British steam railcars

A steam railcar is a rail vehicle that does not require a locomotive as it contains its own steam engine. The first steam railcar was an experimental unit designed and built in 1847 by James Samuel and William Bridges Adams. In 1848, they made the Fairfield steam carriage that they sold to the Bristol and Exeter Railway, who used it for two years on a branch line.

Railcars were built in the early 20th century for the London and South Western Railway (LSWR) and before entering passenger service one was lent to the Great Western Railway (GWR). Between 1902 and 1911, 197 steam railcars were built, 99 by the GWR.^[1]

Introduced either due to competition from the new electric tramways or to provide an economic service on lightly used country branch lines, there were two main designs, either a powered bogie enclosed in a rigid body or an articulated engine unit and carriage, pivoting on a pin. However, with little reserve power steam railcars were inflexible and the ride quality was poor due to excessive vibration and oscillation. Most were replaced by an autotrain, adapted carriages and a push-pull steam locomotive as these were able to haul additional carriages or goods wagons.

After trials in 1924, the London and North Eastern Railway and the London, Midland and Scottish Railway purchased between them a total of 102 railcars using high speed steam motors from Sentinel-Cammell and Claytons in the late 1920s. These had all been withdrawn by 1947.