3.4.3 The unit should have sufficient freeboard
and be subdivided by means of watertight decks and bulkheads to provide
sufficient buoyancy and stability to withstand a wind heeling moment
induced by a wind velocity of 25.8 m/s (50 knots) superimposed from
any direction in any operating or transit condition, taking the following
considerations into account:
-
.1 the angle of inclination after the damage set
out in 3.5.10.2 should not be greater than 17o:
-
.2 any opening below the final waterline should
be made watertight, and openings within 4 m above the final waterline
should be made weathertight;
-
.3 the righting moment curve, after the damage
set out above, should have, from the first intercept to the lesser
of the extent of weathertight integrity required by 3.4.3.2 and the
second intercept, a range of at least 7o. Within this range,
the righting moment curve should reach a value of at least twice the
wind heeling moment curve, both being measured at the same angle.
See figure 3-2 below.
Figure 3-3 Righting moment and wind healing moment curves
3.4.4 The unit should provide sufficient buoyancy
and stability in any operating or transit condition to withstand the
flooding of any watertight compartment wholly or partially below the
waterline in question, which is a pump-room, a room containing machinery
with a salt water cooling system or a compartment adjacent to the
sea, taking the following considerations into account:
-
.1 the angle of inclination after flooding should
not be greater than 25°;
-
.2 any opening below the final waterline should
be made watertight;
-
.3 a range of positive stability should be provided,
beyond the calculated angle of inclination in these conditions, of
at least 7o,