Section 13 Particular requirements for multi-hull craft
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Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Special Service Craft, July 2022 - Part 3 General Requirements and Constructional Arrangements - Chapter 4 Closing Arrangements and Outfit - Section 13 Particular requirements for multi-hull craft

Section 13 Particular requirements for multi-hull craft

13.1 General

13.1.1 In addition to the general requirements given in this Chapter, this Section gives particular requirements for multi-hull craft.

13.2 Multi-hull craft escape hatches

13.2.1 Multi-hull craft are to be provided with a suitable means of escape from each accommodation compartment between watertight bulkheads in the event of inversion of the craft.

13.2.2 Where the requirement given in Pt 3, Ch 4, 13.2 Multi-hull craft escape hatches 13.2.1 is achieved by means of escape hatches in the hull, these are to be fitted in the inboard side of each hull, or in the transom, with the lowest side of the opening at a minimum of 600 mm above the waterline in both the upright and inverted conditions of the craft. Hatch openings are to be a minimum of 450 mm x 450 mm and a maximum of 600 mm x 600 mm.

13.2.3 Escape hatch frames and covers may be of steel, aluminium alloy or FRP construction and are to be of equivalent strength to the unpierced hull side or transom in which they are fitted.

13.2.4 Hatch covers are to be weathertight when closed and the means of securing the hatch cover are to be such that weathertightness can be maintained in any sea condition.

13.2.5 Hydrostatic pressure tests are to be carried out to confirm that the proposed construction, when fitted in the hull, is able to withstand a pressure of four times the design pressure and remain watertight.

13.2.6 Hatch covers are to be flush with the hull and substantially hinged. Where fitted in the inboard side of the hull, the hinges are to be on the forward side.

13.2.7 To facilitate a swift and safe means of escape to the lifeboat and life raft embarkation deck, the following provisions apply to overhead hatches fitted along the escape routes addressed by Regulation 13 - Means of escape:

  1. escape hatches and their securing devices are to be of a type which can be opened from both sides;

  2. the maximum force needed to open the hatch cover is not to exceed 150 N; and

  3. the use of a spring counterbalance, equalising or any other suitable device on the hinge side to reduce the force needed for opening is acceptable.

13.3 Portlights

13.3.1 Where it is proposed to fit portlights in the hulls of wave-piercing and other non-conventional multi-hull craft, the arrangements will be specially considered.


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