DieselShip's Online Content Library

Q1. Explain the following:

(a) Subdivision (4)

(b) Margin line (4)

(c) Floodable length (4)

(d) Watertight bulkhead penetration (4)

Q2. (a) Define any six types of ship motions. (6)

(b) In the context of ship stability, what does static stability refer to: (10)

(i) The ship's resistance to rolling in waves.

(ii) The ship's ability to return to equilibrium after a displacement without wave action.

(iii) The dynamic response of a ship in irregular seas.

(iv) The resistance to hull slamming.

Briefly justify your answer.

Q3. (a) Explain why a Spectacle Frame and Boss Plates are fitted to twin screw ships. (8)

(b) Make a simple sketch of a Spectacle Frame showing how it is attached to the ship structure and to the Boss Plates. (8)

Q4. (a) Sketch the arrangement of rudder stock, bearings, glands and method of suspension of a pintleless rudder, labelling the components parts. (8)

(b) State how the bearing wear down is measured and what prevents the rudder from jumping? (8)

Q5. Describe the construction of chain lockers and how cables are secured in the lockers? Explain how to secure anchors in preparation for a sea passage. (16)

Q6. (a) Explain in brief the term 'bulwark' and 'freeing port'. (6)

(b) A ship has 300 t of cargo in the hold, 24 m forward of the midships. The displacement of the vessel is 6000 t and its centre of gravity is 1.2 m forward of midships. Find the new position of the centre of gravity if this cargo is moved to an after hold, 40 m from midships. (10)

Q7. (a) What is Freeboard of a Ship? Why oil tankers have less freeboard? (6)

(b) A ship’s length at the waterline is 180 meters, with a maximum beam of 30 meters and a draft of 9 meters. If the ship’s volume of displacement is 38,880 cubic meters, calculate its block coefficient. (10)

Q8. The half-ordinates of a ship’s water-plane, which is 80 m long, commencing from forward at equal intervals, are as follows: 0.2, 4.0, 5.0, 5.2, 5.0, 4.0 and 0.2 m respectively. Calculate the area of the water-plane using Simpson’s First Rule.

Q9. (a) What is the purpose of conducting inclining experiment on a new vessel? (6)

(b) A ship of 12400 tonne displacement is 120 m long, 17.5 m beam and floats at a draught of 7.5 m. The propeller has a pitch ratio of 0.75 and, when turning at 100 rev/min, produces a ship speed of 12 knots with a real slip of 30%. Calculate the apparent slip, pitch and diameter of the propeller. The wake fraction w may be found from the expression, w = 0.5Cb – 0.05 (10)