CONSTRUCTION TECHNOLOGY VI (QSM652) CIVIL ENGINEERING CONSTRUCTION: MARINE STRUCTURES HARBOUR AND JETTY STRUCTURES Prepared by
SITI SARAH MAT ISA c
Introduction to Harbour • A harbor or harbour , or haven, is a place where ships, boats, and barges can seek shelter through stormy weather, or else are stored for future use. • Habour is a sheltered port where ships can take on or discharge cargo • Harbour can be natural or artificial. An artificial harbor has deliberately-constructed breakwaters, sea walls, or jetties, or otherwise, they could have been constructed by dredging, and these require maintenance by further periodic dredging
Introduction to Habour The transportation of cargo, internationally or domestically, is mostly by means of maritime transportation. This medium of transportation requires efficient services and facilities of a port in order to be effective A port is a facility at the edge of an ocean, river, or lake as a place for receiving ships and transferring cargo and persons to the land. The main function of a port is to provide an interface between two modes of transportation which are the maritime and domestic transportation.
Capri Habour, Italy
Introduction to Harbour The requirement for sea transport are to provide an adequate area of water of sufficient depth for navigation and berthing and also to provide an adequate shelter so that berthing, loading and unloading can be carried out safely and efficiently. Meanwhile the requirement for the land side are, to provide an adequate land area for working space, loading and unloading vessel and for handling and storage of cargoes and as a suitable access to areas served by the port A port may have warehouses for storage of goods and a system, such as facilities for relaying goods inland. Therefore, ports consist of marine structure such as quays, docks, wharfs, jetties, piers and slips with cranes or ramps and etc. to support the main function of the port.
Port Facilities
Wharf / Quay • Wharf is a structure on the shore of a harbor where ships may dock to load and unload cargo or passengers, Such a structure includes one or more berths (mooring locations), and may also include piers, warehouses, or other facilities necessary for handling the ships. • A wharf commonly comprises a fixed platform, often on pilings. Commercial ports may have warehouses that serve as interim storage areas, since the typical objective is to unload and reload vessels as quickly as possible. • Where capacity is sufficient a single wharf with a single berth constructed along the land adjacent to the water is normally used; where there is a need for more capacity multiple wharves, or perhaps a single large wharf with multiple berths, will instead be constructed, sometimes projecting into the water. A pier, raised over the water rather than within it, is commonly used for cases where the weight or volume of cargos will be low.
Wharf / Quay • Smaller and more modern wharves are sometimes built on flotation devices (pontoons) to keep them at the same level as the ship, even during changing tides. • In everyday parlance the term quay is common in the United Kingdom, Canada, Australia, and many other Commonwealth countries, and the Republic of Ireland, whereas the term wharf is more common in the United States. In some contexts wharf and quay may be used to mean pier, berth, or jetty.
The Barbours Cut Terminal of the Port of Houston, USA. This cargo shipping terminal has a single large wharf with multiple berths.
Docks A dock is an enclosed area of water used for loading, unloading, building or repairing ships. Such a dock may be created by building enclosing harbour walls into an existing natural water space, or by excavation within what would otherwise be dry land. There are specific types of dock structure where the water level is controlled: •A dry dock is another variant, also with dock gates, which can be emptied of water to allow investigation and maintenance of the underwater parts of ships. •A drydock is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Drydocks are used for the construction, maintenance, and repair of ships, boats, and other watercraft.
Docks • A wet dock or impounded dock is a variant in which the water is impounded either by dock gates or by a lock, thus allowing ships to remain afloat at low tide in places with high tidal ranges. • The level of water in the dock is maintained despite the raising and lowering of the tide. This makes transfer of cargo easier. It works like a lock which controls the water level and allows passage of ships. • The world's first commercial enclosed wet dock, with quays and unloading warehouses, was Steers Dock at Liverpool, built in 1715. This reduced ship waiting giving quick turn arounds, greatly improving the throughput of cargo.
Floating docks
Floating docks, Gdynia, Poland
Floating Drydock •A floating drydock is a type of pontoon for dry docking ships, possessing floodable buoyancy chambers and a "U"shaped cross-section. •The walls are used to give the drydock stability when the floor or deck is below the surface of the water. When valves are opened, the chambers fill with water, causing the drydock to float lower in the water. •The deck becomes submerged and this allows a ship to be moved into position inside. When the water is pumped out of the chambers, the drydock rises and the ship is lifted out of the water on the rising deck, allowing work to proceed on the ship's hull.
