A handle operated brake and release mechanism for a cable drum winch provides a winch that can be used in the assembly of inland river barges to form multi-barge tows. The handle of the brake and release mechanism can in one function and entirely by hand (without using any other tools) release the cable tension and apply the brake at the same time. The entire brake and release mechanism is mounted on the outside of a winch frame having winch side plates, thereby allowing the mechanism parts to be replaceable in the field without taking the winch side plates apart.