PART II

STRENGTH, CONSTRUCTION AND WATERTIGHT SUBDIVISION

2.1 Submission of Plans and Particulars

2.1.1 General
2.1.1.1 To determine whether the proposals relating to the construction of the ship comply with the requirements of the Regulations the surveyor should obtain from the shipbuilder, owner, or his consultant, all plans and particulars necessary for the consideration of the case and submit them to Headquarters, together with any observations he may make from his own examination of the plans. 2.1.1.2 All plans, particulars and calculations should be in the English language, or should include an adequate English translation. Measurements should be in metric units.

2.1.2 Importance of early submission of plans

2.1.2.1 The shipbuilder or his consultant should be informed by the surveyor of the importance of the early submission of the drawings and particulars listed in paragraph 2.2.1. Work on the construction of the ship should await the acceptance of the submitted plans and particulars as inconvenience and delay may arise if alterations to the proposals are considered necessary. 2.1.2.2 The receipt of all plans and documents is to be acknowledged immediately. Surveyors should make every endeavour to ensure the expeditious return of submitted plans and documents and/or comments appropriate to them. 2.1.2.3 As the construction of the ship proceeds, the surveyor should ensure that the arrangements and details are in accordance with the accepted plans and particulars.

2.2

Strength of the Hull (Regulation 6)

2.2.1 Plans and particulars to be submitted

The plans and particulars to be submitted should include those specified below, as appropriate to the Class of the ship being considered, and such other information as may be necessary for the full consideration of the proposals being offered for compliance with the MCAs requirements for the issue of a Passenger and Safety Certificate, a Passenger Certificate or a Certificate of Survey.

2.2.2 Hull structural plans:2.2.2.1 (a) Midship section showing longitudinal and transverse material (b) Profile and decks (c) Shell expansion including bilge keel construction and attachment to the hull (d) Watertight and oil-tight bulkheads (e) After end construction (f) Fore end construction (g) Engine room construction and engine and thrust seatings (h) Pillars and girders (i) Double bottom structure (j) Sternframe (k) Rudder, stock and tiller (l) Propeller shaft brackets (m)Ship side doors (n) Stabilising fins and lateral thrust units where fitted. 2.2.2.2 All plans should identify the nature and physical properties of the materials being used and their means of connection, particularly where it is intended to use steels of special quality and aluminium alloy. 2.2.2.3 Where the ship is to be classed with a recognised Classification Society, namely Lloyds Register of Shipping, the American Bureau of Shipping, Bureau Veritas, Det Norske Veritas, Germanischer Lloyd or Registro Italiano Navale it will be sufficient for the surveyor to obtain from the shipbuilder or consultant stamped approved copies of the drawings submitted to the Classification Society together with that Society's approval. 2.2.2.4 The surveyor should ensure that the scantlings are approved for the designed subdivision draught and the strength is sufficient for the service intended. 2.2.2.5 Plans showing the scantlings and details of construction of all watertight bulkheads and all tanks forming part of the internal structure, e.g. oil fuel storage and settling tanks, water ballast and fresh water tanks are to indicate the maximum head of water which they might have to sustain in accordance with Schedule 4 in Merchant Shipping Notice MSN 1699(M) such that the maximum head sustained would include any additional water estimated under Regulation 33, paragraph 4(b) of Part V of the Regulations which may result from flooding or heeling.

2.2.3 Survey of hull before painting etc.

The survey of a ship during construction is for the purpose of enabling the surveyor to form an opinion of the construction and workmanship and the surveyor should not undertake the survey of a new ship after the hull is painted, cemented or otherwise coated. Where such coatings have been applied prior to survey the surveyor should take whatever action he deems necessary in order to satisfy himself that the construction and workmanship are satisfactory for the service intended and in accordance with the submitted plans.

2.2.4 Dry docking

If the outside of the hull and fittings of a new passenger ship have been surveyed and accepted by the surveyor before the ship is launched, they need not be again examined in dry dock after launching unless the surveyor has reason to do so. In either case a suitable record should be made in the Dry Docking Book.

2.3 Quality and Tests of Materials 2.3.1 General

The surveyor should be satisfied with the quality, strength and testing of the materials used in the construction of the hull, bulkheads, decks, superstructures and deckhouses; and the materials used in the attachments thereto, is to be in accordance with the requirements of a recognised Classification Society.

