Traction engine

**History and Evolution:**
– Traction engines appeared in the early 19th century.
– Thomas Aveling modified a portable engine into a self-propelled one in 1859.
– Standard form of traction engine evolved by the end of the 1860s.
– Continuous tracks on American traction engines from 1869.
– Various steam-powered vehicles shared design features with traction engines.
– Portable engines were closely related to traction engines but not self-propelled.
– Traction engine builders like Aveling and Porter built railway locomotives based on traction engines.

**Decline and Preservation:**
– Steam tractors demonstrated economic advantages until the 1920s.
– Tighter restrictions on road steam haulage in the 1920s and 1930s.
– Preservation movement grew in the 1950s.
– Enthusiasts bought and restored remaining traction engines.
– Road Locomotive Society formed in 1937.
– Taxes on fuel oils reduced while Road Fund charge increased in 1934.

**Use in Agriculture and Technical Features:**
– Traction engines revolutionized agriculture in industrialized countries from around 1850.
– American designs were more varied than British designs.
– Technical features included large, robust, and powerful engines.
– Compound engine designs introduced in 1881.
– Steering improved to no longer need a horse.
– Drive chain replaced with gears for better efficiency.

**Types and Usage:**
– Traction engines saw commercial use in various roles.
– Agricultural engines were common in the countryside.
– US traction engines usually pulled ploughs behind them.
– Different roles required different characteristics.
– Various types of traction engines evolved to suit different roles.

**Literature, Television, and Publications:**
– Fred Dibnah of Bolton was known for conserving old traction engines in Great Britain.
– Trevor the Traction Engine is featured in The Railway Series by Rev. W. Awdry.
– Burton’s Traction Engines Two Centuries of Steam Power provides extensive information on traction engines.
– Steam Traction magazine offers a searchable article archive on traction engines and steam-powered machinery.
– Keith Roberts’ novel Pavane prominently includes traction engines for road haulage.