British Rail Class 52
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| BR Class 52 | ||
|---|---|---|
| TOPS numbers | Never carried | |
| Early numbers | D1000–D1073 | |
| Builder | BR Swindon, BR Crewe | |
| Introduced | 1962-1964 | |
| Wheel arrangement | C-C | |
| Weight | 108 long tons | 110 t |
| Height | 12 ft 11.75 in | 3.956 m |
| Width | 8 ft 8 in | 2.64 m |
| Length | 68 ft 0 in | 20.73 m |
| Wheel Dia. | 3 ft 7 in | 1.09 m |
| Wheelbase | 54 ft 8 in | 16.66 m |
| Minimum radius | 4.5 chains | 90.5 m |
| Maximum speed | 90 mph | 145 km/h |
| Engine | 2 x Maybach MD655 | |
| Engine output | 2 x 1,350 hp | 2 x 1010 kW |
| Max. tractive effort | 66,700 lbf | 297 kN |
| Power at rail | 2,000 hp | 1,490 kW |
| Brake type | Air & vacuum | |
| Brake force | 50 tons force | 500 kN |
| Route availability | 7 | |
| Fuel tank | 850 imperial gallons | 3,860 litres |
| Heating type | Steam | |
| Multiple working | Not equipped | |
British Rail assigned Class 52 to the class of 74 large Type 4 diesel-hydraulic locomotives built for the Western Region of British Railways between 1961 and 1964. All were given two-word names, with the first word being Western, and thus the type became known as Westerns.
Contents |
[edit] The Diesel-hydraulic experiment
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 utilising diesel-hydraulic traction, commissioning three classes of main line locomotives—the Westerns, and the lesser-powered Hymeks and Warships.
The theoretical advantage of diesel-hydraulic was simple—it resulted in a lighter locomotive than equivalent diesel-electric transmission. This resulted in better power/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 trains 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 (1120 kW); to build a more powerful locomotive would involve two diesel engines and two transmissions.
[edit] The Western
With the Hymeks and Warships already in service, but proving under-powered for topline services, BR Western Region needed a high-powered locomotive for top-link services - the Western therefore needed two diesel engines to achieve the required power output.
Prototypes sited the engines behind the driving cabs, but drivers found this too noisy; moving the engines centrally meant making the locomotive heavier, removing some of the design's advantage. In production use, the dual-engine arrangement turned out to have some advantages: in particular, the Westerns were able to continue operating with a single engine running in situations where more conventional single-engine designs would require rescue by another locomotive. This valuable property was intentionally duplicated in the later High Speed Trains, and was one reason for them having two power cars.
The most serious continual problem with the class was the design fault mismatch between the Maybach MD655 engines and the Voith L630rV three speed hydraulic transmissions. The top gear ratio in the transmission was too high for the torque characteristics of the engine: the result was that a single locomotive could struggle to reach its claimed 90mph top speed in the absence of down grades, more so when work-weary and due for overhaul. These factors, combined with the Devon banks' (a major part of their running grounds) deleterious effect on tired engines, all conspired against the Westerns continuing in top-line service; their replacement by High Speed Trains provided the speed and comfort increases the Western Region sought. Towards the end, the Westerns were all allocated to Laira Plymouth.
[edit] Competition and Comfort
Whilst the Class was successful, it was non-standard, which added greatly to its high maintenance costs. Resultantly, the early 1970s saw the decision taken to retire all the diesel-hydraulic types. Class 47s and 50s began to take over on the Western Region, whilst the arrival of the High Speed Train was the final nail in the coffin for the Westerns.
Unlike the similar, but lower-powered, Warship class locomotives, most Westerns did receive air brake equipment in addition to their vacuum exhausters, thus significantly extending their working lives. However, as for the Warships, it proved impossible to equip them with electric train heating (ETH, or head-end power in US terminology). The Western Region faced particularly stiff competition for its prime inter-city services in the mid to late 1970s from the M4 motorway, and it was generally felt within BR that significant speed-up and comfort increases on the prime Paddington-Bristol route were necessary. The lack of ETH meant the Westerns could not power the newly-introduced air-conditioned BR Mark 2f coaches - a shortcoming that the Class 50s, which were built with ETH, did not share.
[edit] Withdrawal
With ETH being required for most class 1 traffic on the WR Class 50 & 47/4 adopted more of the top-link passenger turns until the High Speed Train was delivered. However, they were always seen and used as true multi-purpose locomotives, at home on oil, coal or stone duties. Away from the cameras they worked much heavy freight in South Wales right up to the end including turns on the overnight Freightliner from Cardiff to Stratford (East London). A main-stay of the class for many years (up to the mid 1970's) was overnight milk and cream workings from Devon and Cornwall, also from Whitland and Marshfield in South Wales to London. They were a useful machine for Control to use on 1 way specials, lack of driver knowledge off the WR would see them quickly returned and not as with other more widespread types 'lost somewhere in Scotland'.
The final class member was withdrawn in February 1977.
