Q3. The following particulars apply to a ship of length 140 m when floating in sea water of density 1025 kg/m3 at an even keel draught of 7.265 m. displacement = 15800 tonne centre of gravity above the keel (KG) = 7.8 m centre of buoyancy above the keel (KB) = 4.05 m waterplane area = 2146 m2 centre of flotation from midships (LCF) = 3.0 m aft second moment of area of the waterplane about a transverse axis through midships = 2.305 × 106 m4 (a) Calculate the value of the moment to change trim by one centimetre (MCT1cm) in the above condition. (6) (b) The ship in the above condition now undergoes the following changes in loading: 352 tonne added at an Lcg of 10.5 m forward of midships 110 tonne removed from an Lcg of 2.0 m aft of midships 150 tonne restowed at a new position 52.7 m aft of its original position. Calculate the new end draughts of the ship. (10)
Q3. A vessel of constant rectangular section 80 m long and 12 m wide has a KG of 4.77 m and floats on an even keel draught of 5.5 m in water of density 1025 kg/m3 . The vessel is fitted with a transverse watertight bulkhead 10 m from the forward end.
The compartment forward of the transverse bulkhead, which has a permeability of 60 %, is now damaged and laid open to the sea.
Calculate the new end draughts of the vessel. (16)
Q5. A rectangular oil barge of light displacement 300 tonne is 60 m tong and 10 m wide. The barge is divided by four transverse bulkheads into five Compartments of equal length.
When compartments 2 and 4 contain equal quantities of oil and the other compartments are empty, the barge floats at a draught of 3 m in fresh water of density 1000 kg/m3.
(a) Plot EACH of the following curves on a base of barge length:
(i) curve of toads; (4)
(ii) curve of shearing forces; (4)
(iii) curve of bending moments. (5)
(b) State the magnitude and position of the maximum bending moment. (3)
Q7. A ship of length 140 m and breadth 18 m floats at a draught of 8 m in sea water of density 1025 kg/m3. In this condition the block coefficient (Cb) is 0.68.
At a speed of 15 knots the following data applies:
Delivered power = 4720 kW
Quasi-propulsive coefficient (QPC) = 0.70
Ship correlation factor (SCF) = 1.18
Calculate the pull required to tow a similar model of length 5 m at the corresponding speed in fresh water density 1000 kg/m3. (16)
Note: The frictional coefficient to be used:
for the model in fresh water of density 1000 kg/m3 is 1.694
for the ship in sea water of density 1025 kg/m3 is 1.415
Speed in m/s with the speed index (n) for ship and model 1.825
Wetted surface area (S) = 2.57 √(DL ) (m2)
Q9. An end bulkhead of an upper hopper tank is shown in Fig Q9.
The tank is tested by filling with fresh water of density I000 kg/m3 through a fitting pipe to a head of 2.5 m above the upper deck.
Calculate EACH of the following:
(a) the load on the bulkhead; (8)
(b) the distance to the centre of pressure from the upper deck. (8)
Username or email address *Required
Password *Required
Note: Entering wrong username in the login form will ban your IP address immediately. Entering wrong password multiple times will also ban your IP address temporarily.
Log in
Lost your password? Remember me
No account yet?
