DieselShip's Online Content Library

Q1. (a) What are the various Static stresses that act on a vessel at rest in still water? Explain with the aid of sketches. (10)

(b) Give examples for dynamic stresses on a vessel? (6)

Q2. a) What are the basic type of cargo tanks utilized on board gas carriers? (6)

b) Sketch and describe a membrane type tank for a LNG tanker. (10)

Q2. (a) What is bilging and What are the effects of bilging? (8)

(b) How are bulkheads classified? (3)

(c) What are the advantages of water tight bulkheads? How is the water tight bulkhead tested? (5)

Q5.a) What is free surface effect. (6)

b) Explain the methods used to reduce the free surface effect in ship construction and while operating the ship. (10)

Q5.a) Name the different type of rudders. (6)

b) Draw a labelled sketch of an unbalanced rudder fitted onto a rudder post (10)

Q6. a) Explain, with reference to moments about the Centerline, how the list may be removed. (6)

b) A ship of 12,250 tonnes displacement, has KM=8 metres, KB=3.8 metres, KG=8 metres and is floating upright. Find the list if a weight of 2 tonnes, already on board, is shifted transversely through a horizontal distance of 12 metres assuming that the ship is wall-sided (10)

Q6. (a) What is the significance of GM-GZ curve. (6)

(b) The pitch of a propeller is measured by means of a batten and cord. The horizontal ordinate is found to be 40 cm while the vertical ordinate 1.15 m at a distance of 2.6 m from the centre of the boss. Calculate the pitch of the propeller and the blade width at that point. (10)

Q9. a) Explain why an unstable ship is dangerous. (6)

(b) A vessel travelling at 17 knots turns with a radius of 450 m when the rudder is put hard over. The centre of gravity is 7 m above the keel, the transverse metacentre 7.45 m above the keel and the centre of buoyancy 4 m above the keel. If the centripetal force is assumed to act at the centre of buoyancy, calculate the angle of heel when turning. The rudder force may be ignored. (10)

Q7. (a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A lock gate which is 15m wide has salt water on one side to a depth of 8m and fresh water on the other side to a depth of 9m. Find the resultant thrust on the lock gate and state on which side of the gate it acts. (10)

Q1. (a) What is a right-handed and a left-handed propeller? (4)

(b) With the aid of simple sketches explain Rake, Skew and Pitch of the propeller. (6)

(c) What are the advantages and disadvantages of CPP? (6)

Q2. a) With respect to oil tankers, what are LR1, LR2, VLCC and ULCC? (4)

b) Sketch the mid ship section of a double hulled oil tanker with centre tank and wing tanks (12)

Q2. Define the main purpose of the following with respect to tank and pumping system.
(a) Weighted cocks on tank sounding pipes (4)

(b) Remote operated gear for bilge valves (4)

(c) Ventilation pipes for double bottom tanks (4)

(d) Explain why gauze is sometimes fitted to tank ventilation pipes and explain the effect of mesh size. (4)

Q3. Briefly explain the following ship terms used:

(a) LOA (2)

(b) LBP (2)

(c) Breadth Extreme (2)

(d) Breadth Moulded (2)

(e) Depth Extreme (2)

(f) Depth Moulded (2)

(g) Draught Extreme (2)

(h) Draught Moulded (2)

Q4. Define centre of buoyancy and show with the aid of sketches how a vessel which is stable will return to the upright after being heeled by an external force. (16)

Q6. a) State why cargo ships must have collision bulkheads. (6)

b) A double bottom tank is 1.2 m deep and has a sounding pipe extending 11 m above the tank top. The tank is filled with oil (rd 0.89) to the top of the sounding pipe. The double bottom floors are spaced 750 mm apart and are connected to the tank top by riveted angles, the rivets having a pitch of 7 diameters. If the maximum allowance stress in the rivets is 30 MN/m2, calculate the pressure in kN/m2 on the outer bottom and the diameter of the rivets. (10)

Q7. a) Define TPC. Explain why TPC for a given draught will vary with the density of the water in which the ship floats? (6)

b) The pitch of a propeller is measured by means of a batten and cord. The horizontal ordinate is found to be 40 cm while the vertical ordinate 1.15 m at a distance of 2.6 m from the centre of the boss. Calculate the pitch of the propeller and the blade width at that point. (10)

Q8. a) Explain clearly the meaning of the term "reserve buoyancy". (6)

b) The centre of gravity of a ship of 5000 tonne displacement is 6 m above the keel and 1.5 m forward of midships. Calculate the new position of the centre of gravity if 500 tonne of cargo are placed in the t’ween decks 10 m above the keel and 36 m aft of midships. (10)

Q9. a) Explain what is meant by synchronous or resonant vibration (6)

b) A ship's speed is increased by 20% above normal for 8 hours, reduced by 10% below normal for 10 hours and for the remaining 6 hours of the day the speed is normal. Calculate the percentage variation in fuel consumption in that day from normal. (10)