2.3.2 Glass-reinforced plastics

2.3.2.1 When it is intended to use glass-reinforced plastics in the construction of a ship, details of the extent to which the material is to be used should be submitted well in advance of the date it is proposed to commence work. Depending on the extent to which the material is to be used, further details may be required of the resins, fillers, and glass fibre reinforcements which should comply with the relevant parts of BS 3532 of 1990, 3496 of 1989 (1995), 3691 of 1990 (1995) and 3396 and 3749 of 1991, and are to be acceptable to the MCA. 2.3.2.2 The MCA will require to be satisfied that the premises are suitable, and that persons who are employed have been properly trained for the type of work to be undertaken. 2.3.2.3 Whenever glass-reinforced plastic is used in the construction of the hull, decks, superstructure, deckhouses or bulkheads, the laminates should be self extinguishing from fire considerations. The self extinguishing property should be imparted to the whole of the laminate. The test method to be used for ensuring that this requirement is complied with is described in Appendix E to these Instructions.

2.3.2.4 Should it be proposed to construct the hull, decks, superstructure, deckhouses or bulkheads with special laminates to afford the same degree of protection against fire as that obtained by the use of self extinguishing laminates, full details should be submitted for consideration.

2.3.3 Materials for side scuttles and windows

2.3.3.1 Type approved design The materials acceptable to the MCA for use in construction of type approved side scuttles and windows are given in BSMA 24 and 25 or their ISO equivalents, namely ISO 1751 and 3903. To ensure that the materials are of the correct quality, the surveyor should request the side scuttle manufacturer to provide copies of supporting documentation i.e., type approval and test certificates which may be compared with the requirements of the applicable standard. 2.3.3.2 Class approved design Side scuttles and windows constructed in accordance with the requirements of a recognised Classification Society are to have supporting documentation in the form of approved drawings, stamped and endorsed by the society. 2.3.3.3 Non-approved type Side scuttles and windows of a non-approved type are to be approved by the surveyor on an individual basis for the vessel concerned. The constructional drawings, properties and thickness of glass and chemical composition and mechanical strength of materials used in the construction of the frames should be in accordance with the requirements of an applicable standard. The thickness of glass pane is to be appropriate to the size and position on the vessel and in accordance with BSMA 24 or 25 or the equivalent ISO standard 5780 and 1751 or 5779 and 3903. Where nonapproved windows and frames do not conform with a recognised standard, full details including supporting documentation are to be submitted to the certifying authority for consideration of acceptance as an equivalent to the requirements of a relevant standard.

2.3.3.4 Glazing materials other than glass The materials used for side scuttles, windows, promenades and deck spaces should normally be heat treated toughened glass. However, the use of other materials may be considered provided these fulfil relevant provisions for strength, structural fire protection, visibility and location and suitability for use in escapes. In general where it is proposed to use

materials other than toughened safety glass, their use should be in accordance with the requirements of an acceptable standard appropriate to the proposed class and service of the vessel. Otherwise, full details of the proposed materials and their proposed use should be submitted to the MCA for approval. 2.3.3.5 Internal Glazing and other Translucent Divisions Materials other than heat treated toughened glass will be accepted for internal glazed divisions provided they are shown to break safely, comply with the requirements of an accepted standard and are appropriate for the class and service of the vessel. An appropriate standard for consideration would be BS 6206:1981 which relates to the impact testing of glazed constructions used in land based applications, copies of test certificates should be available from the manufacturers on request. Alternatively, appropriate marked toughened glass panes, in accordance with BSMA 25 or ISO 614 may be accepted for internal screen divisions with the recommendation that panes which exceed 0.75 sq m in area have a minimum thickness of 10mm and those smaller in area have a minimum thickness of 6mm. In cases where the surveyor is unsure as to the acceptability of the proposal, full details should be submitted to the MCA for their consideration

2.4

Construction of Watertight Bulkheads (Regulation 7)

2.4.1 General
2.4.1.1 Every watertight subdivision bulkhead or other portion of the internal structure forming part of the watertight subdivision of the ship is to be constructed in accordance with Schedule 4 of Merchant Shipping Notice MSN 1699(M). 2.4.1.2 Bulkhead stiffeners should not be spaced more than 610mm apart on a collision bulkhead or more than 915mm apart on any other watertight bulkhead unless other structural arrangements can be shown to be equally effective.

2.4.2 Initial tests of bulkheads, etc.

2.4.2.1 All watertight bulkheads, decks, etc. should be examined by the surveyor. 2.4.2.2 Main compartments may be tested by filling with water, but this is NOT compulsory. Where this is not carried out, a hose test should be applied to the bulkheads.

