Perhaps one of the most legendary diesels to hit the UK rails, the Class 50’s became a staple of the British Rail diesel fleet, and became the mainstay of many important routes well into the 1990’s.
The origins of the Class 50 lie in an invitation from the British Transport Commission (BTC) to manufacturers to produce a design for a Diesel locomotive with a gross power output of at least 2500hp. In order to produce a prototype quickly, English Electric based their design on that for their Deltic locomotives which were then in production. Other parts related to another current design, the Class 37s were also used. The result was DP2, a 2700hp Diesel-electric locomotive weighing 107 tons and with a top speed of 100mph. The prototype was delivered to British Rail in May 1962
The prototype was deemed successful and negotiations took place with English Electric for a production batch of 50 locomotives for use on the Eastern Region. English Electric intended to build the new batch as similar to DP2 as possible but the British Railways Board (successor to the BTC) had produced a standard locomotive cab with a flat front and headcode box and also had specific requirements relating to the engine room and other
equipment. English Electric produced several alternative front-end designs including one with a wrap-around windscreen but the standard front-end design was eventually adopted for the class.
The complete production run of 50 locomotives was built in just over a year and numbered from D400 to D449. D400 entered service in October 1967 and deliveries were completed with D449 in November 1968. Unusually, the ownership of the locomotives remained with the manufacturer and they were operated by British Rail on a 10-year lease which included certain stipulations relating to availability.
The class was built for working passenger services on the West Coast Main Line (WCML) north of Crewe, to Preston, Lancaster, Carlisle and Glasgow Central. Services south of Crewe would generally be worked by an electric locomotive, with the Class 50s taking over for the journeys that continued north. Initially trains were hauled by a single locomotive, but from May 1970 they were paired on most Anglo-Scottish services north of Crewe, allowing greatly accelerated timings to be applied (including a six-hour schedule for the “Royal Scot” London Euston-Glasgow Central and v.v. service). Once the electric service was introduced as far as Preston, this double-heading by Cl.50s transferred there, although poor availability often resulted in single-heading with consequent delays. The ability to operate using multiple working had been part of the locomotive’s initial design brief, but only two of the class had the facility from new, but with the introduction of the regular double headed duties, this facility was fitted to the whole class.
By 1974 the northern WCML was electrified, and the Class 50 fleet was displaced by new
Class 87 electrics. The fleet was transferred to the Western Region, working mainline passenger services from London Paddington along the Great Western Main Line to destinations such as Oxford, Bristol Temple Meads, Plymouth and Penzance. It was not unusual for locomotives to work services on other routes, such as the Birmingham New Street to Bristol Temple Meads corridor. The introduction of the Class 50s on these routes enabled the last remaining, non-standard, diesel hydraulic “Westerns” to be withdrawn.
In the late-1970s, following a period where the policy of locomotive naming had been abandoned, BR were persuaded to name the class 50s after Royal Navy Vessels with notable records in the First and Second World Wars. As a result, the first locomotive naming occurred in January 1978, when 50035 was named Ark Royal by the captain and crew of then current aircraft carrier HMS Ark Royal. The rest of the fleet was named during the course of the next few years.
From 1977, British Rail introduced the Class 253 High Speed Trains onto the Great Western Main Line which began the displacement of the Class 50 fleet onto other routes, such as services to Birmingham New Street from London Paddington and Bristol Temple Meads. The class also found work on the West of England Main Line from London Waterloo to Salisbury, Exeter and Plymouth. However, due in part to the over-complexity of the design, the class was plagued with reliability problems. As a result, the decision was taken in the late 1970s to refurbish the entire fleet.
To deal with increasing reliability problems, the Class 50 fleet was refurbished at Doncaster Works between 1979 and 1984. Doncaster had taken responsibility for the fleet after BR completed the purchase of the locomotives from English Electric. The work involved simplifying the complex electronics and removing redundant features such as slow speed control and rheostatic braking. In addition, the air intake fan arrangement was modified, because the original setup often prevented fresh air from entering the engine room and stale, oil mist-filled air from escaping, leading to many main generator failures. This was in part due to the moisture in the air in the UK: dust and other particles would lodge in the filter system and become ‘gummed up’ with moisture, preventing circulation which in turn also hampered the intended engine compartment pressure levels which then meant ‘filtered’ air could not be evacuated by the intended means. The filtration system was fundamentally sound and widely used in other countries; the problems arose because relative humidity had not been taken into account at the design stage. This modification eliminated the characteristic “sucking” noise which had earned the “Hoover” nickname.
