should be arranged to prevent entrance of water into the cargo tanks, and at the same time, should direct the vapour discharge upwards in the form of unimpeded $ets.
Cargowork
above such gangway, if vent is fitted within < m of such gangway. The height of vent eit may be reduced to ; m above deck fore and aft gangway, provided high velocity vent valve are fitted, directing the vapour#air upward in an unimpeded $et with an eit velocity of at least ;3 m#s. The vent eist should be at least 23 m from nearest air intake or opening in accommodation, service, spaces and ignition sources. &lammable vapour outlets should be provided with readily renewable and effective flame screw or safety heads of approved type.
Materials O# Constr%tion 7tructural materials used for tank construction, together with associated piping, pumps, vents, valves and their $oining materials, should be suitable at the carriage temperature and pressure for the cargo to be carried. 7teel is assumed to be the normal material of construction. 'here applicable, the following should be taken into account in selecting the material of construction: a5 1otch ductility at the operating temperature0 b5 *orrosive effect of the cargo0 c5 ossibility of ha+ardous reactions between the cargo and the material of construction0 and d5 7uitability of linings and coatings.
Ma4im%m Allo)able 3%antit( O# Cargo Per Tan! The quantity of cargo, required to be carried in a Type I ship, should not eceed 2,?@3 cubic meters in any one tank. The quantity of cargo, required to be carried in a Type II ship, should not eceed ;,333 cubic meters.
+ent E4its
Certi#iate O# Fitness For T*e Carriage O# Dangero%s C*emials /n &%l!
The height of vent eits should not be less than < m above the weather deck or, if a fore and aft gangway is fitted, not less than < m
fter satisfactory inspection of a ship, a certificate should be issued, containing the following information: -
ALAM/July 2002
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Malaysian Maritime Academy
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Cargowork
a5 1ame of ship to about <3 different tanks, each with its own b5 ort of registration system. c5 7hip type d5 *argoes which ship is permitted to carry fter each product has been off loaded the e5 The conditions of carriage tank is frequently ventilated and then washed, f5 ny authori+ed eemptions permitted by sometimes only with a bottom flush. !owever, the *ode. because even the tank drainage can be sufficient to put a chemical off specification, it is necessary to enter the tank to mop out the C*emial Tan!er ,aar"s *hemical tankers differ substantially from oil draining prior to tank inspection by second tankers in the type of operation as they are person. requires to handle a large number of small parcels of differing chemicals on a continuing basis, rather than alternating between oil and ballast voyages. The chemical tanker operation involves frequent cleaning and inspection of the tanks to maintain the highgrade quality of the product and to prevent any interaction of the chemicals.
Prini'al ,aar"s For Cre) The principal ha+ards to which crewmembers are eposed in handling chemicals in this condition are: Tank eplosion Tank over pressuring sphyiation olymeri+ation *hronic and acute poisoning
Tan! E4'losion )plosion occurs when an air#fuel miture within certain specific concentration is ignited.
Incidents of asphyiation in tanks of chemical and other tankers are unfortunately too frequent.
Pol(meriation If a tank containing a monomer starts to polymeri+e heat is liberated which can accelerate the reaction. onomer can then be vapori+ed which can lead to tank overpressure and rupture. olymeri+ation of a monomer can be caused by impurities either in the tank at the start or introduced subsequently by, for eample, inert gas. )clusion of oygen, making the polymer inhibitor ineffective, will aggravate any problems of impurities.
L/3U/F/ED GAS CARR/ERS 25 1"ll !ess"ised ,#ips These ships carry cargo in steel pressure vessels designed to withstand about 2E kg#cm . The tanks are normally cylinders, mounted hori+ontally or vertically. The ships tend to be small, with a cargo capacity of up to about 2333m ; and they normally carry 9" or ammonia in the short sea trade.
Tan! Over Press%ring Tank over pressuring leading to rupture can be caused from hydraulic or gas pressure effects and when the tank relief system is inoperable. ressuring of a ships tank by, for eample, inert gas will tend to increase any leakage from a tank and sub$ect crewmembers to a ha+ard unless the pressure tightness of the tank is ensured.
As'*(4iation /ne particular aspect of chemical tanker operation, which differentiates it from product and oil tankers, is the frequency of ventilating and cleaning tanks. *hemical tankers have up
ALAM/July 2002
?5 ,e%i Refigeated ,#ips These ships have pressure vessels designed to carry cargoes at temperatures below ambient. The grade of steel used governs the temperature limitation. The trend to be larger ships with cargo capacities of up to 2?333m ;. The cargo tanks are insulated and there is usually a reliquefaction plant on board. ;5 1"ll Refigeated ,#ips These are larger ships of cargo carrying capacity varying from @333m ; to 233,333m ;. They carry 9" at temperatures between -
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