Page 263 - statbility for masters and mates

Method (b)
Righting moment W P G1M sin y 5940 1:439 sin y
8549 sin y tonnes metres.
Thus each of the two methods used gives a correct indication of the ship's
stability during the critical period.
Example 2
A ship of 3000 tonnes displacement is 100 m long, has KM 6 m, KG 5.5 m. The centre of ¯otation is 2 m aft of amidships. MCTC 40 tonnes m. Find the maximum trim for the ship to enter a drydock if the metacentric height at the critical instant before the ship takes the blocks forward and aft is to be not less than 0.3 m.
Method (a)
or
But
or
KM 6:0m KG 5:5m Original GM 0:5 m Virtual GM 0:3 m Virtual loss 0:2 m
Virtual loss of GM MM1 P KM W
P Virtual loss W KM
0:2 3000 6
Maximum P 100 tonnes P MCTC t
l
Maximum t P l MCTC
100 48 40
Drydocking and grounding 251
Ans. Maximum trim 120 cm by the stern