Externally, the locomotives all received high-intensity headlights, which changed the appearance of the front end. Starting with 50006, the first six locomotives were outshopped in the standard BR Blue livery. However, in 1980, 50023 Howe became the first to be outshopped in a revised livery with wrap around yellow cabs, large bodyside numerals and BR logo, in a livery that became known as BR Blue Large Logo. The final loco to be refurbished was 50014 which was released to traffic in the latter half of 1983.
Following refurbishment, the fleet was concentrated at two depots; Laira in Plymouth, and Old Oak Common in west London. The class were again used for Western Region services on the GWML out of Paddington, and on the West of England Main Line from Waterloo to Salisbury and Exeter.
In 1984, 50007 Hercules was repainted into lined Brunswick green livery and renamed Sir Edward Elgar, to commemorate the 150th anniversary of the Great Western Railway (GWR). Four Class 47 locomotives were similarly treated, and a Class 117 diesel multiple unit (DMU) was repainted in chocolate and cream livery. As a result, 50007 quickly became a favourite with rail enthusiasts. Another locomotive repainted in a special livery was 50019 Ramillies, which was repainted in a variation of BR Blue by staff at Plymouth Laira depot.
In 1986 the West of England Main Line came under the control of the Network SouthEast (NSE) sector, which saw the introduction of their bright blue, red and white livery. The first locomotive in this livery was again 50023 Howe. The NSE livery had two versions; the original had upswept red and white stripes and the ends, with a white cab surround; the revised livery introduced in 1988 had the red and white stripes continue to the body ends, with a blue cab surround. In the revised livery the blue became a darker shade.
Towards the end of the 1980s, the fleet could be found mostly on the West of England route, as well as fast services from Paddington to Oxford. Some locomotives were also transferred to the civil engineers department to work maintenance and engineering trains. Around this time, the first locomotives were withdrawn, starting with 50011 Centurion in early 1987. This locomotive’s nameplates were later transferred to 50040, which was previously named Leviathan. A further two locomotives, 50006 Neptune and 50014 Warspite were withdrawn in 1987, followed by a further five locomotives in 1988 (50010/13/22/38/47).
In 1987, consideration was given to using the class on freight trains. To this end, 50049 “Defiance” was renumbered to 50149, equipped with modified Class 37, lower-geared
bogies and outshopped in the new trainload grey livery with Railfreight General decals. It was based at Plymouth Laira depot, and tested on local china clay trains in Cornwall as well as heavy stone trains to London from Devon quarries. The project was, however, not an outstanding success, and by 1989, the locomotive had returned to its original identity. Ironically, the electronic anti-wheelslip equipment (with which, the entire class had originally been built) which would have been key to the success of this experiment had been removed during the refurbishment process.
At the start of the 1990s, the reliability of the fleet became a problem again. By this time, the class was solely used on the West of England route, having been replaced on the Oxford route by Class 47/7 locomotives. Arguably, the Class 50s were not suitable for the stop-start service pattern of Waterloo-Exeter services, nor to the extended single-line sections of this route, where a single locomotive failure could cause chaos. Therefore, the decision was taken to retire the fleet, temporarily replacing them with Class 47 locomotives, which were in turn replaced by new Diesel Multiple Units. From 1992, the Oxford route was worked by Class 165 and Class 166 units, whilst Class 159 units were introduced onto the West of England route in 1993.
By 1992, just eight locomotives remained in service, these being 50007/008/015/029/030/033/046/050. Several of these locomotives were specially repainted to commemorate the run-down of the fleet. The first-built locomotive, 50050 Fearless was renumbered D400 and painted in its original BR Blue livery. Two other locomotives, 50008 Thunderer and 50015 Valiant were also repainted, the former in a variation of BR Blue (the same as 50019 had previously carried), and the latter in “Dutch” civil-engineers grey/yellow livery. Of the final eight locomotives, three were retained until 1994 for use on special railtours, these being 50007 Sir Edward Elgar, 50033 Glorious and 50050 Fearless. 50007 was returned to working order using parts from 50046, which surrendered its recently overhauled power unit and bogies. By this time, 50050 had been repainted into Large Logo livery and 50007 also received a repaint into GWR green as the 1985 paint was wearing very thin. The final railtours operated in March 1994, during one of which 50033 was delivered for preservation at the National Railway Museum. The final railtour operated with 50007 and 50050 from London Waterloo to Penzance and returning to London Paddington. Both locomotives were later preserved.
Class 50 locomotives proved popular with rail enthusiasts, with eighteen locomotives saved for preservation and several subsequently registered for use on the mainline.