We saw in the first article in this series how the class 50 locomotives fulfilled a need for faster trains beyond Crewe and Preston to Glasgow and how this was made redundant by electrification. The next phase of the class’s British Rail (BR) career ultimately led BR to dispose of them.
The Western Region of British Rail need for improved service quality
After 1974, when electrification through to Glasgow rendered class 50s redundant on the West Coast main line, BR soon spotted a new use for them. The Western Region of British Rail had always been independent in character – after nationalisation in 1948 it inherited many senior staff from the former Great Western Railway (GWR). This independent thinking had included ordering diesel-hydraulic locomotives in the early 1960s. These were based quite extensively on West German technology and employed advanced construction methods to produce lightweight designs.
Instead of employing generators and traction motors, they used a system analogous to the automatic transmission of a car. At the same time as English Electric were producing an 8 axle 2000hp diesel-electric design weighing nearly 140 tons, the Western Region (WR) had a 4-axle diesel-hydraulic design weighing 80 tons. The logic was that the WR also had steep gradients to cope with on the Exeter-Plymouth line and that the locomotive’s weight saving could translate into an extra revenue-earning passenger coach or two. These were followed by a more powerful 2700hp diesel-hydraulic design weighing 108 tons.
By the mid-1970s the shortcomings of the diesel-hydraulic policy became clear. BR central management considered the WR’s diesel-hydraulic fleet to be non-standard and expensive to operate. BR had aspirations to improve its service quality with air-conditioned coaches to better compete with the M4 motorway but none of the WR’s diesel-hydraulic fleet could provide electric train heat to power such coaches. Some of the WR’s designs, being based on scaled down German designs had little room to spare inside the bodyshells. There was no space to install air braking equipment and they were left with obsolete vacuum train brakes which BR also wanted rid of.
Class 50s second career with the Western Region cross country services
The obvious answer to all of these problems lay in the fleet of 50 class 50s that had just been rendered spare by the extension of electrification to Glasgow. From 1972 to 1976 the fleet migrated towards Bristol and Plymouth area depots to allow WR drivers and maintenance staff to be trained on them. The class was then deployed on express passenger services across the WR out of London Paddington.
The WR main line from Paddington to Swindon and Bristol is a very well-engineered route ideally suited to high speed running. BR took advantage by introducing their first InterCity 125 trains in 1976 on the WR and as a result class 50s were relegated to other work such as taking over cross-country services from the north at Birmingham New Street and hauling them to the south west.
At around this time BR introduced a new computerised system to manage its assets. Until this point a semi-systematic numbering policy had been in place for diesel locomotives: the class upon introduction had been numbered D400-D449. The new numbering system formally introduced the designation of class 50 but could not accept numbers such as 50000, D401-449 became sequentially 50001-50049 with ‘first born’ D400 becoming 50050. It was also at around this time that BR formally purchased the class 50 fleet from English Electric, thus ending the lease agreement.
Class 50s naming and refurbishment
BR had been somewhat averse to naming its diesel locomotive power fleet ever since the rebranding of 1964 that introduced the familiar double arrow symbol and corporate blue livery. The ice was finally broken in 1977 when, especially in light of the use of class 50s on Plymouth services, BR management was persuaded to name the fleet after Royal Navy vessels. The first to be so treated was 50035 in January 1978 when it was named Ark Royal by the aircraft carrier’s captain and crew. Most of the rest of the class followed over the course of the year.
By this stage class reliability was dropping noticeably. In 1977 overall availability had been 70% with a little under 14,000 miles between failure achieved on average. The following year these figures had dropped to 63% and 8,300 miles. Something had to be done. The WR reasoned that it was only using class 50s on express passenger trains (in earlier days, use on freight was just as common as passenger work) and that they did not need some of the ‘toys’ the class was fitted with, such as slow speed control.
The inertial air filtration system fitted from new never worked well and the distinct sucking noise it made led to the class being nicknamed ‘Hoovers’ by WR staff and enthusiasts. More seriously, a design fault had placed the intakes too close to the engine exhaust ports and the air inside the locomotive tended to fill up with an oily, greasy mist which caused many expensive main generator failures.
