The buffers contain large springs to to absorb the impact of vehicles being coupled to the locomotive and to allow movement when running over curved track and pointwork.

The draw hook, on the other hand, is fastened by a large nut and cast steel plate. Between these and the back of the bufferbeam, is a sandwich of steel plates and rubber pads, which allow a little give in the draw hook to take the strain when a load is applied and absorb shock if the coupling is snatched.