DieselShip's Online Content Library

Q2. A virtual rise in the centre of gravity of a ship may be caused by (16)

(a) Filling a partially filled tank

(b) Using an onboard crane to lift a freely swinging heavy object

(c) Emptying a partially filled tank

(d) Transferring pipe from the setback area to the pipe rack Briefly Justify your Answer

Q2. Explain the meaning and purpose of EACH of the following terms:

(a) Bulbous bow (4)

(b) Hawse pipe (4)

(c) Spurling pipe (4)

(d) Cable stopper (4)

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)

Q4. Sketch a plain bulkhead, showing connections to deck, sides and double bottom and the arrangement of stiffeners (16)

Q5. Write short notes on each of the following with respect to their contribution to the strength of ships:

(a) Strake (4)

(b) Bracket (4)

(c) Stringer (4)

(d) Girder (4)

Q6. (a) Describe the provisions of additional structural strength to withstand pounding. (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) Show by means of diagrams how the center of gravity of the liquid in a partly filled tank moves during rolling. (6)

(b) A box barge is 15 m long, 6 m wide and floats in water of 1.016 t/m3 at a draught of 3 m. 150 tonne of cargo is now added. Calculate the load exerted by the water on the sides, ends and bottom. (10)

Q8. (a) Explain what is meant by 'assigned summer freeboard' (6)

(b) A box-shaped vessel 60m long, 10m beam, and 6m deep, is floating in salt water at drafts 4m Forward and 4.4 m. Aft. Find how far forward of amidships a weight of 30 tonnes must be loaded if the draft aft is to remain at 4.4m. (10)

Q9. (a) Explain why the TPC for a given draught will vary with the density of the water in which the ship floats. (6)

(b) A box shaped ship with 12m beam is floating upright at a draft of 6.7 m. Find the increase in draft if the vessel is now listed 18 degrees. (10)

Q4. a) What are the advantages of corrugated bulkheads? (6)

b) Sketch and describe a corrugated transverse watertight bulkhead (10)

Q2. (a) Describe in detail how brittle fracture is instrumental in causing failure of materials. (6) (b) Describe how a material is tested to assess the resistance to this type of failure. (4)

(c) Suggest where this type of failure would be likely and explain how the likelihood of failure is reduced. (6)

Q3. With reference to hull protection against corrosion and fouling, write a brief explanation of each of the following:

(a) Sacrificial anodes (6)

(b) Impressed Current system (6)

(c) Means of preventing marine growth and fouling (4)

Q4. Define the following stating how they affect the ship structure and what component parts of the ship structure help to resist the effect:

(a) Racking (4)

(b) Panting (4)

(c) Pounding (4)

(d) Vibration from engine and propellers. (4)

Q4.a) What is the fundamental purpose of a ‘Load line’ marking on ships? (5)

b) Sketch and describe the features of a ‘Load line’ marking. (6)

c) Name five conditions that must be met before freeboard is assigned to a ship. (5)

Q8. (a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa (6)

(b) A bulkhead 9 m deep is supported by vertical stiffeners 750 mm apart. The bulkhead is flooded to the top edge with sea water on one side only. Calculate: (10)

(a) Shearing force at top

(b) Shearing force at bottom

(c) Position of zero shear

Q6. (a) What is the purpose of conducting an inclining experiment on a new vessel? (6)

(b) When a mass of 6t is moved transversely through a certain distance on a ship of 4300t displacement, the deflection of an 11m pendulum is found to be 120 mm. The transverse meta-centre is 7.25 m above the keel and KG 5.46 m. Find the distance through which 6t was moved. (10)

Q9. A hopper barge of box form 50 m long and 10 m wide floats at a draught of 2 m in seawater when the hopper, which is 15 m long and 5 m wide, is loaded with mud having relative density twice that of the seawater, to the level of the waterline. Doors in the bottom of the hopper are now opened allowing the mud to be discharged. Calculate the new draught. (16)

Q6.a) Sketch and describe the midship section of a bulk carrier, labelling the structural members. (6)

b) A vessel 40 m long has a constant cross-section in the form of a trapezoid 10 m wide at the top, 6 m wide at the bottom and 5 m deep. It floats in sea water at a draught of 4 m. Calculate its displacement. (10)