British Rail Class 47


The British Rail Class 47 or Brush Type 4 is a class of diesel-electric locomotive that was developed in the 1960s by Brush Traction. A total of 512 Class 47s were built at Brush's Falcon Works in Loughborough and at British Railways' Crewe Works between 1962 and 1968, which made them the most numerous class of British mainline diesel locomotive.
They were fitted with the Sulzer 12LDA28C twin-bank twelve-cylinder unit producing though this was later derated to to improve reliabilityand have been used on both passenger and freight trains on Britain's railways for over 55 years. Despite the introduction of more modern types of traction, a significant number are still in use, both on the mainline and on heritage railways.
, 76 locomotives still exist as Class 47s, including 32 which have been preserved. 31 locomotives, including six which are preserved, retain mainline running certificates. A further 33 locomotives were converted to Class 57s between 1998 and 2004.

Origins

The Class 47 history began in the early 1960s with the stated aim of the British Transport Commission to remove steam locomotives from British Rail by a target date of 1968. It therefore required a large build of Type 4 but with an axle load of no more than. The BTC was not convinced that the future of diesel traction lay down the hydraulic transmission path of the Western Region, and concentrated on diesel-electric designs.
Initially, the BTC invited tenders to build 100 locomotives to the new specification. The following responses were received:
Of these bids, the BRCW/AEI/Sulzer bid was the preferred option, but before the prototypes could be assessed, the need to build a large number of locomotives quickly was deemed paramount, and the BTC decided on a new approach: it decided to cancel the final order of twenty Class 46 locomotives and invite bids for twenty locomotives of the new Type 4 specification using the Brush electrical equipment intended for the cancelled order. Brush won the contract.
This initial build of 20 locomotives were mechanically different from the remainder of the type, using Westinghouse-supplied brake systems, and would be withdrawn earlier than the rest of the class which used Metcalfe-Oerlikon brakes.
Based on the success of these initial 20 locomotives an order for 270 was made, which was later revised upwards a number of times to reach the final total of 512. 310 locomotives were constructed by Brush in Loughborough, and the remaining 202 at BR's Crewe Works. Five locomotives, Nos. D1702 to D1706, were fitted with a Sulzer V12 12LVA24 power unit and classified as Class 48s; the experiment was not deemed a success, and they were later converted to standard 47s.

Orders

The locomotives were ordered in 6 batches as follows:
  • D1500–D1519, 28 February 1961.
  • D1520–D1681, 1 January 1962.
  • D1682–D1706, 4 September 1962.
  • D1707–D1781, 28 September 1962.
  • D1782–D1861, 22 July 1963.
  • D1862–D1999 & D1100–D1111, 24 March 1964.

    In service

The first 500 locomotives were numbered sequentially from D1500 to D1999, with the remaining twelve being numbered from D1100 to D1111. The locomotives went to work on passenger and freight duties on all regions of British Rail. Large numbers went to replace steam locomotives, especially on express passenger duties.
The locomotives, bar a batch of 81 built for freight duties, were all fitted with steam heating boilers for train heat duties. The initial batch of twenty, plus D1960 and D1961, were also fitted with electric train heating. With this type of heating becoming standard, a further large number of locomotives were later fitted with this equipment.
In the mid-1960s, it was decided to de-rate the engine output of the fleet from to, significantly improving reliability by reducing stresses on the power plant, whilst not causing a noticeable reduction in performance.

Sub-classes

In the early 1970s, the fleet was renumbered into the 47xxx series to conform with the computerised TOPS systems. This enabled a number of easily recognisable sub-classes to be created, depending on the differing equipment fitted. The original series were based on train heating capability and were as follows;
  • Class 47/0: Locomotives with steam heating equipment.
  • Class 47/3: Locomotives with no train heating.
  • Class 47/4: Locomotives with dual or electric train heating.
However, this numbering system was later disrupted as locomotives were fitted with extra equipment and were renumbered into other sub-classes. For an overview of the renumbering see the List of British Rail Class 47 locomotives. This section summarises the main sub-classes that were created.

