British Rail Class 37

The British Rail Class 37 is a diesel–electric locomotive. Also known as the English Electric Type 3, the class was ordered as part of the British Rail modernisation plan. They were numbered in two series, D6600–D6608 and D6700–D6999.
Built in the early 1960s, the Class 37 became a familiar sight on many parts of the British Rail network, in particular forming the main motive power for InterCity services in East Anglia and within Scotland. They also performed well on secondary and inter-regional services for many years. Many are still in use today on freight, maintenance, and empty stock movement duties. The Class 37s are known to some railway enthusiasts as "tractors", a nickname given due to the similarities between the sound of the Class 37's engine and that of a tractor.

Description

Background

As part of the large scale dieselisation brought about by the British Rail modernisation plan a need was identified for a number of type 3 locomotives with a power output of to. English Electric had already been successful with orders for type 1 and type 4 diesels, and had produced locomotives of similar power for railways in East Africa. A design based on the exported locomotives was put forward and accepted. The design was for a general purpose locomotive and initially found service in British Rail's Eastern Region.

Building

There was no prototype. British Railways placed an order for forty-two Class 37 locomotives in January 1959. The first was delivered in November 1960; it entered service on 2 December. BR had ordered further Class 37s before the last of the original batch had been completed in mid-1962. The final locomotive was delivered to the Western Region on 9 November 1965. English Electric split the construction between Vulcan Foundry at Newton-le-Willows, and Robert Stephenson and Hawthorns of Darlington. The 309 locomotives produced in total were originally numbered in the range D6700–D6999 and D6600–D6608. The bodywork bears a strong family resemblance to other English Electric designs such as the and. Vehicles from D6819 onwards were built without nose-end doors and the headcode display was changed from a split pair of boxes to a panel on the centre of the nose.
Seven orders were placed with English Electric, as follows:

EE order no.	Date	Total	Numbers	Works
CCL 1031	27 January 1959	42	D6700–41	Vulcan Foundry
CCM 1114	5 February 1960	37	D6742–68	Vulcan Foundry
CCM 1114	5 February 1960	37	D6769–78	Robert Stephenson and Hawthorns
CCN 1239	27 April 1961	17	D6779–95	Robert Stephenson and Hawthorns
CCP 1267	13 December 1961	23	D6796–6818	Vulcan Foundry
CCP 1304	July 1962	100	D6819–28, D6859–68, D6879–98	Robert Stephenson and Hawthorns
CCP 1304	July 1962	100	D6829–58, D6869–78, D6899–6918	Vulcan Foundry
CCR 1320	January 1964	20	D6919–38	Vulcan Foundry
CCS 1362	February 1964	70	D6939–99, D6600–8	Vulcan Foundry

Duties

The class was designed for freight work and to haul passenger trains on secondary routes and as such the gearing was kept low. Many of the original locomotives were fitted with boilers for steam heating. D6700–6754 were fitted with boilers from new, along with D6758, D6775, D6781–D6818, D6875–D6892. D6960–6968 received boilers from D6701–6709 during 1967/68. 37247 was fitted with a boiler in 1977. With the withdrawal of many Type 2 and Type 3 locomotives in the 1980s the 37s were selected as the standard Type 3 and many of the fleet were given a heavy overhaul to prolong their life into the 1990s and beyond. Some were fitted with electrical train heating equipment in the 1980s to become the 37/4 sub-class, initially for use on the West Highland Line, the Welsh Marches line and South Wales–Bristol area services and Far North Lines but later seeing use in north/mid Wales and occasionally the West Country. In 2010, they were used on passenger services on the Cumbrian Coast Line and Wherry lines.

High speed trial

In 1965 the Western Region undertook some trials using a pair of Class 37s to operate express passenger trains at up to. These were successful enough for some such running to continue and diagrams using this combination operated between and until 1967. However it was found that there was excessive wear due to constant high-speed running and this resulted in the cessation of these turns.

Rebuilding

A number of locomotives were rebuilt as Class 37/9s in the late 1980s to evaluate Mirrlees and Ruston engines for possible use on a new Class 38 freight locomotive. These locos were heavily ballasted to improve traction and had excellent load-hauling capabilities, but the Class 38, understood to be a 'modular' locomotive based on the approach that gave rise to the diesel loco and the proposed Class 88 electric loco, was never built.

