A box-shaped vessel 60m long, 15m beam, floats on an even keel at 3m draft. An amidships compartment is 12m long and contains coal (SF = 1.2 cu.m per tonne and relative density 1.28). Find the increase in the draft if this compartment is bilged.

 A box-shaped vessel 60m long, 15m beam, floats on an even keel at 3m draft. An amidships compartment is 12m long and contains coal (SF = 1.2 cu.m per tonne and relative density 1.28). Find the increase in the draft if this compartment is bilged.

Reference: Ship Stability for Masters & Mates (6^th edition), Exercise – 22.3

 

Solution:

Space occupied by 1 tonne of solid timber = 1/1.28 = 0.78125

Broken stowage = 1.2 – 0.78125 = 0.41875

μ = BS/SF = 0.41875/1.2 = 0.3489

Increase in draft = (L*B*d*μ)/(L-l) *B

                            = (12*15*3*0.34)/ (60-12)*15

                            = 0.26167 m