Abstract: A hand brake assembly for a railway car in which a self-energizing friction clutch which is associated with the hand wheel shaft permits a graduated release of the car brakes and prevents spinning of the hand wheel. A manually-operable quick release of the car brakes is made possible by the provision of a second manually-shiftable jaw clutch, the components of which are spring-biased to their position of clutch engagement by a positive acting compression spring which is interposed between such components, such second jaw clutch being disposed in the power train between the hand wheel shaft and the chain winding drum, and the two clutches thus being disposed in series relationship.