Section 1 Hatchways and Other Deck Openings

101. Application

Hatchways and other openings are to comply with the following :

(1) Hatchways closed by weathertight covers

(A) Coaming heights are in general not to be less than 100 mm for hatches to weathertight spaces on decks above the datum, and 250 mm elsewhere. For craft of 30 m in length and under, coaming heights may be reduced to the maximum which is consistent with the safe working of the craft;

(B) The height of these coamings may be reduced, or the coamings omitted entirely, on con- dition that this Society is satisfied that the safety of the ship is not thereby impaired in any

sea conditions up to the worst intended conditions.

(C) Where coamings are provided, they are to be of substantial construction and the arrange- ments for securing and maintaining weather tightness shall ensure that the tightness can be

maintained in any sea conditions up to the worst intended conditions.

(2) Machinery space openings

(A) Machinery space openings are to be properly framed and efficiently enclosed by casings of ample strength and, where the casings are not protected by other structures, their strength shall be specially considered. Access openings in such casings shall be fitted with weather- tight doors.

(B) Heights of sills and coaming are, in general, not to be less than 100 mm for openings to weathertight spaces on decks above the datum, and 380 mm elsewhere. For craft of 30 m in

length and under, these heights may be reduced to the maximum which is consistent with

the safe working of the craft.

(C) Machinery space ventilator openings are to comply with the requirements of Sec 201. in this Chapter.

(3) Miscellaneous openings in exposed decks

(A) Manholes and flush scuttles on the datum or within superstructures other than enclosed su- perstructures are to be closed by substantial covers capable of being made watertight. Unless

secured by closely spaced bolts, the covers shall be permanently attached.

(B) Service hatches to machinery, etc. may be arranged as flush hatches provided that the cov- ers are secured by closely spaced bolts, are kept closed at sea, and are equipped with ar-

rangements for portable guardrails.

(C) Openings in exposed decks leading to spaces below the datum or enclosed superstructures other than hatchways, machinery space openings, manholes and flush scuttles shall be pro-

tected by an enclosed superstructure, or by a deckhouse or companionway of equivalent

strength and weather tightness.

(D) The height above the deck of sills to the doorways in companionways are, in general, not to be less than 100 mm for doors to weathertight spaces on decks above the datum, and 250 mm elsewhere. For craft of 30 m in length and under sill heights may be reduced to the maximum which is consistent with the safe working of the craft.