A motion detector for detecting movement of a rail based vehicle and the direction of that movement is provided. The motion detector can be integral with or attachable to an end-of-train unit and can include a single axis accelerometer mounted at an angle from the rails for detecting acceleration in...http://www.google.co.uk/patents/US6087950?utm_source=gb-gplus-sharePatent US6087950 - Detector for sensing motion and direction of a railway device