Axle load

The Class 37 has a relatively low axle loading for its size and power. With the withdrawal of most of the smaller types of diesel locomotive, this left it as the only mainline type available in significant numbers for lines with weight restrictions, and for a number of years 37s handled almost all locomotive-hauled services on the West Highland Line, the lines north of Inverness and in parts of Wales. The Class 37 has Route Availability 5 and this is one of the main reasons it is still in use on the network. Note that class 37/7 and 37/9 have an RA of 7 due to their extra ballast weights.

Regional variations

There are several differences between particular locomotives, some of them easily seen. Western Region Class 37s can be identified by 'cow horns' around halfway up on the outer edge of each end of the lamp brackets. When British Railways took over from the Great Western Railway the use of Great Western lamps continued. Their brackets used an L-shaped upright that was parallel to the direction of travel, unlike the other regions which used transverse brackets.
From the late 1970s some Western Region Class 37s were fitted with additional brackets on the nose to mount an additional headlight for use on the Heart of Wales line.
Another difference between the regions is by the nose end headcodes. Lower-numbered, split-box Class 37s were allocated to northern England and east Anglia; centre-box locomotives were almost all allocated to Wales and the south west. After locomotives were transferred between pools in the 1980s they tended to stray from their original depots.
Regional decorations included the Highland Stag, the Cockney Sparrow the Cornish lizard and Eastfield Highland Terrier. All the Cardiff Canton Class 37/4s received Celtic Dragons below the driver's window whilst in large logo blue. Some Scottish locomotives were later fitted with small Saltire flags by their TOPS data panels or on their noses in a similar fashion to the HAA hoppers allocated to Scottish power stations.

British Rail liveries

On delivery, the Class 37s were painted in plain green with a grey roof, the 'late' British Railways crest and a D prefix to their running number. Some locomotives were delivered as the small yellow warning panel was introduced, earlier locomotives being given these panels during works visits. Towards the late 1960s, the yellow was extended to the full height of the nose.
By the 1970s, all locomotives had received all over British Rail blue with a full yellow nose; by 1975 most locomotives had also received their TOPS numbers. Their livery remained the same until the early 1980s when 'Large Logo blue' was introduced. This entailed the yellow nose continuing round to behind the driver's door and up to the top of the windscreen and a full height 'double arrow' logo. These locomotives had the top of the nose painted black to lower the risk of the driver being dazzled by the sun. Freight-allocated examples received a similar liverythe only difference being the blue was replaced by freight grey. In 1987, the Sectors were launched, incorporating a new livery of 'three tone grey'; a light grey lower bodyside, medium grey cantrail and a dark grey roof, along with a bright Sector logo. In addition a metal double arrow logo was fitted. This livery co-existed with plain blue, large logo blue/grey and the new InterCity and Regional Railways liveries right up to the end of British Rail in 1996.
Some locomotives in the 'sectorised company' pools received Transrail Freight logos or Mainline Freight 'Rolling Balls' over their triple grey colours, while Loadhaul locomotives were painted orange and black and Mainline locomotives received 'aircraft' blue with silver stripes. Departmental locomotives were initially painted in a plain grey livery, but this didn't find favour and was modified into 'Dutch' grey and yellow livery, similar to that of Nederlandse Spoorwegen. Locomotive 37093 was mocked up as a "police" locomotive which pulled over a Class 43 HST power car for speeding in an InterCity 125 advert broadcast in the 1980s.

TOPS renumbering

As with many diesel classes, the TOPS renumbering was implemented in a straightforward manner, with the locomotive numbers remaining in sequence; thus D6701 became 37001, D6999 became 37299 and D6600–D6608 became 37300–37308. The remaining locomotive, D6700, became 37119 instead of D6819, which became 37283; the number was unused as D6983 was destroyed in an accident in 1965. As members of the class were altered later in their careers, they were renumbered, some more than once.
D6983 was withdrawn in October 1966 following a fatal collision in December 1965 with a derailed, D1671 THOR, near Bridgend in South Wales; this was caused by a landslip. D6983 was the first EE Type 3 to be withdrawn and, as a result, the only locomotive in the entire class not to receive a TOPS number. The remains of both locomotives were sold to local scrap merchants, R.S. Hayes, and cut up on site during October 1966.