Fire Resistant Cables Get Tougher

As high prestige buildings become more complex, and architects, engineers and designers incorporate more elaborate layouts, the need for higher performance cables has been identified by a number of manufacturers. Shopping centres, office buildings with atriums, sports stadiums and even some high specification residential premises are all nowadays using advanced fire safety engineering design approaches.

Fire safety engineering allows a more open building structure, but ensures safe evacuation in the event of a fire by a combination of traditional and modern, active fire systems.  Many of these require electrical power supplies and control circuitry to remain functional throughout a potentially serious fire.  Examples include fire-fighting lifts and smoke extract systems.  Robust fire resistant cables are needed.

Such cables need to be robust to not only fire, but also to impact damage and the effects of water spray from sprinklers or the fire brigade.  A new fire test, BS 8491, has been developed to provide this test.  Several cable makers have produced enhanced fire resistant cables to meet this need, incorporating spiral interlocked steel tape armour instead of the usual steel wire armour.

A new edition of BS 7846 for fire resistant armoured cables has just been published.   As well as the traditional steel wire armoured fire resistant cables (category F2), the new type using interlocked steel tape armour has been introduced, classified as categories F30, F60 or F120, reflecting the length in minutes of the BS 8491 fire test.

Installers will begin to see these new types specified soon in buildings.  Because the armour construction is different, new cutting and preparation methods will be needed.  New gland types will be used, and traditional cone-type SWA glands may not be suitable.  Installers will need to make sure they are adequately trained to use such cables.

Further information and assistance is available at,, or contact BASEC directly on 01908 267300.



Go back