The waterplane areas of a ship at 1.5 m intervals of draught, commencing at the keel, are 865, 1735, 1965, 2040, 2100, 2145 and 2215 m2 respectively. Calculate the displacement at 9 m draught.

 The waterplane areas of a ship at 1.5 m intervals of draught, commencing at the keel, are 865, 1735, 1965, 2040, 2100, 2145 and 2215 m2 respectively. Calculate the displacement at 9 m draught.

Reference: REED'S NAVAL ARCHITECTURE FOR MARINE ENGINEERS (4^th edition), Exercise – 3.2

 

Solution:

Waterplane area	SM	f(vol)
865	1	865
1735	4	6940
1965	2	3930
2040	4	8160
2100	2	4200
2145	4	8580
2215	1	2215
		∑ f(vol) = 34890

 

Volume of Displacement = h/3 * ∑f(vol)

                                         = 1.5/3 * 34890

                                         = 17445 m³

Displacement = 17445 * 1.025 = 17881.125 tons