CON & NA-JAN-2020

Q1. With reference to Roll-on Roll-off ferries –

A. Describe the problem of free surface effect;

B. Explain how it is intended that water should be cleared from car or cargo decks;

C. Describe possible methods for improving the stability and survivability of these vessels.

Q2. A rudder of a vessel requires extensive welding repairs and as a Chief Engineer you are requested to supervise ; A. Suggest a suitable type of welding process; B. State with reasons FOUR common welding defects that can occur there; C. State what tests may be carried out before returning the rudder to service.

Q3. With reference to International Load Line Statutory Certification,

A. State the reasons for the freeboard requirements;

B. (i) Explain the term conditions of assignments

(ii) List the items that may be examined during a related survey after major repairs in the drydock.

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. With reference to fatigue of engineering components:

A. Explain the influence of stress level and cyclical frequency on expected operating life;

B. Explain the influence of material defects on the safe operating life of an engineering component;

C. State the factors which influence the possibility of fatigue cracking of a bedplate transverse girder and explain how the risk of such cracking can be minimized.

Q6. 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.
 

Q7. 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.
 

Q8. The speed of a ship is increased to 18% above normal for 7.5 hours, and then reduced to 9% below normal for 10 hours. The speed is then reduced for the remainder of the day so that the consumption for the day is the normal amount. Find the percentage difference between the distance travelled in that day and the normal distance travelled per day.
 

Q9. An oil tanker 160m long and 22m beam floats at a draught of 9m in seawater. Cw is 0.865. The midships section is in the form of a rectangle with 1.2m radius at the bilges. A midships tank 10.5m long has twin longitudinal bulkheads and contains oil of 1.4 m3/t to a depth of 11.5m. The tank is holed to the sea for the whole of its transverse section. Find the new draught.
 

Q10. 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.