2314 Trunk. Ante, p. 22ro. INTERNATIONAL LOAD LINE CONVENTION. JULY 5, 1930. the forward perpdndicular is effective; where the sheer forward is half the standard sheer or less, 50 per cent. of that length is effec- tive; and where the sheer forward is intermediate between the stand- ard and half the standard sheer, an intermediate percentage of that length is effective. 50 per cent. of the length of an open extension beyond the bulkhead or beyond .1 L from the forwftrd perpendicular is effe~tive. Rule LI.- Trunk. A trunk or similar structur~ which does not extend to the sides of the ship is regarded as efficient provided that- (a) the trunk is at least as strong as a superstructure; (b) the hatchways are in the trunk deck, and comply with the requirements of Rules VIII to XVI, and the Width of the trunk deck stringer provides a satisfactory gangway and sufficient lateral stiffness; (c) a permanent wor~ platform fore and aft fitted with guard rails is proviaed by the trunk deck, or by detached trunks connected to other superstructures by efficient permanent gangways; (d) ventilators are protected by the trunk, by watertight covers or by equivalent means; (e) open rails are fitted on the weather portions of the free- board deck in way of the trunk for at least half their length· (f) the machinery casings are protected by the trunk, by a superstructure of standard height, or by a deck house of the same height fI,nd of equivalent strength. Where access openings in poop and bridge bulkheads are fitted with Class 1 closing appliances, 100 per cent. of the length of an efficient trunk reduced in the ratio of its mean breadth to B is added to the effective length of the superstructures. Where the access openings in these bulkheads are not fitted with Class 1 closing appliances 90 per cent. is added. The standard height of a trunk is the standard height of a bridge. Where the height of the trunk is less than the standard height of a bridge, the addition is reduced in the ratio of the actual to the standard height; where the height of hatchway coamings on the trunk deck is less than the standard height of coamings (see Rule IX), a reduction from the actual height of trunk is to be made which corresponds to the difference between the actual and the standard height of coamings.
