TRACTION ENGINE : Comprehensive Encyclopedia

A traction engine is a wheeled steam engine used to move heavy loads, plough ground or to provide power at a chosen location. The name derives from the Latin tractus, meaning 'drawn', since the prime function of any traction engine is to draw a load behind it. They are also known as "Road locomotives" to distinguish them from (railway) steam locomotives - ie steam engines that run on rails.

Traction engines tend to be large, extremely heavy, slow, and poorly manoeuvrable. Nevertheless, they revolutionised agriculture and road haulage at a time when the only alternative prime mover was the cart horse.

The traction engine "Evedon Lad" at Stoke Goldington

The machines typically have two large powered wheels at the back and two smaller wheels for steering at the front. They became popular in industrialised countries from around 1840, when the farm machinery company Ransomes of Ipswich developed a portable steam engine for agricultural use.

Traction engines were cumbersome and ill-suited to crossing heavy ground so their agricultural use was either "in the belt" - powering farm implements by means of a long leather belt driven by the flywheel or in pairs dragging a plough on a cable from one side of a field to another.

History

The earliest mobile steam engine is thought to have been invented by Nicolas Cugnot who demonstrated an engine for hauling artillery at the Paris arsenal on October 23, 1769. Unfortunately the idea was discredited when a similar engine ran into a brick wall during a demonstration in Paris.

The traction engine, in the form recognisable today, developed from an experiment in 1859 when Aveling and Porter modified a Clayton and Shuttleworth portable engine, which had to be hauled from job to job by horses, into a self-propelled one. The alteration was made by fitting a long driving chain between the crankshaft and the rear axle, and this set the basic design for the next 60-odd years.

All types of traction engines have now been superseded by internal combustion engine -powered equivalents.

Operation

See: steam engine for a description of how the actual engine worked

Although the first 'traction engine' had a chain drive, it is more typical for large gears to be used to transfer the drive from the crankshaft to the rear axle.

Usage

Traction engines saw use in a variety of roles between 1840 and 1940. They can be divided according to their use.

Agricultural general purpose engines

The most common form in the countryside. They were used for hauling and as a stationary power source. Even when farmers did not own such a machine they would rely upon it from time to time. Many farms would use draft horses throughout the year, but during the harvest, threshing contractors would travel from farm to farm hauling the threshing machine which would be set up in the field and powered from the engine — a good example of the moveable stationary engine.

Steam tractors

A smaller load hauler, under 7 tons, popular in timber trades in the UK. (Although variations were used designed for general light road haulage and showman's use.)

A Showman's Engine at the Great Dorset Steam Fair

Road locomotives

Used for haulage of heavy loads on public highways. A particular form was the Showman's engine. These were operated by travelling showmen both to tow fairground equipment and to power it when set up; either directly or by running a generator. These could be highly decorated and formed part of the spectacle of the fair. Some were fitted with a small crane that could be used when assembling the ride.

Portable engines

Essentially a small agricultural engine that was not self-propelled. Could be towed by horses to the work site where it would drive machinery using a belt from its flywheel.

Steam rollers (Road rollers)

a steam roller

Main article: Steam roller

A distinct form of the locomotive, used for flattening ground. Designed with a single heavy roller replacing the front wheels and axle, and smooth rear wheels.

Ploughing engine

Another distinct form of engine - the largest and longest of the breed. Characterised by a large winding drum slung under the boiler (which was made especially long to provide for a larger diameter drum). The winding drum contained a long length of wire rope which was used to haul an implement, such as a plough, across a field. Mostly they worked in pairs.

Steam wagons

These were the earliest steam lorries. They resembled traction engines by having a cab built around a horizontal boiler with round smokebox and chimney (eg Foden). And they resembled lorries in having a load-carrying body and being built around a chassis (so they cannot really be called traction engines). Early examples had solid tyres, but various developments, including vertical boilers, enclosed cabs and pneumatic tyres were tried by companies such as the Sentinel Waggon Works in a bid to compete with internal combustion engine -powered lorries.

Modern use

Although no longer used commercially, traction engines of all types continue to be maintained and preserved by enthusiastic individuals and are frequently exhibited at agricultural shows in Europe (particularly the UK), Canada and the United States. They are often a main attraction in a live steam festival.

In fiction

There also has been a traction engine featured in the Rev.W.Awdry's The Railway Series. His name is Trevor the Traction Engine, and was saved from scrap by The Vicar of Wellsworth with the help of Edward the Blue Engine.

From the same series, George the Steamroller is a character with a strong dislike for the railways.

On television

Fred Dibnah of Bolton, England was known as a National Institution for the conservation of old traction engines in Great Britain. His television series, Fred Dibnah's Made in Britain, shows him touring the United Kingdom in his rebuilt, 10 ton traction engine.