Two employees were opening lids on railcars to prepare the cars for loading on a track. Both employees were in full body harnesses and were connected by a self-retracting lifeline (SRL) to a rail fall safety system. The train started moving north and the employees realized that the cars were going to move beyond the fall protection coverage and decided to unhook from the rail fall protection. Employee 1 assisted the injured employee and unhooked from the system. As the injured employee attempted to unhook, the SRL ran out of cable, roughly 25 feet from the rail shed. The injured employee was pulled onto his back and remained stationary on his back, held by the SRL cable, as the rail cars moved under him. The employee sustained a laceration and contusion to the top of the head; bruising and scrapes to the lower back, legs and arms; a cut on the right hand; and a bruised thumb.