Abstract: A device for releasably locking a parked vehicle at a loading dock during loading and unloading thereof. The device is provided with a carriage mounted for vertical adjustment relative to the front wall of the dock and adapted to be yieldably engaged by a depending safety bar of the parked vehicle. A hook-like member is mounted on the carriage for independent rectilinear movement between an operative mode wherein the vehicle safety bar is lockingly engaged thereby and an inoperative safety bar-release mode. A power-actuated unit is mounted on the carriage and is connected by a linkage assembly to the hook-like member and effects movement thereof between the operative and inoperative modes. The linkage assembly includes a pair of pivotally connected links one of which has an end portion pivotally connected to the hook-like member and the other has an end portion pivotally connected to a lower portion of the carriage.