This article was accepted into the corpus but its outbound wikilinks were never NER-processed — typical at the deepest BFS hop or when the run's entity cap was reached. No expansion funnel to show.
| Class 117 | |
|---|---|
| Name | Class 117 |
| Service | 1959–2000s |
| Manufacturer | Pressed Steel Company |
| Yearconstruction | 1959–1961 |
| Numberbuilt | 94 sets |
| Formation | 3-car sets |
| Operator | British Railways |
Class 117
The Class 117 diesel multiple unit appeared in British Railways' modernization era alongside British Transport Commission, British Railways Board, Richard Beeching, Transport Act 1962, British Rail, and Western Region of British Railways, serving suburban and branch services in the West of England, Gloucestershire, Bristol, Cornwall, Devon, Somerset, Wales, and Midlands. Designed during the late 1950s under nationwide reorganization that included Beeching cuts, Dr. Beeching, and rolling stock standardization, the units reflected procurement by the British Transport Commission and construction by the Pressed Steel Company at the same time as other types like the Class 120 and Class 116. Early deployments intersected with industrial changes involving British Leyland, Vickers-Armstrongs, and the wider railway rationalization promoted by Ministry of Transport (UK).
The Class 117 design originated from requirements set by the British Transport Commission and the Rail Research Unit to modernize suburban fleets previously formed of BR Mark 1 coaching stock and heritage rail DMUs, influenced by contemporaneous designs such as the Metropolitan-Cammell sets and the Derby Lightweight prototypes. Built by the Pressed Steel Company between 1959 and 1961, construction techniques referenced practices from Walterscheid and suppliers like AEI and English Electric, while drawing on standards promulgated by the Railway Clearing House and influenced by corridors of the Western Region of British Railways. The three-car formation used underframe and bodyshell methods similar to BR Mark 1 with interiors rivaling commuter arrangements found on Southern Region units and interurban sets serving Birmingham and Manchester.
Powerplants were diesel engines supplied by firms such as British United Traction, with transmission technology echoing developments by Leyland Motors and Rolls-Royce for rail applications; auxiliary systems were provided by Electricity Supply Industry contractors and suppliers including AEI and GEC Traction. Bogies and suspension drew on components standardized across fleets like the BR Mk1 bogie families used by Midland Railway successors, with braking systems compatible with vacuum braking installations and later modifications integrating Air brake elements in parallel with practices at Crewe Works and Doncaster Works. Weight distribution, maximum permitted speed, and multiple-working systems adhered to specifications established by the Ministry of Transport (UK) and coordinated with signalling authorities including British Rail Research and regional depots.
Class 117 sets entered passenger service on commuter routes radiating from Bristol Temple Meads, Reading, Oxford, Plymouth, Exeter St Davids, and suburban termini around Birmingham New Street and Cheltenham Spa replacing steam-hauled services and older DMUs. Operations spanned timetable changes overseen by British Rail managers and unions such as the National Union of Railwaymen and Associated Society of Locomotive Engineers and Firemen, and included seasonal transfers connected to projects at Network SouthEast and regional realignments under Sectorisation (British Rail). Withdrawals coincided with modernization waves leading to replacements from fleets including Sprinter family units, Class 150, Class 153, and Pacer sets.
Throughout their careers, sets underwent modifications by workshops at Bristol Bath Road depot, Tyseley Depot, Exeter Depot, and Cardiff Canton, receiving upgrades such as improved seating, revised heating systems per standards from Railtrack era guidance, and intermittent re-engining or refurbishment programs influenced by policies of the InterCity sector and regional managers. Notable operational variants paralleled conversions seen in other classes like the Class 121 and Class 122 examples, while some sets were repurposed for departmental duties following precedents set by Network Rail predecessors and temporary allocations during infrastructure works involving Railtrack contractors.
A number of incidents involving the units were investigated under procedures administered by the Accident Investigation Branch (UK) and prior arrangements with the Department for Transport (UK), including level crossing collisions near Taunton, derailments on secondary routes around Cornwall and Somerset, and minor operational accidents at stations such as Plymouth and Bristol Temple Meads. Investigations referenced regulations from the Health and Safety Executive (HSE) and recommendations appearing in reports connected to Her Majesty's Railway Inspectorate and influenced subsequent safety modifications adopted across fleets including enhanced door interlocks, improved driver protection and updated braking maintenance schedules promulgated by British Rail and later Network Rail.
Several vehicles entered preservation with organizations such as the Bluebell Railway, Keighley and Worth Valley Railway, Severn Valley Railway, Great Central Railway (Nottingham) preservation movement, and independent groups at depots including Didcot Railway Centre and Midland Railway – Butterley. Preservation efforts involved restoration practices linked to heritage grants by bodies like the Heritage Lottery Fund, collaboration with museums such as the National Railway Museum, and volunteer societies modeled on earlier preservation projects for BR Mark 1 coaches and vintage locomotives. The Class 117 legacy persists in studies of British Rail modernization, regional transport histories of South West England, conservation debates involving Historic England, and technical retrospectives by authors associated with institutions like the Railway and Canal Historical Society.
Category:Diesel multiple units of the United Kingdom