[edit] Names and numbers
All of the Westerns were named, as in the following table:
| Number | Name | Builder | Disposition |
|---|---|---|---|
| D1000 | Western Enterprise | BR Swindon | Scrapped |
| D1001 | Western Pathfinder | BR Swindon | Scrapped |
| D1002 | Western Explorer | BR Swindon | Scrapped |
| D1003 | Western Pioneer | BR Swindon | Scrapped |
| D1004 | Western Crusader | BR Swindon | Scrapped |
| D1005 | Western Venturer | BR Swindon | Scrapped |
| D1006 | Western Stalwart | BR Swindon | Scrapped |
| D1007 | Western Talisman | BR Swindon | Scrapped |
| D1008 | Western Harrier | BR Swindon | Scrapped |
| D1009 | Western Invader | BR Swindon | Scrapped |
| D1010 | Western Campaigner | BR Swindon | Preserved |
| D1011 | Western Thunderer | BR Swindon | Scrapped |
| D1012 | Western Firebrand | BR Swindon | Scrapped |
| D1013 | Western Ranger | BR Swindon | Preserved |
| D1014 | Western Leviathan | BR Swindon | Scrapped |
| D1015 | Western Champion | BR Swindon | Preserved |
| D1016 | Western Gladiator | BR Swindon | Scrapped |
| D1017 | Western Warrior | BR Swindon | Scrapped |
| D1018 | Western Buccaneer | BR Swindon | Scrapped |
| D1019 | Western Challenger | BR Swindon | Scrapped |
| D1020 | Western Hero | BR Swindon | Scrapped |
| D1021 | Western Cavalier | BR Swindon | Scrapped |
| D1022 | Western Sentinel | BR Swindon | Scrapped |
| D1023 | Western Fusilier | BR Swindon | Preserved |
| D1024 | Western Huntsman | BR Swindon | Scrapped |
| D1025 | Western Guardsman | BR Swindon | Scrapped |
| D1026 | Western Centurion | BR Swindon | Scrapped |
| D1027 | Western Lancer | BR Swindon | Scrapped |
| D1028 | Western Hussar | BR Swindon | Scrapped |
| D1029 | Western Legionaire | BR Swindon | Scrapped |
| D1030 | Western Musketeer | BR Crewe | Scrapped |
| D1031 | Western Rifleman | BR Crewe | Scrapped |
| D1032 | Western Marksman | BR Crewe | Scrapped |
| D1033 | Western Trooper | BR Crewe | Scrapped |
| D1034 | Western Dragoon | BR Crewe | Scrapped |
| D1035 | Western Yeoman | BR Crewe | Scrapped |
| D1036 | Western Emperor | BR Crewe | Scrapped |
| D1037 | Western Empress | BR Crewe | Scrapped |
| D1038 | Western Sovereign | BR Crewe | Scrapped |
| D1039 | Western King | BR Crewe | Scrapped |
| D1040 | Western Queen | BR Crewe | Scrapped |
| D1041 | Western Prince | BR Crewe | Preserved |
| D1042 | Western Princess | BR Crewe | Scrapped |
| D1043 | Western Duke | BR Crewe | Scrapped |
| D1044 | Western Duchess | BR Crewe | Scrapped |
| D1045 | Western Viscount | BR Crewe | Scrapped |
| D1046 | Western Marquis | BR Crewe | Scrapped |
| D1047 | Western Lord | BR Crewe | Scrapped |
| D1048 | Western Lady | BR Crewe | Preserved |
| D1049 | Western Monarch | BR Crewe | Scrapped |
| D1050 | Western Ruler | BR Crewe | Scrapped |
| D1051 | Western Ambassador | BR Crewe | Scrapped |
| D1052 | Western Viceroy | BR Crewe | Scrapped |
| D1053 | Western Patriarch | BR Crewe | Scrapped |
| D1054 | Western Governor | BR Crewe | Scrapped |
| D1055 | Western Advocate | BR Crewe | Scrapped |
| D1056 | Western Sultan | BR Crewe | Scrapped |
| D1057 | Western Chieftain | BR Crewe | Scrapped |
| D1058 | Western Nobleman | BR Crewe | Scrapped |
| D1059 | Western Empire | BR Crewe | Scrapped |
| D1060 | Western Dominion | BR Crewe | Scrapped |
| D1061 | Western Envoy | BR Crewe | Scrapped |
| D1062 | Western Courier | BR Crewe | Preserved |
| D1063 | Western Monitor | BR Crewe | Scrapped |
| D1064 | Western Regent | BR Crewe | Scrapped |
| D1065 | Western Consort | BR Crewe | Scrapped |
| D1066 | Western Prefect | BR Crewe | Scrapped |
| D1067 | Western Druid | BR Crewe | Scrapped |
| D1068 | Western Reliance | BR Crewe | Scrapped |
| D1069 | Western Vanguard | BR Crewe | Scrapped |
| D1070 | Western Gauntlet | BR Crewe | Scrapped |
| D1071 | Western Renown | BR Crewe | Scrapped |
| D1072 | Western Glory | BR Crewe | Scrapped |
| D1073 | Western Bulwark | BR Crewe | Scrapped |