Floating Drydock • A typical floating drydock involves multiple rectangular sections. These sections can be combined to handle ships of various lengths, and the sections themselves can come in different dimensions. • Each section contains its own equipment for emptying the ballast and to provide the required services, and the addition of a bow section can facilitate the towing of the drydock once assembled. • For smaller boats, one-piece floating drydocks can be constructed, potentially coming with their own bow and steering mechanism.
Floating Dock
Jetty Structures Introduction : Jetty is any of a variety of structures used in river, dock, and maritime works that are generally carried out in pairs from river banks, or in continuation of river channels at their outlets into deep water; or out into docks, and outside their entrances; or for forming basins along the coast for ports in tideless seas. Jetty is one of the facilities provided within the port designed area. Jetty is a structure built out from the shore and at which vessels berth, either at the head or alongside. Jetty consists of Approach Bridge, jetty head, dolphins and fenders system.
Jetty Structures There are many forms or types of jetties. The type of jetties can be differentiating based on its main function and its form of construction A lot of aspect need to be considered when constructing the jetty structure as it construction was held on open sea. These include the design considerations, the environment impacts, and the method of construction, the facilities and the uses of the jetty.
Design Principles Jetties should be designed to meet the requirements of the appropriate design codes and standards, to sound engineering principles and to be fit for purpose. Jetties should be of sound construction, preferably made of non-combustible materials, and be of sufficient strength to withstand normal berthing forces.
Design Principles 1. general sitting considerations; 2. the civil and structural design requirements for the jetty taking into the location, natural phenomena such as the weather and tidal/marine considerations; 3. impact protection for the approach of the ship to the jetty. Consideration needs to be given to protection of the jetty from impact from the ship and vice versa. A major accident could result if contact between the ship and jetty resulted in damage to the ship and loss of containment of a hazardous substance or if significant damage occurred to the jetty structure;
Design Principles 1. vessel anchorage/mooring requirements at the jetty. The design needs to take into account the requirements for ship anchorage and mooring at low and high tides, and when the vessel is full and empty; 2. ship to shore transfer. Special consideration is required for ship to shore transfer of hazardous substances. The design of the product transfer (typically pipework) system for ship to shore transfer should take into account the changing tides, water levels and displacement of the ship in the water during the transfer cycle and be flexible enough to cope with all foreseen scenarios; 3. access for emergency vehicles and emergency escape.
Design Principles In addition to the correct design of the jetty installation the facility should also be subjected to an adequate maintenance and inspection programme designed to ensure that the integrity of the facility is maintained during operation. Additional consideration should be given to the precautions that should be taken at jetties since there may be a number of different ‘authorities’ which may have a controlling influence. These include the harbour operator, the jetty operator and the master of the ship. There should be a clear definition of the roles and responsibilities of all parties concerned. Consideration may also be needed in respect of other jetties in the vicinity and the impact on management arrangements in the case of interaction arising from domino effects, communication links, etc
General Sitting Consideration As part of the fundamental design process the following strategic factors should be taken into account in the choice of the site and the design of the facility: road and rail access (if appropriate) to the jetty area and storage facilities; the shelter provided by the local landscape to the proposed jetty site; the availability of land for use as storage and material handling areas; the presence of swift access to navigable shipping channels; the ability to keep good access to the navigable shipping channels; the availability of a prevailing breeze to facilitate the early and ready dissipation of vapours resulting from spillage; emergency access and exit routes for emergency services, pollution control equipment and operating personnel; the provision of life-saving aids; the provision of adequate lighting; security control; tidal/current effects; proximity to other jetties and their required ship access; marine movements in the area and necessary manoeuvres for berthing vessels (space).
Civil and Structural Design Jetties should be designed in accordance with BS 6349 – Code of Practice for Maritime Structures. Part 2 provides advice on the design of quay walls, jetties and dolphins. For the civil and structural engineering design consideration needs to be given to the following: i. fire; ii. the type and maximum size of the ship that is to be moored at the jetty; iii. the hazardous substances to be handled and their chemical and physical properties; iv. the relevant meteorological conditions – including consideration of storms; v. other natural phenomena such as lightning, earthquakes/tremors etc; vi. geological information and the geological stability of the area including the river/sea bed; vii.the rise and fall and rate of the tides; viii.cargo handling requirements; ix. materials of construction; x. thermal expansion and contraction; xi. electrical earthing to delivery points and to loading berths since the ignition of flammable vapours can be caused by static electricity. Any electrical cables passed between the vessel and shore need to be adequately insulated and supported and protected against overload and mechanical damage; xii.cathodic protection to under sea steel piles. Corrosion of the jetty support structure below the water line could result in structural weakness in the jetty.
