SQA Navigation Working. FH 2011-11-29 Read the question. Think! Analyse the question. q uestion. Use the data given. Answer the question asked. Updated 2011-11-07
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July-2011 A 115000 GT bul k c arri er i s t o m ake a lo aded p assage ass age bet ween Valparai Valp araiso so (Chil e) to Yokoh Yok ohama ama (Jap an), carryi ng a cargo of p hosph ates and is expected to have a departure draught o f 16.6 16.6 metres. metres. The vessel carries navig ation equip ment as per statute and has a service speed of 16.0 16.0 knots. The vessel is st due to depart Valparaiso on th e 1 September. 1. The The vessel is to use the following departure departure and landfall position s. Departu re Posi tio n Land fall Posi tion ti on
33 03.0 S 35 18.0 N
071 48.0 W 139 42.0 E
Calculate EACH of the following: a) the great circ le dis tance; (10) (10) b) the final cou rse on the great circ le track; (15) (15) c) the positio n of the vertex, vertex, lying North of th e Equator. Equator. 1. A B
33 03.0 S 35 18.0 N
DLon = P
P
071 48.0 W 139 42.0 E 211 30.0 E 148 30.0 W
V
PA = 90 ± Lat A = 90 + 33 03.0 = 123 03.0 PB = 90 ± Lat A = 90 – 35 18.0 = 54 42.0
B
a) cos AB = cos P x sin PA x sin PB + cos PA x cos c os PB -1 AB = cos (cos 148 30 x sin 123 03 x sin 54 42 + cos 123 03 x cos 54 42) AB = 153 57 05.45 x 60 Dis = 9237.1 NM
A
b) A = tan Lat B ÷ tan DLon = tan 35 18 ÷ tan 148 30 = -1.155415399 -1.155415399 = 1.155415399 N B = tan Lat A ÷ sin DLon = tan 33 03 ÷ sin 148 30 = 1.245264647 S C = A ± B = 1.155415399 N - 1.245264647 S = -0.08984924793 = 0.08984924793 S -1 -1 ICo BA = tan (1 ÷ C ÷ cos Lat B) = tan (1 ÷ 0.08984924793 ÷ cos 35 18) = 85 48 21.76 = S 86 E FCo = N 86 W FCo = 274 c) sin PV = cos (90 – B) x cos (90 – PB) -1 PV = sin (cos (90 – 85 48 21.76) x cos (90 – 54 42)) PV = 54 29 01.98 ~ 90 Lat V = 35 31.0 N
P
V V
sin (90 – PB) = tan (90 – B) x tan (90 – P) tan (90 – P) = sin (90 – PB) ÷ tan (90 – B) -1 P = 90 – tan (sin (90 – 54 42) ÷ tan (90 - 85 48 21.76)) P = DLon BV = 007 13 55.57 W
BV
90-PB
2
PV 90-P
90-B Lon V = Lon B ± DLon = 139 42.0 E – 007 13.9 W Lon V = 132 28.1 E
B
July-2011 A 115000 GT bul k c arri er i s t o m ake a lo aded p assage ass age bet ween Valparai Valp araiso so (Chil e) to Yokoh Yok ohama ama (Jap an), carryi ng a cargo of p hosph ates and is expected to have a departure draught o f 16.6 16.6 metres. metres. The vessel carries navig ation equip ment as per statute and has a service speed of 16.0 16.0 knots. The vessel is st due to depart Valparaiso on th e 1 September. 1. The The vessel is to use the following departure departure and landfall position s. Departu re Posi tio n Land fall Posi tion ti on
33 03.0 S 35 18.0 N
071 48.0 W 139 42.0 E
Calculate EACH of the following: a) the great circ le dis tance; (10) (10) b) the final cou rse on the great circ le track; (15) (15) c) the positio n of the vertex, vertex, lying North of th e Equator. Equator. 1. A B
33 03.0 S 35 18.0 N
DLon = P
P
071 48.0 W 139 42.0 E 211 30.0 E 148 30.0 W
V
PA = 90 ± Lat A = 90 + 33 03.0 = 123 03.0 PB = 90 ± Lat A = 90 – 35 18.0 = 54 42.0
B
a) cos AB = cos P x sin PA x sin PB + cos PA x cos c os PB -1 AB = cos (cos 148 30 x sin 123 03 x sin 54 42 + cos 123 03 x cos 54 42) AB = 153 57 05.45 x 60 Dis = 9237.1 NM
A
b) A = tan Lat B ÷ tan DLon = tan 35 18 ÷ tan 148 30 = -1.155415399 -1.155415399 = 1.155415399 N B = tan Lat A ÷ sin DLon = tan 33 03 ÷ sin 148 30 = 1.245264647 S C = A ± B = 1.155415399 N - 1.245264647 S = -0.08984924793 = 0.08984924793 S -1 -1 ICo BA = tan (1 ÷ C ÷ cos Lat B) = tan (1 ÷ 0.08984924793 ÷ cos 35 18) = 85 48 21.76 = S 86 E FCo = N 86 W FCo = 274 c) sin PV = cos (90 – B) x cos (90 – PB) -1 PV = sin (cos (90 – 85 48 21.76) x cos (90 – 54 42)) PV = 54 29 01.98 ~ 90 Lat V = 35 31.0 N
P
V V
sin (90 – PB) = tan (90 – B) x tan (90 – P) tan (90 – P) = sin (90 – PB) ÷ tan (90 – B) -1 P = 90 – tan (sin (90 – 54 42) ÷ tan (90 - 85 48 21.76)) P = DLon BV = 007 13 55.57 W
BV
90-PB
2
PV 90-P
90-B Lon V = Lon B ± DLon = 139 42.0 E – 007 13.9 W Lon V = 132 28.1 E
B
th
2 On the morning o f the 11 September the OOW makes the following simultaneous celestial observations: Time at Ship DR Pos it ion io n Chrono meter read Chronom eter error Sextant Sextant Altitu de of Suns LL Index error Heigh t of Eye
0900 0900 hrs 11 40.0 S 121 42.0 W 5h 06m 06m 28s 28s 3m 16s 16s slow on UT 43 39.3 39.3 2.4 off the arc 12.6 m
Sextant Alt itu de of VENUS on th e meridian 62 17.7 17.7 (Bearing (Bearing Nort h) a) Determin Determin e the direction of th e positi on li ne and and th e intercept fo r the SUN. SUN. (15) (15) b) Determin Determin e the latitud e at the time of th e observation of t he Venus Venus . (15) (15) c) Determin Determin e, by graphic al means, means, th e vessel’s po sit ion at 0900 0900 hrs. (10) a) Ship Time Zone Number Universal Time CT CE UT GHA Inc Lon LHA LHA
11 09:00 08 11 17:00
Zone Time? 121 42 W ÷ 15 =08:07
17:06:28 00:03:16 Slow 17:09:44 075 51.7 Dec N 04 25.0 002 26.0 d 1.0 – 00.2 121 42.0 W Dec N 04 24.8 -43 24.3 316 35.7
A = tan Lat ÷ tan LHA = tan 11 40 ÷ tan 316 35.7 = -0.2183118984 -0.2183118984 = 0.2183118984 N B = tan Dec ÷ sin LHA = tan 04 24.8 ÷ sin 316 35.7 = - 0.1123187025 = 0.1123187025 N C = A ± B = 0.2183118984 S + 0.1123187025 N = 0.3306306009 N -1 -1 Az = tan (1 ÷ C ÷ cos Lat) = tan (1 ÷ 0.3306306009 ÷ cos 11 40) = 72 03 28.97 = N 72 E = 072 PL= AZ ± 90 PL 162 / 342 cos AB = cos P x sin PA x sin PB + cos PA x cos PB -1 CZD = cos (cos LHA x cos Lat x cos Dec ± sin Lat x sin Dec) -1 CZD = cos (cos 316 35.7 x cos 11 40 x cos 04 24.8 - sin 11 40 x sin 04 24.8) CZD = 46 03 56.02 = 46 03.9 SA IE OA Dip AA TC TA TZD CZD Int
43 39.3 00 02.4 Off + 43 41.7 –06.2 43 35.5 00 15.0 43 50.5 46 09.5 46 03.9 00 05.6 A
3
b) Dec N 16 10.7 d 0.8 -00.1 Dec N 16 10.6 SA IE OA D AA TC AC TA TZD Dec Lat
62 17.7 00 02.4 Off + 62 20.1 -06.2 62 13.9 -00.5 00 00.0 62 13.4 27 46.6 16 10.6 11 36.0 S
AP Lat 11 40.0 S Int 00 04.0 N c) Dep = 7.2 NM W
OP 7.2 W 072 4.0 N
AP 5.6 A
MLat = (11 40 + 11 36) ÷ 2 = 11 38 DLon = Dep ÷ cos MLat = 7.2 ÷ cos 11 38 = 7.4 W AP 121 42.0 W DLon 000 07.4 W OP 121 49.4 W OP
11 36.0 S
121 49.4 W
4
th
3 On the 20 September, whil st in p osi tion 17 15 N 164 30 E, the vessel receives th e followi ng typ hoon advis ory f rom the Japanese Weather Centre: 2020000UT Typhoon Charlie Posi tion Track Speed of advance Winds
15 00 N 167 30 E 295 (T) 12 kno ts 55 kno ts out to 120 miles 95 knots within 70 miles
a) Draw a plan view of a northern hemisphere TRS showing all the salient features and indicating the likely paths. (9) b) i) Determine t he range and bearing o f t he sto rm c entre at 20 0000 UT. (6) ii ) Determine, with t he aid of a sketch, whether th e vessel li es North or South o f the for ecast track. (5) c) Describe th e changes that would be observed durin g the next 12 hours with respect to EACH of th e following: i) wind di rection and strength; (6) ii) swell height and direction; (5) ii i) barometric p ressure. (5) d) State the possi ble actio ns th at are available to the Master to ensu re the vessel cl ears th e area as fast as possib le and avoids the worst effects of th e storm. (10) a)
Vertex
Trough Line
Advance
Dangerous Quadrant
Right
Path Left
Rear
Vortex
Probable Paths. Danger Sector. Navigable Semicircle
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Track
b) i) Vessel TRS d
17 15 N 15 00 N 02 15 S 135
164 30 E 167 30 E 003 00 E 180
MLat = (Lat A + Lat B) ÷ 2 = (17 15 + 15 00) ÷ 2 = 16 07.5 Dep = DLon x cos MLat = 180 x cos 16 07.5 = 172.918451 NM
Dis = √(1352 + 172.9184512) Dis 219.4 NM -1
-1
Co = tan (Dep ÷ DLat) = tan (172.918451 ÷ 135) = 52 01 13.13 = S 52 E TB 128 ii) Vessel
128
295
Vessel is North of forecast path. She will be in the Dangerous Quadrant as the storm approaches. TRS c)
Vessel
20 00:00
Relative track 144 NM
120 NM 55 kn
20 12:00 128 x 219 NM 70 NM 95 kn
295
Swell
TRS
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20 00:00 Vessel is outside the storm field. i) Wind Direction. 20 00:00 NE x 20 kn Backing to North at the edge of the storm field, then veering steadily and increasing. 20 12:00 NE x 80 kn. ii) Swell height and direction. 20 00:00 13 metres from SExE Height increasing and direction veering. 20 12:00 15 metres from SExS iii) Pressure. 20 00:00 Diurnal variation apparent. Pressure normal for area and season. Diurnal Variation disappearing then pressure decreasing, with increasing Tendency. 20 12:00 approximately 15 hPa below Normal for area and season. d) Actions. 1. Steer with wind on Starboard Bow to move away from Path and TRS and eventually reach rear of Trough Line. Speed will be less than Service Speed, and less than option 2 due to head weather. 2. Steer with wind on Starboard Quarter to cross path into Navigable Semicircle and then move away from Path and TRS and eventually reach rear of Trough Line. Speed will be less than Service Speed due to weather. In both cases: Proceed at maximum practicable speed. Alter Course to maintain relative wind direction. Report in accordance with SOLAS. Monitor changes in meteorological elements, and be prepared to alter action if circumstances change due to altered TRS movement. 4 Whilst taking evasive action to avoid the storm one of the engine room ratings falls and breaks a leg. The Master decides to th at the rating needs immedi ate attentio n and makes contact with a US warship at 0830 hrs st UT on th e 21 September. The vessel’ s cu rrent po sit ion is 21 30.0N 167 24.0E. The warship is in posi tion 24 54.0N 172 36.0E. It is agreed to rendezvous at sunrise the following day with own vessel maintaining a course of 345(T) and at a maximum sp eed of 18 knots. Calculate EACH of the following: a) the UT of sunrise; (15) b) the rendezvous po sit ion, (15) c) the cou rse and speed required by the warship to make the rendezvous. (10) a) Start 21 08:30 UT ZN 11 167 24 E ÷ 15 to nearest hour 21 19:30 ZT RV 22 06:00 ZT approximately SR 22 06:00 UT@G approximately SR 30 N 20 N 21 30 N 21 30 N LIT SR ZN SR
20 05:47 23 05:49 20 05:48 23 05:49 20 05:48 23 05:49 22 05:49 UT at G By Inspection 11:10 167 24 E ÷ 15 21 18:39 UT at RV 11 22 05:39 ZT at RV 7
SR 21 18:39 UT at RV Start 21 08:30 UT PT 10:09 x 18.0 kn Dis 182.7 NM DLat Dis x cos Co = 182.7 x cos 345 = 176.5 ÷ 60 = 02 56.5 N MLat = Lat ± DLat ÷ 2 = 21 30 + 02 56.5 ÷ 2 =22 58 14.24 N Dep = Dis x sin Co = 182.7 x sin 345 = 47.3 W DLon = Dep ÷ cos MLat = 47.3 ÷ cos 22 58 14.24 = 51 21 31.41 W = 000 51.4 W Lat DR = Lat S ± DLat = 21 30 + 02 56.5 = 24 26.5 N Lon DR = Lon S ± DLon = 167 24 E – 000 51.4 W = 166 32.6 E SR 30 N 20 N 24 26.5 N 24 26.5 N LIT SR
20 05:47 23 05:49 20 05:48 23 05:49 20 05:48 23 05:49 22 05:49 UT at G By Inspection 11:06 166 32.6 E ÷ 15 21 18:43 UT at RV
b) SR 21 18:43 UT at RV Start 21 08:30 UT PT 10:13 x 18.0 kn Dis 183.9 NM DLat Dis x cos Co = 183.9 x cos 345 = 177.6 ÷ 60 = 02 57.6 N MLat = Lat ± DLat ÷ 2 = 21 30 + 02 57. 6 ÷ 2 =22 58 49.01 N Dep = Dis x sin Co = 183.9 x sin 345 = 47.6 W DLon = Dep ÷ cos MLat = 47.6 ÷ cos 22 58 49.01 = 51 41 59.11 W = 000 51.7 W Lat RV = Lat S ± DLat = 21 30 + 02 57.6 = 24 27.6 N Lon RV = Lon S ± DLon = 167 24 E – 000 51.7 W = 166 32.3 E c) W RV d
24 54.0 N 24 27.6 N 00 26.4 S 26.4 S
172 36.0 E 166 32.3 E 006 03.7 W 363.7 W
MLat = (Lat W + Lat RV) ÷ 2 = (24 54.0 + 24 27.6) ÷ 2 = 24 40.8 N Dep = DLon x cos MLat = 363.7 x cos 24 40.8 = 330.5 -1 -1 Co = tan (Dep ÷ DLat) = tan (330.5 ÷ 26.4) = S 85½ W + 180 Co = 265½
Dis = √(DLat2 + Dep2) = √(26.42 + 330.52) = 331.5 NM Sp = Dis ÷ Tim = 331.5 ÷ 10:13 Sp = 32.4 kn. 5 a) Several public ations cont ain guidance to Masters o n determining t he compositi on of the Bridge team under varying operational condition s. Outline TEN factors that should be considered by the Master when determining appropriate manning levels necessary o n th e bridg e. (20) b) Describe FIVE items of information t hat the Pilot sho uld t ell the Master, when proceeding up river to the bert h. (10) a) Visibility, state of weather and sea. Traffic density and other activities occurring in the area in which the vessel is navigating. The attention necessary when navigating in or near traffic separation schemes or other routeing measures. The additional workload caused by the nature of the ship’s functions, immediate operating requirements and anticipated manoeuvres. The fitness for duty of any crew members on call who are assigned as members of the watch. Knowledge of, and confidence in, the professional competence of the ship’s officers and crew. 8
The experience of each officer of the navigational watch, and the familiarity of that officer with the ship’s equipment, procedures, and manoeuvring capability. Activities taking place on board the ship at any particular time, including radio communication activities, and the availability of assistance to be summoned immediately to the bridge when necessary. The operational status of bridge instrumentation and controls, including alarm systems. Rudder and propeller control and ship manoeuvring characteristics. The size of the ship and the field of vision available from the conning position. The configuration of the bridge, to the extent that such configuration might inhibit a member of the watch from detecting by sight or hearing any external development. b) Pilot boarding instructions. Time of boarding. Position of boarding. Side of embarkation. Approach course and speed. Boarding arrangement required. Berth and tug details. Intended berth. Berthing prospects. Side alongside. Transit time to berth. Tug rendezvous position. Number of tugs. Tug arrangement. Bollard pull of tugs. Local weather and sea conditions. Tidal heights and times. Currents. Forecast weather. Passage Plan. Detail to include abort points and contingency plans. Regulations. VTS reporting. Anchor and lookout attendance. Maximum allowable draught.
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March-2011 An 10000 GT general cargo vessel is to make a loaded passage between Charleston (South Carolina, USA) to Odessa (Ukraine) calling at Nouakchott (Mauretania) and Istanbul (Turkey) en route The vessel's owners have indicated they require a service speed of 19.0 knots. 1. The vessel's owners have requested that it follows the shortest possible route between Charleston and Nouakchott, using the following positions for the ocean passage. Departure position Landfall position
32°48'.0N 79°51'.0W I8°03'.0N l6°18'.0W
(a) Calculate the total distance on passage. (10) (b) Determine the latitude and longitude of the vessel at the northernmost point along the track. (20) (c) Determine the distance off the island of Bermuda (32°21'N 64°48'W) when the vessel crosses longitude 64°48'W, stating whether the vessel passes North or South of the island. (10) PA = 90 00 – 32 48 = 57 12 PB = 90 00 – 18 03 = 71 57 P = 79 51 – 16 18 = 063 33 E R A = 50 ÷ tan 32 48 = 78 mm R B = 50 ÷ tan 16 48 = 153 mm a) cos AB = cos P x sin PA x sin PB + cos PA + cos PB Dis – cos-1 (cos 063 33 x sin 57 12 x sin 71 57 + cos 57 12 x sin 71 57) = 58 24 39.38 x60 Dis = 3504.7 NM P
A V W
B
10
A = tan Lat A ÷ tan DLon = tan 32 48 ÷ tan 063 33 = 0.320… S B = tan Lat B ÷ sin DLon = tan 18 03 ÷ sin 063 33 = 0.363… N C = A ± B = 0.320… - 0.363… = 0.043… N ICo = tan-1 (1 ÷ C ÷ cos Lat A) = 87 54 43.26
P
A
sin mid = cos opp x cos opp sin PV = cos (90 – A) x cos (90 – PA) PV = sin-1 (cos (90 – 87 54 43.26) x cos (90 – 57 12)) PV = 57 08 27.67 ~ 90 Lat V = 32 51.5 N
V
V PV
AV 90-A
90-P
sin mid = tan adj x tan adj sin (90 – PA) = tan (90 – P) x tan (90 – A) P = 90 – tan-1 (sin (90 – PA) ÷ tan (90 – A)) P = 90 – tan-1 (sin (90 – 57 12) ÷ tan (90 – 87 54 43.26)) P = 003 51 01.24 E
90-PA
Lon V = Lon A ± DLon AV = 079 51 W – 003 51 01.24 E = 075 59 58.76 W Lon V = 076 00.0 W c) P = Lon V ± Lon W = 075 59 58.76 W – 064 48 W = 011 11 58.76 E PW = 90 – 32 21 = 57 39 sin mid = tan adj x tan adj sin (90 – P) = tan PV x tan (90 – PW) PW = 90 – tan-1 (sin (90 – 011 11 58.76) ÷ tan 57 08 27.67) PW = 57 38 27.99 Lat W = 32 21 32.01
P
V
W
V WV
90-P
90-W
DLat = Lat W – Lat Be = 32 21 32.01 – 32 21 = 00 00 32.01
PV
90-PW
Vessel is 0.5 NM North of Bermuda.
