21.1 The distance “h”
should be measured from the moulded line of the bottom shell plating
at right angle to it (regulation 12A, Figure 1).
-
.1 For vessels designed with a skeg, the skeg
should not be considered as offering protection for the FO tanks.
For the area within skeg’s width the distance “h”
should be measured perpendicular to a line parallel to the baseline
at the intersection of the skeg and the moulded line of the bottom
shell plating as indicated in Figure A.
-
.2 For vessels designed with a permanent trim,
the baseline should not be used as a reference point. The distance
“h” should be measured perpendicular to the
moulded line of the bottom shell plating at the relevant frames where
fuel tanks are to be protected.
Figure A
21.2 For vessels designed with deadrising bottom,
the distance “1.5h” should be measured from
the moulded line of the bottom shell plating but at right angle to
the baseline, as indicated in Figure B.
Figure B
21.3 Paragraphs 1 and 2, above also apply to the
reference to the distance “h” in regulation 12A.11.8.