1 General
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Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.754(18) – Recommendation on Fire Resistance Tests for “A”, “B” and “F” Class Divisions – (Adopted on 4 November 1993) - Annex - Recommendation on Fire Resistance Tests for “A”, “B” and “F” Class Divisions1 - 1 General

1 General

  1.1 Under the provisions of the International Convention for the Safety of Life at Sea, 1974, and subsequent amendments thereto, and the Torremolinos Protocol of 1993 relating to the Torremolinos International Convention for the Safety of Fishing Vessels, 1977, constructions for use in passenger ships, cargo ships, and fishing vessels should have a 'fire insulation' to the satisfaction of, and be approved by, the Administration. In this context 'fire insulation' is the ability of the construction to insulate/protect an area from the influences of a fire in an adjoining area by having separating performance during fire. Such constructions are "A" class bulkheads and decks, "A" class doors, "B" class bulkheads, decks, ceilings and linings, "B" class doors, "F" class bulkheads, decks, ceilings and linings, and "F" class doors.

 The approval will be given by the Administration based on results of tests carried out on the construction and material in question. Tests should be conducted at a testing laboratory recognized by the Administration. The applicant for the test, i.e., the manufacturer or agent, should if required submit test specimens and information to the testing laboratory as prescribed in this document.

  1.2 Approval of constructions will be restricted to the orientation in which they have been tested; therefore bulkheads, linings and doors should be tested vertically mounted and decks and ceilings should be tested horizontally mounted. It is only necessary to test decks with the underside exposed to the heating conditions, and "B" and "F" class ceilings and linings are required only to be tested from the side incorporating the ceiling or the lining.

 For "A" class bulkheads and doors for "general application", i.e. for use of the insulation material on either side of the structural core, and also for "B" class bulkheads and doors, approval usually requires that the construction has been tested from each side separately, using two separate specimens, unless the Administration considers that only a single test to one side, that being the side expected to provide a performance inferior to the other side, is appropriate.

 In tests for "A" class bulkheads for "general application" it may be possible for approval to be granted on the basis of a single test only, provided that the bulkhead has been tested in the most onerous manner, which is considered to be with the insulation on the unexposed face and the stiffeners also on that side.

 In tests for "A" class bulkheads for "restricted application", i.e. where the fire hazard has been identified as being from the insulated side only, the bulkhead can be tested with the insulation on the exposed face and with the stiffeners also on that side.

 If approval of an "A" class bulkhead is being sought involving the use of "double-sided application" of the insulation, the thickness of the insulation being equal on both sides of the structural core, it should be tested with the stiffeners on the unexposed side of the bulkhead, otherwise it should be tested with the side with the thinnest thickness of insulation on the exposed face.

 If insulation of an "A" class division is to be provided by membrane protection, i.e. by a "B" class ceiling to a structural steel core or a "B" class lining to a structural steel core, the distance between the membrane, i.e. the ceiling or the lining, and the structural core should be the minimum for which approval is being sought. For "A" class bulkheads, the division is required to be tested both from the structural core side, and from the "B" class lining side. For both ceilings and linings which may form part of such deck or bulkhead constructions, they should satisfy at least B-0 classification.

 When the insulation of an "A" class division is provided by membrane protection, the stiffeners of the structural core should be positioned in the cavity between the steel plate of the structural core and the membrane protection. For an "A" class bulkhead the Administration may accept or require the stiffeners to be on the opposite side of the steel plate of the structural core to enable the distance between the membrane protection and the structural core to be reduced to a minimum.

  1.3 The dimensions of the structural cores of the test specimens given in section 2 are intended for structural cores of stiffened flat plates of steel or aluminium alloy. The Administration may require tests to be carried out on specimens having structural cores of materials other than steel or aluminium alloy if such materials are more representative of the construction to be used on board ships.

  1.4 "A" class divisions which consist of an uninsulated steel bulkhead or deck of suitable scantlings and without openings can be deemed to satisfy the requirements for class A-0 divisions, i.e. to satisfy the requirements for the passage of smoke and flame, without the need for testing. All other divisions, including class A-0 divisions with a structural core of aluminium, are required to be tested.

  1.5 Results obtained on an insulating material used in conjunction with an "A" class division may be applied to constructions incorporating heavier scantlings than those tested and providing the orientation of the construction is the same, i.e. results from bulkhead tests should not be applied to decks and vice versa.

  1.6 The construction to be tested should be, as far as possible, representative of that to be used on board ships, including the materials and method of assembly.

 The designs of the specimens proposed in this resolution are considered to reflect the worst case situations in order to provide maximum usefulness of the classifications to end use applications. However, the Administration may accept or request special test arrangements which provide additional information required for approval, especially of those types of constructions which do not utilize the conventional components of horizontal and vertical divisions, e.g. where cabins may be of a modular type construction involving continuous connections between bulkheads, decks and ceilings.

  1.7 Constructions should be tested without paint or other superimposed finish, provided that where they are only produced with a superimposed finish, and subject to the agreement of the Administration, they may be tested as produced. Such constructions may be required to be tested with a superimposed finish if such a finish is considered by the Administration to have a detrimental effect on the performance of the construction in the test.


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