Inclining TestKalyan Chatterjea

Singapore Maritime Academy Singapore Polytechnic

Inclining Test: ProblemA ship of 2 500 t displacement (as inclined) and KM 6.6 m, was heeled by moving inclining weights 12 m across the deck giving the deflections on a 6 m plumb line as given in the table (shown in next slide).We need to find the ships metacentric height GM (as inclined).

Singapore Maritime Academy Singapore Polytechnic

Inclining Test: Process

Singapore Maritime Academy Singapore Polytechnic

The Inclining Experiment Carried out to obtainLightship weightLightship KGABCDWeights are each 3 t12 mLength = L mDeflection = x mtanq = x/L

Singapore Maritime Academy Singapore Polytechnic

ABCD50 mm Port3tShift1. Deflection 50 mm for 36 tmB6m lengthDLT = 2500 tThe Inclining Experiment

Singapore Maritime Academy Singapore Polytechnic

ABCD110 mm Port6tShift1. Deflection 50 mm for 36tmShift2. Deflection 60 mm for 36tmBThe Inclining Experiment

Singapore Maritime Academy Singapore Polytechnic

ABCD6t12 mm portShift1. Deflection 50 mm for 36tmShift2. Deflection 60 mm for 36tmShift3. Deflection 98 mm for 72tmABThe Inclining Experiment

Singapore Maritime Academy Singapore Polytechnic

ABCD9t37mm StbShift1. Deflection 50 mm for 36tmShift2. Deflection 60 mm for 36tmShift3. Deflection 98 mm for 72tmShift4. Deflection 49 mm for 36tmDThe Inclining Experiment

Singapore Maritime Academy Singapore Polytechnic

ABCD12t88 mm StbCThe Inclining Experiment

Singapore Maritime Academy Singapore Polytechnic

WWdGoG1MW.d = D.GM.tanq = D.GM. (x/L)

or, GM = --------W.dD. (x/L)or, GM = --------Lx . D ------W.dm/tmOr, GMLT = ------------------6 0.0014 x 2500= 1.68 mAs InclinedThe Inclining Experiment: Calculations

Singapore Maritime Academy Singapore Polytechnic

Theory underlying an inclining test is simple but unless following precautions are taken the results obtained will not be reliable.

Ship should be as nearly complete as possible. Experiment should be carried out in calm weather with no wind and current and level keel condition.All mooring ropes should be slack.All weights capable of moving transversely should be secured.All tanks should either full or completely empty (as far as practicable).There should be minimum number of people on board and those present should have restricted movements.Draughts of ship should be measured at aft, midship & forwardDensity of water around the ship should be measured at several positions round the shipThe Inclining Experiment: Precautions

Singapore Maritime Academy Singapore Polytechnic