2.2.4.1 For access through horizontal openings,
hatches or manholes, the dimensions should be sufficient to allow
a person wearing a self-contained air-breathing apparatus and protective
equipment to ascend or descend any ladder without obstruction and
also provide a clear opening to facilitate the hoisting of an injured
person from the bottom of a confined space. The minimum clear opening
should not be less than 600 mm x 600 mm. When access to a hold is
arranged through a flush manhole in the deck or a hatch, the top of
the ladder should be placed as close as possible to the deck or hatch
coaming. Access hatch coamings having a height greater than 900 mm
should also have steps on the outside in conjunction with the ladder.
2.2.4.2 For access through vertical openings,
or manholes, in swash bulkheads, floors, girders and web frames providing
passage through the length and breadth of the space, the minimum opening
should be not less than 600 mm x 800 mm at a height of not more than
600 mm from the bottom shell plating unless gratings or other footholds
are provided.