The effectiveness of the freeing port area in bulwarks required
by regulation 24(1) and (2) depends on
free flow across the deck of a ship. Where there is no free flow due
to the presence of a continuous trunk or hatchway coaming, the freeing
port area in bulwarks is calculated in accordance with regulation 24(3).
The free flow area on deck is the net area of gaps between
hatchways, and between hatchways and superstructures and deckhouses
up to the actual height of the bulwark.
The freeing port area in bulwarks should be assessed in
relation to the net flow area as follows:
-
.1 If the free flow area is not less than the
freeing port area calculated from regulation
24(3) as if the hatchway coamings were continuous, then the
minimum freeing port area calculated from regulation
24(1) and (2) should be deemed sufficient.
-
.2 If the free flow area is equal to, or less
than the area calculated from regulation 24(1)
and (2), minimum freeing port area in the bulwarks should be
determined from regulation 24(3).
-
.3 If the free flow area is smaller than calculated
from regulation 24(3) but greater than
calculated from regulation 24(1) and (2),
the minimum freeing port area in the bulwark should be determined
from the following formula:
- where
|
F
1
|
= |
is the
minimum freeing port area calculated from regulation
24(1) and (2).
|
|
F
2
|
= |
is the
minimum freeing port area calculated from regulation
24(3).
|
|
f
p
|
= |
is the
total net area of passages and gaps between hatch ends and superstructures
or deckhouses up to the actual height of bulwark. |