DieselShip's Online Content Library

Q1. Define the term "Freeboard". Sketch and describe the freeboard markings. What factors govern the position of these markings?

Q1. A. Sketch the cross-section of a bulk carrier with either deep or shallow double bottom showing the type of framing used;

B. Describe the corrosion problems experienced with ballast tanks;

C. state how such tanks are protected against extensive corrosion.

Q2. A. Describe the arrangement made in a main structural bulkhead for a watertight door aperture; B. Explain a procedure for ensuring that sliding watertight doors are operated safely. C. Differentiate between the categories of watertight door and state the regulation pertaining each type.

Q4. (a) Sketch a section through a funnel's uptake showing how allowances for expansion and contraction are made and the method of funnel support. (b) Describe the arrangement sketched in (a) making reference to its fittings.

Q8. With reference to the ships anchor cable arrangement using simple sketches, illustrate how the following are attached to the ship. A. Cable Stopper B. Anchor Windlass C. Chain locker end of cable elenchus

Q6. (a) Describe the movement of a ship with negative metacentric height. (b) A ship of 8000 tonne displacement has its centre of gravity 4.5m above the keel and transverse metacenter 5m above the keel when a rectangular tank 7.5m long and 15m wide contains seawater. A mass of 10 tonne is moved 12m across the deck. Calculate the angle of heel:(10) (i) If there is no free surface of water. (ii) if the water does not completely fill the tank.

Q7. A. Explain how to distinguish between list and loll and describe how to return the ship to the upright in each case.  (B) A ship 90 long displaces 5200 tonne and floats at draughts of 4.95m forward and 5.35 m aft when in sea water of 1023 kg/m3. The water plane 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

Q10. (a) Explain what is meant by left and right handed propellers, and also explain the rotation of propellers in a twin-screw ship.

(b) A propeller 6m diameter has a pitch ratio of 0.9, BAR 0.48 and, when turning at 110 rev/min, has a real slip of 25% and wake faction 0.30. If the propeller delivers a thrust of 300 KN and the propeller efficiency is 0.65. Calculate:

i. Blade area;

ii Ship speed;

iii. Thrust power;

iv Shaft power

v. Torque.

Q4. (a) List the components of residuary resistance. (b) A ship model 6m long has a total resistance of 40N when towed at 3.6 knots in fresh water. the ship itself is 180m long and displaces 20400 tonne. the wetted surface area may be calculated from the formula S= 2.57, Calculate ePn for the ship at its corresponding speed in sea water. f (model)fw =0.492; f (ship)sw =0.421; n=1.825.

Q9. (a) Describe the effects on centre of gravity of slack tanks. (b) A box-shaped vessel 100-meter-long x 20 meters wide X 12 meters deep is floating in salt water on an even keel at 6 meters’ draft. A forward compartment is 10 meters long, 12 meters wide and extends from the outer bottom to a watertight flat, 4 meters long 12 meters wide and extends from the outer bottom to a watertight flat, 4 meters above the keel. the compartment contains cargo of permeability 25%. find the new draft if this compartment is bilged.