in the gallery below, is an example of an 0-8-0 fireless Heisler locomotive. As of 2020, fireless locomotives were used for shunting the heavy coal hopper trains for the thermal power station in the German town of Mannheim. Motive power types Steam A fireless steam locomotive is similar to a conventional steam locomotive, but has a reservoir, known as a steam accumulator, instead of a boiler. This reservoir is charged with superheated water under pressure from a stationary boiler. The engine works like a conventional steam engine using the high pressure steam above the water in the accumulator. As the steam is used and pressure drops, the superheated water boils, replacing the used steam. The locomotive can work like this until the pressure has dropped to a minimum useful level or the water runs out, after which it must be recharged. European fireless steam locomotives usually have the cylinders at the back, while American ones often have the cylinders at the front, as in a conventional locomotive. Major builders of fireless steam locomotives in the UK included Andrew Barclay and W. G. Bagnall. Compressed air Outside Switzerland the first locomotive to run on compressed air was built in 1890, and by 1895, the basic principles of efficient compressed air engines had been developed. A particularly important engineering breakthrough was the development of the reducing and stop valve which maintains a uniform pressure of air to the engine, even as the pressure in the storage tank reduces with use. Compressed air locomotives have been used for many years, mainly in mines, but have also been used on tramways. (See Mekarski system) Hybrid Several hybrid locomotives have been built that have either used a fire for part of the time, e.g., Fowler's Ghost of London's Metropolitan in 1861, or have used a fire to superheat stored steam, such as the Receiver Locomotives built by Sentinel Waggon Works. None has been a success. Wheel arrangements Most fireless locomotives have been of 0-4-0 or 0-6-0 wheel arrangement but there have been some 0-8-0 and even a few 0-10-0. Some gauge 0-10-0 fireless locomotives from the German company Henschel were used in the construction of the Baghdad Railway, probably to avoid the risk of carbon monoxide poisoning during the boring of tunnels. Another German company, Hohenzollern, built some articulated fireless steam locomotives with a cab at each end. Only one of the bogies was powered,