2 Prior to departure the Master decides to increase the passing distance to 30 miles due south of Bermuda due to the fact that the island is surrounded by low lying islands, banks and reefs on which there are numerous wrecks and obstructions. At the vessel’s intended service speed it will be due to pass Bermuda approx 2 hours after sunrise on the 13th September. The OOW obtains the following observations during morning twilight on the 13th under clear skies, good visibility and calm seas. The vessel was steaming at 19 knots on a course of 0950(T). Time
Object
Azimuth
True Alt
Calc Alt
0545 hrs
Arcturus
037°(T)
41°15'.7
41°10'.9
0550 hrs
Rigel
1300(T)
43°13'.8
43°20'.4
0555 hrs 0603 hrs
Vega Canopus
3I50(T) 2200(T)
36°45'.3 58°19'.5
36°39'.4 58°27'.1
a) Determine the vessel's position at 0600 hrs. using a DR position of 31°45'N 62024'W to work each sight. (25) (b) At 0620 hrs the OOW obtains a radar range and bearing of what is thought to be one of the low lying islands south of Bermuda at a range of 26 miles. The vessel's GPS receiver puts the vessel 0.5 miles to the south of the vessel's charted track, the radar observation puts the vessel 4 miles to the south of the track and the celestial observation above puts the vessel approximately 10 miles to the north of the vessel's track. Discuss the reliability of EACH of the above observations. (I5) 11
(c) State, with reasons, what action should be taken by the OOW to ensure that the Master's orders, regarding the passing distance off Bermuda, are complied with. (5) Object Arcturus Rigel Vega Canopus
19.0 19.0 19.0 19.0
Transfer x 00:15 = 4.7 x 00:10 = 3.2 x 00:05 = 1.6 x 00:03 = 0.9
NM Forward NM Forward NM Forward NM Back
Intercept 41 15.7 – 41 43 13.8 – 43 36 45.3 – 36 58 19.5 – 58
10.9 = 20.4 = 39.4 = 27.1 =
4.8 NM Toward 6.8 NM Away 5.9 NM Toward 7.6 NM Away
Plot. DLat = 7.9 N Dep = 1.5 E MLat = 31 45 + 00 07.9 ÷ 2 = 31 48 57 DLon = Dep ÷ cos MLat = 1.5 ÷ cos 31 48 57 = 1.8 E OP Lat = AP Lat ± DLat = 31 45 N + 00 07.9 N = 31 52.9 N OP Lon = APLon ± DLon = 062 24 W – 000 01.8 E =062 22.2 W b) GPS is normally reliable. It is vulnerable to: Loss of signal due to aerial damage. Solar Flare interference. Malicious jamming. Unintentional jamming. Radar Observations probably unreliable in this case. The target is not clearly identified, low lying and at long range. Celestial observations are reliable. Clear skies, good visibility and calm seas. Good horizon. Bright stars, a good range of bearings and at moderate altitudes. No apparent discrepancy between the four observations. c) The OOW should inform the Master of the discrepancies between the positions. The Celestial Position should be taken as accurate, it is also the worst case from a safety perspective. Course should be set from the Celestial Position to pass 30 NM clear to the south of Bermuda. The GPS should be checked for performance, signal strength and possible switch to DR navigation. Further celestial observations should be taken, Sun, Moon and Venus if available, to confirm the vessel’s position.
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13
3 The UK Maritime and Coastguard Agency publish guidance to mariners in the form of Marine Guidance Notes (MGN's). Outline the current MCA guidance regarding EACH of the following topics: (a) the precautions to be observed when using parallel indexing techniques on a modern marine radar: (15) (b) the dangers of a misaligned heading marker; (3) (c) the procedures for rectifying a misaligned heading marker: (12) (d) the alarms that must be fitted to ECDIS systems to ensure safety of navigation. (l0) a) Targets used should be: Radar conspicuous. Easily identified. Unlikely to be confused with others. Situated so as to provide continuous monitoring of the passage. Unlikely to be obscured by ship shadow sectors. At moderate ranges. Radar should be checked for: Display alignment. Accuracy of EBLs. Accuracy of range measurement and display. b) Misalignment of the heading marker, even if only slightly, can lead to dangerously misleading interpretation of potential collision situations, particularly in restricted visibility when targets are approaching from ahead or fine on own ship’s bow. c) Steer the vessel so that a small target is visually right ahead. Note the discrepancy between the relative bearing of the target and the heading marker. Follow the manufacturer’s procedure for correcting the alignment of the heading marker. This may involve mechanical adjustment or an electronic process. d) ECDIS alarms: Crossing safety contour Deviation from route Positioning system failure Approach to critical point Malfunction of ECDIS Different geodetic datum Area with special conditions. (Default safety contour Information over scale Large scale ENC available Different reference system No ENC available Customised display Route planning across safety contour Route planning across specified area Crossing a danger in route monitoring mode System test failure)
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4 The vessel arrives in Istanbul and anchors to await a pilot, prior to transiting the Bosporus on the northbound passage to Odessa. The Bosporus is covered by a Traffic Separation Scheme for its entire length and in places the passage is extremely narrow (only 8 cables wide from shore to shore). The passage is also very shallow in places with numerous banks, shoals and wrecks. It is also dangerous due to the fact that there are strong currents, sharp bends and frequent close quarters situations during the transit. (a) Describe the preparations to be made on the bridge prior to undertaking such a passage. (20) (b) Discuss THREE factors that the master must take into consideration regarding the manoeuvrability of the vessel during the transit. (9) (c) Outline the precautions that should be taken in the event of an engine or steering gear failure.(6) a) Appraisal Sources of information to be consulted. Charts, Sailing Directions, Light Lists, Current Atlas, Tidal Atlas, Tide Tables, Notices to Mariners, publications detailing traffic separation and other routeing schemes, radio aids to navigation, vessel reporting schemes and VTS requirements. Appropriate meteorological information. Planning Prepare a detailed plan of the passage. This should cover the whole passage, from berth to berth, and include all waters where a pilot will be on board. Depending on circumstances, the main details of the plan should be marked in appropriate and prominent places on the charts to be used during the passage. They should also be programmed and stored electronically on an ECDIS or RCDS where fitted. The main details of the passage plan should also be recorded in a bridge notebook used specially for this purpose to allow reference to details of the plan at the conning position without the need to consult the chart. Supporting information relative to the passage, such as times of high and low water, or of sunrise or sunset, should also be recorded in this notebook. Bridge Team Briefing. Brief Bridge Team about details of the plan and their roles. Bridge Equipment Testing. All Bridge equipment to be tested and accuracy ascertained. Gyro and Magnetic Compasses. Repeater alignment. Radar, Heading Marker, EBLs and Range measurement. Electronic Position Fixing systems display, degree of detail displayed, alarms set appropriately. Log Speed and Distance indication. Echo Sounder indication and recording. Clocks synchronised. Recording equipment and Bridge Movement Book. Engine controls and indicators. Communications, internal and external. Navigations and signal lights. Sound signalling apparatus. Steering gear in all modes and indicators. Prepare master / Pilot Information Exchange. b) Vessel. Speed, turning circle, draught, beam, trim. Channel. Depth and width. Underkeel clearance, effects of squat, bank effect on course keeping. Effects of tidal stream and / or currents altering speed over the ground. 15
Traffic. Interaction with passing and overtaking / overtaken vessels. c) Inform Master. Engine failure Steer toward safest water. Prepare to anchor if practicable. Steering gear failure Engage emergency steering. Bring engines to manoeuvring condition. Reduce speed. Both Exhibit NUC lights and shapes. Sound appropriate signals. Broadcast Urgency messages if appropriate.
5 The vessel is approaching the pilot boarding station, off Odessa, in restricted visibility at a speed of 12 knots. The vessel is steering 355°(T) and the engine is on manoeuvring. Between 0555 hrs and 0615 hrs the OOW obtains a radar plot, of three targets, as shown on Worksheet Q5. (a) Prepare a full report on EACH target. (15) (b) Outline the vessel's most appropriate course of action to resolve the situation for EACH target.(9) (c) Determine the alteration of course and/or speed, at 0620 hrs. which would result in target B passing at a distance of 1.4 miles. (6) Not e: assume a l t e r a t i o n s o f c o ur s e and speed h a v e i n st a n t a n e ou s e f f e c t (d) Determine the range and bearing of targets A and C when target B is abeam, having taken the
action determined in Q5( c). (10) a) Target Bearing Tendency Range Tendency CPA Bearing CPA Range Time to CPA Time of CPA True Course Speed Aspect
A B C 070 141 304 Drawing Forward Drawing Forward Drawing Aft 6.0 3.8 6.4 Decreasing Decreasing Decreasing 351 062 217 1.0 0.8 0.2 00:46 00:30 00:34 07:01 06:45 06:49 322 346 057 13.5 19.5 9.6 R 072 R 025 G 067
WO = Speed x Time = 12.0 x 00:20 = 4.0 NM Time to CPA = AC ÷ OA x Plot Interval A = 5.8÷ 2.5 x 00:20 = 00:46 B = 3.8 ÷ 2.5 x 00:20 = 00:30 C = 6.4 ÷ 3.8 x 00:20 = 00:34 Speed = WA ÷ Plot Interval A = 4.6÷ 00:20 = 13.8 kn B = 6.5 ÷ 00:20 = 19.5 kn C = 3.2 ÷ 00:20 = 9.6 kn
16
b) Treating each target in isolation. A Alter Course to Starboard to increase CPA. B Stop and allow to pass. C Alter Course to Starboard to increase CPA. c) AP = OA x Time Interval ÷ Plot Interval B = 2.5 x 00:05 ÷ 00:20 = 0.6 NM Stop and allow B to pass. d) Time to Abeam = PQ ÷ WA x Plot Interval T = 2.6 ÷ 6.5 x 00:20 = 00:08 AP = OA x Time Interval ÷ Plot Interval A = 2.5 x 00:05 ÷ 00:20 = 0.6 NM C = 3.9 x 00:05 ÷ 00:20 = 1.0 NM PQ = WA x Time to Abeam ÷ Plot Interval A = 4.6 x 00:08 ÷ 00:20 = 1.8 NM C = 3.2 x 00:08 ÷ 00:20 = 1.3 NM A 051 x 5.0 NM C 318 x 5.0 NM
17
18
November-2010 A 58,000 GT bulk carrier is engaged on a long term charter to carry phosphates between, Yap and Prince Rupert (British Columbia, Canada).The vessel is equipped with all aids to navigation as per statutory requirements and is to make a loaded passage northbound in September. The service speed is 15.5 knots. 1 The vessel departs Yap and follows the recommended route from Ocean Passages of the World to the Dixon Entrance as per Datasheets Q 1 ( 1 ) and Q 1 (2). Using the following positions as departure and landfall positions: Departure Position 9°28'.0N 138° 09'.0E Landfall Position 54°30'.0N 132° 30'.0W (a) Calculate EACH of the following: (i ) the total distance on passage: (10) (ii) the final course at the Dixon Entrance: (12) (iii) the position of the vertex. (15) (b) If the vessel leaves the departure position at 0400 ST on the I2th September, determine the ETA at the Dixon Entrance assuming the vessel will be on Standard Time for Prince Rupert at that time. (8) DP 09 28.0 N 138 09.0 E LP 54 30.0 N 132 30.0 W DLon 270 39.0 W DLon 089 21.0 E
30 ÷ tan 09 28.0 = 180 30 ÷ tan 54 30.0 = 21
P FCo LF V
PA = 90 – 09 28 = 80 32 PB = 90 – 54 30 = 35 30
DP
a i) cos AB = cos P x sin PA x sin PB + cos PA x cos PB AB = cos-1 (cos P x sin PA x sin PB + cos PA x cos PB) AB = cos-1 (cos 089 21 x sin 80 32 x sin 35 30 + cos 80 32 x cos 35 30) AB = 81 55 44.7 x 60 = 4915.74504 Dis = 4915.7 NM 19
ii) ICo BA A = tan Lat ÷ tan LHA = tan Lat B ÷ tan DLon = tan 54 30 ÷ tan 089 21 = 0.01590528124 S B = tan Dec ÷ sin LHA = tan Lat A ÷ sin DLon = tan 09 28 ÷ sin 089 21 = 0.1667553297 N C = A ± B = 0.01590528124 S - 0.1667553297 N = -0.1508500484 = 0.1508500484 N tan Az = 1 ÷ C ÷ cos Lat ICo BA = tan-1 (1 ÷ C ÷ cos Lat B) = tan-1 (1 ÷ 0.1508500484 ÷ cos 54 30) = N 84 59 37.4 W FCo = S 85.0 E P
FCo = 095 iii) sin mid = cos opp x cos opp sin PV = cos (90 – B) x cos (90 – PB) PV = sin-1 (cos (90 – B) x cos (90 – PB)) PV = sin-1 (cos (90 – 84 59 37.4) x cos (90 – 35 30)) PV = 35 20 39.27 ~ 90 = 54 39 20.73
V
Lat V = 54 39.3 N
BV
sin mid = tan adj x tan adj sin (90 – PB) = tan (90 – B) x tan (90 – P) P = 90 – tan-1 (sin (90 – PB) ÷ tan (90 – B)) P = 90 – tan-1 (sin (90 – 35 30) ÷ tan (90 – 84 59 37.4)) P = 6 08 29.09 DLon = 006 08.5 W Lon V = Lon B ± DLon = 132 30.0 W + 006 08.5 W
B
V
PV
90 - B
90 - P 90 - PB
Lon V = 138 38.5 W b) Dep TD Dep PT Arr TD Arr
09-12 04:00 ST 10:00 – (Not in Question or Almanac, provided in Examination, ZN 09:00 is acceptable) 09-11 18:00 UT 13 05:09 4915.7 ÷ 15.5 = 317:09 = 13 05:09 09-24 23:09 UT 08:00 – 09-24 15:09 ST
Daylight Saving Time may be kept, it is Summer, question states Standard Time.
2
(a) With reference to Worksheet Q2: (i) identify Ocean Currents A. B, C, D, E and F: (12) (ii) state TWO reasons why the route is ice free throughout the year. (4) (b) Indicate on Worksheet Q2, EACH of the following, for the time of the year stated in Question 1: (i) the normal pressure distribution: (6) (ii) the general wind circulation: (l0) (iii) the maximum limit of sea ice. (3) a) i) A Japan Current B Kamchatka Current C California Current D North Pacific Current E North Equatorial Current F Equatorial Counter Current. 20
ii) The North Pacific Current is relatively warm and prevents ice formation in the area concerned, therefore the Maximum Limit of Sea Ice is North of the Aleutian Islands. The flow of currents is such that no ice bergs are carried into the area concerned. b) i) Low approximately 50 N High centred approximately 35 N 150 W Low ITCZ approximately 10 N ii) Circulation clockwise around High. NE Trades and Westerlies. SE Trades south of Equator. iii) Not on this chart, North of the Bering Strait. Northern Hemisphere, September, Summer.
21
3 Whilst on passage south of the Aleutian Islands the vessel encounters severe weather and a crew member suffers a serious head injury whilst securing equipment on deck. At 0800 hrs UT on the 21st September. whilst in position 52° 48'.0N, 166° 24'.0W the Master makes contact with a US Coastguard cutter in position 55° 18'.0N , 163° 06'.0W and agrees to rendezvous at sunrise the following morning to effect the transfer of the casualty to the cutter. It is agreed that the bulk carrier will maintain a course of 055° (T) and speed of 13.5 knots. Determine EACH of the following: (a) the UT of sunrise; (15) (b) the rendezvous position: (10) (c) the course and speed required by the coastguard cutter to make the rendezvous. (10) a)
Start 21 08:00 UT ZN 11:00 LIT = 166 24 ÷ 15 = 11:06 Start 20 21:00 ZT
SR 21 06:00 ZT at RV, approximately ZN 11:00 SR 21 17:00 UT at RV LIT 11:06 W SR 21 05:54 UT at G. Enter Almanac for SR 21. SR 54 N 20 05:42 23 05:47 52 N 20 05:42 23 05:47 52 48 21 05:44 UTaG LIT 11:06 SR 21 16:50 UT ST SR PT
05:42 + 00:05 ÷ 3 166 24 ÷ 15 West, later.
21 08:00 UT 21 16:50 UT 08:50
Dis = Sp x Tim = 13.5 x 08:50 = 119.25 NM DLat = Dis x cos Co = 119.25 x cos 055 = 68.39… ÷ 60 = 01 08 23.94 N MLat = Lat A ± DLat ÷ 2 = 52 48 N + 01 08 23.94 N ÷ 2 = 53 22 11.97 Dep = Dis x sin Co = 119.25 x sin 055 = 97.68… NM DLon = Dep ÷ cos MLat = 97.68… ÷ cos 53 22 11.97 = 163.721… ÷ 60 = 002 43 43.31 E Start 52 48.0 N 166 24.0 W d 01 08.4 N 002 43.7 E DR 53 56.4 N 163 40.3 W SR 54 N 20 05:42 23 05:47 52 N 20 05:42 23 05:47 52 56 21 05:44 UTaG LIT 10:55 SR
05:42 + 00:05 ÷ 3 163 40.3 ÷ 15 West, later.
21 16:39 UT
b) ST 21 08:00 UT SR 21 16:39 UT PT 08:39
22
Dis = Sp x Tim = 13.5 x 08:39 = 116.775 NM DLat = Dis x cos Co = 116.7… x cos 055 = 66.97… ÷ 60 = 01 07.0 N MLat = Lat A ± DLat ÷ 2 = 52 48 N + 01 07.0 N ÷ 2 = 53 21 29.38 Dep = Dis x sin Co = 116.7… x sin 055 = 95.6… NM DLon = Dep ÷ cos MLat = 95.6…÷ cos 53 21 29.38 = 160.2… ÷ 60 = 002 40.3 E Start 52 48.0 N 166 24.0 W D 01 07.0 N 002 40.3 E RV
53 55.0 N 163 43.7 W
c) CGC RV d
55 18.0 N 163 06.0 W 53 55.0 N 163 43.7 W 01 23.0 S 000 37.7 W 83.0 S 37.7 W
MLat = (Lat A ± Lat B) ÷ 2 = (55 18 .0 + 53 55.0) ÷ 2 = 54 36 30 N Dep = DLon x cos MLat = 37.7 x cos 54 36 30= 21.83… NM Co = tan-1 (Dep ÷ DLat) = tan-1 (21.83… ÷ 83.0) = 14 44 18.99 = S 14½ W Co = 194½ Dis = √(DLat2 + Dep2) = √(83.02 + 21.83…2) = 85.82… NM Sp = Dis ÷ Tim = 85.82… ÷ 08:39 = 9.9 kn
4 (a) State the specific responsibilities of EACH of the following when operating together as a bridge team: (i) the Master: (8) (ii) the Pilot: (6) (iii ) the Officer of the Watch. (6) (b) State the additional responsibilities of the OOW when the master is not present on the bridge when a pilot is on board. (5) (c) With reference to Master/Pilot exchange, outline FIVE items of information that: (i ) the Master should give to the Pilot immediately on reaching the bridge; (10) (ii) the Pilot should give to the Master immediately on reaching the bridge. (10) a) i) Master. In Command, makes executive decisions about the conduct of the passage. Monitors performance of the Pilot, assessing the validity of the Pilot’s advice. Monitors performance of the OOW, assessing the validity of information provided. Monitors performance of Ratings. May delegate conduct of the passage to the Pilot, but retains overall responsibility. ii) Pilot. Informs the Master of details of the port. Informs the Master of the proposed conduct of the passage. Advises the Master as to the conduct of the passage. iii) OOW. Monitors the vessel’s position, course and speed; and relates to the Passage Plan. Informs the Master of progress related to the Passage Plan. Informs the Master of any deviation from the Passage Plan. Monitors the performance of Ratings. b) OOW becomes the Master’s representative and assumes the responsibilities stated above. Informs the Master of progress as required. Informs the Master if there is any concern as to the conduct of the passage.
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c) i) Ship’s head, speed, engine setting. Pilot Card, vessel’s dimensions, bulbous bow, thrusters, draught, displacement, air draft, manoeuvring characteristics, anchor details, type and cable length. Defects of Bridge equipment and machinery. Intended Passage Plan to Berth. Pilot’s LSA. ii) Identity. Passage Plan to berth; speed variations, areas of shallow water or other features requiring particular care, tide and / or current conditions, weather conditions, use of tugs and mooring boats, berth and side alongside, mooring pattern. New hazards to navigation; shoals, wrecks, special operations. Traffic expected, particularly dredgers, restricted craft, deep draught vessels. New local regulations affecting the passage, reporting requirements.
5 The vessel completes cargo operations with a draft of 15.4 metres and en route to the open sea is required to cross a shoal patch with a charted depth of 12.0 meters, in the approaches to Cleveland Passage (ATT 8656). The Master requires that a minimum UKC of 1.2 metres is maintained at all times. The vessel is due to transit the passage on the PM ebb tide on the 2nd August. (a) Using Worksheet Q5, determine the latest time that the vessel can cross the shoal. (25) (b) State, giving reasons, how much reliance the Master should place on the tidal data obtained in Q5(a).(5) (c) Determine the next tide the vessel can safely transit the Cleveland Passage, if the vessel is delayed by 48 hours leaving the berth. (10)
Waterline Draft 15.4
HoT 4.6
Keel
CD
UKC 1.2
Charted Depth 12.0 Sea Bed
Draft 15.4 UKC 1.2 + CD 12.0 – HoT 4.6 2P SP ?
Cleveland Passage 8656 Prince Rupert 8850 Time, HoT 4.6, 08-02 PM Ebb
SPP - SC 8850 SPU D 2PU SC 8656 2PP Duration
T HW 02 16:40
LW 02 23:00
-00:40
-00:40
02 16:00
02 22:20 02 16:00 06:20
H HW 6.5 - -0.1 6.6 -1.7 4.9 -0.1 4.8
LW 1.3 - -0.1 1.4 -1.2 0.2 -0.1 0.1
24
6.5 6.6 -1.7 ? BI -1.7
5.2 -1.5
2.5 1.4 -1.3 ? BI -1.2
1.2 -1.2
HW 02 16:00 Interval +00:52 Tim 02 16:52 b) Annotations to Cleveland Passage in Tide Tables. d Differences approximate. x M.L. inferred. The predictions should be treated with caution. It may be preferable to cross at HW. (The Master should also consider the factors which may affect the Predicted Height and Time of Tide, and actual UKC. Atmospheric Pressure. High pressure reduces, Low Pressure increases water level. Wind. onshore or offshore, may affect height and timing of tides. Seiches. Negative surge. Accuracy of surveys.)
