In cases where the operational trim range is intended to
exceed ± 0.5% of Ls
, the original GM limit line should be designed in the usual manner with the
deepest subdivision draught and partial subdivision draught calculated
at level trim and actual service trim used for the light service draught.
Then additional sets of GM limit lines should be constructed
on the basis of the full range of trims ensuring that intervals of
1% Ls
are not exceeded. The sets of GM limit
lines are combined to give one envelope limiting GM curve.
The effective trim range of the curve should be clearly stated.