Page 171 - statbility for masters and mates

Trim 159
The centre of gravity of No. 1 hold is 40 m forward of amidships The centre of gravity of No. 2 hold is 25 m forward of amidships The centre of gravity of No. 3 hold is 20 m aft of amidships
The centre of gravity of No. 4 hold is 50 m aft of amidships
Also 50 tonnes of cargo is loaded in a position whose centre of gravity is 15 m aft of amidships, and 135 tonnes of cargo centre of gravity 40 m forward of amidships. TPC 15 tonnes. MCT 1 cm 400 tonnes m. The centre of ¯otation is amidships. Find the ®nal drafts.
Using trim to ®nd the position of the centre of ¯otation
14 A ship is ¯oating at drafts 5.5 m F and 6.0 m A. The following cargo is then loaded:
97 tonnes centre of gravity 8 m forward of amidships 20 tonnes centre of gravity 40 m aft of amidships
28 tonnes centre of gravity 20 m aft of amidships
The draft is now 5.6 metres F and 6.1 metres A. Find the position of the
centre of ¯otation relative to amidships.
15 Find the position of the centre of ¯otation of a ship if the trim remains
unchanged after loading the following cargo:
100 tonnes centre of gravity 8 metres forward of amidships 20 tonnes centre of gravity 40 metres aft of amidships
28 tonnes centre of gravity 20 metres aft of amidships
16 A ship arrives in port with drafts 6.8m F and 7.5m A. The following cargo is discharged:
90 tonnes centre of gravity 30 m forward of amidships 40 tonnes centre of gravity 25 m aft of amidships
50 tonnes centre of gravity 50 m aft of amidships
The drafts are now 6.7 m F and 7.4 m A. Find the position of the centre of ¯otation relative to amidships.
Loading a weight to keep a constant draft aft
17 A ship is 150 m long, MCT 1 cm 400 tonnes m, TPC 15 tonnes. The centre of ¯otation is 3 m aft of amidships. Find the position in which to load a mass of 30 tonnes, with reference to the centre of ¯otation, so as to maintain a constant draft aft.
18 A ship 120 metres long, with maximum beam 15m, is ¯oating in salt water at drafts 6.6 m F and 7 m A. The block coef®cient and coef®cient of ®neness of the water-plane is 0.75. Longitudinal metacentric height 120 m. Centre of ¯otation is amidships. Find how much more cargo can be loaded and in what position relative to amidships if the ship is to cross a bar with a maximum draft of 7m F and A.
Loading a weight to produce a required draft
19 A ship 120m long ¯oats in salt water at drafts 5.8m F and 6.6m A. TPC 15 tonnes. MCT 1 cm 300 tonnes m. Centre of ¯otation is amidships.