British Rail Class 52

British Rail (BR) 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, the first word being Western; thus the type became known as Westerns.

Historical context

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— a type 2 and two type 4s (later designations class 22, class 41 and class 42). With pressure to increase the speed of the transition from steam to diesel, volume orders for the class 22 and class 42 followed in 1957, a mere two years after the original orders and well before any idea of performance or reliability could be gained. At the same time it was realised that all the existing orders (diesel-electric and diesel-hydraulic) were for types 1, 2 and 4; thus orders were placed for 101 Type 3 diesel-hydraulics (later Class 35). However the increasing demands for more powerful locomotives prompted a further order, in 1961, for 74 diesel-hydraulics of 2,700 hp (2,000 kW); so when the first locomotive was outshopped from Swindon Works in December 1961, less than a year after the order was placed, the Westerns were born.

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.

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.

The Western

With the Hymeks and Warships already in service but proving underpowered for top-link 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. In keeping with their policy, a new locomotive with a hydraulic transmission was envisaged. Experience had shown that the Maybach engines in the Hymeks were superior to the MAN engines used in the Warships, particularly in power output. Also Maybach were able to offer their 12 MD engines rated at 1,350 bhp (1,010 kW) allied to a Voith transmission; a Mekydro transmission designed to handle such power could not be fitted into the British loading gauge.

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 90 mph (140 km/h) 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 class 50s and High Speed Trains provided the speed and comfort increases the Western Region sought. Towards the end, the Westerns were all allocated to Laira (Plymouth).

Competition and comfort

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. Class 46 and Class 47 took over passenger and heavy freight while Class 25 covered the lighter duties. Following completion of the electrification of the West Coast Mainline throughout from London to Glasgow Class 50 was allocated to the Western Region, the introduction of High Speed Trains 3 years later was the final nail in the coffin for the Westerns.

In 1968–69 the Westerns received train air brake equipment in addition to their vacuum exhausters, thus significantly extending their working lives, unlike the similar but lower-powered, Warship class. The vacuum brake equipment was retained and to fit the additional equipment, it was necessary to remove one of the fuel tanks.^[1] However, as with 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 a significant speed and comfort increase 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 2d/e/f coaches — a shortcoming that Class 50, equipped with ETH from new, did not share.

Names and numbers

While the first Western was under construction, proposals for livery and names were prepared by the BR design panel. The D1000 series locomotives were to be named after famous West of England place names; the illustration from the portfolio shows D1000 bearing the name Cheddar Gorge. This trend was not followed in production, however and the Westerns were named with general heraldic and regimental terms prefixed with the word "Western" as per the following table:

D1029 was originally named Western Legionaire, but renamed Western Legionnaire in 1967, the nameplate being cut to allow the additional letter to be inserted.^[2]

Although designated Class 52 under the TOPS scheme, no Western ever carried its "52 0xx" TOPS number. As withdrawal was already planned when the TOPS numbering scheme was introduced and because of the cast number plates, it was not considered cost effective to renumber the locomotives. Some class members did run with the "D" of their number painted over - TOPS classification removed the need for locomotives to indicate their energy type in the running number (D = Diesel, E = Electric), rather grouping locomotives into relevant class number ranges based on power output and energy type combined, 01-69 being diesel, 70 to 99 reserved for electric (this convention has become somewhat blurred in recent years).

When the display of destination headcodes/reporting numbers on the front of trains was dropped in 1975, the instruction was given for them all to be set to "0000". On many Westerns, the headcode was set to display the loco's number in contravention of this directive and most surviving members of the class ran like this until they were scrapped. If used for routeing, such reporting numbers would be interpreted as a passenger express terminating on the Southern Region.^[3]

Liveries

When the initial batch of Westerns was being built in 1961-2, British Rail was considering a new unified corporate colour scheme but had not yet made a final decision on what it would be. As a result, D1000 was rolled out of Swindon Works in November 1961 painted in Desert Sand. Initially the numbers, borne on the left hand cab when viewed from the side, were painted in white but soon individual numbers and letters, looking like they were cast but apparently made of wood, were fitted. This was in turn replaced by the final design of cast nameplate and numberplate; metal with a black background. This livery was later altered by the addition of a small yellow warning panel and black roof. After this, D1001 was delivered in all over maroon livery with yellow buffer beams and D1002-D1004 in all over green and small yellow warning panel. The remaining deliveries were all in maroon, with small yellow warning panels after D1009 and D1043 of the Crewe built locomotives. Exceptions to this were the initial Crewe-built batch D1035-D1038 which were in green with red backgrounds to the nameplates and D1015, outshopped in the experimental "golden ochre" livery with small yellow warning panels. On one end of D1015, the yellow panel was embellished by the addition of a yellow band which extended sideways from each of the top corners and round and onto the cabside for a short distance, resembling a T shape.

