Section
6 Miscellaneous openings
6.1 Small hatchways on exposed decks
6.1.3 Hatch covers of a greater size than those defined in Table 7.6.1 Hatch cover
scantlings will have their scantlings
and closing arrangements specially considered.
Table 7.6.1 Hatch cover
scantlings
Size of
hatch (mm)
|
Plate
(mm)
|
Stiffeners
|
Toggles
|
600 x 600
|
8,0
|
—
|
4
|
760 x 760
|
8,0
|
—
|
6
|
925 x 925
|
8,0
|
75 x 7,5 mm
flat bar
|
7
|
1220 x 1220
|
10,0
|
75 x 7,5 mm
flat bar
|
8
|
6.1.5 Small hatches, including escape hatches, are to be situated clear of any
obstructions.
6.2 Hatchways within enclosed superstructures
or ‘tween decks
6.2.2 Access hatches within a superstructure or deckhouse in Position 1 or 2
need not be provided with means for closing if all openings in the surrounding
bulkheads have weathertight closing appliances.
6.3 Hatch coamings
6.3.1 The height of coamings of hatchways situated in Positions 1 and 2 closed
by steel covers fitted with gaskets and clamping devices are to be not less than:
- 600 mm at Position 1;
- 450 mm at Position 2.
6.3.2 Lower heights than those defined in Pt 4, Ch 7, 6.3 Hatch coamings 6.3.1 may be considered in relation to operational
requirements and the nature of the spaces to which access is given.
6.3.5 The thickness of the coamings is to be not less than the minimum
thickness of the structures to which they are attached, or 11 mm, whichever is the
lesser. Stiffening of the coaming is to be appropriate to its length and height.
Scantlings of coamings more than 900 mm in height will be specially considered.
6.4 Manholes and flush scuttles
6.4.1 Manholes and flush scuttles fitted in Positions 1 and 2, or within
superstructures other than enclosed superstructures, are to be closed by substantial
covers capable of being made watertight. Unless secured by closely spaced bolts, the
covers are to be permanently attached.
6.5 Companionways, doors and access
arrangements on weather decks
6.5.5 On ship units and other surface type oil storage units, direct access
from the freeboard deck to the machinery space through exposed casings is not
permitted, except when Pt 4, Ch 7, 6.5 Companionways, doors and access arrangements on weather decks 6.5.6 applies. A door complying with Pt 4, Ch 7, 6.5 Companionways, doors and access arrangements on weather decks 6.5.3 may, however, be fitted in an exposed
machinery casing on these units, provided that it leads to a space or passageway
which is of equivalent strength to the casing and is separated from the machinery
space by a second weathertight door complying with Pt 4, Ch 7, 6.5 Companionways, doors and access arrangements on weather decks 6.5.3. The outer and inner weathertight doors are to
have sill heights of not less than 600 mm and 230 mm respectively and the space
between is to be adequately drained by means of a screw plug or equivalent.
6.5.6 For ship units and other surface type oil storage units with freeboards
greater than, or equal to, a Type B ship (as defined in the Load Line Convention),
inner doors are not required for direct access to the engine room.
6.6 Side scuttles, windows and
skylights
6.6.2 A plan showing the location of side scuttles and windows is to be
submitted. Attention is to be given to any relevant Statutory Requirements of the
Coastal State Authority where the unit is to operate and/or the National Authority
of the country in which the unit is to be registered.
6.6.4 Windows and side scuttles are to be of the non-opening type where damage
stability calculations indicate that they would become immersed as a result of
specified damage.
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