A "Rail Motor" to Don Young's rather good design for an altra-compact 0-4-0 tank engine. They go well and, being rather heavier than their size suggests, have a decent amount of pulling power.
Silver soldered copper boiler, feed by injector, axle and hand pumps. Cast iron cylinders with slide valves actuated by Walschaert's gear with pole reverser in cab. Mechanical lubricator. Automatic drain cocks.
This one is an older engine, boiler is sound and it steams ok, valve gear is worn and is coming up to needing some rebushing. Axle pump works ok, both injector and hand pump need a good clean, the mechanical lubricator needs adjustment, it currently doesn't pick up reliably.