25
26
c)Time at SP Depart Delay Depart
02 PM Ebb 02 04 PM Ebb
Predicted Height at SP MHWS MHWN SPU 6.5 5.2 SC -0.1 -0.1 SPP 6.4 5.1 Predicted Height at 2P MHWS MHWN SPU 6.5 5.2 Dif -1.7 -1.5 2PU 4.8 3.7 SC -0.1 -0.1 2PP 4.7 3.6 Require 4.6 at 2P 4.7 6.4
4.6 y
3.6 5.1
y = 6.4 + (4.6 – 4.7) ÷ (3.6 – 4.7) x (5.1 – 6.4) = 6.3 Predicted Height at Standard Port =6.3 No tide up to 08-15. After 08-15 SC for SP unchanged. SC for 2P now 0.0 Predicted Height at 2P MHWS MHWN SPU 6.5 5.2 Dif -1.7 -1.5 2PU 4.8 3.7 SC 0.0 0.0 2PP 4.8 3.7 Require 4.6 at 2P 4.8 6.4
4.6 y
3.6 5.1
y = 6.4 + (4.6 – 4.8) ÷ (3.6 – 4.8) x (5.1 – 6.4) = 6.2 Predicted Height at Standard Port =6.2 Next Tide 08-24 HW 22:55 6.2
27
July-2010 Marks for each part question are shown in brackets All questions refer to the vessel described below. A 70000 GT bulk carrier is to make a loaded passage between Iquique (Chile) to Hobart (Tasmania) via the Cook Strait (New Zealand). The vessel will discharge part of the cargo of sulphate in Wellington (North Island New Zealand). The vessel's owners have indicated they require a service speed of 14.0 knots. On departure Iquique the vessel is overloaded with respect to her Winter displacement by 340 tonnes and is expected to consume 36 tonnes of fuel and 10 tonnes of water per day on passage. 1. The following departure and landfall positions should be used for the passage to Wellington: Departure position Iquique 20° 15'.0S 70° 20'.OW Landfall position Wellington 41° 42'.0 175°18'.OE With reference to Datasheet Q I: (a) (i) determine the distance to steam to bring the vessel to her Winter displacement; (4) (ii) calculate the distance between the departure position and an appropriate vertex on lat 33 degrees South; (5) (b) calculate the shortest legal distance between the departure and landfall positions; (26) (c) if the vessel leaves the departure position on the 5th June at 0300hrs (ST), determine the ET A at the landfall position, assuming that the vessel will arrive keeping Standard Time for Wellington. a) i) 340 MT ÷ (36 MT Fuel + 10 MT Water) x 24:00 x 14 kts = 2483.478261 NM = 2483.5 NM ii)
A B
20 15.0 S 41 42.0 S
d
070 20.0 W 175 18.0 E 245 38.0 E 114 22.0 W V
W
A W? L
V
A
B
P
P
PA = 90 – 20 15 = 69 45 PB = 90 – 41 42 = 48 18 PV = 90 – 33 00 = 57 00 = PW
V
AVV
sin mid = cos opp x cos opp sin (90 – PA) = cos AV x cos PV AV = cos-1 (sin (90 – PA) ÷ cos PV) AV = cos-1 (sin (90 – 69 45) ÷ cos 57 00) AV = 50 32 35.03 x 60 = 3032.583877 NM Dis AV = 3032.6 NM
PV
90 - A
90 - P 90 - PA
28
b) Datasheet Q1 shows a Loadline Zone with Southern Winter Seasonal Zone south of 33 S, Winter from 16 April to 5 October, therefore Winter in June. The vessel may not legally cross 33 S to higher latitude until she is below her Winter displacement. AW = 2483.478261 ÷ 60 = 41 23 28.7 AW ÷ AV = 2483.5 ÷ 3032.6 = 0.8… From the sketch, AW is greater than AW? and less than AV. Triangle PAW is oblique. cos AB = cos P x sin PA x sin PB + cos PA x cos PB cos AW = cos P x sin PA x sin PW + cos PA x cos PW cos AW - cos PA x cos PW = cos P x sin PA x sin PW (cos AW ÷ - cos PA x cos PW) ÷ (sin PA x sin PW) = cos P cos P = (cos AW ÷ - cos PA x cos PW) ÷ (sin PA x sin PW) P = cos-1 ((cos AW – cos PA x cos PW) ÷ sin PA ÷ sin PW) P = cos-1 ((cos 41 23 28.7 – cos 69 45 x cos 57 00) ÷ sin 69 45 ÷ sin 57 00) P = 44 26 55.44 = DLon AW DLon WB = DLon AB – DLon AW = 114 22.0 – 44 26 55.44 = 069 55 04.56 cos AB = cos P x sin PA x sin PB + cos PA x cos PB cos WB = cos P x sin PW x sin PB + cos PW x cos PB WB = cos-1 (cos P x sin PW x sin PB + cos PW x cos PB) WB = cos-1 (cos 069 55 04.56 x sin 57 00 x sin 48 18 + cos 57 00 x cos 48 18) WB = 54 44 15.75 x 60 = 3284.262464 Dis AB = 2483.47… + 3284.26… = 5767.740725 Dis AB = 5767.7 NM 29
c) Daylight Saving Time may be kept at both ports, it is winter, question states ST. Dep TD Dep PT Arr TD Arr
05 03:00 ST 04:00 + 05 07:00 UT 17 03:59 5767.7 NM at 14.0 kn 22 10:59 UT 12:00 + 22 22:59 ST
2 On the evening of the 13th June, whilst in DR position 28°42'.0S 94°36'.0W the Master requests the OOW to obtain a set of star sights to check the vessel's GPS receiver. The vessel clocks are on UT -6hrs and the vessel is steaming on a course of 235°(T) at 14 knots. Weather conditions are clear with some low broken cloud cover to the Northwest of the vessel. (a) Calculate the UT of civil twilight for an evening star sight. (6) (b) The OOW obtains the following results: Time
Star
Azimuth
True Alt
Calc Alt
1745
Canopus
142°(T)
42° 19'.7
42° 23'.6
1750
Arcturus
270° (T)
54° 12'.3
54° 13'.7
1758
Alphard
062° (T)
28° 15'.6
28° 09'.7
1815
Antares
224° (T)
19° 16'.0
19° 21'.7
(i) Plot all FOUR stars for 1800hrs. (12) (ii) State, with reasons, which of these are best suited for determining the vessel's position. (12) (c) Determine the vessel's position at 1800hrs. (5) a) CT 30 S 20 S T1 28 42 S LIT CT
13 17:33 13 17:52 00:17 13 17:35 06:18 13 23:53 UT
b) i) Transfers Can (18:00 – Arc (18:00 – Alp (18:00 – Ant (18:00 –
17:45) x 17:50) x 17:58) x 18:15) x
UT at G UT at G 10 00, 08 42, 00:19 UT at G 094 36 ÷ 15
14.0 = 14.0 = 14.0 = 14.0 =
3.5 2.3 0.5 3.5
Intercepts F F F B
TA - CA -3.9 A -1.4 A +5.9 T -5.7 A
30
31
ii)
CT ZN CT
Tim Mag Can 17:45 -0.9 Arc 17:50 0.2 CT 17:53 Alp 17:58 2.2 Ant 18:15 1.2
23:53 UT 06:00 17:53 ZT TB 142 270
Alt 42 54
062 224
28 19
Canopus, Arcturus, and Alphard are the most suitable for determining the vessel’s position. They have been observed close to Civil Twilight. They are of reasonable brightness. They have a good range of bearings. Their altitudes are reasonable. Antares has been observed late, the horizon may be indistinct; and has a low altitude, more susceptible to abnormal refraction. c) DLat 7.3 N Dep 0.8 E AP Lat DLat OP Lat
28 42.0 S 00 07.3 N 28 34.7 S
MLat = 28 42.0 – 00 7.3 ÷ 2 = 28 38 21 DLon = Dep ÷ cos MLat = 0.8 ÷ cos 28 38 21 = 0.9 E AP Lon DLon OP Lon
094 36.0 W 000 00.9 E 094 35.1 W
3 Vessels approaching the coast of New Zealand often have problems in making a landfall due to heavy cloud cover and poor visibility in winter. (a) List the factors that should be taken into account when planning a landfall after a long ocean passage. (12) (b) Discuss SIX of the most important factors to be taken into account when choosing a safe anchorage. (18) a) Availability of celestial observations during approach. Probable visibility. Ranges of available lights. Probability of other lights which may obscure navigational lights. Availability of radar targets for position fixing. Height and profile of coastal features. Strength and direction of tidal streams. Strength and direction of currents. Strength and direction of prevailing winds. Availability of large scale charts. Water depths in the area. Available methods for ascertaining and monitoring position. Ease of identifying features of shoreline. Probable traffic density. Probable time of day of landfall. Probability of ice in the area. 32
Nature of coastline, ease of identifying landfall. Currency of relevant publications. b) Availability of recommended anchorage from relevant publications. Recommended anchorage will have been carefully surveyed and should be most suitable. Depth of water. Must be adequate for the vessel's draught at all states of the tide, and over the whole area of the swinging circle. Must not be too deep for recovery of the anchor. Extent of area available which is clear of obstructions. Must be sufficient for the swinging circle of radius equal to the full scope of cable and ship's length plus a margin of safety. Nature of sea bed. This will govern holding ability of anchor. Probable weight on the anchor. Governed by the windage and underwater form of the vessel, and the anticipated wind, tidal streams and currents. Shelter by land from prevailing winds. Governs anticipated forces experienced. Availability of marks for position fixing during approach and while at anchor. Readily identifiable marks in appropriate directions will improve precision of approach and of position monitoring. Length of anticipated time at anchor, governs: Number of tidal cycles. Variability of wind, tidal stream and current experienced. Position with regard to traffic movement. Anchored vessel should not obstruct traffic.
4 The vessel is approaching the entrance to Wellington Harbour in heavy seas and poor visibility, estimated to be 2 miles. The OOW commences plotting three radar targets, at 0300hrs and obtains the following radar plot over a 15 minute period as shown on Worksheet Q4. The vessel is steering 315°.(T) at 10 knots and target B is known to be an island, with deep clear water all around. (a) Prepare a full report on targets A and C. (15) (b) Determine the effect of any set and drift the vessel may be experiencing. (6) (c) Determine the alteration of course that should be made at 0320hrs to ensure that ALL targets pass at a distance of at least 1.5 miles. (15) (d) If the vessel alters 50° to starboard at 0325hrs, find EACH of the following: (a) the new CPA of Target B; (6) (b) the time when Target B should be sighted visually. (8) Note: Assume all alterations have an instantaneous effect a) WO = 10 kn x 00:15 = 2.5 NM TtCPA A 3.6 ÷ 1.8 x 00:15 = 00:30 C 3.3 ÷ 2.0 x 00:15 = 00:25 33
Speed A 2.0 ÷ 00:15 = 8.0 kn C 4.2 ÷ 00:15 =16.8 kn
Bearing Tendency Range Tendency CPA Bearing CPA Range Time to CPA Time of CPA Target Course Target Speed Aspect
A 003 Drawing Forward 3.6 Decreasing 278 0.3 NM 00:30 03:45 270 8.0 kn R087
C 179 Drawing Forward 3.2 Decreasing 268 0.1 NM 00:25 03:40 334 16.8 kn G025
b) Target B, AO = 327 x 1.8 NM. 1.8 NM ÷ 00:15 = 7.2 kn. The effect of the Set and Drift is to alter the vessel's Course Made Good to 327 and her Speed Over the Ground to 7.2 kn. (Set Drift Rate c) AP A B C
109 0.8 NM in 00:15 3.2 kn)
1.8 nm x 00:05 ÷ 00:15 = 0.6 1.8 nm x 00:05 ÷ 00:15 = 0.6 2.0 nm x 00:05 ÷ 00:15 = 0.7
Plot Alter A B C
course: Starboard 33 Starboard 33 Starboard 26
Alter 33 degrees to starboard to 348. d) AQ B
1.8 nm x 00:10 ÷ 00:15 = 1.2
a) CPA 294 x 1.5 NM b) Q is 2.0 NM from Own Vessel. Target B should be sighted at 03:25.
34
35
5 Tropical Revolving Storms are common at certain times of the year in the South Pacific Ocean, especially to the North of New Zealand and off the East Coast of Australia. (a) Sketch a plan view of a TRS in the Western South Pacific Ocean, indicating the likely track prior to and after recurving. (12) (b) Outline the actions that should be taken by the Master in EACH of the following scenarios, assuming that the storm has recurved: (i) the vessel is to the north of the storms track but within the storm field; (5) (ii) the vessel is to the south of the storms track but within the storm field; (5) (iii) the vessel is in the path of the storm. (3) (c) Compile a set of Masters standing orders for use when the vessel encounters heavy weather for EACH of the following: (i) the OOW; (7) (ii) general standing orders which are relevant to the safety of the vessel. (8) a) Tropical Revolving Storm Southern Hemisphere
Navigable Semicircle
Track Path
Eye / Vortex
Dangerous Quadrant
Vertex
Trough Line
36
b) After recurving. In all cases the action should be such as will take the vessel away from the Eye and the Path. i) North of Path / Track. Vessel is in Dangerous Quadrant / Semicircle. Steam with wind on the Port Bow, at maximum speed, altering course to maintain relative wind direction. This will take the vessel away from the Eye and Path. ii) South of the Path / Track. Vessel is in the Navigable Semicircle. Steam with the wind on the Port Quarter, at maximum speed, altering course to maintain relative wind direction. This will take the vessel away from the Eye and Path. iii) On the Path. Steam with the wind on the Port Quarter, at maximum speed, altering course to maintain relative wind direction. This will take the vessel off the Path, into the Navigable Semicircle, and then away from the Eye and Path. c) i) Standing Orders. Heavy Weather. OOW. (Alerting personnel and initiating precautionary measures.) Call me at any time that weather deteriorates to the extent of causing concern. Decrease in Atmospheric Pressure. Wind greater than Beaufort Force 6. Waves of sufficient height to cause water to be shipped on deck. Check for fresh forecasts indicating probable severity of conditions. Inform Heads of Department of anticipated conditions. Stop work being carried out in exposed areas on deck. Organise closure of watertight and weather doors. Start second steering motor. Engage hand steering. Post lookout. Record meteorological data hourly, monitor trends. Monitor vessel motion and decrease speed and / or alter course if required, then call Master. Be alert for synchronous rolling and alter course if experienced. ii) Standing Orders. Heavy Weather. General. (Safety of personnel, watertight integrity of the hull, security of items on deck and inside the hull, stability.) Access to the deck and exterior accommodation decks to be appropriately controlled by Permit to Work system. All personnel to be informed of anticipated severity of conditions. All external watertight and weather doors to be closed. Air pipes to underdeck spaces, fuel and water tanks to be covered, or self sealing arrangements proved functional. Lifelines to be rigged along essential routes on deck. Anchor lashings to be checked for security and additional lashings considered. Securing arrangements of cranes, derricks, gangways, accommodation ladders, and similar equipment to be checked; additional lashings to be considered. Deck to be checked for loose items; these to be adequately secured or moved to protected locations. FFA and LSA in exposed locations to be adequately secured or moved to protected locations. Equipment in public spaces to be secured or moved to secure locations. Personal items in cabins to be secured. 37
Improve stability as practicable: fill or empty tanks empty swimming pool/s check that scuppers and freeing ports are clear.
38
March-2010 All questions refer to a 6800 GT refrigerated cargo vessel chartered to carry fruit between ports in the southern and western Caribbean Sea and the East coast of the USA. The vessel has been laid up in the port of Falmouth (UK) and is to proceed to New York to load agricultural equipment for discharge in Caracas (Venezuela). The vessel's service speed is 22 knots and summer draft is 6.8 metres. 1. Vessels are required to ensure that navigational charts and publications are corrected up to date prior to commencing a passage. This is usually done by using weekly Admiralty Notices to Mariners and chart tracings. Vessels are also required to ensure that all relevant radio navigational warnings are taken into account when received. (a) Describe the context and content of EACH of the following: (i) Admiralty Weekly Notices to Mariners; (8) (ii) Navarea warnings; (12) (iii) Coastal warnings. (8) (b) Vessels are required to carry charts and publications sufficient to allow planning of the ships intended voyage. State the publications required, for the vessel in question. (12) a) i) Admiralty Weekly Notices to Mariners Context. Issued by UK Hydrographic Office weekly as paper documents and internet downloads. Admiralty NMs contain all the corrections, alterations and amendments for the UKHO's worldwide series of Admiralty Charts and Publications. Content. Publications List Index of publications affected. ADMIRALTY CHARTS AND PUBLICATIONS NOW PUBLISHED AND AVAILABLE NEW EDITIONS OF ADMIRALTY CHARTS AND PUBLICATIONS ADMIRALTY CHARTS AND PUBLICATIONS TO BE PUBLISHED ADMIRALTY CHARTS AND PUBLICATIONS PERMANENTLY WITHDRAWN I Explanatory Notes. Publications List II Admiralty Notices to Mariners. Updates to Standard Nautical Charts III Reprints of Radio Navigational Warnings IV Amendments to Admiralty Sailing Directions V Amendments to Admiralty Lists of Lights and Fog Signals VI Amendments to Admiralty List of Radio Signals ii) NAVAREA Warnings Context. Issued by the World-Wide Navigation Warning Service for 16 NAVAREAS identified by roman numerals, containing information concerning principal shipping routes which are necessary for mariners to know before entering coastal waters. The coordinating authority of each area collates warnings for that geographical area. The coordinating authority broadcasts warnings through SafetyNet and NAVTEX, and printed in Admiralty Notices to Mariners. Broadcast details are found in ALRS V3.
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Content. a. Failure and changes of major navigation aids. b. Failures of and changes to long-range electronic position fixing systems (GPS/Loran C) c. Newly discovered wrecks or natural hazards. d. Areas where SAR or anti pollution operations are taking place (for avoidance of such areas.) e. Seismic surveys and other underwater activities in certain areas. f. Positions of mobile drilling rigs (RIGLISTS) and other oil/gas related activities. iii) Coastal Warnings. Context. Issued for particular coastal regions and containing information to assist the mariner in coastal navigation up to the entrances of ports. Broadcast on NAVTEX and VHF by HM Coastguard MRCC. Usually identified by prefix WZ and numbered. Content. a. Casualties to major light/fog signals, major floating lights and more important buoys. b. Drifting mines and derelicts in congested waters when the information is resent and sufficiently accurate. c. Large unwieldy tows in congested waters. d. Dangerous wrecks and new or amended shoal depths. e. Establishment of salvage buoys in congested waters. f. Areas where SAR and anti pollution operations are being carried out (for avo idance of such areas.) g. Negative Surges. h. Irregularities in the transmission of differential corrections to the Global Positioning System (DGPS). i. New positions of mobile drilling rigs (RIGMOVES). j. Cable operations or certain other underwater activities. b) For the area and time of year concerned: International Code of Signals (IMO) The Mariner’s Handbook (UKHO). Merchant Shipping Notices, Marine Guidance Notes and Marine Information Notes (MCA). Notices to Mariners (UKHO). Notices to Mariners Annual Summary (UKHO) Lists of Radio Signals (UKHO). Lists of Lights (UKHO). Sailing Directions (UKHO). Nautical Almanac (HMNAO). Tide Tables (UKHO) Tidal Stream Atlases (UKHO) Operating and Maintenance Instructions for Navigation Aids carried by the Ship. Ocean Passages for the World. Navigational charts, to the largest scale available. Planning charts covering the area concerned. Routeing Charts. Mariner’s Routeing Guides.
2. The vessel is due to depart Falmouth, in ballast, on the 4th February. The owners have asked the Master to compare the distances between Bishop Rock and New York via the following routes: The recommended route as per Datasheet Q2( I) and Q2(2) The direct rhumb line route The following departure and landfall positions should be used. Departure Position 49°47'.0N 6°27'.0W (5 miles South of Bishop Rock) Landfall Position 48°20'.0N 73°50'.0W (Approaches to New York) Correction 40°20.0’ N
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(a) Calculate the difference in distance between the two routes. (20) (b) Explain why the recommended route is preferred to the rhumb line track.
(10)
c) Explain how a Gnomonic chart can be used in conjunction with a Mercator chart when planning a great circle passage. (15) a) GC D BS d
49 47.0 N 006 27.0 W 42 30.0 N 050 00.0 W 2.62.1 Not Cape Race until May 043 33.0 W
AB = cos-1 (cos P x sin PA x sin PB + cos PA x cos PB) P = 043 33 PA = 90 – 49 47 = 40 13 PB = 90 – 42 30 = 47 30 AB = cos-1 (cos 043 33 x sin 40 13 x sin 47 30 + cos 40 13 x cos 47 30) AB = 30 34 51.48 x 60 = 1834.857996 NM RL BS L d
42 30.0 N 2806.42 N 050 00.0 W 2.62.1 Not Cape Race until May 40 20.0 N 2633.71 N 073 50.0 W 02 10.0 S 172.71 S 023 50.0 W 130.0 1430.0 W
Co = tan-1 (DLon ÷ DMP) = tan-1 (1430.0 ÷ 172.71) = 83 06 48.2 Dis = DLat ÷ cos Co = 130.0 ÷ cos 83 06 48.2 = 1804.192828 or Dis = √(DMP2 +DLon2) x DLat ÷ DMP = √(172.712 +14302) x 130.0 ÷ 172.71 = 1804.192828 Dis = 1834.857996 NM + 1804.192828 NM = 2919.050794 NM RL D L d
49 47.0 N 3436.41 40 20.0 N 2633.71 09 27.0 S 802.70 S 567.0 S
006 27.0 W 073 50.0 W 067 23.0 W 4043.0 W
Co =tan-1 (DLon ÷ DMP) = tan-1 (4043.0 ÷ 802.70) = 78 46 13.75 Dis = DLat ÷ cos Co = 567.0 ÷ cos 78 46 13.75 = 2911.580074 NM Dis = √(DLon2 + DMP2) x DLat ÷ DMP = √(4043.02 + 802.702) x 567.0 ÷ 802.70 = 2911.580074 NM
Difference = 2919.050794 - 2911.580074 = 7.470723994 NM Difference = 7.5 NM, Great Circle greater. b) The recommended route is preferred to avoid the hazards of crossing the Grand Banks 2.62.1. These include: Many fishing vessels. Oil and Gas rigs and associated vessels. High incidence of fog. Probability of pack ice at this time of year. Possibility of icebergs at this time of year. High incidence of Polar Frontal Depressions, high winds, waves and swell. Strong and variable currents.
