British Rail produced a variety of railbuses, both as a means of acquiring new rolling stock cheaply, and to provide economical services on lightly-used lines.

Railbuses are a very lightweight type of railcar designed specifically for passenger transport on little-used railway lines. As the name suggests, they share many aspects of their construction with a bus, usually having a bus body, or a modified bus body, and having four wheels on a fixed wheelbase, rather than bogies. Some units were equipped for operation as diesel multiple units.

In the late 1950s, British Rail tested a series of small railbuses, produced by a variety of manufacturers, for about £12,500 each^[1] (£261,000 at 2014 prices).^[2] These proved to be very economical (on test the Wickham bus was about 9 mpg_‑imp (31 L/100 km)),^[3] but were somewhat unreliable. Most of the lines they worked on were closed following the Beeching Cuts and, being non-standard, they were all withdrawn in the mid-1960s, so they were never classified under the TOPS system.

In addition to those railbuses, BR ordered three for departmental (non-revenue earning) service. The full list of passenger and departmental units is set out below.

Engines:^[4]

• 79958/59, Gardner 6HLW of 112 bhp (84 kW) at 1,700 rpm
• 79960–62/64, Büssing, 150 bhp (110 kW) at 1,900 rpm
• 79963, AEC A220X
• 79965–69, Meadows 6HDT500 of 105 bhp (78 kW) at 1,800 rpm
• 79970–74, AEC, 150 bhp (110 kW)
• 79975–79, AEC, 150 bhp (110 kW)

British Rail returned to the idea of railbuses from the mid-1970s, and prototype four‐wheel vehicles were developed jointly by British Leyland and the British Rail Research Division. These were named Leyland Experimental Vehicles (LEVs) and consisted of double-ended Leyland National bodyshells (chosen for their strength and cost-effective manufacturing) mounted on top of simple 2-axled railway chassis, which were a derivative of those used on the HSFV.^[5]

The LEVs spent a substantial amount of time abroad in the hope of attracting export orders, however none were ever made. Domestically, the LEVs were the predecessors of the Pacer DMUs, of which the Class 140 is its closest relative.

In total, five LEVs were built, which are listed below:

Lines regularly served by railbuses include:

A number of the BR railbuses, both first and second generation examples have survived into preservation, as follows:

Additionally, AC Cars railbus 79979 was preserved. It was the first of the railbuses to be delivered and spent all its working life in Scotland. In 1968, it was moved to Craigentinny where the chassis was scrapped, and it was used as a battery store. It was moved to make way for the TMD in 1977 and the grounded body sold to the Strathspey Railway in 1977.^[37] It was scrapped by MC Metals, Glasgow, in 1990.^[42][43]

• British Rail Class 139
• Pacerailer - prototype railbus built 1960s, by a private company.