Impact Protection Guidance for the approach of a ship towards a jetty will depend upon the specific details of the waterway, tidal flows, sea/river bed layout etc. However the aim of the approach will be to bring the ship (either by the use of tugs or her own engines) gently alongside the jetty These procedures not be adhered by the pilot/master of the ship and the ship collides with the jetty at excessive speed or at an inappropriate angle then severe damage is likely to result to the jetty and/or the ship. Impact protection for a jetty is normally confined to normal berthing forces and not for the scenario described above. Due to the inherent difficulties in positioning a large ship alongside a jetty it is essential that some form of protection be available associated with the jetty to protect the jetty from the ship and vice versa. Such protection is essential when the ship is being maneuvered into mooring position alongside the jetty and when the ship is moored and the ship may be being pushed onto the jetty by the tides, winds, currents etc.
Impact Protection BS6349: Part 4 : 1994 gives guidance on types of fenders, fendering systems and layouts, mooring devices and ropes, mooring system layouts for commercial vessels, and recommendations as to their suitability for various applications and locations. The function of a fendering system is to protect the jetty structure against damage from ships approaching, lying alongside or leaving the jetty and to limit the reactive forces to the ship’s hull to acceptable values. Fender systems design varies considerably and should be integrated with the jetty design. Consideration should be given to the types of vessels to be moored and their hull designs and upon the characteristics of the location. These will vary depending upon whether the jetty is to be situated on the coast, in an estuary, in a tidal basin or elsewhere.
Vessel Anchorage or Mooring Adequate facilities should be provided at a jetty for safe and secure mooring. The installation should take into account the range of sizes and types of ship, local tidal variations, foreseeable weather conditions and the nature of the cargo and ballasting operations. Close liaison is required between all parties concerned (ship’s crew, harbour master, jetty operator etc.) to ensure that the mooring is done safely and an adequate watch is kept on the moorings while the ship is alongside and particularly during cargo transfer. Local conditions may place additional requirements on vessel mooring. Account needs to be taken of the rise and fall of ships in relation to the jetty as a result of the changing tidal patterns. The extent of tidal fluctuations will vary from location to location and should be considered on an individual basis. In addition the displacement of the ship in the water will also rise and fall as the ship is emptied/filled and this should also be taken into account in the mooring systems. Insufficient depth of water to accommodate the ship in approach or at the jetty, or to accommodate mooring at low tides may result in the ship running aground. This may result in a loss of containment of the hazardous substances and lead to a major accident.
Vessel Anchorage or Mooring Consideration should be given at the design stage to the possibility of berth silting at the jetty leading to an increasing possibility of a vessel running aground. Jetty bollards and mooring arrangements should be designed to hold the ship in position once the ship has docked so that loading/offloading can take place safely. Inadequacies in the mooring arrangements could result in the ship breaking away from the moorings for example during a storm. Often it is necessary to hold the ship in place in relation to the jetty mounted offloading facilities which may have limited flexibility in movement. This is achieved by restraining the movement to within acceptable limits by means of an adequate number of mooring lines compatible with the conditions of wind, tide, weather and previous operating experience of the facility. Failure to properly restrain the ship in position which results in excessive movement may result in fracture of offloading pipework and subsequent loss of containment of hazardous substances.
Ship to Shore Transfer The transfer from ship to shore unavoidably involves the transfer of hazardous substances by pipework system suspended above a watercourse. See HS(G)186 The bulk transfer of dangerous liquids and gases between ship and shore which addresses many of the issues concerning design, operations and procedures at jetties. All ship to shore connections should provide sufficient flexibility to allow for rise, fall and range of the vessel due to tide, wave and current effects and changes in displacement. Flexible pipework should be manufactured to a standard suitable for the application and should be compatible with the substances to be handled (See Technical Measures Document – Design Codes - Pipework). It should be adequately supported (for example by slings, loading arms or saddles) so that it does not become kinked, overbent, abraided or trapped between the ship and the jetty. Where large hoses are used suitable cranes or hose rigs should be used. Care should be taken that hose slinging and securing equipment does not cause excessive curvature of flexible pipework systems.
Ship to Shore Transfer Failure of the transfer lines during transfer could result in spillage of material into the watercourse or on to the jetty resulting in pollution, fire or explosion. This can happen for a variety of reasons and facilities should be available for pollution control should this occur. Excessive movement of the ship which results in the pipework system being pulled apart, or the discharge pipework becoming trapped between the jetty and the ship, may result in fracture of the pipework connection and the release of hazardous substances. When not in use hoses should be properly stored to avoid accidental damage, extremes of temperature and direct sunlight. It is good practice to provide blank ends for the additional sealing of couplings that are frequently broken and remade. All hoses should be externally inspected for damage and deformation prior to use. A more detailed examination, including appropriate internal inspection and hydrostatic pressure testing should be carried out at least annually.
