Bachmann Branchline 39-578 GWR Hawksworth Auto-Trailer BR Crimson & Cream.
The GWR Autocoach, sometimes called an Autotrailer, was used by the Great Western Railway for push-pull trains powered by a steam locomotive. The autocoach has a driving cab at one end, allowing the driver to control the train without needing to be on the footplate of the locomotive. This eliminates the need for the engine to run round to the other end of the coach at the end of each journey. The combination of locomotive and autocoach(es) is known as an auto-train or, historically, a railmotor train, and they were mainly used on small branch lines.
Source: Severn Valley Railway Wiki. Click to read more (opens in new window)