BR Class 47
Resource Type: Image | Posted on 2nd December 2011 by Liam Physick
Here we see an example of British Rail’s Class 47. This class of diesel-electric locomotives arose from the need for lightweight Type 4 diesels in order to meet the British Transport Commission’s aim of completely eradicating steam by 1968. Such diesels would need to produce at least 2500 brake per horsepower but with an axle load no heavier than 19 long tons, while the BTC was also convinced the future lay with diesel-electrics, rather than the diesel-hydraulics seen on the Western Region. Two demonstration locomotives were constructed, D0260 LION, built by Associated Electrical Industries (now British Thomson-Houston) and the Birmingham Railway Carriage and Wagon Company, and using a Sulzer engine, and D0280 FALCON, built by Bush Traction with a Maybach engine, but because of the need for a large number of locomotives, the pilot-building of the new class began before the prototypes were properly assessed. Initially, 20 were build, Nos. D1500-D1519, mechanically different from their younger sisters, but their success and that of LION led to more being commissioned. More Class 47s were built than any other class of main-line diesel locomotive in Britain. In total 512 were produced between 1962 and 1968, 310 at Brush’s Falcon Works in Loughborough (as a result, the Class was originally called Brush Sulzer Type 4) and 202 at Crewe Works: they were initially numbered D1500-D1999 and D1100-D1111. Fitted with the Sulzer 12LDA28C twin-back 12-cylinder unit producing 2750 brake horsepower, they were used for both passenger and goods work. Five, Nos. D1702-D1706 were fitted with a Sulzer V12 12LVA24 power unit and reclassified as Class 48s, but this was not a success and they reverted to their previous form. In the early 1970s, the locomotives were derated to 2580 brake horsepower, thus improving reliability by reducing stresses on the power plant without adversely affecting performance. In the early 1970s, they were renumbered and divided into sub-classes. Initially three sub-classes existed: 47/0, those locomotives with steam heating equipment, numbered 47001 to 47298; 47/3, with no train heating and used exclusively to pull goods, numbered 47301 to 47381; and 47/4, with electric train heating and used for passenger and mail trains, numbered 47401 to 47555. However, as locomotives were fitted with extra equipment, different sub-classes were created - Class 47/6, Class 47/7, Class 47/7b, Class 47/7c, Class 47/8 and Class 47/9, with the locomotives in question renumbered accordingly: additionally, a number of Class 47/0s were reallocated to Class 47/4. By 1986, 507 Class 47s remained in service - the only withdrawals due to damage in accidents - but the introduction of new rolling stock meant there was less work for them, and spare parts were becoming rarer. The original 20 locomotives were withdrawn between 1986 and 1992: 61 others were retired over the same period. However, as new locomotives were introduced, the withdrawal rate accelerated, with 86 pulled off the main line between 1992 and 1995. Most of those withdrawn were the so-called series parallel locomotives, with non-standard electrical equipment: by 1995, most of these had been retired, so withdrawal once again slowed down. Another factor was privatisation, which led to the establishment of new train companies, which needed to use existing traction until they could acquire replacements. Between 1996 and 2006, about 15 Class 47s a year were withdrawn: then the withdrawals ceased. Between 25 and 30 are still used on the main line (that includes 21 owned by the West Coast Railway Company) and are used for goods, charter trains and track maintenance trains, while 37 have been preserved and 33 have been rebuilt at Class 57s
Categorised under: Landmarks, Landscapes & Locomotives
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