BS 6853 Code of practice for fire precautions in the design and construction of passenger carrying trains

1 Scope
This British Standard makes recommendations in respect of fire safety for the design and construction of railway vehicles comprising or forming part of passenger carrying trains. The recommendations are applicable to new vehicles and also to substantial changes to existing vehicles.
NOTE In respect of existing vehicles, the recommendations in this standard are applicable to any item or material which is beingsubstantially replaced or renewed.
Where a vehicle is subject to an engineering change involving the replacement/substitution of materials, or the introduction of new or revised systems/components the fire performance of the vehicle should not be degraded and the relevant sections of this standard should be used to assess the required fire performance.
The recommendations in this British Standard cover:
a) the reaction to fire of materials;
b) the use of fire resisting barriers;
c) general aspects of design for fire safety.
Recommendations on measurement of smoke and toxic fume emission are given in Annex A and Annex B.
Systems and materials that comprise the fire safety component of a passenger carrying train need to
remain effective for the whole working life of the item. Such systems and materials should be compatible
with the expected levels of wear and tear, including ageing, weathering, cleaning and passenger abuse for
that duration. Where materials need to be replaced during the working life of the vehicle then the
replacement materials should meet this standard. Operators of the vehicle should take this into account to
ensure a suitable level of fire safety is maintained throughout the life of the vehicle in so far as it is
reasonably practicable to do so.

2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute
provisions of this British Standard. For dated references, subsequent amendments to, or revisions of, any
of these publications do not apply. For undated references, the latest edition of the publication referred to
applies.
BS 476-4, Fire tests on building materials and structures — Part 4: Non-combustibility test for materials.
BS 476-6, Fire tests on building materials and structures — Part 6: Method of test for fire propagation for
products.
BS 476-7, Fire tests on building materials and structures — Part 7: Method of test to determine the
classification of the surface spread of flame of products.
BS 476-15, Fire tests on building materials and structures — Part 15: Method for measuring the rate of heat
release of products.
BS 476-20, Fire tests on building materials and structures — Part 20: Method for determination of the fire
resistance of elements of construction (general principles).
Reproduced by IHS under license with BSI License provided by I.H.S. Germany
For Internal Use Only
BS 6853:1999
© BSI 4 December 2002 3
BS 476-22, Fire tests on building materials and structures — Part 22: Methods for determination of the fire
resistance of non-loadbearing elements of construction.
BS 4066-3, Tests on electric cables under fire conditions — Part 3: Tests on bunched wires or cables.
BS 5438:1989, Methods of test for flammability of textile fabrics when subjected to a small igniting flame
applied to the face or bottom edge of vertically oriented specimens.
BS 6387, Specification for performance requirements for cables required to maintain circuit integrity under
fire conditions.
BS EN 3 (all parts), Portable fire extinguishers.
BS EN 50200, Methods of test for resistance to five of unprotected small cables for use in emergency
circuits.
BS ISO 4589-2, Plastics — Determination of burning behaviour by oxygen index —
Part 2: Ambient-temperature test.
BS EN ISO 4589-3:1996, Plastics — Determination of burning behaviour by oxygen index —
Part 3: Elevated temperature test.
BS ISO 5659-2, Plastics — Smoke generation — Part 2: Determination of specific optical density.
BS ISO 9239-1, Reaction to fire tests — Horizontal surface spread of flame on floor-covering systems —
Part 1: Flame spread using a radiant heat ignition source.
prEN 28241)2), Aerospace series — Burning behaviour, determination of smoke density and gas components
in the smoke of materials under the influence of radiating heat and flames — Test equipment, apparatus
and media.
prEN 28251)2), Aerospace series — Burning behaviour, determination of smoke density and gas components
in the smoke of materials under the influence of radiating heat and flames — Determination of smoke
density.
prEN 28261)2), Aerospace series — Burning behaviour, determination of smoke density and gas components
in the smoke of materials under the influence of radiating heat and flames — Determination of gas
components in the smoke.
NF X 70-1002), Fire tests — Analysis of pyrolysis and combustion gases — Tube furnace method.