SR West Country and Battle of Britain Classes

Infobox Locomotive
powertype=Steam
name = SR Un-rebuilt West Country/Battle of Britain Classes Herring, pp. 160–161]


caption = Un-rebuilt West Country Class 21C123 "Blackmoor Vale", as preserved, in Southern Railway Malachite Green and "Sunshine Yellow" livery, and featuring part of the Golden Arrow insignia
designer = Oliver Bulleid
builder = SR Brighton/Eastleigh Works
builddate = 1945–1951
totalproduction = 110
whytetype = 4-6-2 ("Pacific")
gauge = RailGauge|ussg
leadingsize = 3 ft 1 in (0.94 m)
driversize = 6 ft 2 in (1.89 m)
trailingsize = 3 ft 1 in (0.94 m)
length = 67 ft 4¾ in (20.26 m)
weight = 128 tons 12 cwt (130.7 tonnes)
fueltype = coal
fuelc

waterc

cylindercount = 3
cylindersize = 16.375 in × 24 in (41.592 cm × 60.959 cm
firearea = 38.25 ft² (3.44 m²)
boilerpressure = 250 lbf/in² (1,723 kPa)
tractiveeffort = 31,000 lbf (137.894kN)
railroad=Southern Railway (Great Britain),
British Railways
(Southern Region)
locale=Great Britain
railroadclass=7P/5FA|

The SR West Country and Battle of Britain Classes, also known as "Light Pacifics" or "Spam Cans", are classes of air-smoothed 4-6-2 "Pacific" steam locomotive designed for the Southern Railway by Oliver Bulleid. Incorporating a number of new developments in British steam locomotive technology, both classes were amongst the first British designs to utilise welding in the construction process, and to use steel fireboxes, which meant that components could be more easily constructed during the wartime austerity and post-war economy. Arlett, p. 29–30]

They were designed to be lighter in weight than their sister locomotives, the Merchant Navy Class, to permit use on a wider variety of routes. They were a true mixed-traffic design, being equally adept at hauling passenger and freight trains, and were used on all types of services. A total of 110 locomotives were constructed between 1945 and 1950, named after West Country resorts and Royal Air Force (RAF) subjects from the Battle of Britain, representing another publicity masterstroke for the Southern Railway, one of the "Big Four" British railway companies formed after the grouping of 1923.Whitehouse & Thomas, p. 6]

Due to problems with some of the more novel features in Bulleid's design, such as the Bulleid chain-driven valve gear, sixty locomotives were rebuilt by British Railways during the late 1950s. Fairclough & Wills, p. 11] This produced a locomotive design highly similar to that of the rebuilt Merchant Navy Class. Fairclough & Wills p. 34] The classes operated until July 1967, when the last steam locomotives on the Southern Region were withdrawn from service. Although most were subsequently scrapped, twenty locomotives avoided this fate and instead found new homes on heritage railways in Britain.

Background

The introduction of the Merchant Navy Class was regarded as a success by the Southern Railway. Nothing like them had been seen before on Britain's railways in terms of design, boiler efficiency, and the ergonomics applied to the footplate to maintain ease of use. Day-Lewis, p. 9] However, the Operations Department of the Southern Railway soon realised that the locomotives were too heavy for use on some of the less significant lines. They needed a locomotive that could be used on more of their routes, a lighter type with a correspondingly greater route availability. The company's Chief Mechanical Engineer, Oliver Bulleid, used the design of his Merchant Navy Class as the template for a smaller, easily maintained locomotive. The 4-6-2 "Pacific" wheel arrangement was chosen again, as this provided stable running at high speeds, as well as allowing the provision of a larger firebox than the 4-6-0 design alternative, which would enable increased boiler efficiency. As the resultant locomotives were lighter than the 'Merchants', they would later become known as Bulleid's "Light Pacifics".

The class was intended primarily for express and semi-fast passenger trains in Southern England, ranging from the channel ports of South East England to the West Country resorts of South West England. As an extra design challenge for Bulleid, the new class had to be equally adept at both freight workings and branch line stopping trains, both of which required low axle loading, and a good turn of speed.