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c) Gnomonic Charts have the property that Great Circle Tracks are straight lines. In practice tracks followed are normally Rhumb Lines, which are straight lines on Mercator Charts. Planning a Great Circle track may be done by: Plotting the Great Circle on a Gnomonic chart. Picking off the Latitudes of Waypoints at regularly space Longitudes, typically 5° apart, from the Gnomonic chart. Plotting the Waypoints on a Mercator Chart. Following the Rhumb Line tracks by Mercator sailing between the Waypoints so plotted. The route is plotted on navigational charts and checked for navigational hazards. Routeing charts may also be used to check for meteorological hazards.
3.
En route the vessel is diverted to Boston USA.
The Master is advised that the vessel will berth in Bangor (ATT Pacific and Atlantic extracts No 2833). On consulting the chart it is found that the vessel will have to pass under a bridge (charted height 22m above MHWS) to reach the berth. The anticipated draught on arrival is 5.3m. The top of the main mast is 28.6m above the keel. The charted depth below the bridge is 6.8m. The Master requires a minimum clearance under the bridge of 2.0m. If the vessel is due to pass under the bridge during the AM ebb tide on the 17th March, determine EACH of the following: (a) the maximum height of tide permissible to safely pass under the bridge; (10) (b) using Worksheet Q3, the earliest time the vessel can pass under the bridge; (20) (c) the underkeel clearance at that time. (5) Obstruction Clearance 2.0 Truck
Keel to Truck 28.6
Height 22.0 MHWS Waterline Draft 5.3
HoT
Keel
MHWS 4.5 CD
UKC
Charted Depth 6.8 Sea Bed
a) Clearance 2.0 + Truck to Keel 28.6 - Draught 5.3 Obstruction to Waterline 25.3 2P Bangor 2833 SP Boston 2809 MHWS Boston Height Difference MHWS Bangor
3.1 1.4 4.5
Charted Height MHWS Obstruction to CD
22.0 4.5 26.5 42
HoT = 26.5 – 25.3 = 1.2 b) Date Mar 17 HW 17-05:01
Boston Predicted Seasonal Change 2809 Boston Unpredicted Differences -00:40 Bangor Unpredicted Seasonal Change 2833 Bangor Predicted 17-04:21
LW 17-11:27
-00:15
17-11:12
HW 2.8 Neg 2.8 1.2 4.0 Neg 4.0
LW 0.3 Neg 0.3 0.1 0.4 Neg 0.4
Interval = 11:12 – 04:21 = 06:51 Interpolation 3.1 2.8 2.7 +1.4 +1.1 y = 1.4 + (2.8 – 3.1) ÷ (2.7 – 3.1) x (1.1 – 1.4) = 1.175 = 1.2 0.4 0.3 0.0 0.2 -0.1 0.2 + (0.3 – 0.4) ÷ (0.0 – 0.4) x (-0.1 – 0.2) = 0.125 = 0.1 Curves Tidal Interval = +04:41 Time = 17-04:21 + 04:41 = 17–09:02 The earliest time the vessel can pass under the bridge is 17–09:02 c) HoT Charted Depth Depth of water Draught UKC
1.2 m 6.8 m 8.0 m 5.3 m 2.7 m
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4 At 1200UT on the 22nd September the vessel is in position 41°N 70°W on passage from Boston to Havana, Cuba. The Master has been monitoring Tropical Storm Mike which has been developing in the Atlantic Ocean some 700 miles to the East of the Leeward Islands. The position of the storm over the previous 24 hours is given below. 211200UT 19.1°N 50.2°W 221200UT 20.2°N 56.5°W The latest advisory from the National Hurricane Centre in Miami is for the storm to maintain its current track of 285°(T) at 16 knots, and expect the storm to reach hurricane strength over the next 24hrs. Gales force winds are expected to extend up to 120 miles from the centre. (a) Describe the preparations that should be made when a vessel is due to encounter heavy weather. (15) (b) The vessel is currently heading for a position due East of Miami on the meridian of 80°W at 20 knots. (i) On Worksheet Q4, plot the positions and future tracks of both the vessel and the storm at 221200UT and for the following 48 hours. (6) (ii) Comment on the advisability of the vessel's planned track given the advisory from NHC Miami. (9) (iii) At 231200UT the Chief Engineer advises the Master that the vessel will have to stop for 12 hours to effect temporary repairs to one of the main engine bearings. He also advises that the vessel will have to proceed at 10 knots for a further 12 hours after repairs have been completed. In light of the Chief Engineers advice, what options are open to the Master at 231200UT. (15) a) Consider deviation to minimise effects of adverse weather. Brief all personnel of anticipated conditions as relevant. Monitor communications for forecasts of weather conditions. Increase frequency of meteorological observations. Inform all departments of anticipated severity of conditions. Anticipate reducing speed. Secure all loose items against anticipated vessel motion. Consider additional securing of vulnerable items, anchors in particular. Check the security and status of all items related to the watertight integrity of the hull. Minimise free surface in tanks. Rig lifelines on deck. Move vulnerable LSA and FFE to safe locations. Advise personnel to secure personal possessions against anticipated vessel motion. Consider issuing motion sickness medication as required. Plan work routines to allow for anticipated conditions, hand steering may be required. Operate Permit to Work system for anticipated conditions. ER change to low suctions. Check navigation and communications aerials for security. Plan catering provision for anticipated conditions. b) i) Plot. ii) 16 kn x 24:00 = 384 NM ÷ 60 = 6.4° 20 kn x 24:00 = 480 NM ÷ 60 = 8.0° At 24 12:00 the vessel is forecast to be 540 NM from the storm. This is outside the storm field of 120 NM. If the present movement persists the storm is likely to reach the Florida Strait approximately 26-06:00. By this time the vessel could be in port in Havana, or proceed onward into the Gulf of Mexico or Caribbean where it would have sea room to avoid the storm. The Danger Sector covers the southwestern North Atlantic and the Eastern Caribbean. 45
The storm is more likely to recurve Northwards into the Atlantic, or proceed westward, than move toward the Equator. DS Q5a 4.1 Most hurricanes track N of Cuba, and they rarely occur south of 15 N. The intensity of the storm is likely to diminish if it proceeds over land into the Caribbean. The vessel’s planned track is unlikely to bring it into the storm field, and has the option of proceeding into the area where the storm is least likely to move. iii) 10 kn x 12:00 = 120 NM ÷ 60 = 2.0° On the basis of the forecast movement of the storm and the vessel’s situation, the vessel is forecast to be in the Florida Strait at 25-12:00, close to the Path of the storm and just outside the storm field. With the possibility that the storm could move faster, and the vessel be slowed by the Gulf Stream and Florida Current, or experience further engine breakdown, the vessel could be within the storm field with very limited sea room. The storm is more likely to recurve Northwards into the Atlantic, or proceed westward, than move toward the Equator. The storm is likely to reduce in intensity if it moves northwards over cooler water. Options: Proceed on a NNE’ly course to maximise the CPA of the storm, and monitor its movement. Stop in the present position with sea room to manoeuvre and monitor the storm’s movement. Proceed at reduced speed, maintaining adequate sea room, and monitor the storm’s movement. proceed at maximum speed, hoping to cross ahead of the storm, outside the storm field, into its future navigable Semicircle. In all cases be prepared to take appropriate action if circumstances change, such as changes in the storm’s movement, recurrence of the engine problem or other factors.
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5. Vessels trading between the East coast of the USA and ports in the Caribbean encounter numerous navigational hazards when approaching and navigating through the Caribbean sea. (a) With reference to Datasheet Q5(a), outline the main navigational hazards to be considered when passage planning in these waters. (20) (b) Vessels transiting the waters are encouraged to take part in the AMVER programme. Describe the various types of AMVER reports to be made. (15) a) Strong N winds over coastal waters in the Gulf of Mexico. Most hurricanes track north of Cuba. From May to December periods of heavy rain and thunderstorms are frequent. High swells in the Caribbean, particularly in June and July. Currents, west bound in the Caribbean, strongly northward through the Yucatan Channel, around the Gulf of Mexico, East to the Florida Strait and strongly northwards through and out of the Florida Strait. In the Caribbean and Gulf of Mexico some charts are based on old and imperfect surveys, requiring great care near cays and banks. Depths over shoals may be reduced by coral growth since the last survey. Many banks are steep to, giving little warning of shoal water. Strong currents are to be expected in the entrance channels to the Caribbean and Gulf of Mexico, particularly the Florida Strait. Caicos Passage is not lighted. Turks Island Passage is not lighted at its southern end. Mona passage is subject to heavy squalls. Sombrero passage is not lighted in its southern approach. Currents near Morant Cays are very variable. New Bank and Alice Shoal are charted mainly from a survey in 1835. Campeche Bank has not been recently surveyed. b) Sailing Plan (SP) This report contains the complete routing information and should be sent within a few hours before departure, upon departure, or within a few hours after departure. It must contain enough information to predict the vessel's actual position within 25 nautical miles at any time during the voyage, assuming the Sailing Plan is followed exactly. Position Report (PR) This report should be sent within 24 hours of departing port and at least once every 48 hours thereafter. The destination should be included (at least in the first few reports) in case Amver has not received the Sailing Plan information. Deviation Report (DR) This report should be sent as soon as any voyage information changes which could affect Amver's ability to accurately predict the vessel's position. Final Arrival Report (FR) This report should be sent upon arrival at the port of destination. This report properly terminates the voyage in Amver's computer, ensures the vessel will not appear on an Amver SURPIC until its next voyage, and allows the number of days on plot to be correctly updated
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Novembr-2009 All questions refer to an 88,000 GT bulk carier which has been chartered to carry coal between South Africa and Australia. The vessel is presently in Durban (S Africa) and due to complete cargo operations and sail for Adelaide (South Australia) on 18 th January. Service speed is 15.8 knots. 1. With reference to Datasheets Q1(1) and Q1(2): a) outline the main factors that the Master should take into account when appraising passages between South Africa and Australia; (10) b) the master decides to follow the recommended route ; calculate the total distance on passage between the following departure and landfall positions. Departure Position 29 51.0 S 31 06.0 E Landfall Position 34 48.0 S 138 23.0 E (22) c) if the vessel departs at 0400hrs (ST) on the 18 th January, calculate the ETA at the landfall position assuming Standard Time for the destination is being kept on arrival. (8) a) Datasheet 6.153 Strong and uncertain currents south of 30 S, particularly near Antarctica. GC Vertex 45 S, in the storm ridden waters of the Roaring Forties. GCs to places further east are further south and may encounter icebergs and possibly pack ice. Hurricanes off the NW coast of Australia. General Polar Frontal Depressions in southern latitudes, high winds, high wind waves, high swell waves, extreme single waves, reduced visibility. Prevailing wind direction is westerly, westbound passages should be planned in lower latitudes. High level of cloud cover in southern depressions, low availability of celestial observations. Abnormal refraction degrading accuracy of celestial observations. Fog likely off SW Australia. Loadline restrictions. Environmental protection restrictions south of 60S. b) D R S L
29 40 40 34
51.0 S 00 S 00 S 48.0 S
031 077 100 138
06.0 E 00 E 00 E 23.0 E
DR cos AB = cos P x sin PA x sin PB + cos PA + cos PB DR = cos-1 (cos P x sin PD x sin PR + cos PD + cos PR) P = 077 00 – 031 06 = 045 54 E PD = 90 – 29 51 = 60 09 PR = 90 – 40 = 50 00 DR = cos-1 (cos 45 54 x sin 60 09 x sin 50 00 + cos 60 09 + cos 50 00) DR = 38 31 38.81 x 60 = 2311.646889 NM RS DLon = 100 00 – 77 00 = 23 00 Dep = Dlon x cos MLat = 23 00 x 60 x cos 40 00 = 1057.141332 NM SL cos AB = cos P x sin PA x sin PB + cos PA + cos PB SL = cos-1 (cos P x sin PS x sin PL + cos PS + cos PL) P = 138 23 – 100 00 = 38 23 PS = 90 – 40 00 = 50 00 PL = 90 – 34 48 = 55 12 49
SL = cos-1 (cos 38 23 x sin 50 00 x sin 55 12 + cos 50 00 + cos 55 12) SL = 30 41 27.27 x 60 = 1841.454577 NM DL = 2311.646889 + 1057.141332 + 1841.454577 = 5210.242798 NM Dis = 5210.2 NM c) ST TD UT PT UT TD ST DST DST ETA DST ETA
18/04:00 02:00 18/02:00 13/17:46 5210.2 ÷ 15.8 31/19:46 09:30 32/05:16 Feb 01/05:16 01:00 32/06:16 Feb 01/06:16 Feb 01/05:16 Standard Time. Summer Time may be kept, it is summer, if DST is being kept; 01:00 Feb 01/06:16 Daylight Saving Time.
2. At 0630hrs the master receives a request from the South African Maritime Rescue Coordination Centre (MRCC) to assist in a search for an overdue fishing vessel. Currently there are four vessels on scene engaged in a parallel track search pattern, some 60 miles SE of the vessel’s present position. a) Describe the preparations that should be made on the bri dge whilst en route to the search area. (15) b) Outline the factors that must be taken into account when selecting a search pattern for SAR operations at sea. (10) c) On arrival in the area visibility is poor and radio communication is made with the On Scene Coordinator (OSC) at 1030hrs own vessel is identified on radar, bearing 306(T) at a distance of 10 miles from the OSC. The OSC is currently steering 100(T) at 8.0 knots with the three vessels assisting on his port beam. The OSC requests that own vessel takes up station 4 miles on his starboard beam. On worksheet Q2, determine the course to steer and the ETA on station if own vessel proceeds at a speed of 15 knots. (15) a) On the Bridge. Maintain communications with MRCC, OSC and other assisting vessels / aircraft. Set GMDSS equipment appropriately for the required communications. Prepare publications required for assessing situation, charts plotting charts and instruments… Obtain weather analysis and forecasts for the area. Prepare visual signalling equipment. Brief all personnel appropriately. Modify work routines to allow for SAR operations considering increased workload and hours of work factors. Organise preparations on deck to render assistance in the anticipated situation, with due allowance for contingencies. Preparation of searchlights, LSA, lifeboats and rescue craft, means of recovery of personnel from the water, boat ropes, messengers, ladders, scrambling nets, heaving lines. Organise preparation of medical facilities for reception of casualties.
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b) Available number and types of assisting craft. Single vessel, expanding square or sector search Size of area to be searched. Type of distressed craft. Size of distressed craft. Probability of personnel in the water. Meteorological visibility. Cloud ceiling if aircraft involved. Type of sea conditions. Time of day. Arrival time at datum. Accuracy of Datum. c)
Own
OSC
From Distance Plot Relative Vector 143 Relative Distance 12.3 NM From Speed Plot Course to Steer 121½ Relative Speed 8.0 kn ETA 12.3 NM ÷ 8.0 kn = 01:32 + 10:30 = 12:02
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3. Vessels engaged on passages across the Southern Indian Ocean may encounter icebergs at any time of year. a) Describe the sources and type of information that are available to the Master regarding icebergs. (10) b) Outline the factors that should be considered by a prudent Master when determining the risks involved in encountering dangerous ice. (20) c) Outline the reporting procedure that is to be followed by the Master on encountering dangerous ice. (8) a) Admiralty List of Radio Signals. Details of transmission of text messages and facsimile charts of areas where icebergs have been detected. The Mariner’s Handbook. General information. Arctic icebergs. Origins and movement. Characteristics of icebergs. Ice island. Antarctic icebergs. Origin and form. Tabular icebergs. Glacier icebergs. Weathered Icebergs. Capsized icebergs. Pictures of various ice forms and icebergs. Ocean Passages for the World. Ice limits and drift. Ice in specific localities. Ice information services. Admiralty Sailing Directions Climatological data of areas where icebergs are likely. Sources of information about current iceberg conditions. Admiralty Routeing Charts. Show ice limits for the area covered. Internet General information and details of areas where icebergs have been detected. b) Types of ice likely to be encountered, icebergs and pack ice. Concentration of ice, whether leads will be available through pack ice. Sizes and nature of icebergs expected. Potential for altering the planned route to avoid ice. Availability of information regarding current ice extent and conditions. Probable visibility governing visual detection of ice, presence of fogs banks caused by ice formations. Use of searchlights if available. Use of sound detection equipment, if fitted. Probable sea state, relates to detection of smaller formation in amongst foam patches. Radar status, correctly tuned as adjusted. Echoes from ice may not relate to the size of the formation. Smaller formations may be difficult to distinguish from wind and swell wave echoes. Efficiency of navigational equipment; GPS in high latitudes, availability of celestial observations, effects on Loran positions. Vessel’s power and manoeuvrability. Vessel’s draughts, with regard to rudder and propeller immersion. Personnel availability and experience with conditions expected Briefing personnel, information in publications available. Expected duration of passage through ice conditions with high personnel requirements, fatigue may become an issue. Adjustment of ETA due to reduced speed in conditions expected. 53
Availability of Ice Pilots. Availability of icebreakers. Availability of assistance from other vessels in the event of severe damage to the vessel. c) SOLAS. Report by all available means to vessels in the vicinity and the nearest coast station: Type/s of ice, Position/s of ice, UT date/time of observation/s.
4. Bad weather and poor visibility are common on southern Ocean Passages. After several days with very poor visibility the Officer of the Watch manages to obtain two observations of the SUN’s lower limb on the 26th March. At 1532hrs the following observation was obtained. GPS Position 39 07.0S 95 16.0 E Chronometer read 9h 26m 26s Chronometer error 1m 54s Fast on UT Sextant Altitude 24 44.8 (SUN’s Lower Limb) Index Error 3.4 on the arc Height of eye 21.4m a) Determine EACH of the following: i) the direction of the position line; (15) ii) the intercept. (15) b) A forenoon sight taken at 1020hrs gave an intercept of 3.2 away on a bearing of 025(T) using a DR position of 39 07.0S 93 36.0E. The vessel was steering 090(T) at 14 knots throughout the period. Determine the observed position of the vessel at 1532hrs using the information from both sights. (20) a) ZT ZN UT
26/15:32 06 26/09:32
CT CE UT
09:26:26 00:01:54 F 09:24:32
GHA Inc Lon LHA
313 33.9 006 08.0 095 16.0 414 57.9 360 054 57.9
95 16 E ÷ 15 = 06:21
Dec N 02 13.3 d 1.0 00 00.4 Dec N 02 13.7
Reasonable for afternoon sight.
i) A = tan Lat ÷ tan LHA = tan 39 07 ÷ tan 54 57.9 = 0.5701221052 N B = tan Dec ÷ sin LHA = tan 02 13.7 ÷ sin 54 57.9 = 0.04752235253 N C = A ± B = 0.5701221052 N + 0.04752235253 N = 0.6176444578 N Az = tan-1 (1 ÷ C ÷ cos Lat) = tan-1 (1 ÷ 0.6176444578 ÷ cos 39 07) = 64 23 45.29 Azimuth = N 64.4 W TB = 295.6 Reasonable for afternoon sight, Southern Latitude, Northerly Declination. PL = TB ± 90 = 295.6 ± 90 PL 025½ / 205½
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ii) cos AB = cos P x sin PA x sin PB + cos PA x cos PB cos ZX = cos P x sin PZ x sin PX + cos PZ x cos PX ZX = cos-1 (cos P x sin PZ x sin PX + cos PZ x cos PX) P = 054 57.9 PZ = 90 ± Lat = 90 – 39 07 = 50 53 PX = 90 ± Dec = 90 + 02 13.7 = 92 13.7 ZX = cos-1 (cos 54 57.9 x sin 50 53 x sin 92 13.7 + cos 50 53 x cos 92 13.7) ZX = 65 07 53.34 CZD = 65 07.9 or cos AB = cos P x sin PA x sin PB + cos PA x cos PB cos ZX = cos P x sin PZ x sin PX + cos PZ x cos PX ZX = cos-1 (cos P x sin PZ x sin PX + cos PZ x cos PX) ZX = CZD P = LHA sin PZ = cos Lat sin PX = cos Dec +=± CZD = cos-1 (cos LHA x cos Lat x cos Dec ± sin Lat x sin Dec) Lat and Dec different names, ± = CZD = cos-1 (cos 54 57.9 x cos 39 07 x cos 02 13.7 - sin 39 07 x sin 02 13.7) CZD = 65 07 53.34 CZD = 65 07.9 SA LL 24 44.8 IE 00 03.4 On OA 24 41.4 Dip 00 08.1 AA 24 33.3 TC 00 14.2 + TA 24 47.5 90 TZD 65 12.5 CZD 65 07.9 Int 00 04.6 Away b) OP Time AM Sight Time Passage Time Dis = Spe x Tim
True Tiny Towards
15:32 ZT 10:20 ZT 05:12 = 14 x 05:12 = 72.8 NM
Co 090, TP Lat = DR Lat = 39 07.0 S, Dis = Dep = 72.8 NM DLon = Dep ÷ cos MLat = 72.8 ÷ cos 39 07.0 ÷ 60 = 001 33.8 E TP Lon = DR Lon ± DLon = 093 36.0 + 001 33.8 = 095 09.8 E GPS 39 07.0 095 16.0 TP 39 07.0 095 09.8 d 00 00.0 N 000 06.2 W Dep = DLon x cos MLat = 6.2 x cos 39 07.0 = 4.8 NM W
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Plot From GPS 295½, 4.6 NM A. 4.8 NM W, 025, 3.2 NM A DLat = 6.6 S Dep = 2.0 E MLat = Lat ± DLat ÷ 2 = 39 07.0 + 00 06.6 ÷ 2 = 39 10 18 S DLon = Dep ÷ cos MLat = 2.0 ÷ cos 39 10 18 = 2.6 E OP Lat = GPS Lat ± DLat = 39 07 + 00 06.6 =39 13.6 S OP Lon = GPS Lon ± DLon = 095 16.0 E + 000 02.6 E = 095 18.6 E OP
39 13.6 S
095 18.6 E
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5. a) State the appropriate manning levels on the bridge, outlining the duties of EACH member of the bridge team, for EACH of the following situations, in clear weather: i) navigation in a Traffic Separation Scheme with dense traffic; (15) ii) navigation during darkness on an ocean passage. (5) b) Describe the content of the Masters Night Orders. (12) a) i) Master. In command, receiving information, making decisions regarding conduct of passage. Monitoring Bridge Team performance. OOW. Navigation, position fixing, informing Master, communications, record keeping. Monitoring rest of Bridge Team. OOW. Monitoring traffic visually and by radar, informing Master. Monitoring rest of Bridge Team. Rating. Helmsman. Steering as instructed. Monitoring performance of steering equipment and compasses. Rating. Lookout, monitoring externally, sight and sound, informing Master and OOWs. ii) OOW. Navigation, position fixing, collision avoidance, communications, record keeping, monitoring Rating. Rating. Lookout, monitoring externally, sight and sound, informing OOW, monitoring OOW. b) Night Orders supplement Standing Orders for periods when the Master is absent from the Bridge at night. Circumstance in which to call the Master, including, in general, at any time that the OOW requires assistance. Navigational requirements. Position, course and speed. Alterations anticipated. Hazards expected. Meteorological conditions expected. Action to take if Passage Plan requires amendment. Engine Room status, UMS / EOOW. Changes to engine status anticipated. Calls for specific personnel. Communications required. Operations in progress. Security status. Abnormalities to the normal state of the vessel at night.
