Buffer stop
A buffer stop or bumper (US) is a device to prevent railway vehicles from going past the end of a physical section of track.
The design of the buffer stop is dependent, in part, on the kind of couplings that the railway uses, since the coupling gear is the first part of the vehicle that the buffer stop touches. The term "buffer stop" is of British origin, since railways in Great Britain principally use buffer-and-screw couplings between vehicles.
Types
Several different types of buffer stop have been developed. They differ depending on the type of coupler used and on the intended application.
Buffer stops with anticlimbers. These are particularly important for passenger railway applications, because the anticlimbers prevent telescoping of the railroad cars during a head-on impact.
Buffer stops for a knuckle coupler or an SA3 coupler (centrally positioned between the two rails)
Buffer stops with traditional "buffers" on either side
Hydraulic buffer stops
Friction buffer stops (bolted down to the rail)