Electro-Diesels & Hybrids
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Electro-Diesels & Hybrids Back in the 1950s, the Southern Region of former private companies had begun British Railways inherited 3rd rail experiments in non-steam traction, but electrification on its main lines – itself a with little significant growth. Most legacy of a decision made back in the published plans of what they expected to 1930s – despite the overhead contact do in the late 1940s, but the poor state of system having already been used the country’s economy, and the railways successfully on the LB&SCR out of London. run-down, wartime condition really In retrospect, it seems that the main demanded more than piecemeal proposals. reason behind the use of 750V d.c. and 3rd That major step-change in thinking and rail between London and the South Coast, investment began after 1956. That was the was the First World War and the 1929 watershed year, when the “Modernisation Wall Street Crash! & Re-Equipment Programme” began, and The originally successful overhead after the decision was taken to implement electrification used a.c. technology, but the electrification at 25kV a.c. This forced the equipment was supplied from Germany, restriction of d.c., with conductor rails, to and the intervention of hostilities and its the Southern Region, and scrap the limited aftermath put paid to any further overhead 1500V d.c. overhead scheme already begun. systems being undertaken. Following the The Southern Region of BR was effectively Wall Street Crash in 1929, and the split between steam and diesel traction economic crises of that period and into the after 1956 for long distance main line and 1930s, the Government sought to ease the express services, and electric multiple unit horrendous unemployment levels, in part rolling stock for short haul and suburban at least, by removing rail passenger duty. workings. The express passenger services As a result of these events, the Southern included boat trains running to the ferry Railway had sufficient capital to press ports from London, from the prestigious ahead with the electrification of the main “Golden Arrow” to international Pullman line from London to Brighton. The major workings like the “Night Ferry”. The downside for later rail operations was the isolated examples of higher-powered diesel decision to opt for 3rd rail systems, with and electric locomotives offered some contact shoes on the outside of rolling improvement for main line and express stock, and at ground level. haulage, but for mixed traffic, there was Looking back, with 21st century hindsight, it really only steam. Similarly, freight seems a risky and perhaps dangerous workings were generally in the hands of decision, giving the impression that the steam, and later, medium powered diesel lines radiating south from London were locomotives, as the modernisation plan treated as just an extension of suburban took hold. and commuter routes, as none were of any So, what was the point of a locomotive great length. But of course, economic that housed both a diesel engine, and conditions could and did change, including picked up its power from the conductor the expansion of port facilities at places rail? The answer of course was “gaps”. like Southampton, and for main line These were breaks in the third rail – of operations, steam was still the principal which there were quite a few – and motive power until after World War 2. without current collection, no power, and During the early British Railways era, there no traction. Aside from that, the sudden was no example of main line ‘hybrid’ or loss of electrical energy, and its equally electro-diesel locomotive, although the sudden restoration would have its impact on the locomotive, of course, this was well known, as was the effect of the weather on engine, and designed to fit the narrow the contact mechanism. The gap problem ‘Hastings Gauge’, with 6 of these appearing was avoided by equipping the first electric from Eastleigh Works, between February locomotives with a motor-generator set and November 1962. These were and a flywheel, enabling energy to be designated type JA, or under the TOPS stored by the power unit, to cover the loss coding system they became Class 73/0. of supply at those gaps. The basic design of the six prototype Then there was the operational problem – locomotives was carried out at Eastleigh by freight and mixed traffic workings and BR, and in co-ordination with English track possessions at night. The Electric, who provided the traction and international traffic came via Dover and control equipment, along with the diesel over the former LB&SCR lines into engine. London, and in the 1950s, BR were also extending the third rail network to Bournemouth, and