1 Where a step exists in the freeboard deck, creating
a discontinuity extending over the full breadth of the ship, and this
step is in excess of 1 m in length, regulation
3(9) should apply (figure 1).
A step 1 m or less in length should be treated as a recess in accordance
with paragraph 2.
Figure 1
2 Where a recess is arranged in the freeboard
deck, and this recess does not extend to the side of the ship, the
freeboard calculated without regard to the recess is to be corrected
for the consequent loss of buoyancy. The correction should be equal
to the value obtained by dividing the volume of the recess by the
waterplane area of the ship (A
w) at 85% of
the least moulded depth (figure 2).
-
.1 The correction should be a straight addition
to the freeboard obtained after all other corrections have been applied,
except bow height correction.
-
.2 Where the freeboard, corrected for lost buoyancy
as above, is greater than the minimum geometric freeboard determined
on the basis of a moulded depth measured to the bottom of the recess,
the latter value may be used.
Figure 2
3 Recesses in a second deck, designated as the
freeboard deck, may be disregarded in this interpretation provided
all openings in the weather deck are fitted with weathertight closing
appliances.
4 Due regard is to be given to the drainage of
exposed recesses and to free surface effects on stability.
5 This interpretation is not intended to apply
to dredgers, hopper barges or other similar types of ships with large
open holds, where each case should require individual consideration.