DieselShip's Online Content Library

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.

Q7. With respect to trim and stability, describe the following - A. Effects on centre of gravity of slack tanks; B. Effect on stability of ice formation on superstructure; C. Effects of wind and waves on ship’s stability; D. Effect of water absorption by deck cargo and retention of water on deck.

Q1. (a) State the reasons for the freeboard requirement, (b) Explain the term condition of assignment and explain how these are maintained for a ship. (c) Using a diagram indicate the freeboard of type A, type B, type B60 and type B100 vessels giving an example of each type.

Q4. Discuss the importance of the following to be examined for meeting EEDI limitations: A. Slimmer vessels with lower block coefficients; B. Long-Stroke engines; C. Low revolution large diameter propellers.

Q5. Regarding the carriage of crude oil and its associated products:

a) (i) State the dangers involved.

(ii) State what publications give guidance on safety.

b) Sketch and describe the operation of an explosimeter suitable for testing pump rooms or tanks.

c) Define the terms lower and upper flammable limits Illustrating your answer by means rough sketch of a hydrocarbon vapour oxygen graph.

Q6. A. Describe the effect of cavitation’s on the propeller blades.

b) A ship has a constant cross-section in the form of a triangle which floats apex down in sea water. The ship is 85 m tong, 12 m wide at the deck and has a depth from keel to deck of 9 m. Draw the displacement curve using 1.25 m Intervals of draught from the keel to the 7 .5m waterline. From this curve obtain the Displacement in fresh water at a draught of 6.50 m. (10)

Q7. A. Explain how wave profile affects the shear force and bending moment curves.

b) The wetted surface area of a container ship is 5946 m2, when travelling at its service speed, the effective power required is 11250 KW with frictional resistance 74% of the total resistance and specific fuel consumption of 0.22 Kg/kW h. To conserve fuel, the ship speed is reduced by 10%, the daily fuel consumption is then found to be 83.0 tonne, Frictional coefficient in sea water is 1.432.

Speed in m/s with index (n) 1.825.

Propulsive coefficient may be. assumed constant at 0.6.

Determine

(i) the service speed of the ship

(ii) the percentage increase in specific: fuel consumption when running at reduced speed. (10)

Q8. A. Explain the purpose of non-watertight longitudinal subdivision of tanks.

b) A box -barge 30 m long and 9 m beam floats at a draught of 3 m. The centre of gravity lies on the centreline and KG is 3.50 m. A mass of 10 tonne, which is already on board, is now moved 6m across the ship.

i) Estimate the angle to which the vessel will heel, using the formula

ii) Compare the above result with the angle of heel obtained by the metacentric formula. (10)

Q9. A. With reference to dynamical stability, describe the effect of an increase in wind pressure when a vessel is at its maximum angle of roll to windward.

(b) A ship of 5000 tonne displacement has three rectangular double bottom tanks A: 12m long and 16m wide; Tank B: 14m long and 15m wide; C 14m long and 16m wide.

calculate the free surface effect for any one tank and state in which order the tanks should be filled when making use of them for stability correction.

Q10. (a) List the variables which affect the force on Rudder (6)

b) A ship of 15000 tonne displacement has an Admiralty Coefficient, based on shaft power, of 420. The mechanical efficiency of the machinery is 83%, shaft losses 6%, propeller efficiency 65% and QPC 0.71. At a particular speed the thrust power is 2550kW.

Calculate:

(i) Indicated power,  (ii) Effective power,   (iii) Ship speed.