Steamroller

A steamroller (or steam roller) is a form of road roller – a type of heavy construction machinery used for leveling surfaces, such as roads or airfields – that is powered by a steam engine. The levelling/flattening action is achieved through a combination of the size and weight of the vehicle and the rolls: the smooth wheels and the large cylinder or drum fitted in place of treaded road wheels.

The majority of steam rollers are outwardly similar to traction engines as many traction engine manufacturers later produced rollers based on their existing designs, and the patents owned by certain roller manufacturers tended to influence the general arrangements used by others. The key difference between the two vehicles is that on a roller the main roll replaces the front wheels and axle that would be fitted to a traction engine.

In many parts of the world, the term steam roller is still used regardless of the method of propulsion. This typically only applies to the largest examples (used for road-making).

Before about 1850, the word steamroller meant a fixed machine for rolling and curving steel plates for boilers and ships. From then on, it also meant a vehicle. An early steamroller was demonstrated by Louis Lemoine in France in 1860 and in Britain in 1863 by William Clark and partner W.F. Batho.

The company Aveling & Porter was the first to successfully sell the product commercially. In 1866 they produced a prototype roller with 3 foot wide rollers fitted to the rear of a standard 12 nominal horsepower traction engine. This experimental machine was described by local papers as 'the world's first steamroller' and it caused a public spectacle.

In 1867 the company began production of the first practical steam roller - the new machine's rollers were mounted at the front instead of the back and it weighed in excess of 30 tons. It was tested on the Military Road in Chatham, Star Hill in Rochester and in Hyde Park, London and the machine proved a huge success. Within a year, they were being exported around the world, including to France, India and the United States. A New York City chief engineer said of one of these, that "in one day's rolling at a cost of 10 dollars, as much work was accomplished as in two days' rolling with a 7 ton roller drawn by eight horses at a cost of 20 dollars a day."

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Wikipedia