Lima 0-4-0 Fireless locomotive Rubicon
Photographed in Carillon Park, Dayton, Ohio, on 6 September 2006. Built by Lima in 1910.
Standard gauge locomotive, but look at the tiny wheels! Operated by the National Cash Register company.
All the BTUs are in the water which is heated to somewhere around 400F. Lots of available power is contained in the hot water charge and once the throttle is opened the charge starts letting steam off into the valves and cylinders.
Picture added on 14 February 2011 at 09:11