CON & NA-MAR-2021

Q1. A. Sketch a transverse section through the hold space of a container ship hull; 

B. Referring to the sketch in (A) describe how adequate structural strength is built into the hull.

Q2. Describe the effect of the following on the ship’s stability; A. Ice formation on superstructures B. Effects of wind and waves C. Changes that takes place during the ships voyage D. Bilging of a compartment E. While water is being pumped out from the dry dock.

Q3. Describe the arrangement of tank top and double bottom in the machinery space making particular reference to the structure and scantlings below the main engine. Show the method adopted in the arrangement of D.B. tanks to avoid contamination of fresh water, fuel oil and lube oil stored in D.B. tanks.

Q4. 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.

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 90 m 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

Q7. A. Describe briefly the significance of the factor of subdivision..

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 centreline, 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.

 

Q8. A ship 160m long and 8700 tonne displacement floats at a waterline with 

Station	AP	1⁄2	1	2	3	4	5	6	7	71⁄2	FP
1⁄2ordinate	0	2.4	5.0	7.3	7.9	8.0	8.0	7.7	5.5	2.8	0m

While floating at this waterline, the ship develops a list of 10° due to instability. Calculate the negative metacentric height when the vessel is upright in this condition

Q9. With respect to Inclining Experiments onboard vessel; A. Sketch and Describe briefly the inclining experiment and explain how the results are used. B. A forward deep tank 12 m long extends from a longitudinal bulkhead to the ship’s side. The widths of the tank surface measured from the longitudinal bulkhead at regular intervals are 10, 9, 7, 4 and 1 m. Calculate the second moment of area of the tank surface about a longitudinal axis passing through its centroid.

Q10. The daily fuel consumption of a ship at 17 knots is 42 tonne. Calculate the speed of the ship if the consumption is reduced to 28 tonne per day, and the specific consumption at the reduced speed is 18% more than at 17 knots.