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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.

Q4. With reference to Underwater Inspection in lieu of Dry  docking (UWILD)

A. Explain in detail, how an underwater survey is carried out;

B. State the requirements to be fulfilled before an underwater survey is acceptable to the survey authority.

C. Construct a list of the items in order of importance that the underwater survey authority should include.

Q6. A. Describe briefly the significance of the factor of sub-division;

B. A box shaped vessel 65m X 12m X 8m has KG 4m and is floating in self water upright on an even keel at 4m draft F and A. Calculate the moments of statically stability at i. 5 degrees and ii. 25 degrees’ heel.

Q4. A. Explain why the GM must remain positive until the critical instant at which the ship takes the blocks overall. B. A Ship of 5000 tonnes displacement enters a dry dock trimmed 0.45m by the stern. KM=7.5m., KG=6.0m. MCTC=120 tonnes-m.  The centre of flotation is 60m. Frome aft. Find the effective metacentric height at the critical instant before the ship takes the blocks overall, assuming that the transverse metacentre rises 0.075m.

Q6. 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 15000 tonne displacement has righting levers of 0, 0.38, 1.0, 1.41 and 1.2 m at angles of hell of 0 , 15 , 30 , 45  and 60  respectively and an assumed KG of 7.0 m.  The vessel is loaded to this displacement but the KG is found to be 6.80m and GM 1.5m –

(i) Draw the amended stability curve; (ii) Estimate the dynamic stability at 60

Q1. A. Sketch a transverse section through the hold space of a container ship hull;

B. Referring to the sketch in (A) describe how adequate structural strength is built into the hull.

Q4. A. Define the purpose of cofferdams,

B. State where cofferdams are most likely to be found on:

(i) Dry cargo ships;

(ii) Oil tankers.

C. (i) State what information is available about danger of entering void spaces.

(ii) Identify, with reasons, the precaution to be observed before and during entry to cofferdams.

Q2.A. Describe the arrangement of tank top and double bottom in the machinery space making particular reference to the structure and scantlings below the main engine.

B. Show the method adopted in the arrangement of D.B. tanks to avoid contamination of fresh water, fuel oil and lube oil stored in D.B. tanks.

Q10. A. Explain the effects on stability when a tank is partially filled with liquid.

B. A ship of 11200 tonne displacement has a double bottom tank containing oil. Whose centre of gravity is 16.5m forward and 6.6m below the centre of gravity of the ship? When the oil is used the ship’s centre of gravity moves 380mm calculate - (i) The mass of oil used; (ii) The angle which the centre of gravity moves relative to the horizontal.