Class 47/0

Originally numbered D1520–1781, D1837–74, D1901–59, D1962–99 and D1100, these locomotives were the "basic" Class 47 with steam heating equipment fitted. In the 1970s and 1980s, with steam heating of trains gradually being phased out, all locomotives fitted with the equipment gradually had their steam heating boilers removed. Some were fitted with ETH and became 47/4s, whilst the others remained with no train heating capability and were therefore used mainly on freight work. In the 1990s, the class designation 47/2 was applied to some class 47/0s and class 47/3s after they were fitted with multiple working equipment. The locomotives involved also had their vacuum braking systems removed or isolated, leaving them air braked only. This was mainly a paper exercise, however, and the locomotives were not renumbered; in this article they are included in Class 47/0.

Class 47/3

Originally numbered D1782–1836 and D1875–1900, this sub-class was originally built with no train heating equipment and therefore remained as freight locomotives almost exclusively for their working lives. They were all fitted with slow speed control for working MGR coal trains. However, during the summer months when train heat was not required, 47/3s could regularly be found hauling the extra trains that the holiday season brought. The sub-type remained stable until withdrawals started, although an "extra" 47/3, 47300, was created in 1992 when 47468 had its train heating equipment removed and was renumbered. This was a direct replacement for collision damaged 47343. Also, 47364 was renumbered to 47981 in 1993 for use on RTC test trains.

Class 47/4

The designation for standard locomotives fitted with ETH and therefore used for passenger, mail and parcels use. The original batch of twenty locomotives were built with dual steam and electric train heating, the electric heating being tapped from the locomotive's DC generator. However, no more were constructed in this way until 1967 when the final two Brush-built locomotives, D1960 and D1961, were fitted with a new type of electric heat system using an AC alternator. Approximately 112 more locomotives had been fitted with this system by the time TOPS renumbering occurred, and shortly afterwards the sub-class had settled down to 154 locomotives, numbered 47401–47547 and 47549–47555. Later, further Class 47/0s were converted to Class 47/4s and renumbered into the series from 47556 onwards, which eventually reached 47665.

Class 47/6 and Class 47/9

After being severely damaged in a derailment near Peterborough in 1974, locomotive 47046 was selected to be a testbed for the projected Class 56, and was fitted with a 16-cylinder Ruston 16RK3CT engine rated at for assessment purposes. To identify it as unique, it was renumbered 47601. Later, in 1979, it was used again for the Class 58 project, fitted with a 12-cylinder Ruston engine, and renumbered 47901. It continued with this non-standard engine fitted until its withdrawal in 1990.

Class 47/7

In the late 1970s, BR authorities identified a need to replace the ageing trains operating the Glasgow to Edinburgh shuttle services, in order to increase speed and reliability. The trains were operated by pairs of Class 27s, one at each end of this train. It was decided to convert twelve 47/4s to operate the service in push-pull mode. The locomotives would be known as Class 47/7 and would be fitted with TDM push-pull equipment and long-range fuel tanks, and be maintained to operate at. The conversions began in 1979 and the service was operated completely by them from 1980. In 1985, the push-pull service spread to Glasgow-Aberdeen services, and a further four locomotives were converted. The sub-class therefore comprised 47701 to 47716, though a further locomotive, 47717, was converted in 1988 after the fire-damaged 47713 was withdrawn.

Class 47/7b and 47/7c

In the 1990s, further 47/4s were converted with long-range fuel tanks and equipment to allow them to work with a type of rolling stock known as propelling control vehicles-PCV, which utilised RCH cables to allow the PCV driver to signal to the driver on the locomotive to apply power and operate the brakes - neither these locomotives nor the PCVs were equipped with TDM push-pull equipment. They were also numbered into the 47/7 series, from 47721 onwards. With dwindling passenger work for them, a number of 47/8s, already fitted with the extra fuel tanks, were also renumbered into this series.
Two locomotives, 47798 Prince William and 47799 Prince Henry, were dedicated for use on the Royal Train, and were designated as Class 47/7c. The two locomotives were replaced by a pair of Class 67 locomotives in 2004, and were subsequently withdrawn for preservation.