Design features

Based on the mechanical experience gained through working with the Merchant Navy Class locomotives, Bulleid incorporated his novel chain-driven valve gear into the new design. This now-infamous component was unique amongst British locomotive design practices. It gained notoriety because it was difficult to access when things went wrong and, in tandem with the fast-moving Bulleid steam reverser, could cause highly irregular valve movements. The entire system was located in a sealed oil bath, another unique design, that provided constant lubrication to the moving parts. Several other refinements and innovations were included, such as electric lighting and the Bulleid-Firth-Brown, or BFB, wheel design, both seen previously on the larger Merchant Navy locomotives. [ [http://www.watercressline.co.uk/tw/pics/wc-valve.jpgChain-driven valve gear diagram] , retrieved April 13, 2007] The locomotive also carried a similar "air-smoothed" casing. This was not regarded as streamlining by Bulleid, a fact demonstrated by the extremely flat front end; it was intended to be an aid in cleaning the locomotive via the use of a carriage washer, representing another attempt to reduce labour requirements during the post-war period, creating a unique-looking locomotive. [ Creer & Morrison, p. 13] The tender could carry 4,500 gallons of water and featured streamlining panels, or "raves", that gave the top of the tender a similar cross-sectional outline to the carriages hauled by the locomotive.

The boiler design was also very similar to that of the Merchant Navy Class, and was one of the first in Britain to incorporate welding and steel into the fabrication of the firebox, as the usual material was copper. This made for cheaper construction and easier maintenance, whilst thermic syphons were implemented to improve the efficiency of water flow in the boiler. Weight-saving came from use of a shorter boiler, which was rated at an operating pressure of 280 psi. Fairclough & Wills, p. 5] A shorter boiler required shorter frames, resulting in a reduced-length locomotive and further weight-savings.

The footplate was frequently regarded as ergonomically superior to other express passenger locomotives, as the controls required for operation were grouped according to the needs of both fireman and driver. Other innovations provided on the footplate included electric lighting and gauges lit by ultra-violet light, which enabled clearer night-time vision of the boiler steam pressure gauge and the brake pipe vacuum pressure gauge. The footplate was also entirely enclosed, improving crew working conditions in winter, and the supporting trailing wheels gave the smoothest of rides; their design was utilised in the future BR standard class 7. Further modifications were applied to the class during the brief time they operated under the Southern Railway, such as the redesign of the footplate spectacle plates. These are the small windows on the front face of the cab, which were redesigned to an angled profile, a feature to be seen on all Bulleid-designed locomotives post-Nationalisation and introduced in Britain in 1934 with the Gresley Cock o' the North. Originally, the spectacle plates of the Bulleid Pacifics were at the conventional right-angle to the direction of the locomotive, and offered limited vision ahead along the air-smoothed casing.Creer & Morrison, p. 13]

Construction history

The Southern Railway constructed seventy "Light Pacifics" at Brighton Works: the first, prototype West Country Class locomotive 21C101 "Exeter", was completed in May 1945; the last was Battle of Britain Class number 21C170 "Manston" in November 1947. The Southern-built batches had a narrower footplate than those constructed later, due to the intention for the type to work the width-restricted Hastings Line between Tonbridge and Hastings. In the event the type was never used on this duty. Fairclough & Wills, p. 10]

The final forty engines were constructed after the nationalisation of the railways in 1948. This meant that they never carried Southern Railway numbers. The British Railways batch had detail differences to previous versions, the most significant being the footplate, which was widened to 9 feet; [Southern E-Group (2004) [http://www.semgonline.com/steam/blp02.html Footplate sizes] , retrieved April 13, 2007] and the tender, which had an increased water capacity of 5,500 gallons.

Naming the locomotives

The two classes are mechanically identical, the distinction between the West Country and Battle of Britain being purely concerned with the theme of the names given to the individual locomotives. As built by the Southern Railway, 48 of the class were named after places in the West Country served by its trains or close to its lines, and the rest took their names from RAF squadrons, airfields, commanders and aircraft that participated in the Battle of Britain over Kent.Burridge, p. 72] This represented a publicity success due to many of the locomotives being able to visit their namesake areas. Many of the West Country locomotives sported an additional plaque depicting the coat of arms associated with the town or region the locomotive was named after. This plaque was mounted on the casing between the locomotive nameplate and the "West Country Class" scroll, above the middle driving wheel.

