Anna University Naval Architecture Model Test Paper

MARINE ENGINEERING

Time : 3 Hours                                                                                    Maximum Marks-  100

Answer All Questions                                                                       PART – A  (10 x 2 = 20 marks)

1.Draw neat sketches of the following ship’s members:

(a) Rise of Keel     (b) Bulbous Bow.

2.Explain the meaning of the following terms:

(a) BMT     (b) MCT 1 cm

3.The Water plane area of a ship is 1730 sq.m. Calculate TPC and the increase in             draught if a mass of 270 tonne is added to the ship.

4.Define Prismatic Co-efficient and Mid-ship section area Co-efficient.

5.Explain dynamical stability?

6.What is free Surface Effect? How it affects the metacentric height of the ship?

7.Define     a) Trim     b) LCF

8.A ship of 10,000 tonne displacement has a Water plane area of 1,300 sq.m. The ship loads in water of 1.010 t/cu.m and moves into water of 1.026 t/cu.m. Find the change in Mean draught.

9.On what factors the frictional resistance of a ship depends?

10.Explain what is ‘Ship Correlation Factor’?

PART – B  (5 x 16 = 80 marks)

Question No. 11 is compulsory, Question Nos. 12 to 15, Answer (a) or (b) from each unit.

UNIT – I

11.Draw a typical mid-ship section of a general cargo ship and name all the structural members.                                                                                                   (16 marks)

UNIT – II

12.a)i)A ship 13.5 m long, 18 m beam and 7.6 m draught has a displacement of                14,000 tonne. The area of the load water plane is 1,925 sq.m. and the area of the immersed mid-ship section is 130 sq.m. Calculate (1) Cw (2) Cm  (3) Cb  (4) Cp.

(12 marks)

ii)A ship of 5,000 tonne displacement, 95 m. long floats at a draught of 5.5 m.                Calculate the wetted surface area of the ship using Denny’s formula.      (4 marks

OR

12.b)A double bottom tank 21 m. long has a water tight center girder. The widths                  of the tank top measured from the center line to the ship side are 10.0, 9.5, 9.0, 8.0, 6.5, 4.0, and 1.0 m respectively. Calculate the second moment of area of the tank surface about a longitudinal axis through its centroid for one side of the ship only.                                                                                                              (16 marks)

UNIT – III

13.a)Sketch the transverse section of a ship, showing the positions of Centre of Gravity, Centre of Buoyancy, and Initial Metacentre, when the ship is in (1) stable (2) unstable and (3) neutral equilibrium.

OR

13.b)i)  A small vessel has the following particulars before modifications are carried out.     Displacement-150 tonne, GM: 0.45 m, KG: 1.98 m, KB: 0.9 m., TPC: 2.0, and draught: 1.65 m. After modification, 20 tonne has been added and KG: 3.6 m, Calculate the new GM, assuming constant water plane area over the change in draught.                                                                                                       (8 marks)

ii) A ship of 12,000 tonnes displacement has a metacentric height of 0.6 m. and a Centre of Buoyancy of 4.5 m above the keel. The second moment of area of water plane about the centre line is 42.5 x 103m4. Calculate the height of CG above keel.

(8 marks)

UNIT – IV

14a) A ship 80m, long has a light displacement of 1,050 tonne and LCG 4.64 m, aft of midships. The following items are then added:

Cargo 2,150 tonne, LCG 4.71 m, Fwd of midships.

Fuel 80 tonne, LCG 32.55 m, Aft of midships.

Water 15 tonne, LCG 32.9 m, Aft of midships.

Stores 5 tonne, LCG 33.6m, Fwd of midships.

Following hydrostatic particulars are available :

 Draught Mtr. Displacement Tonne MCT 1 cm Tonne m. LCB from midship (m) LCF from midship (m) 5.00 3,533 43.10 1.00 F 1.27A 4.50 3,172 41.26 1.24 F 0.84 A

Calculate the final draughts of the loaded vessel.                                    (16 marks)

OR

14.b) The draught of a ship 90 m. long are 5.80 m forward and 6.40 m. aft.  MCT 1 cm is 50 tonne m., TPC: 11, LCF: 2 m. aft. of midships. Determine the point at which a mass of 180 tonnes should be placed so that the aft. draught remains unaltered and calculate the final draught forward.                                                 (16 marks)

15.a) A 6 m, model of a ship has a wetted surface area of 8 sq. m. When towed at speed of 3 knots in fresh water, the total resistance is found to be 38 N. If the ship is 130 m. long, calculate the effective power at the corresponding speed. Take n = 1.825, SCF : 1.15. Calculate ‘f’ from the formula.                                              (16 marks)

OR

15.b)A ship’s speed is increased by 20 % above normal for 8 hours, reduced by 10 % below normal for 10 hours and for the remaining 6 hours of the day, the speed is maintained normal. Calculate the percentage variation in fuel consumption in that day form normal.                                                                                          (16 marks)

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