By the Great War, if not before, both sides realised that steam engines were particularly vulnerable near the Front. It was impossible to muffle the smoke and fire-box. Internal combustion engines were the only solution. The Baldwin Locomotive Works were already supplying the French War Office with steam locomotives and so they turned to them for locotractors. No less than 600 50 hp petrol locomotives were supplied to the French and 125 to the US Expeditionary Force. They were extremely successful and very popular with all the Allies when they could be obtained, and also the German forces used them whenever they were captured.

It was ruggedly built with cast steel frames and a simple reliable four cylinder petrol engine fitted with a DC generator and
Bagnall Excelsior
  
From Broadbelt Collection Courtesy Bob Paule Works Photograph of the completed prototype 50 hp Baldwin Gas Mechanical Locomotive (Locotractor)
starting motor. Additionally, the engine could be started from the cab by means of a long startinghandle. On the front of the engine was mounted a well proven clutch operated by a foot pedal through the floor of the cab in front of the operator’s seat. This drove a two-speed bevel gearbox. From this gearbox a jack-shaft drove the coupled wheels. The maximum speed was around eight miles an hour. The locomotive was equipped with 12v electric headlamps front and rear.

There are several survivors in near-original state running preserved railways in France. Unfortunately, a survivor on the Festiniog Railway was much rebuilt during the early days of preservation. Moelwyn had an addition made at the
front of the frames to carry a pony truck. It was re-engined with a Gardiner Diesel that meant that the front gear-box had to be lowered and the jack-shaft lowered also. The petrol tank was moved to the front raised footplate. Given the current interest in the Great War, possibly the FR might rebuild the locomotive so that it is closer to the original.
Cénac Baldwin 50 hp drawing
Courtesy of Dr Christian Cénac Baldwin 50 hp drawing

Photo Right Wrightscale One of many  photographs of the prototype measured  and modelled by Wrightscale as seen at the  Froissy (Somme) Museum www.appeva.org
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