In the hot seat…

Members of the CERN Fire and Rescue Service and the Swiss fire services* have been taking part in a series of experiments organised by the Federation of Swiss Fire Services (FSSP), designed to test out new materials for fire-fighters’ clothing. Today’s exercise -  being locked inside a burning chamber.


The fire-fighters sit patiently in the test chamber with fire raging around them...

Friday, 5 July. 9.15 a.m. at the Prévessin training site. The fire is building nicely
and the flames are starting to lick across the floor of the CERN fire-fighters’ simulation chamber. Five fire-fighters wearing prototype under-garments and heat and flame-resistant coveralls prepare to enter this inferno. One by one they take their seats in the blaze where they must remain for 15 minutes. Under their clothes they are wired up to an array of sensors which measure their heart rates, humidity levels and body temperatures.

Inside the chamber, temperatures begin to soar: 180°C at mid-height and up to 480 °C at ceiling level. Under the close scrutiny of their instructors, the five guinea-pigs sit and wait, impassive. Once the fifteen minutes are up, they are taken to an air-conditioned room at 22°C for fifteen minutes of respite. But they aren’t allowed a drop of water, as this would skew the results. They then head back into the chamber to “cook” for another fifteen minutes.

A few minutes’ respite before going in for a second roasting.

At the end of the exercise, everything is weighed - socks, pants, stockings, glove liners, trousers etc. – to determine precisely how much water has been absorbed by each of the new equipment items. At these temperatures, the body loses several litres of water in a few minutes. “This new equipment has been designed to allow the body to breathe without losing too much water,“ explains Heiko Clicque, a fireman at CERN, who was taking part in the tests. ”Fire-fighters in Switzerland and elsewhere are encountering safety problems with their coveralls, which are too hermetic and thus accumulate too much heat. This generates a sharp rise in body temperature which can cause loss of consciousness, with disastrous consequences.”

Ten fire-fighters took part in this series of tests in vivo that follow on from a first campaign at the Swiss Federal materials testing laboratory (EMPA) in Saint Gallen last spring. The same subjects underwent various exercises where they had to run inside a chamber heated up to 40°C with 0% humidity. The results of these experiments, which are the fruit of a broad interdisciplinary collaboration, are expected in September and will contribute to the development of new, improved equipment. This will be good news for fire-fighters and victims alike.

*Fire and Rescue Services of Neuchâtel, Fire and Rescue Services of Geneva, Vaud fire insurance establishment, Schutz und Rettung Zürich, Feuerwehr und Zivilschutz St Gallen, Ausbildungszentrum für Sicherheit Büren, Gebäudeversicherung Kanton Zürich.

by Anaïs Schaeffer