Page 132 - statbility for masters and mates
P. 132
120 Ship Stability for Masters and Mates
Example 5
A ship of 9900 tonnes displacement has KM 7.3 m, and KG 6.4 m. She has yet to load two 50 tonne lifts with her own gear and the ®rst lift is to be placed on deck on the inshore side (KG 9 m and centre of gravity 6 m out from the centre line). When the derrick plumbs the quay its head is 15 m above the keel and 12m out from the centre line. Calculate the maximum list during the operation.
Note. The maximum list will obviously occur when the ®rst lift is in place on the deck and the second weight is suspended over the quay as shown in Figure 13.7.
Moments about the keel
Weight KG
9900 6.4 50 9.0 50 15.0
10 000
Moment
63 360 450 750
64 560
Fig. 13.7
Final KG Final moment Final displacement
64:560 10 000
Final KG 6:456 m (KG1) i.e. a rise of 0.056 m above the original KG of 6.4 m.
