Editing Traction engine (section)

===Steam wagon===
{{main|Steam wagon}}
[[File:Foden 5 ton steam lorry registration WX 2682.jpg|left|thumb|1930 [[Edwin Foden, Sons & Co.|Foden]] C-Type 5 ton 'overtype' steam wagon]]
A steam wagon is a [[steam]]-powered road vehicle for carrying [[freight]]. It was the earliest form of [[lorry]] (truck) and came in two basic forms: ''overtype'' and ''undertype'' – the distinction being the position of the [[steam engine|engine]] relative to the [[boiler]]. Among the firms that specialized in them in the 1900s was the short-lived Invicta Works of Maidstone, owned by [[Jesse Ellis]].

The overtype had a steam engine mounted on top of a [[fire-tube boiler]], in a similar manner to a traction engine. The front of an overtype steam wagon bears a close family resemblance to traction engines, and manufacturers who made both may well have been able to use some common parts.

The undertype had the steam engine mounted under the boiler, usually between the frames of the chassis. The boiler was usually mounted well forward and was often a vertical and/or water tube type.

Steam wagons were the dominant form of powered road traction for commercial haulage in the early part of the twentieth century, although they were a largely British phenomenon, with few manufacturers outside Great Britain. Competition from [[internal-combustion engine|internal-combustion]]-powered vehicles and adverse legislation meant that few remained in commercial use beyond the [[Second World War]].