Section 5 Deck plating

5.1.1 This Section covers the requirements for the deck plating, which is to be maintained over the midship region and may be tapered to the end thickness in the forward and aft end region (see Pt 3, Ch 5 Fore End and Aft End Structure), according to the requirements for taper given in Pt 3, Ch 3, 2.5 Principles for taper.

5.1.2 Where openings are made in the deck plating for access or where a deckhouse is sunk into the deck, the deck plating in way is to be increased in thickness to compensate for the material cut out. No compensation need be fitted if the loss of sectional area has already been taken into account when calculating the actual midship hull section modulus.

5.1.3 Circular openings in the deck plating of a diameter of 150 mm or less need not be compensated, provided they are situated well clear of other openings and the area cut out transversely over the deck does not exceed three per cent of the total cross-sectional area.

5.1.4 Plate panels, in which openings are cut, may have to be adequately stiffened at the edges of the openings.

5.2.1 The deck plating thickness is to be not less than as required in Table 9.5.1 Deck plating, but for ships of a length, L, of 65 m and over the deck plating may require to be increased to meet the requirements of Pt 4, Ch 9, 3 Longitudinal strength.

5.2.2 The thickness of deck plating within superstructures or deckhouses having a length of at least 0,2L or 10 m whichever is the greater and situated within the midship region is to comply with the requirements of Table 9.5.2 Deck plating within superstructures and deckhouses, but the exposed deck plating at the sides of the deckhouse is to be carried into the deckhouse over a breadth of at least 75 per cent of the frame spacing in way. The exposed deck plating is to be extended into the superstructure or deckhouse at the ends over two frame spaces.