Section 6 Miscellaneous openings

6.1.1 The requirements of Pt 3, Ch 11, 6.1 Small hatchways on exposed decks of the Rules for Ships are to be complied with, as applicable.

6.1.2 In general, small hatch cover scantlings and securing devices are to be in accordance with Pt 4, Ch 7, 6.1 Small hatchways on exposed decks 6.1.3 or with an acceptable standard.

6.1.4 When applicable, large hatch covers are to comply with the requirements of Pt 3, Ch 11 Closing Arrangements for Shell, Deck and Bulkheads of the Rules for Ships.

6.1.5 Small hatches, including escape hatches, are to be situated clear of any obstructions.

6.1.6 The height and scantlings of coamings are to be in accordance with Pt 4, Ch 7, 6.3 Hatch coamings.

6.2.1 The requirements of Pt 4, Ch 7, 6.1 Small hatchways on exposed decks are to be complied with, where applicable.

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.

6.3.2 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.

6.3.3 Coamings with height less than given in Pt 4, Ch 7, 6.3 Hatch coamings 6.3.1 may normally be accepted for column-stabilised and tension-leg units after special consideration, see also Pt 4, Ch 7, 6.3 Hatch coamings 6.3.4.

6.3.4 Coaming heights on all units are also to satisfy the requirements for intact and damage stability, see Pt 4, Ch 7, 4.5 External openings related to damage stability and Pt 4, Ch 7, 4.7 Weathertight integrity related to stability.

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.

6.4.1 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.

6.5.1 The requirements of Pt 3, Ch 11, 6.4 Companionways, doors and accesses on weather decks of the Rules for Ships are to be complied with, as applicable.

6.5.2 For access to spaces in the oil storage area on units with tanks for the storage of oil in bulk, see Pt 3, Ch 3, 2.11 Access arrangements and closing appliances.

6.5.3 The height of doorway sills above deck sheathing, if fitted, is to be not less than 600 mm in Position 1, and not less than 380 mm in Position 2. For semi-submersible units, see Pt 4, Ch 7, 5.2 Column-stabilised units and tension-leg units 5.2.3.

6.5.4 Doorway sill heights on all units are also to satisfy the requirements for intact and damage stability, see Pt 4, Ch 7, 4.5 External openings related to damage stability and Pt 4, Ch 7, 4.7 Weathertight integrity related to stability.

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.

6.6.1 For ship units and other surface type units and self-elevating units, when afloat, the requirements of Pt 3, Ch 11, 6.5 Side scuttles, windows and skylights of the Rules for Ships are to be complied with, as applicable.

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.

6.6.3 The location of windows and side scuttles and the provision of deadlights or storm covers on semi-submersible units will be specially considered in each case, see also Pt 4, Ch 7, 4.5 External openings related to damage stability 4.5.1 and Pt 4, Ch 7, 5.2 Column-stabilised units and tension-leg units 5.2.5.

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.