Page 154 - statbility for masters and mates

142 Ship Stability for Masters and Mates
Similarly, when a weight is being discharged, if the weight is ®rst shifted to the centre of ¯otation it will produce a change of trim, and if it is then discharged from the centre of ¯otation the ship will rise bodily. Thus, both a change of trim and bodily rise must be considered when a weight is being discharged away from the centre of ¯otation.
Example 1
A ship 90m long is ¯oating at drafts 4.5m F and 5.0m A. The centre of ¯otation is 1.5 m aft of amidships. TPC 10 tonnes. MCT 1 cm. 120 tonnes m. Find the new drafts if a total weight of 450 tonnes is loaded in a position 14 m forward of amidships.
e Fig. 15.6
Bodily sinkage
w TPC
450 10
Bodily sinkage Change of trim
45 cm
Trim moment
MCT 1 cm 450 15:5
Change of trim Change of draft aft
120
58:12 cm by the head
Ll Change of trim 43:5 58:12
Change of draft aft Change of draft forward Change of draft forward
90 28:09 cm
46:5 58:12 90
30:03 cm