GWR Route: Banbury to Wolverhampton

Acocks Green & South Yardley Station: gwrag2439

Western Region D1046 'Western Marquis' is seen at the head of a Pullman express leaving Acocks Green station on 7th January 1963. When the 'Blue Pullman' was not available, as with the 1:00pm Birmingham Snow Hill to Paddington service, a locomotive hauling Pullman stock would be substituted, known locally as 'the Wells Fargo' set. Built by Crewe works in December 1962, 'Western Marquis' was withdrawn in November 1976 from Laira (LA) to be scrapped by Swindon works. Later assigned by British Rail as Class 52 locomotives, some seventy-four of these large Type 4 diesel-hydraulic locomotives were built for the Western Region of British Railways between 1961 and 1964. All were given two-word names, the first word being 'Western' and thus the type became known as Westerns.

When switching to diesel traction as part of the Modernisation Plan of the 1950s, BR designed, and commissioned designs for, a large number of locomotive types. At this time (and arguably right up until Sectorisation in the 1980s), BR's regions had a high degree of autonomy, which extended as far as classes of locomotives ordered and even the design criteria for those locomotives. Whilst almost all other diesel locomotives were diesel-electric, the Western Region employed a policy of using diesel-hydraulic traction, originally commissioning three classes of main line locomotives: the Hymeks', 'Warships' and Western Classes. The theoretical advantage of diesel-hydraulic was simple - it resulted in a lighter locomotive than equivalent diesel-electric transmission. This resulted in a better power to weight ratio and decreased track wear. Unfortunately, it had two key disadvantages:

     The technology was proven in continental Europe, particularly Germany but was new to the UK. It was considered politically unacceptable at the time for the UK government to order railway rolling stock from foreign companies, let alone German companies so soon after the Second World War.

     The most robust hydraulic transmissions were only capable of handling engines with power output of around 1500 hp; to build a more powerful locomotive would involve two diesel engines and two transmissions.

Experience showed that the Bristol-Siddeley-Maybach engines were superior to those made by NBL-MAN and although the use of twin engines in the same locomotive was new, the process did not produce any insurmountable problems. In the end the diesel-hydraulic experiment foundered on low fleet numbers, poor maintenance conditions and design issues; not on its German heritage or development of a novel configuration. Whilst the design was largely successful the working life of the class was relatively short. It was a non-standard design adding greatly to its maintenance costs while the national British Rail policy was also moving away from diesel-hydraulics. When the Westerns were introduced in 1962 the Western Region had 226 diesel-hydraulics and 10 diesel-electrics (excluding shunters); by 1966 the numbers were 345 and 269 respectively. As a result the early 1970s saw the decision taken to retire all the diesel-hydraulic types. This resulted in Class 46 and Class 47 diesel electric locomotives taking over passenger and heavy freight while Class 25 locomotives covered the lighter duties. Following completion of the electrification of the West Coast Mainline throughout from London to Glasgow, Class 50 locomotives were allocated to the Western Region. The introduction of High Speed Trains three years later was the final nail in the coffin for the Westerns.

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