2.4.2.3 A hose or flooding test should be applied to watertight decks, and a hose test to watertight trunks, ventilators and tunnels. 2.4.2.4 Hose testing of watertight bulkheads, including the watertight doors and the attachments of the door frame to the bulkheads, decks and tunnels, should be simultaneously inspected on both sides of the plating while the water is being played upon all connections. 2.4.2.5 The pressure of the water in the hose should not be less than 2 Bar. 2.4.2.6 The forepeak, double bottom, duct keel and inner skin should be subjected to a head of water up to the margin line. In some cases this requirement may be waived for adjacent tanks. It may not be possible to test a duct keel without causing damage to equipment therein in which case a close examination and tests of adjacent tank bulkheads should be acceptable. 2.4.2.7 Tanks which are intended to hold liquids, and which form part of the subdivision of the ship, should be tested for tightness with water to a head to the deepest subdivision load line, or to a head corresponding to two-thirds of the depth from the keel to the margin line in way of the tanks, whichever is the greater, provided that in no case should the test head be less than 900mm above the top of the tank. These tests are for the purpose of ensuring that the subdivision structural arrangements are watertight, and should not be regarded as a test of the fitness of any compartment for the storage of liquids, or for other special purposes for which a test of a superior character may be required; such superior tests may be accepted in substitution, depending on the height to which the liquid has access in the tank or its connections. 2.4.2.8 The hose and pressure tests should be carried out in the presence and to the satisfaction of the surveyor. 2.4.2.9 When alternative testing arrangements considered equivalent to the above are proposed, full details are to be submitted to the MCA.

2.5

Watertight Subdivision Arrangements (Regulation 8)

The plans and particulars to be submitted for approval are as follows,

2.5.1 Structural arrangements above and below the bulkhead deck

2.5.1.1 Plans showing the positions, sizes, types and details of all side scuttles and windows. In the case of side scuttles below the margin line the height of the sill of the side scuttle above the summer load line and/or the deepest subdivision load waterline should be stated. Where side scuttles and windows comply with BSMA 24 and BSMA 25 or an equivalent acceptable to

the MCA, it will not be necessary to submit structural details provided that those are retained on file for records. 2.5.1.2 Plans showing the arrangement and details of all gangway and cargo loading doors fitted in the shell or boundaries of enclosed super-structures, bow visors where fitted, weather-tight ramps used instead of doors for closing openings for cargo or vehicle loading, cargo loading doors in the collision bulkheads, and small doors used for pilot access, fuelling or other matters necessary for the operation of the ship. 2.5.1.3 Plans showing the arrangements and particulars of ship's side discharges. 2.5.1.4 Plans showing the details of the oil fuel, fresh and feed water, bilge and ballast, salt water and sewage systems and air, filling, sounding and scupper arrangements. 2.5.1.5 Plans showing the means of closing openings in the weather deck and means for clearing water from such a deck for compliance with Regulation 10 of Part II of the Regulations.

2.5.2 Arrangements and calculations for subdivided ships:2.5.2.1 Fully dimensional outline elevation, plan and section views of the ship showing the margin line (corrected where appropriate, see paragraph 2.5.3.2) all watertight transverse and longitudinal bulkheads, decks, inner skins, shaft and other tunnels, trunks and ventilators; the appropriation of spaces below the bulkhead deck; the position of equivalent plane bulkheads, the lengths of the main transverse compartments, and the weathertight arrangements above the bulkhead deck at the forward end. Tunnels, recesses and steps are to be shown in plan and elevation, and typical sections of the double bottom should be given. 2.5.2.2 Outline elevation, plan and section views of the ship showing the dimensions, number, location and type of all watertight doors and any other openings in watertight divisions which are closed only by portable bolted plates. 2.5.2.3 Either on a separate drawing or superimposed on that drawing referred to in paragraph 2.5.2.1, flooding curves are to be submitted for every ship which is subdivided in compliance with Regulation 32 of Part V of the Regulations and Section 2 of Schedule 2 to Merchant Shipping Notice MSN 1699(M), except that where a ship is shown to be in full compliance with Regulations 2 to 8, 11 and 13 of IMO Resolution A.265(VIII), i.e. subdivision requirements based on the concept of the probability of survival, the development of flooding curves is not required.

2.5.2.4 The flooding curves should be developed using recognised computer techniques and to enable the MCA to carry out an independent check of the submitted information, it will be necessary for the shipbuilder to submit, along with the drawing referred to in paragraph 2.5.2.1 and 2.5.2.3 above, calculations to determine the position of equivalent plane bulkheads and allowances for local subdivision. 2.5.2.5 Where the opportunity arises, the surveyor should examine the shipbuilder's input data sheets prior to these being offered to the computer. To assist in the confirmation of input data, use should be made (if the facility exists) of perspective presentation of body sections etc.