BS 6853

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

As a Code of practice, this British Standard takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of compliance are not misleading.

As the Introduction in the British Standard states:

“The aim of the  BS 6853 standard is to ensure the safety of passengers in the event of fire on or around a vehicle or vehicles comprising a passenger carrying train. Fire safety in this environment depends upon a range of interdependent measures which may include: detection and alarm/warning systems, manual or automatic fire suppression systems, emergency lighting and way-guidance systems, means of escape and egress provisions, escape route or exit door widths, places of safety, occupancy levels, normal supervision, staff management of an incident (which includes staff training), control of materials and contents, ventilation, compartmentation and fire resistance.

This standard necessarily concentrates upon the properties and fire performance of the construction and materials that form the train, with some advice provided on a number of other aspects. The engineer does, however, need to be aware that the fire safety design of the train may need to include all the above range of measures.”

NOTE: BS 6853 was replaced by BS EN 45545 -2 Railway applications. Fire protection on railway vehicles. Requirements for fire behaviour of materials and components

BS 6853 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.

The recommendations in this standard cover:

1. the reaction to fire of materials;
2. the use of fire-resisting barriers;
3. general aspects of design for fire safety.

The objectives of BS 6853 Standard are:

• to control the power and duration of ignition sources and the frequency of their occurrence;
• to control the reaction of materials to ignition sources of a variety of sizes;
• for smaller ignition sources, of the order of 1 kW, to ensure that conditions within the affected vehicle remain tenable almost indefinitely;
• for larger ignition sources, of the order of 10 kW, to ensure that the period during which conditions remain tenable is consistent with the time required for people to move from or through the affected vehicle;
• for the largest ignition sources, of the order of 100 kW, to ensure that the probability of a transition to flash-over within the vehicle is minimized;
• to limit the rate of heat release from the vehicle on flash-over;
• to limit the impact of the products of fire on areas remote from the seat of the fire.