DieselShip's Online Content Library

Q1. a) Describe a method of the attachment of bilge keels. (5)

b) State THREE reasons for not extending bilge keels the entire length of the vessel. (6)

c) Explain TWO principles of roll damping that bilge keels exploit. (5)

Q5. With reference to membrane tanks for the carriage of liquefied gas at very low temperatures.

a) Describe with a sketch one method of building up the insulation. (6)

b) State which alloy is used for the membrane and the reason. (5)

c) Explain why a secondary barrier is installed. (5)

Q1. A. Explain in detail, how an underwater survey is carried out. (7)

B. State the requirements to be fulfilled before an underwater survey is acceptable to the survey authority. (5)

C. Construct a list of the items in order of importance that the underwater survey authority should include. (4)

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Q3. With reference to Underwater Inspection in lieu of Dry docking (UWILD)

A. Explain in detail, how an underwater survey is carried out. (6)

B. State the requirements to be fulfilled before an underwater survey is acceptable to the survey authority. (5)

C. Construct a list of the items in order of importance that the underwater survey authority should include. (5)

Q5. a) Sketch the cross-section of a bulk carrier with either deep or shallow double bottom showing the type of framing used. (8)

b) i) Describe the corrosion problems experienced with ballast tanks. (4)

ii) State how such tanks are protected against extensive corrosion. (4)

Q3. With regard to ship construction details for transverse watertight bulkheads: -

A. State the purpose of this type of bulkhead;

B. State how the bulkheads are tested for water tightness;

C. If it is necessary to penetrate the bulkhead, precaution must be taken to ensure that the watertight integrity and the strength of the bulkhead is maintained. In view of above, describe, using simple sketches, how the following pass through bulkheads.

i. Main transmission shaft;                ii. Electrical cables;

iii. Fuel oil transfer pipes;                iv. Air and sounding pipes.

Q6. A. Explain the purpose of non-watertight longitudinal subdivision of tanks. B. A ship 90 long displaces 5200 tonne and floats at draughts of 4.95m forward a nd 5.35 m aft when in sea water of 1023 kg/m3. The waterplane area is 1100m2, GML 95m, LCB 0.6m forward of midships and LCF 2.2m aft of midships. Calculate the new draughts when the vessel moves into fresh water of 1002 kg/m3

Q9. (a) Describe how thrust power is determined. (6)

(b) The following information relates to a model propeller of 400mm pitch:

(i) Plot curves of thrust and torque against rev/min

(ii) When the speed of advance of the model is 150 m / min and slip 0.20, calculate the efficiency.

Q8. A. Explain why the amplitude of ship motion should be limited B. A ship of 8100 tonne displacement floats upright in seawater. KG = 7.5m and GM = 0.45m A tank, whose centre of gravity is 0.5m above the keel and 4m from the centreline, contains 100 tonne of water ballast neglecting free face effect, calculate the angle of heel when the ballast is pumped out.

Q9. a) Explain the effect of bilging a centreline compartment located away from amidships. (6)

B. A ship of 5000 tonne displacement has a double bottom tank 12m long. The ½ breadths of the top of the tank are 5, 4 and 2m respectively. The tank has a watertight centreline division. Calculate the free surface effect if the tank is partially full of fresh water on one side only. (10)

Q6. A. Describe the stability requirements of a ship for dry-docking.

B. A ship of 8000 tonne displacement, 110m long, floats in sea water of 1.024t/m3 at draughts of 6m forward and 6.3 m aft. The TPC is 16, LCB 0.6 m aft of midships, LCF 3m aft of midships and MCT1cm 65 tonne m, the vessel now moves into fresh water of 1.000t/m3. Calculate the distance a mass of 50 tonne must be moved to bring the vessel to an even keel and determine the final draught.