Ship to Shore Transfer Additional features such as emergency release or breakaway couplings with automatic shut-off valves for isolation of the inventory can be installed to minimise the potential for spillage. It is also necessary to consider the ability to shut off transfers from both shore side and ship side, and necessary ship to shore communications arrangements. For pipework transfer systems consideration should also be given to pressure relief, fire engulfment relief and the possibility of pressure surges causing ruptures to the hoses/flanges. Pressure surges in pipelines caused by closing valves too rapidly, may lead to failure of vulnerable parts such as flanges. Pigging operations are often carried out to clean pipelines. The hazards associated with the pigging operations should be carefully assessed. Further guidance is available in HS(G)186 The bulk transfer of dangerous liquids and gases between ship and shore.
Ship to Shore Transfer Special consideration should be given to installations where manifold systems are used to ensure that the correct connections between ship and storage tank are made. In instances where the storage tanks are situated on land above the level of the jetty then consideration needs to be given to the control of gravity flow from the storage tanks. Suitable facilities for the isolation of the inventory should be included to avoid spillage and pollution. As a precaution against spillage or other emergency on the jetty, shut-off valves should be considered at or near the shore end of all jetty pipelines which carry hazardous substances. Such valves should not introduce unacceptable surge pressures in the pipeline in the event of closure. Such valves should be fail safe and be capable of manual operation in an emergency. Procedures and facilities should be in place for emptying out residual contents from flexible pipework systems after use and then cleaning pipework systems as necessary. Suitably designed areas which provide containment of releases to avoid pollution should be considered.
Construction Sequences SITE POSSESION
PRELIMINARIES AND GENERAL ITEMS
IN-SITU CONCRETE WORKS
DREDGING WORKS
DECK FURNITURE
SITE CLEARANCE AND REVETMENT WORKS
FABRICATION AND INSTALLATION OF STRUCTURAL STEEL WORKS
PILING WORKS
NAVIGATIONAL AIDS
PILE LOAD TEST- STATIC AND DYNAMIC
HAND OVER
CONSTRUCTION OF SUBSTRUCTURE, DOLPHINS AND PILE CAP INSTALLATION OF PRECAST PRESTRESSED BEAMS
Construction of Jetty
Construction of Jetty • In general, the jetty are of lighter construction than general cargo-handling docks as they usually do not required warehouse or extensive cargo-handling equipment like large crane used to load and unload containers. • Jetty head is protected by breasting dolphins against the mooring tankers and also provided with separated dolphins to take the ship’s mooring lines. • The jetty is equipped with the pipelines systems to transport the products to or from the ships
Revetment Works
The piles are stored on a material barge to be transferred at the driving point. The size of the material barge is based on the length of piles. The piles must not over hang more than 3 meter from the bow and stern of the material barge. The material barge is towed to the front of the piling barge by the tug or anchor boat.
Pile Installation • the anchoring positioning plan for driving of piles is predetermined for each location. A piling sequence is work out before piling works is carried out to ensure all piles can be driven without interferences. • The anchors are spread by anchor boat. This anchor boat is equipped with a 10 tons line pull hydraulic winch an A frame at the front. • The piling barge anchor positioning is predetermined for each piling location. Minimum of four-point mooring was used to anchor the piling barge in position. When the anchor spreading works is completed the piling barge is ready for pile driving.
Piling Works - pre-stressed spun piles and steel pipe piles
• The pile was lifted until it is vertical. The lower sling is slacken and removed. The pile is slotted into the hammer cap and griped by the piling leader hydraulic clamp. • The pile is straightened fully by lifting both hammer and pile. When the pile is pitch and it was ready for driving.
Elevation of Jetty Head
Substructure and Dolphins The jetty was designed to capable to carry load such as the total dead load, super loading and plant loading on deck, storm wind loading and current load on design ship alongside, the berthing force transferred through the fender system, mooring forces transferred to the jetty from the ship through quick release hook and the friction forces transferred to the jetty through the fender system. The substructure and the dolphins play and important roles to ensure the stability of the jetty towards all the loads involved.