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July-2009 All questions refer to a 63.000 GT container ship which is to make a passage from Botany Bay (New South Wales, Australia) to Seattle (Washington State, USA) in early August. The vessel is fitted with all navigational equipment in accordance with statutory requirements. 1. Ocean Passages of the World advises that the vessel should proceed from Botany Bay as for routes from Sydney to Honolulu but when crossing the Equator in longitude 178 50.0 W, take a great circle track to a landfall position off the entrance to Juan de Fuca Strait 48 30.0 N 124 47.0 W. a) Calculate the distance on passage between the position where the vessel crosses the equator and the landfall position. (10) b) Determine the vessel’s initial course, on the great circle track crossing the equator. (10) c) State the position of the vertex nearest to the landfall position. (6) d) Ocean Passages of the World warns mariners that the above track passes close to a dangerous shoal in position 08 16.0 N 173 26.0 W. Determine the distance off the shoal when the vessel crosses longitude 173 26.0 W, stating whether the vessel will pass North or South. (14) P
a)
VN
B ICo
W
A
cos AB = cos P x sin PA x sin PB + cos PA x cos PB AB = cos-1 (cos P x sin PA x sin PB + cos PA x cos PB) P = DLon AB = Lon B ± Lon A = 124 47.0 W – 178 50 W = 054 03.0 E PA = 90 – Lat A = 90 – 00 00 = 90 00 PB = 90 – Lat B = 90 – 48 30.0 = 41 30.0
P
Dis = cos-1 (cos 054 03 x sin 90 00 x sin 41 30 + cos 90 00 x cos 41 30) Dis = 67 06 25.44 x 60 Dis = 4026.4 NM Alternatively. PAB is quadrantal, PA = 90. A
sin mid = cos opp x cos opp sin (90 – AB) = cos P x cos (90 – PB) AB = 90 - sin-1 (cos P x cos (90 – PB))
A
P = DLon AB = Lon B – Lon A = 124 47.0 W – 178 50 W = 054 03.0 E PB = 90 – Lat B = 90 – 48 30.0 = 41 30.0 AB = 90 - sin-1 (cos 054 03.0 x cos (90 – 41 30.0)) = 67 06 25.44 x 60 AB = 4026.42399 NM Dis = 4026.4 NM
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B
PA
P 90 - PB
90 - AB B - 90
b) A = tan Lat A ÷ tan DLon = tan 00 00 ÷ tan 054 03 = 0.000 B = tan Lat B ÷ sin DLon = tan 48 30 ÷ sin 054 03 = 1.396235975 N C = A ± B = 0.000… + 1.396235975 = 1.396235975 ICo = tan-1 (1 ÷ C ÷ cos Lat A) = tan-1 (1 ÷ 1.396235975 ÷ cos 00 00) ICo = 35 36 38.4 = N 35½ E ICo = 035½ Alternatively. PAB is quadrantal, PA = 90. sin mid = tan adj x tan adj sin P = tan A x tan (90 – PB) tan A = sin P ÷ tan (90 –PB) A = tan-1 (sin P ÷ tan (90 – PB)) A = tan-1 (sin 054 03.0 ÷ tan (90 – 41 30.0)) A = 35 36 38.4 ICo = N 35.6 E = 035½ c) Lat V = angle between GC and Equator = 90 – ICo = 90 - 35 36 38.4 = 54 23 21.6 Alternatively PV = ICo Lat V = 90 – PV = 90 - 35 36 38.4 = 54 23 21.6 P
Lat V = 54 23.4 N Lon V = Lon A ± 90 00 = 178 50 W – 90 00 = 088 50 W d) P = DLon VW = Lon W ± Lon V = 173 26 W – 088 50 W = 084 36 W PV = 35 36 38.4 sin mid = tan adj x tan adj sin (90 – P) = tan PV x tan (90 – PW) tan (90 – PW) = sin (90 – P) ÷ tan PV PW = 90 - tan-1 (sin (90 – P) ÷ tan PV) PW = 90 - tan-1 (sin (90 – 084 36) ÷ tan 35 36 38.4) PW = 82 30 51.72 Lat W = 90 = PW = 90 - 82 30 51.72 = 07 29 08.28 Lat W = 07 29.1 N
W
V
V
PV
VW 90 - W
90 - P
90 - PW
DLat = 08 16.0 – 07 29.1 = 00 46 .9 Vessel is 46.9 NM south of shoal.
P
PAW is quadrantal, PA = 90 sin mid = tan adj x tan adj sin P = tan A x tan (90 - PW) tan (90 – PW) = sin P ÷ tan A PW = 90 – tan-1 (sin P ÷ tan A) DLon AW = Lon W – Lon A = 173 26.0 W – 178 50.0 W = 005 24 E P = 005 24.0 E PW = 90 – tan-1 (sin 005 24.0 ÷ tan 35 36 38.4) PW = 82 30 51.72 Lat W = 90 - 82 30 51.72 = 7 29 08.28 Lat W = 07 29.1 N DLat = 08 16.0 – 07 29.1 = 00 46 .9
A
A
P 90 - PW
90 - AW W - 90
Vessel is 46.9 NM south of shoal. 60
W
PA
2. The voyage plan indicates that the vessel will pass off the shoal at 2200hrs on the 8 th August. The visibility in the area is clear with only light cloud cover. The Master instructs the Chief Officer to obtain stars during evening twilight to check the vessel’s position with the GPS prior to passing the shoal later in the evening. sunset is expected at 1820hrs with civil twilight occurring at 1826hrs. The following results are obtained whilst steering 040(T) at 23 knots, using a GPS position of 3 30.0 N 173 59.0W for each sight. Time Star 1821 Vega 1825 Arcturus 1831 Fomalhaut 1835 Nunki 1839 Altair 1844 Alphecca
Brg(T) 010 082 175 240 290 045
True ZD 40 18.2` 56 29.6` 60 51.7 60 08.7 40 16.4 48 29.0
Calc ZD 40 22.1 56 25.0 60 58.0 60 12.3 40 20.1 48 26.3
a) Identify, giving reasons, which of the above are best suited to obtain a FIVE star fix of the vessel’s position. (10) b) The Chief Officer eventually chooses Vega, Altair and Nunki to plot a fix. Determine the vessel’s most probable position (MPP) at 1830hrs, assuming there are no random errors. (20) c) Comment on the reliability of EACH of the following: i) the MPP, (5) ii) the GPS position. (5) a) Magnitudes. Vega 0.1, Arcturus 0.2, Fomalhaut 1.3, Altair 0.9, Nunki 2.1. Brightest stars, easier to take in cloudy conditions. Best range of bearings to give accurate plot. Adequate altitudes, to minimise effects of refraction near horizon. Vega and Fomalhaut good N/S pair for latitude, Arcturus and Altair good E/W pair for longitude. Alphecca taken late, and bearing eastwards, horizon deteriorating. b) Veg (18:30 – 18:21) x 23 = 3.5 F 010 Nun (18:30 – 18:35) x 23 = 1.9 B 240 Alt (18:30 – 18:39) x 23 = 3.5 B 290
40 18.2 - 40 22.1 = 3.9 T 60 08.7 - 60 12.3 = 3.6 T 40 16.4 - 40 20.1 = 3.7 T
DLat 0.3 S Dep 2.0 NM E MLat = Lat A ± DLat ÷ 2 = 03 30.0 N – 00 00.3 ÷ 2 = 03 29 51 N DLon = Dep ÷ cos MLat = 2.0 ÷ cos 03 29 51 = 000 02.0 E OP Lat = AP Lat ± Dlat = 03 30.0 – 00 00.3 = 03 29.7 N OP Lon = AP Lon ± DLon = 173 59.0 W – 000 02.0 E = 173 57.0 W c) i) the MPP, The plot indicates a systematic error of 6.0 minutes, which could be an index error on the arc, or a bias on the part of the observer. This reduces the confidence in the position, although the errors are known to be systematic, not random. The Celestial position is 2.0 NM from the GPS position, which is within the accuracy expected of celestial observations. ii) the GPS position. The vessel is close to the Equator, a high proportion of the satellite constellation is likely to be above the horizon, the GPS position should be highly accurate.
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3. Tropical Revolving Storms (TRS) are common in the North Pacific Ocean in the late summer months especially from August to October. a) Describe the warning signs of an approaching TRS. (10) b) For a vessel, within the storm field of a TRS, in the Northern Hemisphere: i) Explain how onboard observations can be used to determine the vessel’s position relative to the storm’s track; (10) ii) outline the actions a prudent master should take to avoid the worst of the storm. (15) a) High swell, from high wind waves in the vicinity of the eye. Atmospheric pressure, initially loss of diurnal variation followed by decreasing pressure in excess of 3 hPa, TRS probable, and 5 hPa, TRS confirmed. Wind force increasing from approximately force 4 to gale force and above. Wind direction probably changing, but not necessarily. Cloud cover changing from trade wind cumulus to cirrus from the canopy to large cumulonimbus. Precipitation occurring and then increasing. When close up, the rain pattern may be seen on the radar. b) i) The change of wind direction indicates the vessel’s position relative to the path / track. Veering wind indicates that the vessel is right of the path / track, steady wind that the vessel is close to, or on the path / track and backing wind that the vessel is left of the path / track. Furthermore, with the vessel hove to, if atmospheric pressure is decreasing the vessel is in advance of the storm, increasing pressure indicates that the vessel is to the rear. ii) In the northern hemisphere: In the Dangerous Quadrant, steam with the wind on the starboard bow, On the Path, steam with the wind on the starboard quarter, In the Navigable Semicircle, steam with the wind on the starboard quarter, To the rear of the storm, steam with the wind on the starboard bow. In all cases make maximum practicable speed and alter course to maintain the relative wind direction. Weather forecasts and the local weather parameters must be monitored closely and the situation reassessed to ascertain the relative position to the storm’s path and action modified if necessary.
4. Vessels engaged on passages between Australia and the west coast of the USA often have to pass through groups of islands where accurate navigation is essential. Discuss the availability, accuracy and sources of error in EACH of the following: a) Celestial Observations; (10) b) Global Satellite Navigation System (GSNS); (15) c) Radar. (15) a) Availability is likely to be good apart from the area of the ITCZ where cloud cover will restrict the opportunities. Accuracy in the order of 1 NM can be achieved in good conditions. Accuracy is likely to be good as abnormal refraction is unlikely to be significant. Errors may arise from sextant inaccuracy if inadequately maintained, observational error if the observer is inexperienced or lacks practice, abnormal refraction may cause errors if temperatures are high in the tropics, or low in middle latitudes. b)Availability should be high throughout the passage as latitudes are not extreme. Accuracy is in the order of 33 metres. Accuracy can be expected to be high as a high proportion of satellites should be available. Sources of error. Accuracy will be degraded if the number of satellites above the horizon is low or if the bearings of the satellites are not widespread. Surveys may not be accurate, so accurate positions of vessel may be obtained, but not match those of the land. 63
c) Available for navigation only when in range of land. Accuracy, range 2.5% of the range scale, bearing ±2°. Accuracy depends on calibration of the radar. Land targets may be low and sloping, giving inaccurate ranges at a distance. Coral islands may have changed shape since last surveyed.
5. On the approach to Port Angeles Pilot Station the vessel is approaching in the appropriate lane of the Juan de Fuca traffic separation Scheme, steering 100(T) at a speed of 12 knots. Visibility is estimated to be one nautical mile. At 1220hrs the Officer of the Watch completes a 20 minute radar plot as indicated on Worksheet Q5. Target A is known to be a beacon in the middle of the 2 mile wide traffic separation zone. a) Prepare a full report and analysis for targets B, C and D. (21) b) Determine the set and rate of any tidal stream affecting the vessel. (4) c) Determine the reduction in speed required at 1224hrs to ensure target D passes the vessel with a CPA of 2 miles. (4) d) Assuming the reduction has an instantaneous effect, determine the new CPA for targets A, B and C. (6) e) With respect to target A, state, giving reasons, what action the vessel should take once target D has passed its CPA. (10) a) Report B Bearing 010½ Tendency Increasing Range 2.9 Tendency Decreasing CPA Range 0.1 Bearing 098 Time to 00:39 Time of 12:59 Course 119½ Speed 13.2 Aspect G 072
C 257 Decreasing 4.4 Decreasing 1.8 190½ 00:42 13:02 100 18.0 R 022½
D 138 Steady 6.2 Decreasing 0.0 00:24 12:44 010½ 9.3 R 052½
TCPA B 2.9 ÷ 1.5 x 00:20 = 00:39 C 4.0 ÷ 1.9 x 00:20 = 00:42 D 6.2 ÷ 5.1 x 00:20 = 00:24 WO = 12.0 x 00:20 = 4.0 NM Speed B 4.4÷ 00:20 = 13.2 C 6.0÷ 00:20 =18.0 D 3.1÷ 00:20 =9.3 Analysis A Port bow, beacon. Relative movement indicates current / tidal stream B Port Beam, crossing, collision course, may be passing through separation Zone and joining TSS. C Starboard quarter, overtaking, parallel course. D Starboard bow, crossing, collision course, crossing TSS. b) 325½ 1.0 ÷ 00:20 = 3.0 kn
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c) AP = 5.1 x 00:04 ÷ 00:20 = 1.0 WO1 = 1.7 Speed = 1.7 ÷ 00:20 = 5.1 kn Reduce speed by 6.9 knots to 5.1 knots. d) A B C
AP = 3.4 x 00:04 ÷ 00:20 = 0.7 AP = 1.5 x 00:04 ÷ 00:20 = 0.3 AP = 1.9 x 00:04 ÷ 00:20 = 0.4
A B C
155 x 1.4 041 x 2.2 190 x 1.8
e) D T = PC1 ÷ O1A x 00:20 = 4.6 ÷ 3.6 x 00:20 = 00:26 A PP1 = O1A x 00:26 ÷ 00:20 = 1.2 x 00:26 ÷ 00:20 = 1.6 At 12:50 resume speed of 12.0 knots and alter course to 110. To keep out of Separation Zone CPA of A must be at least 1.0 NM A greater alteration to Starboard would increase the distance off the Separation zone. Check positions of other vessels B PP1 = O1A x 00:26 ÷ 00:20 = 2.8 x 00:26 ÷ 00:20 = 3.6 C PP1 = O1A x 00:26 ÷ 00:20 = 4.2 x 00:26 ÷ 00:20 = 5.5 D PP1 = O1A x 00:26 ÷ 00:20 = 3.6 x 00:26 ÷ 00:20 = 4.7 All vessels clearing after manoeuvre.
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March-2009 All questions refer to the vessel described below. A 12,500GT refrigerated cargo vessel has been chartered to carry fruit from Ecuador to the UK. The vessel will carry general cargo on the southbound passage. The vessel is due to make a fully loaded passage from Barry (European Tide Tables No 513) to Guyaquil (Ecuador), via the Panama Canal, in the month of January. The vessel is expected to sail with a draught 5.2m and the service speed is 19.5 knots. 1. The vessel is due to complete cargo operations on the morning of the 8 th January. In order to leave the dock the vessel must pass through a set of locks which have a sill with a charted depth of 0.5m. The Master requires a minimum underkeel clearance of 1.5m to be maintained at all times. a) Calculate the height of tide required to clear the lock sill. (5) b) Using Worksheet Q1, determine the latest time on the afternoon ebb of the 8th January that the vessel can pass though the locks. (25) c) Describe TWO meteorological factors which can affect tidal heights, stating what effect they have on the height of tide experienced compared to that predicted. (10) a) Waterline Draft 5.2
HoT
Keel
CD Charted Depth 0.5
UKC 1.5
Sea Bed
Draught UKC Depth Charted Depth HoT
5.2 1.5 + 6.7 0.5 6.2
b) Standard Port Secondary Port Require Time Zone
Bristol (Avonmouth) 523 Barry 513 Latest Time of HoT 6.2 Afternoon Ebb Jan 08 UT Times Heights HW LW HW LW Standard Port Predicted 13:24 19:48 11.0 3.2 - Seasonal Changes 0.0 0.0 Standard Port Uncorrected 11.0 3.2 Differences - 00:20 -00:32 -1.5 0.2 Secondary Port Uncorrected 9.5 3.4 Seasonal Changes 0.0 0.0 Secondary Port Predicted 13:04 19:16 9.5 3.4
Range 7.8
Interpolation 11:00 13:24 18:00 -00:15 -00:30 -00:15 + (13:24 – 11:00) ÷ (18:00 – 11:00) x (-00:30 - -00:15) = - 00:20 15:00 19:48 20:00 -01:25 -00:30 -01:25 + (19:48 – 15:00) ÷ (20:00 – 15:00) x (-00:30 - -01:25) = -00:32 67
13.2 11.0 10.0 -1.8 -1.3 -1.8 + (11.0 – 13.2) ÷ (10.0 – 13.2) x (-1.3 - -1.8) = -1.5 3.5 3.2 0.9 0.2 0.0 0.2 + (3.2 – 3.5) ÷ (0.9 – 3.5) x (0.0 – 0.2) = 0.2 Mean Ranges Spring 12.3 Predicted 7.8 Neap 6.5 Factor from Neaps = (7.8 – 6.5) ÷ (12.3 – 6.5) = 0.22 Spring 03:25 Neap 03:20 Interval = 03:20 + (03:25 – 03:20) x 0.22 = +03:21 HW Predicted Interval Time Required
13:04 03:21 16:25
c) Atmospheric Pressure. Low pressure increases Height of Tide, High Pressure reduces Height of Tide, by approximately 0.01 m per hPa variation from normal. Wind. Wind into an area increases Height of Tide, wind out of an area decreases Height of Tide, particularly in estuaries or other confined areas.
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2. The Master has been asked to consider two routes between the following positions: Departure Position 49° 47.0’ N 006° 50.0’ W Arrival Position 18° 20.0’ N 067° 50.0’ W The routes being considered are: a direct great circle track or a direct rhumb line track a) calculate the distance on passage for EACH route. (18) b) Assuming the direct great circle route experiences an adverse current of 1 knot for a distance of 1500 miles, calculate the difference in the ETA’s for each route. (10) c) Plot the direct great circle track on Worksheet Q2(c)(1) and on Worksheet Q2(c)(2) (17) a) A B d
49 47.0 N 3436.41 18 20.0 N 1111.91 31 27.0 S 2324.50 1887.0
006 50.0 W 067 50.0 W 061 00.0 W 3660
Cos AB = cos P x sin PA x sin PB + cos PA x cos PB P = 061 00 PA = 90 – 49 47 = 40 13 PB = 90 – 18 20 = 71 40 AB = cos-1 (cos 061 00 x sin 40 13 x sin 71 40 + cos 40 13 x cos 71 40) = 57 29 52.05 x 60 Distance = 3449.867563 NM Co = tan-1 (DLon ÷ DMP) = tan-1 (3660 ÷ 2324.50) = 57 34 47.97 Dis = DLat ÷ tan Co = 1887.0 ÷ tan 57 34 47.97 = 3519.723691 NM or Dis = √(DLon2 + DMP2) x DLat ÷ DMP = √(36602 + 2324.502) x 1887.0 ÷ 2324.50 = 3519.723691 NM Great Circle Distance = 3449.9 NM Rhumb Line Distance = 3519.7 NM b) Great Circle Reduced speed = 19.5 – 1.0 = 18.5 kn PT = 1500 ÷ 18.5 = 81:04:52 Full speed distance = 3449.9 – 1500 = 1949.9 NM PT = 1949.9 ÷ 19.5 = 99:59:42 PT = 81:04:52 + 99:59:42 = 181:04:34 = 181:05 Rhumb Line PT = 3519.7 ÷ 19.5 = 180:29:51 = 180:30 Difference in ETA’s = 181:05 – 180:30 = 00:35 Great Circle ETA is later.
