3.4.1 Compliance with 3.3 should be confirmed by calculations which take into consideration the design characteristics of the vessel, the arrangements, configuration and permeability of the damaged compartments and the distribution, specific gravities and the free surface effect of liquids.
3.4.2 The permeability of compartments assumed to be damaged should be as follows:
Spaces | Permeability |
Appropriated to stores | 60 |
Occupied by accommodation | 95 |
Occupied by machinery | 85 |
Void spaces | 95 |
Intended for dry cargo | 95 |
The permeability of tanks should be consistent with the amount of liquid carried, as shown in the
loading conditions specified in 3.1. The permeability of empty tanks should be assumed to be not
less than 95.
3.4.3 The free surface effect should be calculated at an angle of heel of 5 degrees for each
individual compartment or the effect of free liquid in a tank should be calculated over the range of
positive residual righting arm, by assessing the shift of liquids by moment of transference
calculations.
3.4.4 Free surface for each type of consumable liquid should by assumed for at least one
transverse pair of tanks or a single centreline tank. The tank or tanks to be taken into account
should be those where the effect of free surface is the greatest.
3.4.5 Alternatively, the actual free surface effect may be used provided the methods of calculation
are acceptable to the Administration.