Fire resistance tested

Press, Volume CXI, Issue 32553, 12 March 1971, Page 15

Fire resistance tested

Fire - resistant overalls give racing drivers considerably less protection from burns than might have been thought, Britain’s Jim Clark Foundation has reported after a survey of fire-resistant materials. A summary of the findings has been sent to all members of the Grand Prix Drivers Association, which informed the foundation last year of the need for a

study by an independent body because of conflicting claims made by clothing manufacturers.

The four-month investigation was conducted in the Nottinghamshire laboratories of the Hosiery’ and Allied Trades Research Association. The association’s scientists carried out a total of 168 separate tests —eight experiments on each of 21 materials or combinations of materials. The foundation claims that it was the first comparative test programme ever conducted on the subject.

The main finding was that even the best garment systems now in use protect a driver for much shorter periods than was generally believed. Protection against serious bums in a petrol fire is guaranteed for no more than 30 seconds.

Another fact to emerge from the test programme is the absolute necessity of a "multiple layer” approach to protective clothing. The emphasis on the need for both an outer layer, to act as a shield against the flames, and under garments to provide insulation, is thought to be the most important lesson for drivers. At present, says the survey, there is little awareness of the importance of protective under garments. Some articles of protective clothing have even been promoted as requiring nothing to be worn underneath. Fabrics were tested in both a dry condition and when soaked in petrol. Experiments revealed that at least during the first stages of a fire, petrolsoaked garments slow down the build-up of temperature and thus increase protection for the wearer. This may be due to the evaporative cooling of the fuel itself. After 30 to 40 seconds of a fire, however, temperature build-up accelerates in fuelsoaked garments. But it is thought by the foundation that the generally reassuring results of the tests with “wet” clothing will help allay at least some of the fears of drivers being soaked with petrol in race accidents. Technical information gained during the survey is already being referred to fabric manufacturers and designers of garments.