DieselShip's Online Content Library

Q1. a) Explain the six types of ship motions along different axes. Discuss the causes of these motions and their impact on the vessel’s stability and performance. (8)

b) Discuss the methods employed to reduce these motions and enhance the vessel’s stability and comfort. (8)

Q2. Explain the GZ (Righting Arm) curve used in ship stability. Discuss its significance, the information that can be obtained from the curve, and its role in assessing a ship’s stability under various conditions. (16)

Q3. Explain the different types of framing systems used in ship construction. Discuss their design, structural arrangement, and advantages in ensuring the vessel’s strength and stability. (16)

Q4. (a) List SIX hazards associated with the carriage of liquefied gas in bulk. (8)

(b) Sketch and describe the details of construction of a free-standing prismatic tank within a gas carrier designed to carry liquefied gas (LPG). (8)

Q5. a) With reference to fatigue of hull structures explain the influence of stress level and cyclical frequency on expected operating life. (6)

b) Explain the influence of material defects on the safe operating life of forged components of stern fittings. (5)

c) State the factors which influence the possibility of fatigue cracking of a bed-plate transverse girder and explain how the risk of such cracking can be minimized. (5)

Q6. a) List the variables which affect the force on a rudder. (6)

b) A triangular bulkhead is 7 m wide at the top and has a vertical depth of 8 m. Calculate the load on the bulkhead and the position of centre of pressure if the bulkhead is flooded with sea water on only side.

(i) to the top edge

(ii) with 4 m head to the top edge. (10)

Q7. A. Explain the effect on GM during the filing of a double – bottom tank. (6)

B. An oil tanker 160m long and 22m beam floats at a draught of 9m in seawater. Cw is 0.865. The midships section is in the form of a rectangle with 1.2m radius at the bilges. A midships tank 10.5m long has twin longitudinal bulkheads and contains oil of 1.4 m3/t to a depth of 11.5m. The tank is holed to the sea for the whole of its transverse section. Find the new draught. (10)

Q8. A. What is meant by the Admiralty Coefficient and the Fuel Coefficient? (6)

B. A ship of 14900 tonne displacement has a shaft power of 4460 kW at 14.55 knots. The shaft power is reduced to 4120 kW and the fuel consumption at the same displacement is 541 kg/h. Calculate the fuel coefficient for the ship. (10)

Q9. A) Describe the stability requirements of a ship for dry-docking. (6)

B) The ½ ordinates of a waterplane at 15m intervals, commencing from aft, are 1, 7, 10.5, 11, 11, 10.5, 8, 4 and 0m. Calculate:

(a) TPC.

(b) Distance of the centre of flotation from midships.

(c) Second moment of area of the waterplane about a transverse axis through the centre of flotation. (10)

Q10. a) Describe the effect of cavitations on the propeller blades. (6)

b) The following data are available from the hydrostatic curves of a vessel.

Calculate the TPC at a draught of 5.05m. (10)