Wheel chocks are devices placed against wheels to prevent movement. In car and locomotive repair shops, chocks are typically wood or polymer wedges, although chain chocks are occasionally used as well. In autoracks, automobiles are held in place with special chocks that clamp to the grating on the floor.
Tools & Equipment
A device attached to the last coupler on the rear of a train consisting of a flashing light and a radio-controlled dump valve for activating the emergency brakes remotely, as well as telemetry circuitry for determining train length and a trainline air pressure sensor. When linked to a Head of Train Device (HTD), the HTD will display train length and the air pressure at the rear of the train to the Locomotive Engineer.
See End of Train Device (EOT)