twin bottle framed single cylinder stem engines, with crank couple between the 2 engines, both engines on machined cast iron bases, crank with split bronze bearings, oiled via drip from oil reservoirs above, bronze big end bearings, steel conrods, eccentric driven valve chests, brass and copper steam inlet with inline oilers, brass and copper exhaust, both cylinders with blow down valves, both engines with counter weighted 6 spoke flywheels, mounted on a painted base, approx 2" bore 2.5" stroke, engine height 35cm