DieselShip's Online Content Library

Q3. A. Explain what is meant by permissible length of compartments in passenger ships;

B. Describe how the position of bulkheads is determined.

C. Describe briefly the significance of the factor of subdivision.

Q1. 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; B. State which alloy is used for the membrane and the reason; C. Describe with the aid of a sketch, how the tanks are located and supported. i) Longitudinally; ii) Transversely

Q2. State how and why the following machinery items are effected when the maximum service speed of a Vessel is consistently maintained in heavy weather.

A. Intermediate shafting,

B. Propeller shafting,

C. Shafting coupling bolts,

D. Main thrust pads.

Q1. A. Sketch the cross-section of a bulk carrier with either deep or shallow double bottom showing the type of framing used;

B. Describe the corrosion problems experienced with ballast tanks;

C. state how such tanks are protected against extensive corrosion.

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 how wave profile affects the shear force and bending moment curves. B. A ship 125m long displaces 12000 tonne. When a mass of 100 tonnes is moved 75m from forward to aft there is a change in trim of 65 cm by the stem. Calculate - MCTI cm; The longitudinal metacentric height; The distance moved by the centre of gravity of the ship.

Q7. A. what is the effect on fuel consumption per unit time, if the ship’s speed is outside its operation range? B. The frictional resistance of a ship in fresh water at 3m/s is 11N/m2.  The ship has a wetted surface area of 2500m2 and the frictional resistance is 72% of the total resistance and varies as speed 1.92.  If the effective power is 1100Kw, calculate the speed of the ship.

Q8. A. List the variables which affect the force on a rudder. B. A propeller of 4m pitch has an efficiency of 67%.  When turning at 125 rev/min the real slip is 36% and the delivered power 2800Kw.Calculate the thrust of the propeller.

Q9. A. Explain what is meant by torsional stress B. The ½ ordinates of a water plane at 15m intervals, commencing from aft, ar. 1, 7, 10.5, 11, 11, 10.5, 8, 4 and 0m. Calculate: i. TPC; ii. Distance of the centre of flotation from midships. Iii. Second moment of area of the water plane about a transverse axis through the centre of flotation.

Q10. A. List the main factors which affect the rolling period of a vessel; B. A box-shaped vessel is 20 m long and 10 m wide.  The weight of the vessel is uniformly distributed throughout the length and the draught is 2.5 m.  The vessel contains ten evenly spaced double bottom tanks, each having a depth of 1m. Draw the shear force diagrams: With No.1 and No.10 tanks filled; With No.3 and No.8 tanks filled; With No.5 and No.6 tanks filled. Which ballast condition is to be preferred from the point of view of strength?