This is an unusual locomotive - it does not burn wood or coal or diesel fuel. It does not receive electricity from overhead wires or from batteries. This is an 0-8-0F fireless steam locomotive - a "fireless cooker". It "fuels" up on steam and hot water, which is stored in the large reservoir in front of the cab. The unit was built by Heisler Locomotive Works in September 1939 - it is the world's largest-ever fireless steam engine. The unit was retired from service in 1969. It has been restored and is now on display at the Railroad Museum of Pennsylvania in the town of Strasburg.

Museum info.: "Large industries rely heavily on the railroads to supply raw materials and transport finished goods. Additionally, large mills and factories require constant switching of cars for loading and unloading. Rather than pay the railroads for this costly service, many companies purchase small switch engines, hire their own crews, and perform the work themselves. in some locations, such as power plants, steel mills, and other heavy industries, boiler houses provide a ready source of steam for heating or machinery. This same steam can also be used to run a locomotive.

Fireless steam locomotives such as this receive their fuel from a stationary boiler. Like a thermos bottle on wheels, enough steam is stored in the engine's tank to operate for several hours without refueling. Because this type of locomotive did not require a fire, it could also be used in munitions factories, textile mills, or hauling flammable materials in close quarters.

Heisler built this fireless locomotive for display at the 1940 New York World's Fair to showcase the quality of their work. Outfitted with a streamlined shroud and ornamented with chrome-plated bell and air horn, it was easily the largest and most extravagant fireless locomotive ever built. At the conclusion of the fair, the locomotive was delivered to the Hammermill Paper Company in Erie, Pennsylvania. Its 95 ton weight proved too much for Hammermill's rails, however, and it was soon purchased by the Pennsylvania Power and Light Company in July 1941 It was renumbered "D" and was put to work switching coal hopper cars at the Hauto electricity generating plant located near Tamaqua, Pennsylvania. The engine remained in service at that plant until 1969.