Several members of the West Country Class were issued with only the nameplate and the "West Country Class" scroll, a corresponding gap being left between the two where a crest would have been mounted.Burridge, p. 66] The background of the nameplate was usually painted red, though sometimes examples could be found in black if the locomotive works undertaking overhaul of the engine could not locate the correct colour paint.Burridge, p. 68] The Battle of Britain Class nameplates incorporated the name of the locomotive, with the class name below, in a design that resembled the wings of an aircraft. This was painted air force blue, though other colours were sometimes substituted for the same reasons as above.Burridge, pp. 72–78] A crest of the aircraft, personality or squadron was placed below the nameplate, in the same position as the West Country Class equivalent. Incidentally, the nameplates were constructed from sheets of gunmetal.

British Railways engines

The first locomotives constructed under the new regime were of the Battle of Britain Class, numbers 34071–34090, although naming policy reverted back to the West Country Class from 34091–34108. The final two constructed by British Railways were once again BBs, these being 34109 "Sir Trafford Leigh-Mallory" and 34110 "66 Squadron". The completion of 34110 was delayed due to proposals for a major modification to a standard two-cylinder design, without the chain-driven valve gear. In the event the loco entered service as Bulleid intended. The result of this delay was that the squadron crest for "66 Squadron" was never made (although there is a drawing of it in "The Book of the West Country/Battle of Britains" (Irwell Press)), as the manufacturer had gone out of business during the intervening period.Burridge, p. 74] Thus "66 Squadron" was the only BB Class member not to have a crest.

Rebuilding

Infobox Locomotive
powertype=Steam
name = BR Rebuilt West Country/Battle of Britain Class


caption = Preserved Rebuilt West Country Class 34027 "Taw Valley" masquerading as 34045 "Ottery St. Mary".
designer = R. G. Jarvis (after Oliver Bulleid)
builder = SR Brighton/Eastleigh Works
builddate = 1955–1961
totalproduction = 60
whytetype = 4-6-2 ("Pacific")
gauge = RailGauge|ussg
leadingsize = 3 ft 1 in (0.94 m)
driversize = 6 ft 2 in (1.89 m)
trailingsize = 3 ft 1 in (0.94 m)
length = 67 ft 4¾ in (20.26 m)
weight = 132 tons 13 cwt (134.7 tonnes)
fueltype = coal
fuelc

waterc

cylindercount = 3
cylindersize = 16.375 in × 24 in (41.6 cm × 61 cm)
firearea = 38.25 ft² (3.44 m²)
boilerpressure = 250 lbf/in²
tractiveeffort = 27,720 lbf (123.304 kN)
railroad=Southern Region of British Railways
locale=Great Britain
railroadclass=7P/5FA|

Between 1957 and 1961, British Railways rebuilt sixty of the class to a more conventional design, adopting many features from the BR 'Standard' locomotive classes that had been introduced. [Creer & Morrison, pp. 84–87] The streamlined casing was removed and replaced with conventional boiler cladding, and the chain-driven valve gear was replaced with modified Walschaerts valve gear. The rebuilt versions were similar to the rebuilt Merchant Navy Class design of R. G. Jarvis.Derry, p. 70 ] As a result of the rebuilding and the implementation of Walschaerts valve gear, the rebuilt examples were slightly heavier, and were prone to hammerblow on the track, a complaint that was not evident with the original design. The increased weight reduced their route availability rating, and rebuilt examples could not be used on certain routes previously available to un-rebuilt examples, such as the Ilfracombe Branch.Arlett, p. 32] The onset of the during the early 1960s meant that the remaining fifty locomotives were not rebuilt, and continued in as-built condition until eventual withdrawal from service. [ Southern E-Group (2004) [http://www.semgonline.com/steam/blp03.html Discontinuation of rebuilding programme] , retrieved April 13, 2007] Many rebuilt locomotives were scrapped relatively soon after their rebuilding, an indication of the waste in resources made by British Railways, as some engines had only existed in this form for as little as three years, as in the case of 34109 "Sir Trafford Leigh-Mallory".

