Abstract: A locking mechanism for sliding doors, particularly of railway freight cars, has a hasp pivotally connected to a member defining an edge of the door opening, the pivotal connection being resiliently mounted on the edge defining member so as to keep the hasp under tension when the door is locked, the other end of the hasp being removably connected to the door by a manually actuable element pivoted on the door and manually swingable by means of a movable handle from locked position, in which the hasp is held in tension by a resilient connection to the door edge defining member, to an over-center unlocking position, movement of the hasp between locking and unlocking position being accommodated by the resiliency of the mounting of the hasp pivotal connection to the relatively movable member. An improved seal latch is also provided.