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3. With reference to Admiralty Routeing Charts: a) outline the information that can be obtained from a wind rose; (10) b) state the other information that can be found on a routeing chart; (14) c) describe how the information found on a routeing chart can be used when appraising a passage. (16) a) The arrows fly in the direction of the wind. Frequency of winds from different directions. Percentage of winds of different Beaufort forces for each d irection. The number of observations that have been used in the compilation of each wind rose. The percentage of variable wind observations in the area, a 5° x 5° block. The percentage of calm observations for the area b) Chart Number, Title, UKHO references. Title, Edition Number, Edition Date, relevant month, scale, projection. Explanation of Wind Roses, Ocean Currents, Ice Limits, Load Lines, Weather Ships, Shipping Routes. Tropical Storm Tracks. Percentage frequency of winds of Beaufort force 7 and higher. Dew point temperature Mean sea temperature Mean air pressure Mean air temperature Fog, percentage frequency of visibility less than 1000m Low visibility, percentage frequency of visibility less than 8050m Wind roses as above. Current directions, rates and constancy. Ice Limits, Pack Ice: minimum limit, average limit, maximum limit. Mean Maximum Iceberg limit. Load Line limits and related information. Shipping routes with indication of direction and distances between ports. The identity and approximate borders of countries. The positions of selected ports. c) The proposed route, shortest legal distance with adequate margins of safety is plotted on the relevant Routeing Chart/s. The route is inspected for adverse conditions on the route. Adverse winds with associated wind waves will reduce speed. Adverse currents will reduce speed. Hazards such as fog, reduced visibility, pack ice, icebergs and/or a high probability of TRSs may exist. The area adjacent to the route is inspected for favourable conditions. Favourable ocean currents will increase speed. Favourable wind may increase the speed of certain v essels. The adverse and favourable factors are quantified in order to assess whether a deviation from the original route is justified to reduce the adverse effects, or take advantage of favourable effects. The route is modified to achieve an optimum route avoiding adverse factors and / or taking advantage of favourable factors.
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4. Vessels on passage between Central America and NW Europe may encounter tropical revolving storms. (TRS) a) Describe the warning signs of an approaching tropical revolving storm. (12) b) Sketch a plan view of a TRS, in the northern hemisphere, indicating ALL the relevant features. (8) c) Explain how shipboard observations can be used to determine the vessel’s position relative to the centre of a tropical revolving storm. (10) d) If the Master suspects that his vessel is within 200 miles of the centre of a TRS, state the recommended actions open to the master to avoid the worst effects of the storm (12) a) Swell, generated by strong winds in the vicinity of the Eye, radiates outward from the storm centre. Therefore a swell, probably long and high, and not related to the current wind, is an indicator of the presence of a TRS. Atmospheric pressure. The normal pattern of pressure in the tropics is diurnal variation, a small cyclic change around the normal pressure. The damping of the diurnal variation may be the first indication of the presence of a TRS. Subsequent decreases in pressure indicate increasing probability of the presence of a TRS, a fall of more than 3 hPa indicates that a TRS is probably in the vicinity, and a fall o f more than 5 hPa must be taken as confirmation of a TRS’s presence. Wind speed increasing above the seasonal normal level indicates the presence of lower pressure associated with a TRS. Wind direction differing from the normal direction for the area and season similarly indicates a disturbance in the pressure pattern. Cloud cover increasing and cloud types changing to Cirrus bands and then Cumulonimbus are further indicators of the strong convection associated with TRSs. b)
Vertex
Trough Line
Advance
Right
Rear
Dangerous Quadrant Path
Vortex
Track
Left
Tropical Revolving Storm Northern Hemisphere
Navigable Semicircle
c) The direction of the storm can be determined using Buy’s Ballot’s Law. Face the wind. The storm centre is then to the right of the observer in the Northern Hemisphere (left in the southern hemisphere) by an angle of 90° plus the Angle of Indraft from the wind direction. The Angle of Indraft varies from four points at the outer edge of the storm field to zero at the Eye Wall.
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The distance from the Eye can be determined approximately by the pressure drop and wind speed. This will be approximately 200 NM if the pressure has fallen by 5 hPa and the wind is approximately Force 6, and 100 NM if the wind is Force 8. The vessel should be stopped in order to determine the change of pressure and wind direction accurately. Additionally, whether the vessel is in advance or rear of the trough line can be determined by the change of pressure. Falling pressure indicates that the vessel is in advance of the trough line, and rising pressure that the vessel is to the rear. Also, the change of wind direction can be used to determine the relationship of the vessel to the Path of the storm. If the wind is veering, the vessel is to the right of the path; if steady, on the path; if backing, to the left. d) In the northern hemisphere the Advance Right quadrant is the Dangerous Quadrant, the left semicircle is the Navigable Semicircle. In the Dangerous Quadrant, the vessel should steam with the wind on the starboard bow; On the Path, and in the Navigable Semicircle, the vessel should steam with the wind on the starboard quarter. In all cases the vessel should make maximum practicable speed, and alter course to maintain the relative wind direction. In the Dangerous Quadrant, close to the Path and at some distance from the Eye, it may be practicable to cross the Path into the Navigable Semicircle by steaming with the wind on the starboard quarter. If to the rear of the Trough Line the vessel should heave to, or steam away from the storm, with the wind on the starboard bow in the northern hemisphere, and port bow in the southern hemisphere. In the southern hemisphere the Advance Left quadrant is the Dangerous Quadrant and the Right semicircle the Navigable Semicircle. The relative wind directions are port bow and quarter respectively.
5. The coastline in the vicinity of Guyaquil is mainly low lying and appears indistinct when approaching from the North. There is a prominent lighthouse situated one mile offshore and the Master intends to use this as a target for parallel indexing. The cross index range will be taken as 3 miles to port when the vessel is steering 180°(T) When the light bears 061°(T), the Master intends to alter course to 120°(T) to make the final three mile approach to the fairway buoy. a) On worksheet Q5, indicate the parallel index lines that would be required for the track, using the lighthouse as a target, as they would appear on the radar display, assuming it is on the 6 mile range. (10) b) On Worksheet Q5 indicate on the parallel index line the position of the lighthouse when the vessel passes the fairway buoy and determine the range and bearing of the light at that time. (10) Note: On worksheet Q5 candidates should only indicate the parallel index lines. No attempt should be made to indicate a coastline. c) Describe the precautions that should be observed when using parallel index techniques. (13)
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a)
b) 3.2 NM x 007°(T) c) The objects selected should be a good radar targets, prominent and easily identified, not likely to be obscured by shore objects or ship’s structure during the period of use, at suitable ranges, spaced so that PIs will overlap, providing continuous monitoring, The Radar should be appropriately adjusted to provide a clear picture, checked for errors of range and orientation, and these corrected or allowed for, set to an appropriate scale for the area concerned, Cross Index Range lines and Margin of Safety lines should be plotted. PIs should overlap, providing continuous monitoring.
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November-2008 All questions refer to the vessel described below. A 38,000 GT container vessel is to make a fully laden passage from Gothenburg (Sweden) to Montreal (Quebec, Canada) in September. The vessel has an all seasons load line and has a service speed of 19.5 knots. 1. The vessel’s owners have indicated that the vessel is to pass to the North of Scotland and transit the Belle Isle Strait prior to entering the St Lawrence river. The departure and landfall positions for the trans oceanic leg of the passage are as follows; Departure Position 58 43.0 N 005 00.0 W Landfall Position 51 44.0 N 056 00.0 W With reference to the departure and landfall positions, calculate each of the following: a) the great circle distance; (10) b) the initial course of the great circle track (10) c) the position of the vertex. (15) d) the ETA at the landfall position if the vessel departs from Cape Wrath at 2130hrs (Daylight Saving Time) on the 21st of September. Note: Assume the vessel will be on Quebec Standard Time when entering the Belle Isle Strait. a) Cos AB = cos A x sin PA x sin PB + cos PA x cos PB A = DLon AB = Lon B – Lon A = 056 00 – 005 00 = 051 00 W PA = 90 – 58 43 = 31 17 PB = 90 – 51 44 = 38 16 Dis = cos-1 (cos 51 00 x sin 31 17 x sin 38 16 + cos 31 17 x cos 38 16) Dis = 29 08 49.39 x 60 = 1748.8 NM b) A = tan Lat ÷ tan LHA = tan Lat A ÷ tan DLon = tan 58 43 ÷ tan 051 00 = 1.33273393 S B = tan Dec ÷ sin LHA = tan Lat B ÷ sin DLon = tan 51 44 ÷ sin 51 00 = 1.631270502 N C = A ± B = 1.33273393 S - 1.631270502 N = -0.2985365727 = 0.2985365727 N Tan Az = 1 ÷ (C x cos Lat) ICo = tan-1 (1 ÷ C ÷ cos Lat A) = 81 11 17.08 = N 81 W = 279 P
c) sin mid = cos opp x cos opp sin PV = cos(90 – A) x cos (90 – PA) PV = sin-1 (cos(90 – 81 11 17.08) x cos (90 – 31 17)) PV = 30 52 23.88 Lat V = 90 – PV = 90 – 30 52 23.88 = 59 07 36.12 Lat V = 59 07.6 N sin mid = tan adj x tan adj sin (90 – PA) = tan (90 – P) x tan (90 – A) tan (90 – P) = sin (90 – PA) ÷ tan (90 – A) P = 90 – tan-1 (sin (90 – PA) ÷ tan (90 – A)) P = 90 - tan-1 (sin (90 – 31 17) ÷ tan (90 – 81 11 17.08)) P = 10 16 52.78 DLon AV = 10 16.9 W Lon V = Lon A ± DLon AV = 005 00 + 10 16.9 Lon V = 015 16.9 W
V
A
V
PV
AV 90 - A
90 - P 90 - PA
Lat V = 59 07.6 N Lon V = 015 16.9 W
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d) PT = Dis ÷ Sp = 1748.8 ÷ 19.5 = 89 40 55.38 = 03/17:41 DST DST UT PT UT UT TD QST
21/21:30 01:00 – 21/20:30 03/17:41 24/38:11 25/14:11 04 25/10:11
ETA Sep 25/10:11 QST Quebec Standard Time is stated, Daylight Saving Time has not been applied.
2. Vessels approaching Newfoundland and the Grand Banks from seaward are likely to encounter several navigational hazards. a) With reference to Datasheets Q2(a)(1) and Q2(a)(2), outline six hazards which a vessel may encounter during passage at any time in the year.(18) b) Vessels encountering certain types of navigational hazards are required by law to pass on information to other vessels and coast radio stations in the vicinity. i) Detail the circumstances to which these regulations apply (10) ii) Describe the information that is required to be transmitted for each type of hazard. (16) a) Currents, pack ice, icebergs, fog and reduced visibility, gales, fishing vessels, platforms. 2.17 Currents off the coasts of Labrador and Newfoundland are complex; Set and drift may be unpredictable. 2.36 Currents between the Grand Banks and Newfoundland may be affected by gales . 2.27 Icebergs may be encountered in any month N of 52 N. 2.27.2 Strait of Belle Isle is generally not navigable from late December until June, due to pack ice. 2.27.4 Icebergs may be encountered between March and July. 2.36 Fog is exceedingly prevalent off the S coast of Newfoundland. It may also be encountered in the approaches to Belle Isle Strait. Many depressions pass close to the area so that gales are frequent and severe. Many fishing vessels are found throughout the year on the Grand Banks. There are vessels and platforms used to exploit oil, gas and mineral deposits. b) i) The master of every ship which meets with dangerous ice, a dangerous derelict, or any other direct danger to navigation, or a tropical storm, or encounters sub-freezing air temperatures associated with gale force winds causing severe ice accretion on superstructures, or winds of Beaufort force 10 and for which no storm warning has been received, is bound to communicate the information by all means at his disposal to ships in the vicinity and also to the competent authorities. ii) Ice, derelicts and other direct dangers to navigation. The kind of ice, derelict or danger observed. The position of the ice, derelict or danger when last observed. The time and date (UCT) when the danger was last observed. Tropical cyclones, hourly, if practicable, but not more than three hourly, while under the influence of the storm. A statement that a tropical cyclone has been encountered. Date and time UT. Position of the vessel. Barometric pressure corrected to sea level. 76
Barometric tendency. True wind direction. Wind force Beaufort. Sea state. Swell height, true direction, period and length. Vessel’s true course and speed. Storm force winds. A statement that storm force wind has been encountered. Date and time UT. Position of the vessel. Barometric pressure corrected to sea level. Barometric tendency. True wind direction. Wind force Beaufort. Vessel’s course and speed. Ice accretion. Time and date UTC. Air temperature. Sea temperature if practicable. Wind force and direction.
3. a) The following observation was obtained during morning twilight on the 22 nd September. DR Position 59 01.6 N 009 40.6 W Chronometer read 04:30:18 Chronometer Error 00:03:26 Slow on UT Compass Bearing of Polaris 354 C Variation 6E Calculate the deviation of the compass for the direction of the ship’s head. (20) b) A short time later, whilst in DR position 59 04.0 N 010 26 W, the sun was observed to rise bearing 080 C, Assuming that the variation and the vessel’s course remained constant throughout the period determine the compass deviation for the second observation. (15) c) Outline two factors which should be taken into account when deciding which of the two values for deviation is likely to be more accurate. (10) a) CT CE UT
22/04:30:18 00:03:26 S 22/04:33:44
GHA A 22/04 I A 33:44 Lon LHA A Az TB CB CE V D
060 54.4 008 27.4 009 40.6 W 059 41.2
359.3 354.0 005.3 E 006.0 E 000.7 W
Deviation ½ W
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SR 60 58 T1 SR TD SR LIT SR
20/05:39 23/05:46 20/05:40 23/05:46 00:01 00:00 2, 01 04, -00:01, 00:00 20/05:39 23/05:46 00:05 00:07 x 2 ÷ 3 = 04:40 22/05:44 UTG 00:42 10 26.0 ÷ 15 = 00:41:44 22/06:26 UT
Dec S 22/06 d 1.0 – 00:26 Dec
N 00 20.9 00 00.4 N 00 20.5
sin Amp = sin Dec ÷ cos Lat Amp = sin-1 (sin 00 20.5 ÷ cos 59 04.0) Amp = 00 39 52.85 = E 0.7 N TB CB CE V D
089.3 080 009.3 E 006 E 003.3 E
Deviation 3½ E c) Altitude of the body. Polaris is at approximately 59 degrees, and therefore care is needed to take an accurate bearing by keeping the compass bowl horizontal. The sun is just above the horizon, and therefore it is easy to observe a bearing accurately. Lateral movement of the body. Polaris has very little lateral movement to affect the accuracy of the observation. In high latitude the sun is moving obliquely to the horizon, and care is needed to judge the altitude of Amplitude accurately. Abnormal refraction may affect the perceived altitude and therefore the judgement of the moment of Amplitude. The observation of Polaris is likely to give a more accurate value of the Deviation.
4. At 0600hrs UT on the 25th September the vessel receives a request from MRCC Halifax to take part in a search and rescue operation for a 38ft lobster boat. The crew have reported that the lobster boat collided with a submerged object and sank within minutes. They have abandoned the vessel and were last reported to be adrift in a 12 man liferaft. a) Outline six factors to be considered when choosing a vessel to act as On Scene Coordinator (OSC) during search and rescue operations. (12) b) i) State the publications that should be consulted during a search and rescue operation. (5) ii) Outline the information that is available to determine a search datum position, from the publications stated in Q4(b)(i).(6) c) Explain, with the aid of a sketch, the method used to determine a datum search position, assuming the distress position is known. (12) a) Communications facilities of the vessel, GMDSS and Inmarsat. Experience of the Master and crew. ETA at the datum position. First vessel to arrive is OSC until relieved. Language capability. Sea keeping qualities of the vessel with regard to the situation. Number of crew. Constraints of fuel and legal factors such as Charter Party. 78
(Equipment of the vessel, radar, lifeboats, fast rescue craft. Freeboard of the vessel. Facilities for accommodation and medical care of personnel recovered.) b) i) IAMSAR Manual Volume III Routeing Charts. Current and Tidal Stream atlases. Sailing Directions. Weather analysis and forecast charts. Admiralty List of Radio Signals. Company Emergency Plan for assisting a vessel in distress. Annual Summary of Notices to Mariners. ii) IAMSAR V III describes the procedure to be used to determine the search datum position from a knowledge of the distress position, expected movement related to the nature of the object, due to current, tidal stream and wind. Drift rates are given for different objects, ship, liferaft, person in water, in various wind conditions. Routeing Charts give climatological information relating to wind and currents. Current and Tidal Stream Atlases give information relating to currents and tidal streams. Weather analysis and forecast charts may be used to determine current and forecast weather conditions, particularly wind and sea state. ALRS, none. Company Emergency Plan may contain information similar to IAMSAR VIII. ASNM none. c) The Distress Position is established. The time from the distress to the ETA at the Datum is calculated. The effect of wind is estimated from the nature of the object, the expected wind conditions and the expected time interval. The effect of current / tide is estimated from the expected current and tidal stream as relevant and the expected time interval. These effects are used as vectors to estimate the most likely position of the search object at the time of ETA. Current / Tide Rate. Knots
Leeway. Knots
Drift. Knots.
Distress Position Search Datum Drift distance
79
5. a) For a vessel operating in pack ice in the approaches to the Belle Isle Strait, outline five factors that should be taken into account when maintaining a navigational plot of the ship’s position. (15) b) Outline six factors that the Master must take into account when manoeuvring the vessel in ice. (18) a) Fast ice on land will give a false coastline on radar, and the edge of the fast ice must be distinguished from the land when taking radar bearings and distances. The presence of ice may make the identification of shore marks uncertain when taking visual bearings. Ice on shore lights will reduce the detection range, may alter the bearings of light sectors, and may alter the colour of lights. Floating marks are unlikely to be present, and are likely to be out of position if present. Loran may be subject to errors due to the different propagation of radio s ignals over ice compared to land and water, for which the system will be calibrated. The gyrocompass may be subject to transient errors due to alterations of speed from that set. The log may be inaccurate due to temperature variations within the water body. The ice field may be drifting due to the effect of wind and current. Celestial observations may be inaccurate due to abnormal refraction. b) The experience of the Master and staff. The ice class of the vessel in relation to the type of ice encountered. The thickness of the ice. Approximately 90% of the ice is below the water. Forecast weather conditions, which may lead to ice closing in on the vessel and causing damage. The high probability of reduced visibility due to fog caused by the presence of ice. The availability of ice breakers. Draught and depth of water over propeller tips and rudder. The increased thickness of the ice due to deformation which will lead to increased thickness, particularly when rafted or below hummocks and ridges. The hardness of the ice, which will depend on its age and source. The probable accuracy of the available information about ice conditions. The availability and characteristics of searchlights for night navigation. The need to maintain adequate speed to avoid becoming beset while not causing damage to the vessel.
