Derails are emergency car stopping devices to prevent unauthorized movement of a locomotive or railcar. The derail lifts the flange of the car wheel and drops it clear of the rail impeding forward movement. OSHA, FRA, and DOT regulations require derail protection for all active rail siding. Derails help prevent these railroad accidents:1. Railcars rolling into each other. 2. Unauthorized or premature removal of cars by locomotive. 3. Rollaway car escaping out onto mainline. Permanently Installed Hinged Derails For permanent derailing capability use these Hinged Derails on exposed rail track and wooden ties. Derail ?shoe? swings on or off the rail and can be padlocked in either position. Derail blue flag and holder (manually- operated) are included. To Order: 1. Specify one-way (left throw or right throw) or two-way model 2. Specify height of rail as measured from top of tie to top of rail (including thickness of tie plate) or request our derail sizing form.