Class 74

In the late 1960s Southern Region required some more electro-diesels for the Bournemouth electrification scheme. Instead of building more Class 73s BR decided to rebuild 10 Class 71 DC electric locomotives as these could be more powerful than the Class 73s and rebuilds were thought to be cheaper than building new locomotives [1]. As with other Southern locomotives they could work in multiple with multiple units and other SR locomotives and be used for push-pull operations.

Number built: 10
Built: 1958-60 (Electric locomotives)
1967-68 (Rebuilds)
Builder: BR Doncaster, rebuilds at BR Crewe
Engine: 4 EE532A traction motors (750v DC third rail)
Paxman 6YJXL diesel
Power: 2, 300 hp (1, 715 kW) electric
650 hp (485 kW) diesel
Wheel arrangement: Bo-Bo

While the Class 74 seemed a great idea the execution let it down. The conversions were not simple with a lot of modifications and strengthening needed to fit the additional equipment [2]. Reliability in the early days was poor, the Paxman diesel not being as reliable as the English Electric unit in the Class 73, there were numerous problems with the complicated control equipment (the Class 74s were test beds for new thyristor controls [3]) and crews disliked the noise of the engine due to the location of the engine silencer near the cab.

By the late 1970s SR saw it had enough Class 33s and 73s to cover traffic requirements and the Class 74s were withdrawn by 1977 as non-standard. All have been scrapped though a Class 71 has been preserved.
74 009, location unknown (KD Collection)

[1] Brian Haresnape, Electric Locomotives (Ian Allan, 1983) p. 78
[2] David Brown, Southern Electric Vol 2 (Capital Transport, 2010) p. 220
[3] R.L. Vickers, DC Electric Trains and Locomotives in the British Isles (David & Charles, 1983) p. 81

Class 312

The Class 312 was based on the earlier Class 310 and built for the Great Northern Line from Kings Cross to Royston, the Great Eastern and also 4 sets for the West Coast Main Line [1]. The Class 312 was the last Mark 2 based EMU to be built by British Rail. It was also the last new build with slam doors to be built.

Number built: 196 (49 4-car sets)
Built: 1975-78
Builder: BREL York
Engine: 4 EE546A traction motors (6.25 (312/1 only) / 25kV AC OHLE)
Power: 1, 080 hp (810 kW)
Formation: Battery Driving Trailer Standard Open Lavatory (BDTSOL)+
Motor Brake Standard Open (MBSO)+Trailer Standard Open (TSO)+
Driving Trailer Composite Open Lavatory (DTCOL)

Twenty six sets were allocated to the Great Northern as 312/0 but they were transferred to the Great Eastern due to their unsuitability for driver only operation [2]. Sets for GE Liverpool Street services were fitted for dual voltage (6.25 as well as 25 kV AC) as 312/1. The WCML sets (312/2) were restricted to 75mp/h running so they could run in multiple with the Class 310. When they were later transferred to join the rest of the fleet on Great Eastern the speed restriction was removed.

By the end of the 1980s the fleet was concentrated on the Great Eastern and London, Tilbury & Southend Railway. In the privatised era some returned to the WCML and were operated by Central Trains, the rest were operated by c2c, First Great Eastern and LTS Rail. At the turn of the century they were gradually withdrawn from service with the last being withdrawn in 2004, the fact they were Mark 2 based and having slam doors meaning they had shorter lives than some EMUs have had. Two cars have been preserved at the Electric Railway Museum.
78037 at the Electric Railway Museum

[1] Colin J Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013) p. 232
[2] Alec Swain, Overhead Line Electric Multiple Units (Ian Allan, 1990) p. 59

Class 82

The Class 82 (or AL2) was another of the 5 classes of locomotive built for the West Coast Main Line electrification. The Class 82 used Metropolitan-Vickers equipment though the locomotive building was sub-contracted out to Beyer Peacock [1]. The Class 82 used a number of components in common with the Class 81 though were overweight to British Rail's specification due to a sturdier more traditional method of construction. To get back within the weight limit some parts of the structure were replaced with aluminium or fibre glass and lighter versions of some items of electrical equipment were fitted [2].

Number built: 10
Built: 1960-62
Builder: Beyer Peacock / Metropolitan-Vickers
Engine: 4 Metropolitan-Vickers 189Z traction motors (6.25 / 25kV AC OHLE)
Power: 3, 300 hp (2, 460 kW) continuous
Wheel arrangement: Bo-Bo

Although they also had problems with their mercury-arc rectifiers like some of the other early electric locomotives they had less problems with them though the rectifiers were replaced with silicon-diode as with the other classes in the early 1970s. One problem the Class 82 did have at times was a tendency to overheat when stationary if the equipment was still running due to inadequate ventilation [3].

One was withdrawn due to fire damage in 1966, another in 1971, but the rest survived into the 1980s but began to be withdrawn as sufficient more modern traction was available. Two survived (along with 2 Class 83s) on Euston empty stock movements until 1987. One (82 008) has been preserved.
82 005, photographer unknown

82 008, photographer unknown

[1] Gavin Morrison, AC Electric Locomotives (Ian Allan, 2013) p. 11
[2] Brian Haresnape, Electric Locomotives (Ian Allan, 1983) p. 49
[3] Morrison p. 11