Section 1 General

1.1.1 This Chapter applies to all ship types detailed in Pt 4 Ship Structures (Ship Types). Only requirements particular to machinery spaces, including protected machinery casings and engine seatings, are given. For other scantlings and arrangement requirements, see the relevant Chapter in Pt 4 Ship Structures (Ship Types) for the particular ship type concerned.

1.1.2 Requirements are given for machinery spaces situated as follows:

1. In the midship region.

2. In the aft end region but with a cargo compartment between it and the after peak bulkhead.

3. In the aft end region where the after peak bulkhead forms the aft end of the machinery space.

1.1.3 The requirements in this Chapter are not applicable to Double Hull Oil Tankers or Bulk Carriers with a CSR notation. See Pt 1, Ch 2, 2.3 Class notations (hull).

1.2.1 Requirements are given for ships constructed using either a transverse framing system or a longitudinal framing system, or a combination of the two.

1.2.2 For midship machinery spaces, where the shell and decks (outside line of openings) are longitudinally framed in way of adjacent cargo spaces, this system of framing is also to be adopted in the machinery space.

1.2.3 For machinery spaces situated aft, where the longitudinal framing terminates and is replaced by transverse framing, a suitable scarfing arrangement of the longitudinal framing is to be arranged, see also Pt 3, Ch 6, 1 General.

1.2.4 The maximum spacing, S _max, of transverses in longitudinally framed machinery spaces is not to exceed the following:

1. where L ≤ 100 m, S _max = 3,8 m

2. where L > 100 m, S _max = (0,006L + 3,2) m

In addition, the spacing in way of a machinery space situated adjacent to the after peak is not to exceed five transverse frame spaces.

1.3.1 Suitable scarfing arrangements are to be made to ensure continuity of strength and the avoidance of abrupt discontinuities where structure which contributes to the main longitudinal strength of the ship is omitted in way of a machinery space.

1.3.2 In cargo ships, suitable taper brackets are, in general, to be arranged in way of deck ends.

1.3.3 In oil tankers and bulk carriers with machinery aft (see Pt 3, Ch 6, 1.1 Application 1.1.3), continuity of the longitudinal bulkheads and topside tank structure is to be maintained as far as possible into the machinery space with suitable taper brackets at the end.

1.3.4 In container or similar ships having side tanks or double skin construction in way of the cargo spaces, the longitudinal bulkheads are generally to be carried through the machinery space where this is situated amidships or separated from the after peak by a cargo compartment. Where the machinery space is situated adjacent to the after peak, the longitudinal bulkheads are to be continued as far aft as possible and suitably tapered at their ends.

1.4.1 For symbols not defined in this Chapter, see Pt 4, Ch 1 General Cargo Ships. L, B, D and T are defined in Pt 3, Ch 1, 6.1 Principal particulars. Other symbols are defined in the appropriate Sections.