Problems On Coefficients (Naval Architecture)

 

Problems on Form Coefficients and Flotation

1.  Following data of a ship are given L=200m, B=22m, T=7m, CPL=0.75, AWP=3500m2  Displacement in SW=23000 tonnes. Calculate CB, CWP & CM  2.  Following data of a ship are given L=122m, B=20m, T=14m, CB=0.82, CPL=0.93, CWP=0.75 Miship area and waterplane area of ship. 3.  A lifeboat, when fully laden, displaces 7.2 tonnes. Its dimensions are 7.5m, 2.5m, 1m, and its block coefficient 0.6. Find the percentage of its volume under water when floating in fresh water. 4.  A ship displaces 9450 tonnes and has a block coefficient of 0.7. The area of immersed midship section is 106 sq. meter. Assume sea water density =1.025 t/cub.meter. If the beam =0.13 Length=2.1 draught, Calculate the length of the ship and its prismatic coefficient. 5.  Two similar right circular cones are joined at their bases. Each one has a height equal to the diameter of its base. The composite body floats so that both apexes are in the water surfaces. Calculate the midship section coefficient, prismatic coefficient and the waterplane area coefficient. 6.  The ship’s length in the above problem is now increased by increasing a parallel middle body and the displacement becomes 512199 tonnes in SW at the same draft. Calculate for the new ship a.  CP if CB=0.8210

 

b.  If the waterplane area remains constant, find the C P at a draft of 26m. 7.  A ship is 150m long, has 20m beam, load draft 8m, light draft 3m. The block coefficient at the load draft is 0.766, and at the light draft is 0.668. Find the ship's deadweight deadweight 8.  A ship 120m long 15m beam has a block coefficient of 0.700 and is floating at the load draft of 7m in fresh water. Find how much more cargo can be loaded if the ship is to float at the same draft in salt water 9.  The KB of a rectangular block which is floating in fresh water is 50 cm. Find the KB in salt water 10.  A box-shaped barge 55m 10m 6m. is floating in fresh water on an even keel at 1.5m draft. If 1800 tonnes of cargo is now loaded, find the difference in the height of the centre of buoyancy above the keel. 11.  A box-shaped vessel floats upright on an even keel in fresh water of density 1000 kg per cu. m, and the centre of buoyancy is 0.50 m above the keel. Find the height of the centre of buoyancy above the keel when the vessel is floating in salt water of density 1025 kg per cubic metre. (14 Marks) 12.  A ship 180m long has half widths of waterplane of 1, 7.5, 12, 13.5, 14, 14, 14, 13.5, 12, 7, and 0m respectiv respectively. ely. Calculate:i) waterplane area, ii) TPC, iii) Waterplane area coefficient 13.  Following data of a ship are given

 

L=420m, B=55m, T=7m, CPV=0.9375, CM=0.96 Displacement in SW=436683 tonnes. TPC= 186.37 tonnes. Calculate Draft & CB. 14.  A homogeneous log is 3m long, 60 cm wide, 60 cm deep, and has relative density 0.9. Find the distance between the centres of buoyancy and gravity when the log is floating in fresh water. 15.  A homogeneous log of rectangular cross-section is 5m long, 60 cm wide, 40 cm deep, and floats in fresh water at a draft of 30 cm. Find the mass of the log and its relative density. 16.  A ship of 15000 tonne displacement floats at a draught of 7 metres in water of 1.000t/m3. It is required to load the maximum amount of oil to give the ship a draught of 7.0 metre in sea water of density 1.025 t/m 3. If the waterplane area is 2150 square metre, calculate the mass of oil required 17.  Determine an expression for the difference in draught of a ship moving from sea water to fresh water in terms of water plane area coefficient, block coefficient and the draught in sea water. 18.  A ship is loading in a river port, when the density of river water is 1.008 t/m³ and her present mean draught is 6.98 m. Her Summer Draught is 7.165 m. FWA=116mm. TPC(sw)=17.91. Calculate how much more cargo, she can load in order to float at the summer load line on reaching sea water, if she is expected to consume 32 tonnes of fuel and stores on the river passage to sea.