Abstract: A brake disc for disc brakes on rail vehicles comprises an intermediate member connected to the inner peripheral surface of an annular element. The intermediate member is spaced radially from a hub and there are a pair of radially opposed annular grooves in the hub and intermediate member with blocks of resilient material in the opposed grooves. The blocks are pre-stressed and completely occupy the widths of the grooves. Heat inhibiting material is provided for inhibiting heat flow from the annular braking element to the resilient blocks.

Abstract: A modified AB test rack for testing freight car brake equipment valves in which excessive noise produced during standard tests by air exiting the quick action exhaust port of the emergency portion and the duplex release valve of the service portion is eliminated by connecting, by a quick action valve operating by an air cylinder, the respective port and release valve, to a manifold which is in turn connected to a muffler having an inlet at one end, a number of baffles and apertured plates forming a tortuous path to an outlet formed by a number of holes through the opposite end and adjacent sides.