After the adoption of Rail Blue with full yellow ends in 1966 (D1048 was the first of the class painted in this livery in 1966), for some unexplained reason a small batch of locos (D1017, D1030, D1036, D1037, D1043, D1047 and D1057) received this variant married to small yellow warning panels, D1030 even carried red buffer beams for a short while. All other repaints were with full yellow ends which extended from the body line above the buffer beam up to the base of the window frames, along the sill of the cab-side windows onto the vertical end reveal. The valance above the cab windows on the front was also painted yellow, leaving the window frames in their base aluminium. The drive to repaint the locomotives in "Corporate Blue" was outstripped by the safety directive dictating full yellow ends for all powered vehicles and some locomotives ran for a time with their original maroon bodies and full yellow ends.

The last loco to be repainted into Rail Blue was D1046, outshopped from Swindon in May 1971. Some early photographs of the blue livery give it a more metallic shade which is even more evident on the locos with small yellow panels. This has been referred to in the past as "chromatic blue". This however is likely just to be a photographic anomaly with early colour film. It is commonly accepted amongst Western enthusiasts in recent years that none of the class or any other British Rail locomotive of the period were ever painted with a metallic paint.

Incidents

• 15 August 1963. Knowle and Dorridge rail crash. No. 1040 Western Queen collided with a freight train, crushing the cab killing the three train crew. The locomotive was repaired and returned to service.
• 19 December 1973. Ealing rail crash. No. 1007 Western Talisman derailed while hauling an express passenger train, after an unlocked battery box door fell open, broke off and changed points under the locomotive. Ten people died.^[4]
• 3 January 1976 (Worcester Tunnel). No. 1055 Western Advocate crashed into a stationary parcels train killing the Driver and Guard of the Western.^[5]
• 4 October 1976 (Stoke Canon, Exeter). No. 1001 Western Pathfinder was working an overnight parcels train from London Paddington to Penzance when the train was in collision with a workers van at a level crossing. One workman in the van died in the accident. The locomotive was removed to Exeter St Davids depot. Despite sustaining relatively minor damage, the imminent demise of the entire fleet of Class 52's resulted in condemnation of the locomotive. Up to this point, Western Pathfinder had been a serious contender for preservation.

See also

• Krauss-Maffei ML 2200 C'C', RENFE Class 340, contemporary twin engined, twin transmission C'C' diesel hydraulic locomotives
• Voith Maxima, modern (2000s) single engined, single transmission high power diesel hydraulic locomotive

References

1. ^ Reed 1978, pp. 70–71
2. ^ Walker, M (September 2002). "Loco profile of the Westerns.". The Marlow Donkey (101): 8–10. 
3. ^ Bailey, M.R. (February 1968). British Rail Headcodes (5th ed.). Shepperton: Ian Allan. pp. 5–7. ISBN 0 7110 0000 X. 458 GEX 268. 
4. ^ "Official accident report". HMSO, reproduced at The Railways Archive. http://www.railwaysarchive.co.uk/documents/DoE_Ealing1973.pdf. Retrieved 2009-09-16. 
5. ^ King, A.G.B. (28 September 1977). "Report on the Collision that occurred on 3rd January 1976 at Worcester Tunnel Junction". http://www.railwaysarchive.co.uk/documents/DoT_WorcesterTunnel1976.pdf. Retrieved 7 September 2010. 

Sources

• Ford, H L (1973). Diesels on Cornwall's main line. Truro: D Bradford Barton. 
• Hall, Stanley (2006). Railway Milestones and Millstones. Hersham: Ian Allan Publishing. pp. 125–130. ISBN 0 7110 3110 X. 
• Judge, Colin (1977). The Power of the Westerns. Oxford: OPC. ISBN 0 902888 98 6. 
• Kichenside, Geoffrey (1975). Farewell to the Westerns. Newton Abbot: David & Charles. ISBN 0 715370 69 3. 
• Preedy, Norman E; Gillham, G F (1974). WR Diesel Hydraulics. Truro: D Bradford Barton. 
• Reed, Brian (1978) [1975]. Diesel-Hydraulic Locomotives of the Western Region. Newton Abbot: David & Charles. ISBN 0 7153 6769 2. 
• Taylor, Ken. A Decade After. Walsall: Midland Railfans. 
• Till, J O (1977). Western Stock List. Camberley: Steam & Diesel Publications. 
• Vaughan, John (1977). Western Diesels in Camera. Shepperton: Ian Allan. ISBN 0 711008 31 0. 
• Watts, Peter (1977). Western Memories. Gloucester: Peter Watts. ISBN 0 906025 00 1. 

Further reading

• McManus, Michael. Ultimate Allocations, British Railways Locomotives 1948 - 1968. Wirral. Michael McManus. 

External links

• D1023 at Bury
• www.westernprince.co.uk
• www.westernchampion.co.uk
• www.westernloco.com