4 CONSTRUCTION AND STRENGTH
Objective:- The purpose of this section is to ensure that all vessels are constructed to a consistent standard in respect of strength and watertight integrity. New Vessels are to be built to the requirements of one of the recognised Classification Societies listed in the National Annex and issued with a Class Certificate. Existing Vessels which are not already Classed should be taken into Class, however for vessels under 500 GT alternative arrangements for Short Range operation may be agreed by the Administration. The Class Notation should include as a minimum the following hull, machinery, shafting, steering gear, and anchoring and mooring. The extent of the watertight bulkheads defined in Section 4.3, is to ensure that sufficient buoyancy is maintained by the vessel to meet the damaged stability requirements of Section 11.
4.1 General Requirements
4.1.1 All vessels should have a freeboard deck.
4.1.2 All vessels should be fitted with a weather deck throughout the length of the vessel and be of adequate strength to withstand the sea and weather conditions likely to be encountered in the declared area(s) of operation.
4.1.3 The declared area(s) of operation and any other conditions which restrict the use of the vessel at sea should be recorded on the load line certificate issued to the vessel.
4.1.4 The choice of hull construction material affects fire protection requirements, for which reference should be made to section 14.
4.2 Structural Strength
4.2.1 For unlimited operation, all vessels must be classed.
4.2.2 For operation within the Short Range Yacht Category, all new vessels must be classed.
4.2.3 Existing un-classed vessels of less than 500GT may be considered for restricted operation within the Short Range Category.
4.2.4 Attention should be paid to local or global hull strength requirements for the fitting of ballast.
4.3 Watertight Bulkheads
Section 11 of the Code deals with subdivision and damage stability requirements which will determine the number and positioning of watertight bulkheads defined below.
4.3.1 Watertight bulkheads should be fitted in accordance with the following requirements.
.1 The strength of watertight bulkheads and their penetrations, and watertight integrity of the division should be in accordance with the requirements of one of the Classification Societies referred to in the National Annex.
.2 Generally, openings in watertight bulkheads should comply with the standards required for passenger vessels, as defined in SOLAS regulations II-1. Specific requirements are contained in Annex **
. 3 Approved hinged doors may be provided for infrequently used openings in watertight compartments, where a crew member will be in immediate attendance when the door is open at sea. Audible & visual alarms should be provided in the wheelhouse.
.4 With the exception of doors referred to in section 4.4.1, watertight doors in yachts under 500GT may be approved hinged doors provided that there is an audible and visual alarm on the Bridge indicating when the door is open. The doors are to be kept closed at sea and marked accordingly. A time delay for the alarm is acceptable.
.5 Procedures for the operation of watertight doors should be agreed with the administration and posted in suitable locations. Watertight doors should be normally closed, with the exception of sliding watertight doors providing the normal access to frequently used living and working spaces. Additionally when an access is unlikely to be used for lengthy periods, the door should also be closed.
4.4 Enclosed Compartments within the Hull and below the Freeboard Deck provided with Access through Openings in the Hull
4.4.1 Compartment(s) below the freeboard deck, provided for recreational purposes, oil fuelling/fresh water reception or other purposes to do with the business of the vessel and having access openings in the hull, should be bounded by watertight divisions without any opening (i.e. doors, manholes, ventilation ducts or any other opening) separating the compartment(s) from any other compartment below the freeboard deck, unless provided with watertight doors complying with 4.3.1.
4.4.2 Openings in the hull should comply with SOLAS regulation II-1/25-10 - External openings in cargo ships. Provision should be made to ensure that doors may be manually closed and locked in the event of power or hydraulic failure.
4.5 Rigging on Sailing Vessels
(Note - the section is currently subject to rewriting)
4.5.1 General
The condition of the rig should be monitored in accordance with a planned maintenance schedule. The schedule should include, in particular, regular monitoring of all the gear associated with safe work aloft and on the bowsprit (see 22.3).
4.5.2 Masts and spars
4.5.2.1 Dimensions and construction materials of masts and spars should be in accordance with the recommendations of one of the Classification Societies referred to in 4.2.1. or a recognised national or international standard.
4.5.2.2 The associated structure for masts and spars (including fittings, decks and floors) should be constructed to absorb the forces involved.
4.5.3 Running and standing rigging
4.5.3.1 Wire rope used for standing rigging (stays or shrouds) should not be flexible wire rope (fibre rope core).
4.5.3.2 The strength of all blocks, shackles, rigging screws, cleats and associated fittings and attachment points should exceed the breaking strain of the associated running or standing rigging.
4.5.3.3 Chainplates for standing rigging should be constructed to support and absorb the forces involved. Only one shroud or stay should load an individual attachment point, unless the design specifically allows for more.
4.5.4 Sails
4.5.4.1 Adequate means of reefing or shortening sail should be provided.
4.5.4.2 Sailing vessels operating as Short Range Yachts need not carry storm canvas.
4.5.4.3 All other vessels should either be provided with separate storm sails or have specific sails designated and constructed to act as storm canvas.