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July-2008 A product carrier with a load displacement of 88,000 tonnes is to make a ballast passage between Colombo (Sri Lanka), and Aden (Yemen), in June. In Aden the vessel will load a full cargo of petroleum, kerosene and naphtha for Antwerp (Belgium). The vessel’s owners have indicated they require a service speed of 14.0 knots for both passages. 1. With reference to Datasheet Q1: a) Outline THREE reasons why there are multiple routes recommended for the passage from Colombo to Aden; (9) b) The Master decides to follow the appropriate route for large vessels, calculate the distance on passage to Aden, using the following departure and landfall positions: Departure Position 06 55.0 N 079 47.0 E Landfall Position 12 45.0 N 044 55.0 E (20) c) If the vessel departs Colombo at 1800hrs (ST) on the 5 th June, determine the ETA at the landfall position; (6) d) Indicate on Worksheet Q1(d), the weather likely to be encountered on passage from Colombo to Aden. (19) a) This an area of monsoon winds which blow in different direction in summer and winter. In summer winds are predominantly SW and strong, particularly in the area SE of Suqatra. Wave heights are therefore high, and there is a cross swell in the area SE of Suqatra. Currents are strong NE wards near the African coast. In winter winds are predominantly NE and less strong. Wave heights are lower, the cross swell is absent, and currents are less strong and predominantly westwards. Therefore different routes are recommended for differently powered vessels in different times of year to avoid the adverse weather during the SW Monsoon in particular. b) Route 6.79.1. DP G O Q LF
06 07 10 13 12
55.0 N 30 N 00 N 00 N 45.0 N
079 072 060 055 044
47.0 E 45 E 00 E 00 E 55.0 E
Mercator Sailing DP G D
06 55.0 N 413.19 07 30 N 448.24 00 35 N 35.05 35
079 47.0 E 072 45 E 007 02 W 422
tan Co = DLon ÷ DMP Co = tan-1 (DLon ÷ DMP) Co = tan-1 (422 ÷ 35.05) = 85 15 07.52 Dis = DLat ÷ cos Co = 35 ÷ cos 85 15 07.52 = 422.849 NM (Dis = √(DMP2 + DLon2) x DLat ÷ DMP = √(35.052 + 4222) x 35 ÷ 35.05 = 422.849) G O D
07 30 N 10 00 N 02 30
448.24 599.01 150.77
072 45 E 060 00 E 12 45 W 81
150
765
Co = tan-1 (DLon ÷ DMP) = tan-1 (765 ÷ 150.77) = 78 51 02.71 Dis = DLat ÷ cos Co = 150 ÷ cos 78 51 02.71 = 775.733… NM (Dis = √(DMP2 + DLon2) x DLat ÷ DMP = √(150.772 + 7652) x 150 ÷ 150.77 = 775.7336137 NM) O Q D
10 00 N 599.01 060 00 E 13 00 N 781.52 055 00 E 03 00 182.51 005 00 180 300 -1 Co = tan (DLon ÷ DMP) = tan-1 (300 ÷ 182.51) = 58 41 06.23 Dis = DLat ÷ cos Co = 180 ÷ cos 58 41 06.23 = 346.325… NM (Dis = √(DMP2 + DLon2) x DLat ÷ DMP = √(182.512 + 3002) x 180 ÷ 182.51 = 346.3257736) Q LF D
13 00 N 781.52 055 00 E 12 45.0 N 766.23 044 55.0 E 00 15 15.29 010 05 15 605 -1 Co = tan (DLon ÷ DMP) = tan-1 (605 ÷ 15.29) = 88 33 08.24 Dis = DLat ÷ cos Co = 15 ÷ cos 88 33 08.24 = 593.714… NM (Dis = √(DMP2 + DLon2) x DLat ÷ DMP = √(15.292 + 6052) x 15 ÷ 15.29 = 593.7146951) Dis = 422.849 + 775.7336137 + 346.3257736 + 593.7146951 = 2138.623082 Distance = 2138.6 NM Great Circle Sailing. (Shortest Distance, but does not conform to tracks on data sheet.) DP G D
06 55.0 N 079 47.0 E 07 30 N 072 45 E 007 02 W
PA = 90 00 – 06 55 = 83 05 PB = 90 00 – 07:30 = 82 30 P = 007 02
cos AB = cos P x sin PA x sin PB + cos PA x cos PB AB = cos-1 (cos P x sin PA x sin PB + cos PA x cos PB) AB = cos-1 (cos 007 02 x sin 83 05 x sin 82 30 + cos 83 05 x cos 82 30) Dis = 7 00 07.15 x 60 = 420.1… NM G 07 30 N 072 45 E O 10 00 N 060 00 E D 012 45 W -1 Dis = cos (cos 012 45 x sin 82 30 Dis = 12 50 44 x 60 = 770.7…
PA =82 30 PB = 80 00 P = 012 45 x sin 80 00 + cos 82 30 x cos 80 00)
O 10 00 N 060 00 E Q 13 00 N 055 00 E D 005 00 W -1 Dis = cos (cos 005 00 x sin 80 00 Dis = 5 44 40.28 x 60 = 344.7…
PA = 80 00 PB = 77 00 P = 005 00 x sin 77 00 + cos 80 00 x cos 77 00)
Q 13 00 N 055 00 E LF 12 45.0 N 044 55.0 E D 010 05 W -1 Dis = cos (cos 010 05 x sin 77 00 Dis = 9 49 56.5 x 60 = 589.9…
PA = 77 00 PB = 77 15 P = 010 05 x sin 77 15 + cos 77 00 x cos 77 15)
Dis = 420.1… + 770.7… + 344.7… + 589.9… = 2125.5 NM 82
c) Rhumb Lines ST 05 18:00 TD 06:00 UT 05 12:00 PT 06 08:45 RL 2138.6 @ 14.0 UT 11 20:45 TD 03:00 ST 11 23:45 ETA 0000-06-11 20:45 UT 0000-06-11 23:45 ST Aden Great Circles ST 05 18:00 TD 06:00 UT 05 12:00 PT 06 07:49 GC2125.5 @ 14.0 UT 11 19:49 TD 03:00 ST 11 22:49 ETA 0000-06-11 19:49 UT 0000-06-11 22:49 ST Aden d) Wind. W f5 on east side, SW f6-7 on west side Seas and swell heavy on west side. Little cloud near African coast. Low rainfall off Sri Lanka and toward west side of Arabian Sea. Visibility good except in rain, haze off Arabian Coast. Current generally eastwards, strong NEwards near African coast.
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84
2. On approach to Aden pilot station the vessel encounters thick haze reducing visibility to less than 5 cables. The wind is SW’ly force 6. The OOW is plotting FOUR targets on radar, on the 6 mile range, and the situation at 0200hrs is shown on Worksheet Q2. From information received from the Pilot station it is known that target B is a vessel at anchor. The vessel’s course is 298°(T) and speed 10knots. The plots were commenced at 0148hrs. a) For targets A, C and D, determine EACH of the following: i) the vessel’s course; (3) ii) the vessel’s speed; (3) iii) the vessel’s aspect. (3) b) determine the set and rate of the current. (3) c) Summarise the situation at 0200hrs. (4) d) i) On Worksheet Q2 determine, the single alteration of course required at 0200hrs to ensure that ALL targets will pass with a CPA of at least 1 mile. (12) ii) Determine the revised CPA of ALL targets. (12) Note: Assume alteration of course has immediate effect. 02:00 – 01:48 = 00:12 x 10 kn = 2.0 NM a) A C D
i) ii) 262 1.9 ÷ 00:12 = 9.5 kn 321½ 1.9 ÷ 00:12 = 9.5 kn 306 2.9 ÷ 00:12 = 14.5 kn
iii) Red 080½ Green 087 Red 004
b)
Set 051
c)
A. Broad on starboard bow, crossing close ahead. CPA 0.2 NM in 00:33 at 02:33 B. Starboard bow, stationary, clearing to starboard. CPA 0.8 NM in 00:23 at 02:23 C. Broad on port bow, crossing, collision course. CPA 0.0 NM in 00:55 at 02:55 D. Fine on port quarter, overtaking, clearing to starboard. CPA 0.8 NM in 00:25 at 02:25
Rate 0.4 ÷ 00:12 = 2.0 kn
d) i) Target B is the critical target. Minimum 29 to starboard to 327, assuming that current continues unchanged. A prudent Master would make a broad alteration of course so as to be readily apparent to other vessels observing by radar. ii)
A 291 x 1.2 in 00:18 at 02:18 B 247 x 1.0 in 00:21 at 02:21 C 228½ x 3.6 in 00:00 at 02:00 range increasing D 179½ x 1.1 in 00:17 at 02:17
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86
3. At 1800 hrs UT on the 23rd June the vessel has an engine room fire which results in one of the GP ratings suffering severe burns. The Master contacts a French warship in the area and it is agreed to transfer the casualty to the warship to receive medical treatment. It is agreed to rendezvous at sunrise the following morning to effect the transfer. The tanker will maintain its current course of 285°(T) and increase speed to 16.0 knots. Position of tanker at 1800hrs UT 37 25.0 N 006 51.0 E Position of Warship at 1800hrs UT 40 09.0 N 004 32.0 E Calculate EACH of the following: a) the UT of sunrise; (15) b) the rendezvous position; (15) c) the course and speed required by the warship to make the rendezvous. (15) a) Require Sunrise on June 24. SR
40 N 22/04:31 25/04:32 35 N 22/04:46 25/04:47 Therefore as difference is 1 minute: 40 N 24/04:32 UTG 35 N 24/04:47 UTG T1 5, 02 25, 00:15 00:07 37 25 N 24/04:40 UTG LIT 006 51 ÷ 15 00:27 SR 24/04:13 UT PT = 24/04:13 – 23/18:00 = 10:13 Dis = 10:13 x 16.0 = 163.46… NM DLat = Dis x cos Co = 163.46… x cos 285 = 42.30… = 00 42 19 N Dep = Dis x sin Co = 163.46… x sin 285 = 157.89… W MLat = Lat A ± DLat ÷ 2 = 37 25 + 00 42 19 N ÷ 2 = 37 46 09 N DLon = Dep ÷ cos MLat = 157.89 ÷ cos 37 46 09 = 199 74… W ÷ 60 = 003 19 45 W Lat DR = Lat ± DLat = 37 25.0 + 00 42 19 = 38 07 19 = 38 07.3 N Lon DR = Lon ± DLon = 006 51.0 E – 003 19 45 W = 003 31 15 E = 003 31.3 E SR
40 N 22/04:31 25/04:32 35 N 22/04:46 25/04:47 Therefore, as difference is 1 minute: 40 N 24/04:32 UTG 35 N 24/04:47 UTG T1 5, 03 07, 00:15 00:09 38 07 N 24/04:38 UTG LIT 003 31 ÷ 15 00:14 SR 24/04:24 UT PT = 24/04:24 – 23/18:00 = 10:24 Dis = 10:24 x 16.0 = 166.4 NM DLat = Dis x cos Co = 166.4 x cos 285 = 43.06748911 N Dep = Dis x Sin Co = 166.4 x sin 285 = 161.7300575 W MLat = Lat A ± DLat ÷ 2 = 37 25 + 00 43.06… N ÷ 2 = 37 46 32.02 N DLon = Dep ÷ cos MLat = 161.73… ÷ cos 37 46 32.02 ÷ 60 = 003 23 20.92 W Lat RV = Lat ± DLat = 37 25.0 + 00 43 04 = 38 08.1 N Lon RV = Lon ± DLon = 006 51.0 E – 003 23 20.92 W = 003 27.7 E SR 24/04:23 UT b) RV 38 08.1 N 003 27.7 E
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c) W RV D
40 09.0 N 004 32.0 E 38 08.1 N 003 27.7 E 02 00.9 S 001 04.3 W 120.9 64.3 MLat = (Lat A + lat B) ÷ 2 = (40 09.0 + 38 08.1) ÷ 2 = 39 08 33 N Dep = DLon x cos Mlat = 64.3 x cos 39 08 33 = 49.86968986 NM Co = tan-1 (Dep ÷ DLat) = tan-1 (49.86… ÷ 120.9) = 22 24 55.86 = S 22.4 W = 202½ Dis = DLat ÷ cos Co = 120.9 ÷ cos 22 24 55.86 = 130.781… Speed = Dis ÷ Tim = 130.781… ÷ 10:24 = 12.6 kn Co 202½ Speed 12.6 kn
4. The UKHO produces a number number of charts c harts that are specifically designed to assist mariners in planning passages in areas of heavy traffic and confined waters, such as Dover Straits, Red Sea and Malacca Strait. a) Outline the main categories of information that can be found on these charts. (18) b) Explain how Co Tidal / Co Range Charts can be used by deep draught vessels transiting the Dover Straits (10) c) State, with reasons, FOUR other publications which should be consulted when appraising a passage. (12) a) Admiralty Routeing Guides contain the following information. Admiralty Charts and Publications relevant to the Area. 1. Passage Planning Using This Guide. 2. Routeing: General Rules and Recommendations. Recommendations. 3. Routeing: Special Rules and Recommendations. Recommendations. 4. Passage Planning: Special Classes of Vessel. 5. Oil and Dangerous Cargoes: Marine Pollution. 6. Radio Reporting Systems Applying to Through Traffic. 7. Reporting to a Port of Destination in the Area. 8. Maritime Radio Services. 9. Tidal Information and Services. 10. Pilot Services. Passage Planning Charts. b) Co-Range/Co-Tidal charts show: Amphidromic points in the area. Isopleths of Mean High Water Interval, Mean Low Water Interval, Mean Spring Range and Mean Neap Range. Positions of ports in the area. Standard Ports in the area with Time Intervals and Tidal Ranges. The time at which a required height of tide occurs, or the height of tide at a particular time can be found for a point off shore. s hore. The tidal data for a port, ideally a standard port, centred on the same amphidromic point as that being considered, is used. This information allows planning and speed adjustment to maintain adequate UKC and pass critical points at high water or with a rising tide. (Extract the High and Low Water times and heights for the Standard Port. Determine whether whether the tides are Springs or Neaps from the mean range. Extract the Mean High Water and Mean Low Water Intervals for the Standard Port and the positon. Apply the differences between the two sets of times to those extracted from the tide tables. Extract the co-range data for the standard port and the position from the appropriate Mean Spring or Neap Range chart. Calculate the Factor by dividing the mean range at the position by the mean range at the standard port. 88
Multiply the ranges obtained from the tide tables by the factor. When the tide lies between springs and neaps obtain factors from both charts and interpolate. For heights at intermediate times, or times of intermediate heights, find the duration and range of tide at the position, then use the Pacific tidal procedure.) c) The Mariner’s Handbook. General information about Navigational Publications and their use, Regulations and Operational information, Oceanography, Meteorology, Meteorology, Ice and Ice Navigation, Navigation, buoyage systems. Ocean Passages for the World. Climatology, recommended routes taking into account vessel power and climatological conditions. co nditions. Sailing Directions for the area. Detailed information about the area, Navigation and Regulations, Countries and Ports, Natural Conditions and routes within the area. Routeing Charts. Climatological conditions for the month concerned; to identify adverse factors to be avoided, or favourable factors which may be used, to optimise the passage.
5. a) State the appropriate manning levels on the Bridge, outlining the duties of EACH member of the bridge team, for EACH of the following situations: i) navigation in a Traffic Separation Scheme Scheme with dense traffic with restricted visibility. (12) ii) navigation in clear weather, during darkness, on an ocean passage. (6) b) Outline the information that should be contained in the Master’s Night Orders for making the landfall of Aden. (12) a) i) Master. In Command. Overall responsibility responsibility for safe navigation. Receives data from bridge team, analyses and makes decisions, issues commands to give effect to those decisions. OOW. Radar. Monitors position and progress. Informs Master as relevant. Monitors Master’s commands and performance of ratings. OOW. Radar. Monitors traffic. Informs Master as relevant. Monitors Master’s commands and performance performance of ratings. Rating, Helmsman. Steering to Master’s orders. Rating, Lookout. Keeps a visual and aural lookout. Informs Master and OOWs of observations. Rating. Standby, called if required. ii) OOW. Monitors position, traffic and performance of rating. Acts in accordance with IRPCaS and Master’s Standing and Night Orders. Rating, Lookout. Keeps a visual and aural lookout. Informs OOW of observations. Monitors OOW performance. Rating. Standby, called if required. b) Details of circumstances when the Master should be called. Details of the expected landfall. Details of communications required with port. Details of communications required within vessel, Engine Room, crew. Details of known navigational hazards expected. Details of other possible hazards.
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March-2008 1. The vessel intends to take a coastal route, via the Balintang channel, to a departure position of 31 00.0 N 140 00.0 E, then sail the shortest allowable distance to a landfall position, off Juan de Fuca Strait, in 48 30.0 N 124 47.0 W. The distance from Manila to the departure position is 1810 miles and on arrival at the departure position it is expected that the vessel’s Winter loadline will be overloaded by 240 tonnes. The vessel consumes 42 tonnes of stores and water per day. The vessel departs Manilla at 0400hrs Standard Time on the 12th October. With reference to Data Sheet Q1, calculate each of the following: a) the shortest distance between Manilla and the landfall position posit ion off Juan de Fuca Strait which complies with all the relevant regulations; b) the ETA (local Standard Time) at the landfall position. 30
40
50
60
70
80
P
80
70
60
50
40
30
B
A
V
W
a) Steaming to WLL. DP to WLL = 240 mt ÷ 42 MT/d = 05/17:09 x 24 x 15.0 = 2057.142857 NM Manila to WLL = 1810 + 2057.1 = 3867.1 NM ÷ 15.0 kn = 257.8… h = 10/17:48 Dep Oct 12/04:00 ST TD 08:00 UT 11/20:00 PT 10/17:48 UT Oct 22/13:48 Zone is Winter from Oct 16.
P
PA = 90 – 31 00.0 = 59 00.0 PV = 90 – 35 = 55 00.0 Sin (90 – P) = tan PV x tan (90 – PA) 90 – P = sin-1 (tan PV x tan (90 – PA)) P = 90 - sin-1 (tan PV x tan (90 – PA)) P = 90 - sin-1 (tan 55 00 x tan (90 – 59 00)) P = 30 53 38.71
A
PV
sin (90 – PA) = cos (AV) x cos (PV) cos AV = sin (90 – PA) ÷ cos PV AV = cos-1 (sin (90 – PA) P A) ÷ cos PV) -1 AV = cos (sin (90 – 59 00) ÷ cos 55 00)
V
V
AV 90 - A
90 - P 90 - PA 90
AV = 26 06 40.36 x 60 = 1566.67262 NM Dep VW = 2057.142857 – 1566.67262 = 490.4702372 NM DLon = Dep ÷ cos Lat = 490.4702372 ÷ cos 35 = 009 58 45.22 E Lon W = 140 + 30 53 38.71 + 009 58 45.22 = 180 52 23.93 ~ 360 = 179 07 36.07 W DLon WB = 179 07 36.07 W – 124 47.0 W = 54 20 36.07 E Cos AB = cos P x sin PA x sin PB + cos PA x cos PB AB = cos-1 (cos P x sin PA x sin PB + cos PA x cos PB) WB = cos-1 (cos P x sin PW x sin PB + cos PW x cos PB) P = 54 20 36.07 PW = 55 00 PB = 90 – 48 30 = 41 30 WB = cos-1 (cos 54 20 36.07 x sin 55 00 x sin 41 30 + cos 55 00 x cos 41 30) WB = 41 45 21.47 x 60 = 2505.357771 NM Dis = 1810 + 2057.142857 + 2505.357771 = 6372.500628 Dis = 6372.5 NM b) PT = 6372.5 NM ÷ 15.0 = 424:50:00.15 = 17/16:50:00.15 DST Oct 12/04:00 DST 00:00 ST 12/04:00 TD 08:00 UT 11/20:00 PT 17/16:50 UT 28/36:50 UT 29/12:50 TD 08:00 ST 29/04:50 If “local Standard Time” implies DST, then: DST 01:00 + DST 29/05:50
2. At 1800 hrs UT on the 4th October, whilst in position 25 55.0 N 129 45 E the vessel receives a Typhoon advisory from the Japanese National Weather Centre. Super Typhoon Irma is presently 360 miles to the SSE of the vessel’s position and is proceeding NNW at 15 knots. Winds of 100 knots are forecast within 120 miles of the storm centre. a) On Worksheet Q2, plot the position of the vessel and the storm, indicating the likely area the storm will move into in the next 24 hours. (4) b) Describe the wind, weather and swell conditions likely to be encountered at the vessel’s present position during the next 24 hours. (15) c) Outline the actions a prudent Master should take to avoid encountering the worst of the storm, described in Q2(b) (15). d) Outline the bridge procedures that should be followed on board the vessel, prior to encountering the storm. (12)
91
a)
b) Vessel is currently out of storm field. Trade wind conditions, then approach of storm to centre of eye. Pressure Normal, with diurnal variation. Diurnal variation disappears, then pressure drops rapidly to minimum at eye. Wind Trade Winds. ENEly Within Storm Field, becoming NNE then veering to ENE with changing Angle of Indraft. F4 increasing to 100 kn at eye wall then becoming calm in eye. Wind waves 1 m increasing to approximately 15 m at eye wall then becoming calm in eye. Cloud. Cumulus and cirrus of canopy, changing to cumulonimbus then dense cumulonunimbus, clearing in eye. Precipitation. None, followed by heavy showers, then continuous heavy rain, ceasing in eye. Swell From NE part of TRS, SE x S, 10 m. Direction changing to east near eye wall, then becoming confused in eye. Height increasing to 15 m. c) The vessel is on the Path. The Dangerous Quadrant lies to the east, the Navigable Semicircle to the west. Proceed at maximum speed NW between the islands, then westward. This will keep the vessel Out of the Storm Field and maximise the CPA and TCPA of the storm. The vessel will be protected from the sea and swell in the lee of the islands. 92
d) Record all weather parameters hourly. Report in accordance with SOLAS, hourly if practicable, but not more than three hourly, ship’s position, all relevant meteorological parameters and ship’s course and speed. Analyse observations at every set to determine: direction of storm, whether in advance or to rear, whether left, on, or to right of path, therefore which quadrant the vessel is in. Monitor all relevant communications for reports, and forecasts of the storm’s position and movement. Increase bridge manning to allow for increased workload and hand steering. Inform all departments to prepare for heavy weather.
