This report describes a standard design for using railcar subframes as superstructures for temporary bridges on forest roads in British Columbia. The design was prepared by the British Columbia Ministry of Forests in response to a need for a standard design acceptable to both government and the British Columbia forest industry. The Forest Engineering Research Institute of Canada (feric) facilitated initial discussions and assisted in the development of the standard design. The design assumptions and specifications are detailed. A comparison with alternative superstructures finds the standard design railcar superstructure to be cost competitive.