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Q10. A. List the precautions necessary before an inclining experiment is carried out.

B. A box shaped vessel, 50 metres long × 10 metres wide, floats in salt water on an even keel at a draft of 4 metres. A centre line longitudinal watertight bulkhead extends from end to end and for the full depth of the vessel. A compartment amidships on the starboard side is 15 metres long and contains cargo with permeability 30%. Calculate the list if this compartment is bilged. KG = 3 metres.

Q8. A. Define longitudinal centre of gravity (LCG) and longitudinal centre of buoyancy (LCB).

B. A ship 120m long floats has draughts of 5.50m forward and 5.80m aft; MCT1 cm 80 tonne m, TPC 13, LCF 2.5m forward of midships. Calculate the new draughts when a mass of 110 tonne is added 24m aft of midships.

Q8. A. Explain the use of KN curves. B. A ship of 12000 tonne displacement has a rudder 15m2 in area, whose centre is 5m below the waterline.  The metacentric height of the ship is 0.3m and the centre of buoyancy is 3.3m below the waterline.  When travelling at 20 knots the rudder is turned through 30 .  Find the initial angle of heel if the force Fn perpendicular to the plane of the rudder is given by: Fa=577 Av2 sin  N, Allow 20% for the race effect.

Q1. Describe the relationship between frictional resistance and

(a) Ship’s speed;

(b) the wetted area;

(c) surface roughness;

(d) The length of the vessel.

Q6. A. Describe how water tightness is maintained where bulkheads are pierced by longitudinal beams or pipes.

B. A triangular bulkhead is 7 m wide at the top and has a vertical depth of 8 m.  Calculate the load on the bulkhead and the position of centre of pressure if the bulkhead is flooded with sea water on only side:

(i) to the top edge,               (ii) with 4 m head to the top edge.

Q6. A. Explain the purpose of non-watertight longitudinal subdivision of tanks. B. A ship 90 long displaces 5200 tonne and floats at draughts of 4.95m forward a nd 5.35 m aft when in sea water of 1023 kg/m3. The waterplane area is 1100m2, GML 95m, LCB 0.6m forward of midships and LCF 2.2m aft of midships. Calculate the new draughts when the vessel moves into fresh water of 1002 kg/m3

Q9. (a) Describe how thrust power is determined. (6)

(b) The following information relates to a model propeller of 400mm pitch:

(i) Plot curves of thrust and torque against rev/min

(ii) When the speed of advance of the model is 150 m / min and slip 0.20, calculate the efficiency.

Q8. A. Explain why the amplitude of ship motion should be limited B. A ship of 8100 tonne displacement floats upright in seawater. KG = 7.5m and GM = 0.45m A tank, whose centre of gravity is 0.5m above the keel and 4m from the centreline, contains 100 tonne of water ballast neglecting free face effect, calculate the angle of heel when the ballast is pumped out.

Q9. A. Explain the effect of bilging a centreline compartment located away from amidships. 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.

Q7. A. Describe stability requirement for dry-docking.

B. A ship of 8000 tonne displacement floats upright in seawater. KG = 7.6m and GM = 0.5m. A tank, KG is 0.6m above the keel and 3.5m from the centre line, contains 100 tonne of water ballast. Neglecting the free surface effect, calculate the angle which the ship will heel, when the ballast water is pumped out.