Hornby TT3037M Class 37 EWS Co-Co No.37704 Diesel Electric Locomotive

Expected Delivery November 2025 (Subject to Change at Manufacturer's Discretion).

Released from Vulcan Foundry in March 1962, this locomotive went new to Hull Dairycoates depot as D6734. Under the BR TOPS reclassification scheme, it became Class 37 No. 37034 in March 1974. As built, the locomotive had split-headcode boxes, which allowed for an end gangway door between them, but these were later removed. 

In January 1986, it became part of a dedicated heavy freight fleet of 44 locomotives which were given the sub classification 37/7 and received the new number, 37704. 

These locomotives were given extra ballast weight and were particularly common on heavy South Wales steel and coal trains. They also worked 32-wagon ‘merry-go-round’ trains trains of 32-tonne air-braked ‘HAA’ hopper wagons. After 1996, No. 37704 became part of the EWS fleet and received its distinctive maroon and yellow livery. 

By the time the locomotive was withdrawn in October 2003, it had completed an incredible 41 years and six months of service. It was scrapped at T.J. Thomson & Sons Ltd’s yard in Stockton by June 2009.

Given the designation Class 37 under the TOPS classification system rolled out by British Railways in 1973, 309 examples of what until then had been known as English Electric Type 3s were built between 1960 and 1965.

These locomotives had two bogies, each with six powered wheels, referred to as Co-Co, and a power output of 1,750hp (1,305kW) from their turbocharged V12 diesel engines.They were designed for freight work, but also for passenger duties on secondary routes, for which many of the class were fitted with steam-heat boilers to warm the passenger coaches. 

They had relatively low gearing, which was ideal for moving heavy freight trains, yet they were also capable of speeds of 90mph (140km/h) which was equally useful on passenger trains.

Originally numbered D6700-D6999 and D6600-D6608, under TOPS they became Nos. 37001-37308. Although it was an English Electric design and built at its Vulcan Foundry at Newton-le-Willows, a number were also built by Robert Stephenson and Hawthorns in the north-east, the company having become part of English Electric in 1955.

The class 37s were extremely versatile machines and saw service across the whole of the UK, apart from on the Southern Region south of London. In the 1980s, they were selected as a standard Type 3 and many were given overhauls to extend their working lives into the 1990s. 

Fitted with Electric Train Heating (ETH), several examples went to Scotland to work passenger services on the West Highland Line and also the Far North Line, while others were deployed on Welsh Marches trains, the Wherry Line in Norfolk, South Wales, the West Country and the Cumbrian Coast line.

Some were given replacement Mirrlees or Ruston engines for a proposed Class 38, but in the event were given the sub-classification 37/9. The locomotives’ relatively low-axle loading for their weight and power left it as the only main line type available in significant numbers for lines with weight restrictions. 

Many are still in use to this day, used mainly on freight, maintenance/engineering trains and empty stock movement, with a growing number finding their way onto charter work with operators such as West Coast Railways. As of 2024, 65 examples were still registered for main line work, plus there are more than 30 that have been preserved in the UK.