British Rail Class 37


The proud and powerful workhorse that even 50 years after its construction, continues to be a major part of the British Rail scene. I am of course talking of one of the most successful diesel locomotives of all time, the Class 37.

In the 1950’s, British Rail was in desperate need to replace its ageing fleet of steam locomotives on both freight and passenger usage, and even though the new BR Standard locomotives were starting to make inroads into the Victorian built fleet, it was apparent that diesel and electric haulage was the only way forward. As such, English Electric, who had already had success with the construction of the Class 20 light freight loco and the Class 40 heavy passenger loco, were assigned to help deliver a new mulit-purpose diesel locomotive with a power output of more than 1,500bhp. Although the Class 40 could have been easily capable of handling this task, problems with these locomotives were that it was far too heavy and underpowered, which meant that in addition to hauling a heavy train, it also had the added task of hauling the actual locomotive itself! The earlier Class

Class premier, D6700, sporting original split-headcodes, is now preserved by the National Railway Museum

40’s were especially known for their unreliability, having to be frequently rescued by the steam locomotives they were built to replace!

Essentially, what English Electric did was build a scaled down version of the Class 40, shorter than its predecessor by 8 feet, weighting 33 tons less, and being powered by a much more reliable English Electric 12CSVT engine developing 1,750bhp. A batch of 42 locomotives were delivered in 1960 from the Vulcan Foundry in Newton-le-Willows, these being initially designated English Electric Type 3’s, but this order was increased to 309 following the initial success of these engines, with production finishing in 1965. Work on the class was separated between several different plants, with construction primarily taking place at Vulcan Foundry, but also with assistance from Robert Stephenson & Hawthorns factory in Darlington.

The class was initially tasked with both freight and passenger workings, but the rough n’ tumble nature of these engines meant they were more at home on goods trains. Some of the earlier locomotives were fitted with Steam Heating Boilers to warm passenger carriages as earlier coaches did not feature Electric Train Heating, although other locomotives had boilers added in 1967/68. Beyond the end of steam in 1968 and

A Class 37 working a passenger service in the West Highlands

throughout the 1970’s the Class 37’s were dispersed among the many administrative Regions of British Rail, travelling the length and breadth of the country and working all manner of trains from Class 1 Express Passenger services to lower class breakdown trains and short goods services. This became apparent in its variety of liveries, especially following sectorisation of British Rail in the 1980’s, with Class 37’s sporting the livery of InterCity, Regional Railways and Railfreight Distribution.

Throughout their time however the fleet continued to be interchanged, especially after the introduction of the TOPS computer system which designated them Class 37. The variety of Class 37 sub-classes included:

– Class 37/3: Extended fuel tanks replacing the steam heating boiler
– Class 37/4: Addition of Electric Train Heating for use in passenger service
– Class 37/5: No major changes, a designation for engines with original split headcodes
– Class 37/6: Engines modified for use with Eurostar Class 373 units
– Class 37/7: Heavily modified for heavy freight workings, with extra ballast for more dragging power
– Class 37/9: Used as testbed for experimental Mirrlees MB275T engine

Two LoadHaul Class 37’s working a rake of coal wagons in Scotland

However, as the 1990’s drew in and with privatisation on the horizon, it was apparent that the Class 37’s were starting to look very tired. Their reliability was starting to falter, and the demands on the class were much greater than before. As such, newly formed primary freight operator EWS, made an order for a new fleet of Class 66 locomotives from General Motors to replace the many ageing British Rail classes. Upon their introduction in 1999, these engines were quick to see off many Class 37’s, which went on a variety of their own journeys. In the summer of 2000 and 2001, many Class 37’s were exported to France and Spain to help with the construction of their many High Speed Lines, including the LGV Méditerranée route from Lyon to Marseilles. While many of the French ones have since returned, a small fleet of Class 37’s continued to work in the sun of Spain on the High Speed route between Perpignan and Figueres, but have since returned upon its opening in 2010.

In 2007, EWS was taken over by DB of Germany to become DB Schenker, which continued to operate a small fleet of Class 37’s until 2010 when the last engines were retired. Throughout the 2000’s these locomotives were placed into storage and scrapped, this particular era being their darkest hour. But as said, many continued to find their way into new leases of life, their reliable nature and flexible abilities making them a key part of many private fleets.

DRS Class 37, 37423 ‘Spirit of the Lakes’, fitted with modified light clusters, passes Tamworth

Direct Rail Services, the former rail arm of British Nuclear Fuels, took on a batch of Class 37’s to operate their various freight trains, including the haulage of Nuclear Flasks, a task they continue to do till this day, with 29 of the class still on its books and in regular service. Colas Rail took on a fleet of 4 Class 37’s in 2014 to expand their fleet, whilst charter company West Coast Railways owns four and four others were converted for use with Network Rail on engineering services.

Either way, it is apparent that these plucky and powerful little locomotives, of which 48 are preserved and 38 remain in mainline operation, will continue to be an integral part of the British Railway scene for many years to come.

Who knows, maybe they’ll live to see mainline service when they’re 100!