//SYS21///INTEGRA/BST/VOL1/REVISES 21-7-2001/BSTC03.3D ± 72 ± [52±90/39] 26.7.2001 4:14PM
72 Basic ship theory
Fig. 3.27
Fig. 3.28
The trim is then e e 1 MCT
w2 w1
L approx e 1 GML
w2 w1
L Iw2
It must be remembered that the trim occurs in w2 water and MCT must be related to that; if the value of MCT is given for w water, approximately, since MCT is proportional to wI=L, MCT2 MCT
w2 w
It is not di cult to produce formulae for changes in draught for particular changes of condition and to invent rules which give the direction of trim. The student is advised to commit none to memory. Each problem should be tackled with a small diagram and an understanding of what actually happens. Summarizing, the process is (a) using Archimedes' principle, calculate the volume and thence the weight of the layer, (b) calculate the parallel sinkage using TPI pertinent to the new water, (c) calculate the trim due to the movement of the layer buoyancy from B to F, using MCT pertinent to the new water. Worked example 7 is an illustration.