About as large as you get in 3 inch scale (well in any scale really, but you know what I mean) - this is a Minneapolis traction engine, modelled on one of the early twentieth century straw-burning engines. This one runs on coal, but retains the double firebox doors of the prototype. Built in 1994, the engine has been unused for several years - last club certificate expired in 2005.
Steel boiler with expanded tubes, 100psi working pressure, feed by injector and mechanical pump. Cast iron cylinder with slide valve acutated by Woolf gear, mechanical lubricator. It runs well on air, on hydraulic test one tube is leaking.
We had another one of these a couple of years ago - impressed with the way it went at the time, there are pictures and some video of that one in the archive here.
Length 59 inches
Width 27 inches
Rear wheels 21 inch diameter