Class 108

Class 108
Name	Class 108
Powertype	Diesel Multiple Unit
Builder	British Rail British Railways Derby Works York Works
Builddate	1958–1961
Totalproduction	333
Formation	2-car and 3-car sets
Maxspeed	70 mph (112 km/h)
Transmission	Mechanical
Brakes	Vacuum
Operator	British Rail Network Rail Greater Anglia Northern Trains

Class 108

Class 108 was a type of first-generation diesel multiple unit introduced by British Railways in the late 1950s as part of the Modernisation Plan. Built to replace steam locomotives on regional and branch lines, the units served extensively across England, Scotland, and Wales, and later saw operations under Privatisation of British Rail successors. They became notable for robust mechanical transmissions, straightforward maintenance, and widespread secondary use on freight and departmental duties.

Overview

Developed during the 1955 British Transport Commission Modernisation Plan era, Class 108 units were produced to accelerate dieselisation on routes previously operated by British Railways steam fleets. Designed by engineers from British Rail workshops at Derby Works and York Works, the units complemented contemporary types such as the Class 101 and Class 104. Deployment patterns included services radiating from hubs like Manchester Piccadilly, Liverpool Lime Street, Bristol Temple Meads, Leeds City, and Glasgow Central.

Design and Specifications

The units featured a two-car or three-car set formation with mechanical transmissions supplied by British United Traction components and engines from BUT or AEC. Bodies were constructed with steel underframes and aluminium panels, drawing on techniques used at Swindon Works and influenced by earlier designs from Great Western Railway. Performance characteristics included a top speed of 70 mph (112 km/h), hydraulic cooling systems, and vacuum braking compatible with Mark 1 coaching stock in multiple working. Passenger accommodation followed regional standards with compartments and open saloons, incorporating seating patterns familiar from Midland Main Line suburban stock. The electrical systems linked to standard National Rail multiple-working protocols, allowing interoperability with contemporaneous units such as Class 107 and Class 111.

Production and Manufacturing

Manufacture took place across British Rail's major workshops, notably Derby Works and York Works, alongside subcontracting to private firms active in the British rolling stock sector during the 1950s industrial expansion. Production runs between 1958 and 1961 yielded over 300 vehicles, assembled using jigs and presses typical of postwar British manufacturing. Quality control involved inspection regimes influenced by practices at British Standards Institution and coordination with British Transport Commission procurement divisions. Supply chains linked engine makers like AEC and component suppliers in the West Midlands and Lancashire industrial districts.

Operational History

Upon introduction, units replaced steam-hauled services on branch lines inherited from pre-nationalisation companies such as the London and North Western Railway and Great Western Railway. Regular diagrams included services on routes from Manchester Victoria to coastal branches, and rural services in Cornwall and the Scottish Borders. During the Beeching cuts, some units were redeployed to maintain self-contained shuttle services; others worked alongside coaching stock on excursions to destinations like Blackpool North and Scarborough railway station. Crews were typically based at depots such as Longsight Depot, Bristol Bath Road Depot, and Heaton TMD. The units saw secondary roles in parcels and departmental operations under successors like Railtrack and Network Rail before eventual withdrawal.

Variants and Modifications

Throughout their service life, many units underwent localised modifications: re-engining programs using units from Leyland Motors or retrofitted heating systems compatible with Electric Train Heating standards. Interior refurbishments adapted compartment layouts to contemporary expectations similar to conversions carried out on Class 101 sets. Some vehicles were modified for non-passenger use, including conversions into mess coaches, sandite wagons for Autumn railhead treatment, and route-learning units employed by training centres such as Crewe Works and Doncaster Works. A number served in departmental liveries for British Rail Research and infrastructure monitoring tasks.

Preservation and Legacy

A number of vehicles were rescued by preservation societies and heritage railways including North Yorkshire Moors Railway, Keighley and Worth Valley Railway, Great Central Railway (Nottingham) and Bluebell Railway. Preserved sets appear at galas alongside contemporaries such as Class 101 and Class 117, illustrating mid-20th-century diesel multiple unit development. The class influenced later rolling stock procurement practices and remains referenced in studies of postwar British transport policy, shedding light on the effects of the 1955 Modernisation Plan and the Beeching Report. Surviving examples are maintained by organisations like the National Railway Museum and volunteer groups, and parts are used to restore other first-generation DMUs in the UK heritage fleet.

Category:Diesel multiple units of Great Britain