Abstract: A low-profile railway car retarder having a pair of braking bars disposed parallel and on opposite sides of a track rail and having an upper and lower pivotal lever carrying a respective one of the pairs of braking bars. A pneumatic motor pivotally connected to the outer extremities of the upper and lower levers, and the height of the pivotal connection of the upper lever is substantially at the same level as the track rail so that a humped railway vehicle is permitted to freely pass through the car retarder. The pneumatic motor lifts the upper lever and depresses the lower lever to move the pair of braking bars to a closed braking position wherein pressure is supplied to the pneumatic motor so that the pair of braking bars engage the opposite side of the wheels of a traversing vehicle at a relatively high point to exert a greater amount of retardation of the vehicle.

Abstract: A pneumatic pressure actuator including a cylinder assemblage having a pair of metallic cylinder heads and a fiberglass cylinder casing held together by a plurality of tie bolts and nuts. A piston and piston rod reciprocally movable within the cylinder assemblage and including a greased nylon cushion ring and polyurethane wiper ring for reducing frictional wear between the relatively movable surfaces.