Scammell Scarab

The London Midland & Scottish Railway experimented with various ideas and in late 1930 announced, jointly with Karrier Motors, a tractor unit for this purpose.

The vehicle, the Karrier Cob, was powered by a twin-cylinder Jowett engine and utilised a mechanism to couple existing horse trailers to the tractor units.

Their designer, O. D. North, refined and further developed the concept of the three-wheel tractor unit which automatically coupled and un-coupled trailers and in 1934 announced the introduction of the Mechanical Horse.

The railways for which this style of vehicle was originally designed continued to be a primary customer, although there were many other users, the manoeuvrability proving popular for companies operating in city environments.

The Townsman utilised many developments in large vehicles including vacuum-assisted hydraulic brakes and although the same automatic coupling feature was used, this now used a vacuum-operated release mechanism rather than the hand lever found in earlier models.

Despite numerous improvements, the Townsman was mainly sold to British Rail and the Royal Mail and production ended in 1968 as forthcoming construction and use regulations mandating dual-line brakes on articulated combinations could not be met.

[citation needed] The Scammell or "FAR" was also made under licence by the French company Chenard-Walcker and used the Citroën Traction Avant engine.

[6] The final filming session took place at the Vintage Carriage Trust at Ingrow station, on the Keighley & Worth Valley Railway in West Yorkshire, on 22 November 2003,[7] where it was handed back to its owner, Chris Waye, out-shopped in the standard British Railways road vehicle livery of carmine and cream, colloquially referred to as blood and custard.