CON & NA-DEC-2020

Q1. Give a reasoned opinion as to the validity of the following assertions concerning ship structure: A. Crack propagation in propeller shaft ‘A’ brackets or spectacles frames is indicative of inadequate scantlings and strength; B. The adequate provision of freeing ports is as critical to seaworthiness as watertight integrity.

Q2. If a ship is seriously damaged under water in way of a large fuel side bunker tank what is the immediate effect and what may ultimately happen? What features in the ship would enhance safety?

Q3.A. Explain what is meant by permissible length of compartments in passenger ships; B. Describe how the position of bulkheads is determined. C. Describe briefly the significance of the factor of subdivision.

Q4. (a) Considering the vessel as a compound beam define Bending moment shearing force. Which is the point of Maximum Bending Moment?

(b) Sketch and Describe Hatch coaming of a large bulk carrier.

Q5. Explain how the period of roll varies with –A. The amplitude of roll; B. The radius of gyration; C. The initial metacentric height; D. The location of masses in the ship.

Q6. A ship 75m long has semi ordinates at the load water plane commencing from forward as follows: 0, 1, 2, 4, 5, 5, 5, 5, 4, 3, 2 and 0 metres respectively. 

The spacing between the first three semi-ordinates and the last three semi-ordinates is half of that between the other semi-ordinates. Find the position of the Centre of Floatation relative to amidships.

Q7. A box barge 45 m long and 15 m wide floats at a level keel draught of 2 m in sea water, the load being uniformly distributed over the full length. Two masses, each of 30 tonne, are loaded at 10 m from each end and 50 tonne is evenly distributed between them. Sketch the shear force diagram and give the maximum shear force..

Q8. 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 if flooded with sea water on only side - (i) to the top edge; (ii) with 4 m head to the top edge.

Q9. A. What is meant by the Admiralty Coefficient and the Fuel Coefficient?

B. A ship of 14900 tonne displacement has a shaft power of 4460 Kw at 14.55 knots. The shaft power is reduced to 4120 kW and the fuel consumption at the same displacement is 541 kg/h. Calculate the fuel coefficient for the ship.
 

Q10. 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 5.80 forward and 5.80m aft; MCTI cm 80 tonne m, TPC 13, LCF 2.5m forward of midships. Calculate the new draughts which a mass of 110 tonne is added 24m aft of midships.