Abstract: A boarding platform for transferring personnel between a fixed dock structure and a barge or the like is disclosed. The boarding platform includes a pair of vertical tracks having a carriage mounted for raising and lowering movements relative to the tracks. A boarding ramp is mounted on the carriage which is normally biased to a vertical or raised position. Counterweights are provided on the carriage so that a main raising cable carries only a portion of the weight of the carriage and the ramp. A winding motor for the main cable is suspended from a high-low weight sensing load cell which operates a mechanism to lock the carriage relative to the tracks (a) if a person stands on the ramp, (b) if the main cable breaks, or (c) if one or more of the counterweights releases.