Leaves on the line, a bizarre hazard that disrupts UK train services every fall, may soon be under control through the use Global Positioning Satellites to pinpoint problem areas. AEA Technology Plc has linked up with Thames Trains and devised a system to overcome the problem of falling leaves, which cause safety problems by making the train’s wheels slip when braking and spin under traction. To control the hazard, AEA has developed the Low Adhesion Warning System (LAWS). An on-board computer monitors the train for an indication of wheel slip and when it encounters low adhesion, a message is automatically transmitted to a central control room by mobile phone. The message includes the train’s position and speed, the duration of the event and how powerfully the brakes were applied at the time. Using this information the system produces a color-coded map showing areas of low adhesion. This can then be used to keep drivers up to date with the location and severity of low adhesion sites and to direct teams to clear the hazard. The system also has the potential to display messages in the cab of a train equipped with the system to warn drivers when they were approaching areas of low adhesion.