The WR therefore received authorisation for a comprehensive refurbishment programme for the class. This was carried out in phases between 1979 (50006 Neptune) and 1983 (50014 Warspite). Slow speed control, rheostatic braking, inertial air filtration and low speed wheelslip control features were all removed and the electronic control system was considerably simplified. All the major electrical machines in each locomotive received a full overhaul. Externally, the most visible changes were a central high intensity headlight fitted at each end and the train reporting number blinds above the cabs were plated over. Changes in signalling practice from many small lineside signal boxes to centralised facilities covering hundreds of miles of track meant signallers no longer watched over passing trains. The practice of each train showing its reporting number was abandoned as of 1976.
Regrettably, the refurbishment programme did not authorise replacement of the troublesome DC main traction generator with an alternator as had been used on subsequent diesel-electric builds after the 50s. Running 2700hp through a DC generator had always been pushing the technology to its limits. Main generator failures plagued the class for the rest of their BR career and continue to do so in preservation. Refurbishment improved reliability to 76% availability and nearly 17,000 miles between failure in 1981.
Sectorisation and Network SouthEast
In 1982 BR reorganised its internal structure away from the geographic regions it had maintained since formation in 1948. Instead, operations would now be defined by business sector. For passenger services these sectors were InterCity (express services), Network SouthEast (NSE, London commuter services) and Regional Railways (non-London provincial services not falling under the purview of InterCity).
Class 50s migrated slowly to NSE for working London Paddington-Oxford services. The London-Oxford market is unusual in that road coaches abstract a substantial market share from rail, making speed and comfort a priority for rail operators. The class also worked the London Waterloo-Exeter line; this route had belonged to the Southern Railway between 1923 and 1945 and was a rival to the former Great Western Railway (GWR) routes to Devon and Cornwall.
Reshuffling of BR’s regions saw control of this route transfer to the Western Region west of Salisbury in the mid-1960s. The latter, invoking the spirit of the GWR and happy to get one over its former rival, reduced the route to single track for long distances between Salisbury and Exeter and sold off the ‘redundant’ land to make redoubling more difficult. This meant failed trains could cause chaos.
New livery for Network SouthEast but the end of the line was inevitable
In June 1986 Network SouthEast formally launched with 50017 Royal Oak and 50023 Howe being present in NSE livery for the day. The original NSE livery was soon nicknamed ‘toothpaste’ after the bodyside stripes. One exception was 50007 Hercules which had been repainted all-over green in early 1984 and renamed Sir Edward Elgar to commemorate the 50th anniversary of the composer’s death. This locomotive became something of a celebrity and was the pride of Plymouth Laira depot.
On 1 January 1987 all BR motive power was assigned to one of the business sectors. InterCity did not want any class 50s and the allocation became NSE (29), parcels (9), provincial (6), freight (2) and departmental (BR internal civil engineering use; 2), totalling only 49 locomotives. Cracked underframes were a problem at this time. Suffering both cracked frames and being due for a major service, 50011 Centurion was the first withdrawal in February 1987. 50006 and 50014 followed as the parcels sector dispensed with class 50s and they were withdrawn for similar reasons to 50011. Celebrity 50007 narrowly escaped thanks to some hasty frame repairs in late 1986.
Major servicing was authorised for a total of 17 class 50s keeping them in traffic until the early 1990s. By this stage NSE had stopped authorising significant expenditure on the class and if a locomotive suffered a serious failure it tended to be withdrawn unless a donor part could be sourced from an already withdrawn machine. The last two 50s in regular NSE service were 50029 and 50030 Repulse which both survived until early 1992.
NSE had class 159 diesel multiple units on the horizon by this stage which would be cheaper to operate and more reliable. The Waterloo-Exeter route was quite punishing for class 50s with a combination of high speed running but frequent station stops, especially in the London area. Jointed track beyond Basingstoke caused mechanical shock to internal components. 50007, 50033 Glorious and 50050 Fearless were kept on for enthusiast railtour use until the demise of British Rail on 31 March 1994. All three plus many other class members would be saved for preservation.
