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.

Information
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By the late 1970s SR saw it had enough Class 33s and 73s to cover traffic requirements and the Class 74s were withdrawn by 1977 as non-standard.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 83

As with the early diesel locomotives British Railways ordered a number of different AC electric locomotives in small batches (for a total of 100 locomotives) for the electrification of the West Coast Main Line. Unlike the diesels however BR exerted a lot more control over the Classes 81 to 85 which looked very similar but differed in internal equipment used. Fifteen of the 100 locomotives ordered were by English Electric as the AL3 later Class 83. Unfortunately while English Electric diesel locomotives were hard to beat the Class 83 disappointed [1].

Information
Number built:	15
Built:	1960-62
Builder:	English Electric Vulcan Foundry
Engine:	4 EE435A traction motors (25kV AC OLHE)
Power:	2, 950 hp (2, 200 kW)
Wheel arrangement:	Bo-Bo

The Class 83s were lighter (three tons less than the Class 82 for example) and less powerful than the other prototype classes though English Electric considered this a virtue as it made them cheaper to build, a quarter of the price of a Deltic! The main weakness of the Class 83 was with their mercury-arc rectifiers which gave a lot of trouble and a time in the late 60s the entire class was put into storage [2].

In the early 1970s they were restored into service with silicon-diode rectifiers and continued in service until the early 1980s their relative lack of power compared to other electric locomotives saw them surplus to requirements and withdrawals began. A few managed to survive in service until the end of the decade on Euston empty coaching stock duties and even received Intercity livery. One of these 83 012 has been preserved.

83 013, locations and photographer in all photos unknown

83 012 in Intercity livery

83 015 looking a bit worse for wear

[1] Gavin Morrison, AC Electric Locomotives in Colour (Ian Allan, 2013) p. 13
[2] Brian Haresnape, Electric Locomotives (Ian Allan, 1983) p. 53