Substructure and Dolphins Dolphins are marine structures for mooring vessels. They are commonly used in combination with piers and wharves to shorten or reduced the length of these structures. Dolphins are designed principally for the horizontal loads of impact and/or wind and current forces from a ship when it is docking and during the time the ships are moored. In this project, three types of dolphins will be constructed. They are breasting dolphins, mooring dolphins and protective dolphins.
Trestle
Mooring Dolphins
Protective Dolphins
Completed Pile Cap
Installation of In-situ Reinforced Concrete Slab
Installation of In-situ Concrete at Deck Slab
Installation of In-situ Reinforced Concrete Slab and structural steel works
Completion of the Jetty structure
DECK FURNITURE
Fender System The principal function of fenders is to prevent the ship and/or the jetty head being damaged during mooring. Even under an ideal condition and under perfect control a ship might approach the jetty head without striking a severe blow, but it is essential to separate it from the jetty head with a fendering system.
Fender System type of fenders is made from rubber as rubber has become into extensive use for fender systems. The side exposed to the ship is covered with rubber pads to protect the ship. This lower level of the fender panel will allow the fender to be low enough to accept the smaller range vessel to come to the terminal in loaded draft at low water and accept tugs
Fender system at auxiliary platform
Fender system at the Jetty Head
Fender system
Installation of Fender
Installation of Fender The contractor must ensure that the face of concrete to support the fender shall be sufficiently wide and truly flat and vertical to provide sound bearing surface to the fender. During the placement of the fenders, slinging and hoisting of the rubber section is permissible but caution was required to avoid tearing of the rubber. The use of canvas sling or other protective device can be adopted.
Installation of Fender The use of stainless steel cut washer under attachment bolts are required to prevent cutting and tearing the rubber All inserts shall be incorporated in the fender elements during moulding and lamination and the like is not be permitted The fixings shall be accurately cast into the concrete. A template or other device will be used for this purpose. Fixings and fittings must be protected against damage until the fenders are fixed.
Detail of Fender
Detail of Fender Bil.
Item
Function
1
Anchor Bolt
Attaches fender to wharf
2
Tension Chain
Restrains fender body under low impact condition
3
Shear Chain
Restrains shear deflection of fender
4
Weight Chain
Supports frontal frame
5
Frontal Frame
Protects hull of vessel by reducing contact pressure
6
Frontal Pad
Reduces friction coefficient to protect ship's hull
7
"U" Anchor
Attaches chain to wharf
Bollards Bollard is an essential part for the jetty structure. Its function is to hold the vessel line while berthing and usually constructed of cast steel. The method of installation of bollards: Special care need to be considered before the installing the anchor bolts in order not to conflict with reinforcement, wiring, pipe sleeve and etc. The bolts must have at least two clear threads protruding above the nuts.
Bollards The position of the bolts should be checked against the bollard prior to the pouring concrete. The nut and washer seated into the recess in the bollard base covered with bitumen completely leaving a smooth surface Any parts to be embedded in the concrete shall be cleared and free from rust, oil and etc.
Bollards
Quick Release Hook
Quick Release Hook • The Quick Release Hook (QRH) was installed at the mooring dolphin and breasting dolphins. Both dolphins were installed with the QRH when heavy lines are to be handled. • The installation of the QRH was done after the constructing the mooring dolphins.
Rubber Ladder • Rubber ladder were installed at breasting dolphins area. This type of rubber ladder is tough, durable, weather-resistant, and able to absorb considerable contact form vessels without damage. • Ladder rungs are 300mm steel rods which are an integral part of the rubber end supports. Ladder units can be bolted into concrete, steel, and wood, or welded directly to steel.
Rubber Ladder
Maintenance of Jetty
The integrity of the jetty system should be routinely checked and confirmed. The following items should be routinely inspected as a minimum requirement:
the fendering systems for vessel impact protection should be inspected to ensure that there has been no damage as a result of vessel movements;
the depth of the approach channels, the berthing location and the exit channels from the jetty should be routinely checked to ensure that silting has not occurred to an extent that may result in a ship running aground. It may be necessary to have a programme for the removal of silt;.
the bollards/securing points located on the jetty should be inspected to ensure that they have not been damaged or loosened during storm conditions;
Maintenance of Jetty
the underwater structure of the jetty should be routinely inspected to ensure that significant corrosion has not occurred and the structure has not been significantly weakened as a result of corrosive attack; any ropes/mooring systems used for fastening ships to jetties should be inspected on a routine basis to ensure that they are not damaged; all land based pipework, pumps and transfer systems, lifting apparatus and support structures should be routinely inspected; fire access routes and emergency equipment should be regularly inspected; wash down facilities for flexible pipework systems should be regularly inspected and emptied/cleaned as necessary.