operationally were in need of ‘mixed traffic’ motive power. This extension, together with other projects such as the Kent Coast scheme, were all part of BR’s plan to eliminate steam from the Southern Region. In Kent, the electrified lines back to London’s Victoria station also saw the arrival in 1958-60 of 24 new 2,300hp electric locomotives, The English Electric publicity shot of the first of the production series, just built at BR’s Doncaster Works. out shopped from the Vulcan Foundry Works at Newton-le-Willows. These proved a success with those prestigious passenger Photo: RPB/GEC Collection trains, as well as the heavy freight workings on these routes, but the Following successful trials in service of the ‘gap’ and track possession for PW work new electro-diesels, in 1964 BR placed an remained a challenge, and a more flexible order for 30 from English Electric, and design of mixed traffic power was needed. which were built at Vulcan Foundry, in The initial success of the new high- Newton-le-Willows, where the diesel powered electric locos rapidly faded, and engine was also built. This order was later barely 2 to 3 years after the arrival of the extended by a further 13 locomotives, to a last of these locomotives a new approach total production run of 43. The electrical was decided on. equipment, in common with many other The end result of discussions was the orders at the time, was manufactured in arrival in 1962 of a 1,600hp electric Preston, at what we could say is, or rather locomotive, also fitted with a 600hp diesel was, the ‘home’ of electric traction in the UK. Design Basics As a ‘secondary’ main line electric within goods yards. This option for locomotive, the Class 73 met the shunting meant the provision of dual Southern’s mixed traffic requirements, controls in the cab. The design of what alongside the bonus of operating freight was originally described as Type JB trains along the main lines, and shunting locomotives was identical to the prototype units built by BR a couple of years earlier. English Electric had a solid history of Operating on the 675V d.c. third-rail supplying traction equipment from Preston system, the maximum power available was to railways around the world, and in the 1,600hp, whilst over lines where the UK, BR’s Southern Region was no power has been switched off, or on non- exception. The 2,300hp straight electrics electrified lines, an English Electric Type 4 built at Doncaster Works were fitted with SRKT diesel engine provided 600hp. EE traction motors and control equipment. Leading Dimensions Gauge 4' 8 1/2" Wheel arrangement Bo-Bo Maximum service speed 90 m.p.h. Power rating-I hour 1,600 h.p. electric 600 h.p. diesel Tractive effort (nominal maximum) 42,000 lb. at 25% adhesion Tractive effort (1 hr Full Field) 18,600 lb. Nominal supply voltage 675V d.c. Weight in W.O. 75 tons Length over buffers 53' 8'" Width over footsteps 8' 8" Overall height 12' 5 7/16"; max Bogie pivot centres 32' 0" Bogie wheelbase 8 ' 9 " Wheel diameter 3' 4" General Layout and Construction These locomotives followed the basic were not sufficiently developed for use design pattern of all BR’s 1950s and 1960s within the structure of the body. designs, with a cab at each end and a full The body was divided by a central width body, supported on fabricated bulkhead into two compartments, with the longitudinal frameworks, and with 2 or 3- diesel engine housed at the No.1 end, and axle bogies. There were exceptions to this electrical equipment at the No.2 end, as approach, primarily in the Western shown in the diagram. Region’s later “Warship” class design, and the use of glass fibre, or GRP mouldings The underframes were fabricated from rolled steel joists, with solebars from channel section steel, and at each end, the fabricated dragboxes carried the buffing and drawgear. The buffers were retractable, and able to be rotated through 90 degrees, to enable these locomotives to be close-coupled and operated in multiple. The body sides were fabricated in the form! of a lattice structure known as Warren girders – in much the same way as a girder bridge might be built - the outside faces were then covered in steel sheets, and sloped towards cantrail level to match existing multiple unit rolling stock. The inner face of the body structure was covered in aluminium sheet, which was also used for the The driving cabs at either end were the partitions between compartments, and the height of luxury compared to the steam driving cabs. Aluminium sheet – as tread locomotives still in everyday service in the plates was used on the floors. 1960s, and were a double walled structure, with glass fibre matting used for insulation. Power and Control The engine - an English Electric Type generator, via a common shaft.