Refurbishment
Between 1979 and 1984, the Class 50 fleet was refurbished at Doncaster Works, which had taken responsibility for the fleet after purchase 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 (50010/13/22/38/47) in 1988.
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 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.
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