Special cut-protection clothing is part of legally prescribed personal protective equipment for the 25,000 professional foresters in Germany, who work with chain saws on public and private land. Overalls with several layers of ultra-strong fibers stop the saw before wearers are injured, but are clumsy and hot, hampering and heating foresters. The Hohenstein Institute, Bönnigheim, Germany, sought a more comfortable solution. An innovative sensor system called HORST embedded in cut-protection trousers switches off the saw before it gets too close to the legs.
Magnets on the chainsaw’s guide bar and magnetic field sensors incorporated into cut-protection textile create a magnetic field around the forester. If the saw comes too close (a minimum of 5 to 10 centimeters in trials), a radio signal stops the saw. Only the radio transmitter uses a battery. Besides being lighter and more comfortable, the sensor textile stands up to washing and doesn’t restrict cutting or manufacture of the garments, so may be viable for many other applications.