3. During severe weather an engine room rating suffers a serious injury after falling in the engine room. At 1000 hrs UT on the 17th September the rating’s condition starts to deteriorate and contact is made with an American warship which agrees to rendezvous with the vessel at sunrise the following day, to render medical assistance. After consultation between the two vessels it is agreed that own vessel will maintain present heading of 083(T) and speed of 13.0 knots. Own vessel position at 1000hrs UT 35 24.0 N 146 42.0 E Warship position at 1000hrs UT 33 36.0 N 149 04.0 E Claculate EACH of the following: a) the UT of sunrise; (15) b) the rendezvous position; (10) c) the course and speed required by the warship to make the rendezvous. (10) a) UT ZN ZT
17/10:00 10 17/20:00
LIT 146 42 E ÷ 15 = 09:47
SR Sep 40 N 17/05:43 20/05:45 35N 17/05:44 20/05:46 T1 00:00 00:00 5, 00 24, 01 SR 17/05:44 20/05:46 SR 18/05:45 UTG LIT 09:47 – 146 42 E ÷ 15 SR 17/19:58 UT 17/10:00 UT PT 09:58 Dis = 13.0 x 09:58 = 129.56666667 NM DLat = Dis x cos Co = 129.56666667 x cos 083 = 00 15 47.41 N MLat = Lat A ± DLat ÷ 2 = 35 24.0 N + 00 15 47.41 N ÷ 2 = 35 31 53.71 N Dep = Dis x sin Co = 129.56666667 x sin 083 = 128.6008964 NM DLon = Dep ÷ cos MLat = 128.6008964 NM ÷ cos 35 31 53.71 ÷ 60 = 002 38 01.57 Lat B = Lat A ± DLat = 35 24 + 00 15 47.41 = 35 39 47.41 N Lon B = Lon A ± DLon = 146 42.0 E + 002 38 01.57 = 149 20 01.57 E 40 N 35N T1 SR SR LIT SR
17/05:43 20/05:45 17/05:44 20/05:46 00:00 00:00 17/05:44 20/05:46 18/05:45 UTG 09:57 – 17/19:48 UT
5, 00 24, 01
149 20 01.57 E ÷ 15
93
b) SR
17/19:48 UT 17/10:00 UT PT 09:48 Dis = 13.0 x 09:48 = 127.4 DLat = Dis x cos Co = 127.4 x cos 083 = 00 15 31.57 N MLat = Lat A ± DLat ÷ 2 = 35 24.0 N + 00 15 31.57 N ÷ 2 = 35 31 45.78 N Dep = Dis x sin Co = 127.4 x sin 083 = 126.4503797 NM DLon = Dep ÷ cos MLat = 126.4503797 NM ÷ cos 35 31 45.78 ÷ 60 = 002 35 22.76 Lat B = Lat A ± DLat = 35 24 + 00 15 31.57 = 35 39 31.57 N Lon B = Lon A ± DLon = 146 42.0 E + 002 35 22.76 = 149 17 22.76 E RV = 35 39.5 N 149 17.4 E c) RV W d d
35 39.5 N 149 17.4 E 33 36.0 N 149 04.0 E 02 03.5 N 000 13.4 E 123.5
MLat = (Lat A +Lat B) ÷ 2 = (35 39.5 N + 33 36.0 N) ÷ 2 = 34 37 45 N Dep = DLon x cos MLat = 13.4 x cos 34 37.45 = 11.02615246 NM E Tan Co = Dep ÷ DLat Co = tan-1 (11.02… ÷ 123.5) = N 05 06 06 E = 005 Dis = DLat ÷ cos Co = 123.5 ÷ cos 05 06 06 = 123.991… = 124.0 NM (Dis = √(DLat2 + Dep2) = √(123.52 + 11.026152462) = 124.0 NM) Sp = Dis ÷ Tim = 124.0 ÷ 09:48 = 12.7 kn
4. A vessel encounters restricted visibility whilst proceeding in a traffic separation scheme on a heading of 115 (T) at 10.0 knots. Four targets are observed on radar (12 mile range), as depicted on Worksheet Q4. It is noted that target C is a lighthouse, marking the middle of the separation zone. The plot covers the period from 1218 hrs to 1236 hrs. a) Prepare a full report for targets A, B and D. (15) b) Analyse the situation at 1236 hrs. (15) c) State, with reasons, an action a prudent master could take at 1242 hrs to resolve the situation and ensure that all targets have a CPA of at least 1 mile. (20)
94
95
a) 12:36 – 12:18 = 00:18 x 10.0 = 3.0 NM A TB 145 Tendency Drawing aft slowly Range 7.0 NM Tendency Decreasing CPA 234 x 0.2 NM TtCPA 7.0 ÷ 2.0 x 00:18 = 01:03 ToCPA 13:39 Co 076½ Sp 1.6 ÷ 00:18 = 5.3 kn Aspect Red 113½
B 270 Steady 4.0 NM Decreasing 0.0 NM 4.0 ÷ 2.0 x 00:18 = 00:36 13:12 105 4.9 ÷ 00:18 = 16.3 kn Red 015
D 040 Steady 1.0 Steady 038 x 1.0 Infinite Never 115 10.0 kn Green 104
b) A Starboard Bow, crossing, collision course. B Starboard Quarter, overtaking, collision course. D Port beam, same course and speed. Set 021½ Rate = 0.9 ÷ 00:18 = 3.0 kn c) AC to 137½ minimum, 155 preferable. C is stationary. AC for A, R19, not to Port. Sufficient to increase CPA of B to >1.0 NM. Readily seen by other vessels. Places A on port bow. Away from D. A has CPA in >01:00, not inconvenienced. Away from TSZ. Stopping will not result in an adequate CPA for Target B.
5. A tug and tow is due to transit through the Seymour Narrows, British Columbia at 0840hrs Standard Time on the 20 th March. The maximum speed of the tow is 9.0 knots and the vessel is steering a course of 180° (T) during the transit. a) With reference to the Pacific and Atlantic Ocean Tide Tables and using Worksheet Q5, determine the vessel’s speed over the ground at 0840hrs. (12) b) Discuss the implications of the vessel’s speed determined in Q5(a), including any actions that the Master should take. (7) a) 00:30 03:20 06:20 09:40 12:40 15:50
0.0 11.1 0.0 -13.2 0.0 13.4
Values calculated, plotting may give different results. 08:40 Set 000 Rate 11.8 Speed 9.0 – 11.8 = -2.8 kn Vessel is making sternway over the ground at 2.8 knots. Vessel should anchor until the stream slackens below 9 knots, at approximately 11:14.
96
97
November-2007 All questions refer to a 100,000 tonne product tanker which is to make a fully laden passage from Belize (Central America) to Southampton (UK) in mid September. 1. The vessel's owners have requested that the Master follow the shortest possible route, as per Ocean Passages of the World, to a landfall position 5 miles South of Bishop Rock. (49 47.0 N 006 27.0 W) Using Datasheets Q1(1), Q1(2) and Q1(3) a) Analyse the possible routes that the vessel could follow and determine the most suitable route, stating the distance on passage. (25) b) For the route chosen in Q1a, describe sequentially, the navigational hazards the vessel will encounter until the vessel clears the Caribbean. (15) a) Possible Routes. 4.29.4 Turks Island Passage via Windward Passage. Belize 1030 NM + Bishop’s Rock 3450 = 4480 NM 4.29.5 Mona Passage. Belize 1180 NM + Bishop’s Rock 3470 = 4650 NM 4.29.6 Sombrero Passage. Belize 1410 NM + Bishop’s Rock 3310 = 4720 NM 4.29.7 Saint Lucia/Saint Vincent Passage. Belize 1590 NM + Barbados 85 NM + Bishop’s Rock 3410 NM = 5085 NM 4.21 Belize. Providence Channels or Turks Island Passage and Windward Passage are suitable. Belize, Yucatan Channel, Florida Strait, NE Providence Channel. Greater distance? Distance not available from data sheets provided. More navigational hazards, Yucatan Channel, NE Providence Channel. 4.1 Most hurricanes track north of Cuba. 4.11 Strong currents in Yucatan Channel. 4.16 Crooked Island Passage and Caicos Passage, longer distances than Turks Island Passage. Belize, Windward Passage, Turks Island Passage. Shortest Distance. Fewer navigational hazards. Adverse current. Decision, Rhumb Lines through Windward Passage to Turks Island Passage, Great Circle to Bishop’s Rock. 4.29.4 Turks Island Passage via Windward Passage to Belize TIP E BRLF DLon
1030 miles.
21 48 N 071 16 W 49 47 N 006 27 W 064 49 E
Dis = cos-1 (cos DLon x cos Lat A x cos Lat B ± sin Lat A x sin Lat B) = cos-1 (cos 064 49 x cos 21 48 x cos 49 47 ± sin 21 48 x sin 49 47) = 57 24 22.63 x60 = 3444.37709 Turks Island Passage to Bishop Rock Landfall = 3444.4 NM Total Distance = 1030 + 3444.4 = 4474.4 NM b) Mid September, Northern Hemisphere, TRS season. TRSs may be encountered at any point of the passage in the Caribbean. Periods of heavy rain and thunderstorms are frequent. 98
Chartlet. Course close to banks near Grand Cayman. 4.1 Squalls may occur at any time. Reduced visibility in rain. 4.5 High swells on western side. 4.11 WNW current. 4.15 Old and imperfect surveys of areas, care near cays and banks. Depths less than charted due to coral growth. Banks are steep-to, little warning from echo-sounder. 4.15.1 Strong currents in entrance channels, Windward Passage through to Turks Island Passage. 4.16 Turks Island Passage not lighted in its southern approach, not recommended for N-bound vessels at night. WNW current in Atlantic affecting transit of Turks Island Passage.
2. At 15:30 hours UT on the 21st September, whilst in DR position 18 50.0 N 080 00.0 W the vessel receives the following tropical storm advisory from the National Hurricane Centre in Miami. The vessel is currently making 17 knots on a course 0f 080 T. 21st September 15:00 hrs UT Tropical Storm Grace Position 16 45.0 N 067 00.0 W Central Pressure 976 hPa Predicted Track 295 T at 17 knots Forecast Winds 60 knots within 90 NM 50 knots within 130 NM 40 knots within 170 NM Storm is expected to maintain track for the next 24 hrs and reach hurricane intensity within the next 12 hours. a) Using Worksheet Q2: i) plot the position of the vessel and the storm centre at 15:30 hrs UT. (4) ii) indicate the likely positions of the storm centre for the next 12 and 24 hours. (4) b) Briefly describe the changing weather conditions that the vessel would expect to encounter if it were to maintain its present course and speed for the next 24 hours. (16) c) Outline the possible courses of action open to the Master to avoid the worst of the storm, indicating which one would be most suitable if action was taken at 1830 hrs UT. (16) a)i) 17 x 12 = 204 NM ÷ 60 = 3° 24'
99
100
b) The course goes overland Jamaica and Haiti. Hurricane Intensity is 65 knots, little more than present maximum. Initially the vessel is outside the storm field. Vessel will experience trade wind conditions, with a swell from the direction of the storm. Pressure: Seasonal normal, with diurnal variation. Wind: ENE f4, Wind waves: ENE 1 metre Swell: ESE 5 metres. Cloud amount: 3/8 Cloud types: Cumulus / Cumulonimbus. Precipitation: Showers. At approximately 21/23:30 UT vessel will reach the coast of Jamaica and cannot proceed further on the course. At approximately 22/10:00 UT TRS will reach the coas t of Hispaniola. Thereafter it is likely to be decreasing in intensity over land. The vessel will not enter the storm field, and conditions will not change significantly.
101
Assuming that the latitude scale is incorrectly placed one degree low.
102
22/03:00 Approximately. The storm will move overland Hispaniola. It will then interact with the land and significantly decrease in intensity and the storm field will diminish. The path is also likely to change as a result of interaction with land. Assuming that the path and intensity remain unchanged. Trade wind conditions will persist. The swell will diminish as the vessel passes north of Jamaica, and then increase steadily in height. 22/09:00 Storm will be approximately 100° x 240 NM from the vessel. 22/15:30 Storm will be approximately 120° x 30 NM from the vessel. From 22/09:00 approximately until 22/15:30. The vessel will begin to enter the storm field, and be sheltered from the swell by Hispaniola. Pressure: Diurnal Variation will cease, then pressure will decrease sharply toward the minimum as the vessel and storm converge. Wind direction: Backing to NWly, then veering to NNEly through the rest of the period. Wind force: Increasing through 35 kn to >65 kn. Wind Wave height: Lower than expected for the wind force, as there is little fetch from the coast of Cuba to the vessel. Increasing to approximately 3m. Swell direction: Changing to Sly as vessel moves north of Hispaniola, swell is refracted. Then coming from ENEly as storm field moves over Atlantic Ocean. Swell height: Less than expected from proximity of storm due to shelter of Hispaniola and loss of energy due to refraction. Then due to short duration of wind over Atlantic. Approximately 3m. Cloud cover: Increasing to 8/8. Cloud types: Cirrus of the Canopy, becoming obscured by Cumulonimbus increasing in depth and coverage. Precipitation: Increasing in frequency and intensity. Visibility: Initially good, deteriorating in precipitation, and further with spray in intense winds near eye. The vessel may enter the Eye of the storm. Pressure: Steadies at the minimum. Wind direction: Becomes variable. Wind force: Decreases to light airs. Wind Wave height: Decreases to slight. Swell direction: Becomes confused, probably predominantly from NEly. Swell height: Less than expected from proximity of storm due to short duration of wind north of Hispaniola. Approximately 3m. Cloud cover: Decreasing to approximately 2/8. Cloud types: Towering cumulus of Eye Wall around vessel. Precipitation: Ceases. c) 1. Proceed in a WSW direction. This will maximise the distance from the current storm path, and probably keep the vessel clear of the storm field if the path varies by up to 40° and the speed of movement increases to an extent. 2. Proceed in a SSW direction. This will maintain the distance from the current storm path, and probably keep the vessel clear of the storm field if the path varies by up to 40° and the speed of movement increases to an extent. 3. Stop the vessel and allow the storm to pass before proceeding. The vessel is in open water, and can take evasive action in good time if the storm path changes westward. 4. Proceed at reduced speed south of Jamaica in the lee of the island. This allows the vessel to make some progress while maintaining an escape route. 103
5. Proceed at reduced speed north of Jamaica until the storm has passed ahead. Vessel is proceeding into restricted waters, and may not be able to take effective evasive action. 1. Is the most suitable of these for the reasons given. Monitor communications and current conditions to detect any change in the storm's path.
3. The vessel has successfully cleared the storm and exited the Caribbean, the vessel receives new orders to proceed to Antwerp via the Dover Straits. The British Admiralty produces Admiralty Routeing Charts and also a number of charts that give passage planning guidance for certain areas of the world. a) Compare and contrast the different types of information contained in each of the above and comment on how they may be used by the navigator. (30) b) Explain how the Master of a deep draught vessel can make use of Co-Tidal/Co Range Charts when planning a passage through shallow, confined waters. (15) 512X (Y) Routeing Charts. Show climatological data for each ocean and month of the year. Wind roses. Predominant ocean currents. Shipping routes and distances. Sea ice and iceberg limits. Loadline Zone limits. Inset chartlets of: Air pressure and temperature. Dewpoint and sea temperature. Percentage fog and low visibility. Tropical storm tracks and percentage wind greater than force 7. 5500 Mariner's Routeing Guide North Sea and English Channel Shows the following: Admiralty Charts and Publications relevant to the Area. 1. Passage Planning Using This Guide. 2. Routeing: General Rules and Recommendations. 3. Routeing: Special Rules and Recommendations. 4. Passage Planning: Special Classes of Vessel. 5. Oil and Dangerous Cargoes: Marine Pollution. 6. Radio Reporting Systems Applying to Through Traffic. 7. Reporting to a Port of Destination in the Area. 8. Maritime Radio Services. 9. Tidal Information and Services. 10. Pilot Services. Passage Planning Charts. Routeing Charts contain climatological data for the relevant month and area, and a small amount of routeing data. They are used to predict the weather on a proposed passage o n a climatological basis, and to make routeing decisions to achieve an optimum route with regard to meteorological and oceanographic factors. Mariners' Routeing Guides contain information about s ervices available and legal requirements relevant to passage planning through the area covered. They contain a relatively small amount of oceanographic data. They are used to assist in planning passages through the area and ensure that legal requirements are observed. Admiralty Sailing Directions should be used in conjunction with these charts when planning coastal passages. 104
b) Co-Range/Co-Tidal charts show: Amphidromic points in the area. Isopleths of Mean High Water Interval, Mean Low Water Interval, Mean Spring Range and Mean Neap Range. Positions of ports in the area. Standard Ports in the area with Time Intervals and Tidal Ranges. The time at which a required height of tide occurs, or the height of tide at a particular time can be found for a point off shore. The tidal data for a port, ideally a standard port, centred on the same amphidromic point as that being considered, is used. This information allows planning and speed adjustment to maintain adequate UKC and pass critical points at high water or with a rising tide. (Extract the High and Low Water times and heights for the Standard Port. Determine whether the tides are Springs or Neaps from the mean range. Extract the Mean High Water and Mean Low Water Intervals for the Standard Port and the positon. Apply the differences between the two sets of times to those extracted from the tide tables. Extract the co-range data for the standard port and the position from the appropriate Mean Spring or Neap Range chart. Calculate the Factor by dividing the mean range at the position by the mean range at the standard port. Multiply the ranges obtained from the tide tables by the factor. When the tide lies between springs and neaps obtain factors from both charts and interpolate. For heights at intermediate times, or times of intermediate heights, find the duration and range of tide at the position, then use the Pacific tidal procedure.)
4. At 0400 hrs, whilst proceeding in the NE bound lane of the Straits Traffic Separation Scheme, four targets are plotted on radar, over a 20 minute period, as shown on Worksheet Q4. Visibility was estimated to be 0.5 miles and the vessel was steering 015°(T) at 12 knots. Target A has been identified as a lighthouse. An extensive area of shoal water lies 4 miles to starboard. a) Analyse the situation at 0420 for targets B, C and D. (15) b) Determine the set and rate of the tide affecting the vessel. (5) c) Outline the action the Master should take at 0425 hrs the ensure that targets C & D have minimum CPA of 2.0 miles and any subsequent action necessary, stating full reasons for the answer. (25) a) WO = 12 kn x 00:20 = 4.0 NM B OA 1.6 NM ÷ 00:20 = 4.8 kn AC = 4.3 nm ÷ 4.8 kn = 00:54 + 04:20 = 05:14 WA = 5.5 nm ÷ 00:20 = 16.5 kn C OA 2.7 NM ÷ 00:20 = 8.1 kn AC = 3.5 nm ÷ 8.1 kn = 00:25 + 04:20 = 04:45 WA = 4.6 nm ÷ 00:20 = 13.8 kn D OA 4.6 NM ÷ 00:20 = 13.8 kn AC = 5.0 nm ÷ 13.8 kn = 00:22 + 04:20 = 04:42 WA = 3.7 nm ÷ 00:20 = 11.1 kn
105
Full Report Bearing and tendency Range and tendency CPA Time to / of CPA Target track and speed Aspect
B 161 drawing forward 4.4 NM decreasing 085 x 1.2 NM 00:54 at 05:14 010 x 16.5 kn Red 29
C 291 steady 3.5 NM decreasing 0.0 NM 00:25 at 04:45 050.5 x 13.8 kn Green 60.5
D 325 steady 5.0 NM decreasing 0.0 NM 00:22 at 04:42 088 x 11.1 kn Green 57
Analysis B On starboard quarter, overtaking to starboard. C On port beam, converging, collision course. D On port bow, crossing to starboard, collision course. b) A AW 094 x 0.9 nm ÷ 00:20 = 2.7 kn c) 00:05 A OA = 4.2 ÷ 4 = 1.1 NM B 1.6 ÷ 4 = 0.4 NM C 2.7 ÷ 4 = 0.7 NM D 4.6 ÷ 4 = 1.1 NM C and D are going to be in a close quarters situation at 04:42. Reduce speed. WO' = 1.6 NM ÷ 00:20 = 4.8 kn An alteration of course to port is prohibited in reduced visibility. An alteration of course to starboard produces a very slow relative movement, and brings the vessel toward the shoal ground. The tidal stream is setting toward the shoal ground. Monitor the movements of all vessels. C and D in particular as they are likely to manoeuvre. A O’A = 2.0 NM ÷ 00:20 = 6.0 kn B O’A = 3.8 NM ÷ 00:20 = 11.4 kn A CPA 1.8 NM P-CPA = 4.5 NM ÷ 6.0 kn = 00:45 B CPA 2.0 NM P-CPA = 3.6 NM ÷ 11.4 kn = 00:19 In approximately 00:20 it should be practicable to resume speed. Course will have to be adjusted to compensate for the tide.
106
107
5. A vessel is due to enter the port of Antwerp via the locks at Boudewijnsluis (European Tide Tables port no 1539a). The vessel is expected to arrive off the lock entrance on the AM flood tide on the 18th April. The charted depth of the lock sill is 6.8 m and the vessel's draught is 9.8 m. The vessel must clear the locks with 1.5m under the keel. Using Worksheet Q5, determine the earliest time (UT) the vessel can enter the locks. (30)
Waterline Draft 9.8
HoT 4.5
Keel
CD UKC 1.5 Charted Depth 6.8
HoT = Draught + Under Keel Clearance - Charted Depth = 9.8 + 1.5 - 6.8 = 4.5 m Standard Port Time/Height required Secondary Port Date Time Zone Standard Port Seasonal Change Uncorrected Height Differences Uncorrected Height Seasonal Change Secondary Port Duration
Antwerp 4.5 m Boudewijnsluis Apr 18 AM Flood - 01:00 Time LW 00:28 Standard Port Standard Port +00:25 Secondary Port Secondary Port 00:53
1539 1539a
Height HW LW HW Range 06:03 0.2 5.6 5.4 - -0.1 - -0.1 0.3 5.7 +00:06 0.0 0.0 0.3 5.7 -0.1 -0.1 0.2 5.6 06:09
Differences. 5.8 5.7 4.2 0.0 +0.1 0.0 + (5.7 – 5.8) ÷ (4.2 - 5.8) x (0.1 – 0.0) = -0.0 Or, by inspection… 1.0 0.3 0.0 0.0 0.0 0.0 + (0.3 - 1.0) ÷ (0.0 - 1.0) x (0.0 – 0.0) = 0.0 Or, by inspection… 05:00 06:03 12:00 +00:05 +00:25 00:05 + (06:03 – 05:00) ÷ (12:00 – 05:00) x (00:13 – 00:05) = 00:06 Ranges Springs 5.8 m Range 5.4 m Neaps 3.2 Proportion = (Predicted Range – Neap Range) ÷ (Spring Range – Neap Range) = (5.4 -3.2) ÷ (5.8 – 3.2) = 0.85 108
HW Interval Required Time Time Difference Required Time
06:09 ST 01:08 – 05:01 ST 01:00 – 04:01 UT
109
110
