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Q1. A RO-RO ferry of length 80 m has a displacement of 3800 tonne in sea water of density 1025 kg/m3 with BM = 3.4 m. The breadth of the ship at the waterline, between sections 3 and 7 is constant at 13 m. To increase stability, sponsons, 1.8 m deep and of constant plan area are to be fitted as shown in Fig Q1.

The sponsons extend over the midships length between sections 3 and 7, with sponson widths as shown in Table Q1.

For the new condition, there is no change in draught and the load waterline is at mid-depth of the sponson. Calculate the increase in BM due to the sponsons.