This CDC-developed invention entails a system of electrical and hydraulic circuits used to stop a rotating winch in an emergency. Amongst other locations, one stop switch can be positioned on a capstan winch horn. This location makes it available to a victim entangled in rope being retrieved on a gypsy drum. As designed, the stop circuit could be used with an electrically, hydraulically or pneumatically operated winch. A variant of this safety system has been successfully tested on a purse seining fishing vessel in Alaskan waters.