CON & NA-OCT-2019

Q1. 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 on the vessel and marine environmental protection aspects in such a case?

Q2. Describe the relationship between frictional resistance and: (i) Ship’s speed; (ii) the wetted area; (iii) surface roughness; (iv) The length of the vessel.

Q3. With reference to collision bulkhead explain the following using sketches as required: a. Purposes of collision bulkhead. b.Construction of collision bulkhead. c. Regulations governing the position and construction of such a bulkhead.

Q4. With reference to Ship stability:a. With the help of a neat sketch explain the relevant features of a G-Z curve. b. What are the effects of the below mentioned conditions on the G-Z curve:i. Increased freeboard, ii. Increased beam, and iii. Increased GM.

Q5. Explain with sketches the terms hogging and sagging Which structural members are affected to these conditions? State the type of stresses these members are subjected to under conditions.
Q6. With the aid of sketches:a. Explain various lines plan.
b. The half -breadths of waterplane of a ship of 120m length ad 15m breadth are given below:
station 0 1 2 3 4 5 6 7 8
Half breadths 1.6 2.8 5.5 6.4 7.3 6.2 4.2 2 0
Calculate i) Water plane area ii) TPC in salt water iii) Cw iv) LCF from Mid-ship.
 

Q7. What is Prismatic Co-efficient (CP).a. Derive the formula CP =Cb/Cm, where Cb = Co-efficient of fineness and Cm = midship section area coefficient.
b. The length of a ship is 18 times the draught. while the breadth is 2.1 times the draught. At the load water plane, the water plane area co-efficient is 0.83 and the difference between the TPC in sea water and the TPC in fresh water is 0.7. Determine the length of the ship and the TPC in fresh water.
 

Q8. With respect to Ship Propulsion: a. Explain the various efficiencies associated with propeller and shafting arrangement.
b. When a propeller of 4.8 m pitch turns at 110 rpm, the apparent slip is found to be —S % and the real slip is 1.5 S. If the wake speed is 25 % of the ship speed, calculate the ship speed, apparent slip and the real slip.
 


Q9. A ship 100 m long floats at a draught of 6 m and in this condition the immersed cross-sectional areas and water plane areas are as given below. The equivalent base area (Ab) is required because of the fineness of the bottom shell.
section AP 1 2 3 4 5 FP
Immersed cross section(m2) 12 30 65 80 70 50 0
Draught(m) 0 0.6 1.2 2.4 3.6 4.8 6.0
WP AREA(m2) Ab 560 720 880 940 1000 1030
Calculate EACH of the following: (a) The equivalent base area value Ab; (b) The longitudinal position of the center of buoyancy from midships; (c) The vertical position of the center of buoyancy above the base.
 

Q10. With reference to the wake of a vessel: a. Explain Wake fraction and Quasi Propulsive co-efficient(QPC).

b. A ship travelling at 15.5 knots has a propeller of 5.5 m pitch turning at 95 rev/min. The thrust of the propeller is 380 KN and the delivered power 3540 KW. If the real slip is 20% and the thrust deduction factor O.198, calculate the Quasi Propulsive Coefficient (QPC) and the wake fraction.
 

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