Fiberoptic system warns trains of landslides

The Japan Aviation Electronics Industry Ltd. and East Japan Railway Co. (EJR) have developed a landslide warning system that notifies trains to make emergency stops less than two seconds after a track has been obstructed. Using a fiberoptic network containing light emitters and detectors, the system gives a warning and also pinpoints the location of the landslide. While conventional monitors permit only fixedpoint observations with a limited range of only a few meters, the fiberbased system has continuous coverage of u¥to 5 km. The system has been installed along a portion of EJR`s Narita line.