British Rail Diesels
The "Hoover" (class 50)

The'D400' class of locomotives (as they were originally known) were built by the English Electric Company at their Vulcan Foundry Works at Newton-le-Willows. The design of this class was based very much on the DP2 prototype locomotive built by the same company. Fifty of these locomotives were ordered in March 1965 but construction did not commence until February of the following year. The first of the locomotives (D400 later 50 050) was completed in September 1967 and underwent numerous trials before being handed over to BR (under a lease) at the end of the year. By that time only two other locomotives (D402 and D401 respectively) had been completed. The remaining 47 locomotives entered service progressively through 1968. The removal of steam locomotives meant that the last 13 members of the class did not have the 'D' (indicating diesel) on the front of their number when they first entered service.

All 50 of the locomotives in the class entered service in BR blue and yellow livery and while the numbering changed with the introduction of TOPS and the position and size of the BR arrow symbol has varied their appearance changed little over the years prior to the first livery change in 1980.

This class of locomotive was the first to be leased from the manufacturing company rather than being purchased outright by British Rail but ten years later when the lease expired the locomotives were purchase by BR (for use on the Western Region) rather than renewing the lease.

D400 and D401 were the only two locomotives of the class to be fitted with multi-control jumper equipment when built. This equipment allowed these two locomotives to run in multiple either with each other or with other similarly fitted locomotives. The other 48 locomotives had the internal wiring for this but did not initially have the external equipment fitted.

When the locomotives entered service they started out operating class one passenger services in most parts of the north west of England (on the Midland Region) with D406 being loaned to Scotland and making regular runs between Glasgow and Edinburgh often at speeds exceeding 100 mph. In 1968 the BR Research Establishment at Derby acquired D401 and D406 and various load and static control tests were carried out to determine the performance capabilities of the class.

After a short period of mainline service the operational capabilities of the locomotives were recognised and the remaining locomotives were fitted with multi-control jumper equipment in 1969/70. From then up until May 1974 these locomotives were regularly run in pairs on the most heavily graded routes in the north-west including operation at over 80 mph over Shap and Beattock Banks. Their place on the midland region was eventually taken by electric locomotives following completion of electrification on the various routes.

In 1972 the Western Region were looking for replacements of their aging and non-standard 52 class locomotives which were incapable of providing electric train heating to the air-conditioned Mark 2D coaches. The class 50 were prime candidates for the job. Locomotive D400 was reallocated to Bristol on 11th October and was soon joined by D401. After driver training, passenger runs using these locomotives commenced on the Western region on 24th June 1973. By March 1974 a further three locomotives were transferred to Western Region followed by a further 31 in 1975 and the remainder of the class was transferred to Western Region by the summer of 1976. The locomotives were distributed between Old Oak Common, Bristol, and Laira Sheds.

Initially the availability of the locomotives on Western Region was low due to the unfamiliarity of WR train crews and fitters with these locomotives, lack of regular maintenance, and a too sophisticated electronic control system relative to the work that the locomotives were required to perform. The control systems were modified and the train crews became familiar with the locos and availability figures improved dramatically over the next few years. Although still poor in relation to some other classes it must be remembered that the Class 50s were covering twice the annual mileage at double the speed of those other locomotives.

In 1977 there was a change in the policy of naming locomotives and during 1978 all fifty of the 50 class locomotives received alloy nameplates with red backgrounds. It was at this time that the locomotive class gained the nickname "Hoover" (named after the sound made by the cooling fan mechanism). The original intention was to class "Warships" as the names given to each of the locomotives were those of famous warships but it was still too soon after the demise of the class 42/3 Warships and the reuse of that name was not acceptable to the public.

Originally the locomotives were overhauled at Crewe but in 1980 this work was transferred to Doncaster. Major overhauls are carried out every four years. Laira depot in Plymouth also has the equipment necessary to perform all overhauls except those that require engines to be removed.

Although primarily intended as a high speed main line passenger locomotive, the locomotives have also seen service hauling parcels trains and goods trains, working branch lines, as well as working regular services in all areas of England.

All fifty locomotives were still in service in 1983 having just undergone a full refurbishment. All but eight were still in service in 1989. Those withdrawn were 50 006, 50 010, 50 011, 50 013, 50 014, 50 022, 50 038, and 50 047. In addition 50 049 was rebuilt using the bogies and traction motors from a 37/5 locomotive during this period and was renumbered 50 149.

1980 saw the first livery change for a class 50 locomotive with 50 023 being repainted in Network SouthEast livery. Subsequently 50 001, 50 002, 50 003, 50 005, 50 017, 50 018, 50 019, 50 024 through 50 030, 50 032, 50 034, 50 035, 50 037, 50 041, 50 043, 50 044, 50 048, and 50 050 have also been repainted into this livery and 50 149 has been repainted into Railfreight General livery. In 1984, 50 007 was repainted in Brunswick Green with black and orange lining and a black roof. The locomotive was also renamed to "Sir Edward Elgar" at the same time.

The early eighties saw the class 50s displaced from the Western main line by the InterCity 125 HST services but the locomotives soon found a new home on the Waterloo - Exeter route.

During their life the class 50 locomotives have found their way to most corners of the British Rail system. The locomotives have taken over from aging equipment to provide faster more efficient services only to eventually themselves be displaced by even more efficient services. They have then gone on to repeat the process several more times on yet other services. Few other locomotive classes upon being replaced on their original services have so easily found a new place for themselves as the Class 50 has done.