Operational details

The utilisation of welded steel construction and several innovations that had not previously been seen in British locomotive design meant that the classes followed the Merchant Navys in earning Bulleid the title 'Last Giant of Steam'. Day-Lewis, p. 7] The constant concern for ease of maintenance and utility had not previously been seen on locomotives of older design, whilst their highly efficient boilers represented the ultimate in British steam technology, the hallmark of a successful locomotive design. Because of their utilitarian appearance, enhanced by the flat, boxy "air-smoothed" casing, the class soon gained the nickname of their larger siblings, "Spam Cans", due to the resemblance to the distinctive tin cans that "SPAM" was sold in.

Originally, the West Country Class locomotives were intended to work the lines around South West England in Devon, Dorset and parts of Somerset, whilst the Battle of Britain Class were to work the lines of Kent, Hampshire, Sussex and Surrey. In practice, this did not occur and both classes were to be found all over the network."Bulleids in Retrospect"] However, they were not without their problems, as so many innovations in one design meant that there was more to go awry. The light loading on their driving axles meant that they were often prone to wheelslip, requiring very careful control when starting a heavy train, but once underway they were noted for their free running, excellent steam production and rapid turn of speed.

A perennial problem with the un-rebuilt "Light Pacifics" lay with the leaks from the oil bath onto the wheels, which in turn splashed oil onto the boiler lagging. Once saturated with oil, the lagging attracted coal dust and ash which provided combustible material, and as a result of the heavy braking of the locomotives, sparks would set the lagging on fire underneath the air-smoothed casing.Whitehouse & Thomas, p. 47] When the local fire brigade was called to put the fire out, the cold water used to douse the flames came into contact with the hot boiler; hence both casings and boiler plating suffered thermal shock and stress. Many photographs show an un-rebuilt "Light Pacific" with "cockled" (or warped) casings resulting from a fire in the lagging.

Another problem was experienced with the soft exhaust, which beat down onto the air-smoothed casing when the engine was on the move, obscuring the driver's vision from the footplate. [Creer & Morrison, p. 69] There was much experimentation in order to resolve this problem, with varying degrees of success, and photographic evidence shows the many guises of this project. [Creer & Morrison, pp. 72–73] The problem was never fully resolved, though the rebuilts were provided with British Railways-style smoke deflectors; the lack of casings on the rebuilds also helped reduce the problem. [Creer & Morrison, pp. 94–95]

An unusual but frequent sight on the "Withered Arm" (the Southern Region's railways west of Exeter) was of a "Light Pacific" hauling a local stopping service with a single carriage to destinations as diverse as Padstow and Wadebridge. This highlighted the fact that more of these "Pacifics" were built than were actually needed, and so could be reduced to undertaking tasks that would usually befit a much smaller locomotive. One highly recorded event occurred on 30 January 1965, when the un-rebuilt No.34051 "Winston Churchill" hauled the funeral train of its namesake from London's Waterloo station to his final resting place, close to Blenheim Palace in Oxfordshire. [ Southern E-Group (2004) [http://www.semgonline.com/steam/mn_00.html 34051 preparing for Churchill's funeral train] , retrieved April 13, 2007]

Livery and numbering

outhern Railway

Livery was Southern Railway Malachite green with "Sunshine Yellow" horizontal lining. A circular cast brass plate with a red background was mounted on the smokebox door featuring the word "Southern" and the date of manufacture.Harvey, p. 93] Bulleid advocated a continental style of numbering, basing this upon his experiences at the French branch of Westinghouse Electric before the First World War, and his tenure in the rail operating department during that conflict. The Southern Railway number adapted the UIC classification system where "2" and "1" refer to the number of un-powered leading and trailing axles respectively, and "C" refers to the number of driving axles – in this case three.Burridge, p. 60] However, since "21C" was the prefix already used by the Merchant Navy class, the suffix "1" was added; all these locomotives therefore carried numbers which started "21C1" followed by the individual two-digit identifier.

Post-1948 (nationalisation)

Initial livery after Nationalisation in 1948 was modified to British Railways Malachite Green and Sunshine Yellow lining and lettering, with British Railways on the tender. The Bulleid numbering system was temporarily retained with the addition of an "s" prefix (e.g. s21C101). The classes were given the power classification 7P 5FA, the "A" standing for route availability.Ian Allan Abc 1958–59 "WC/BB"] The locomotives after their first overhaul under new ownership were turned out in British Railways Brunswick Green livery with orange and black lining, with the British Railways crest on the tender tank side. This was unlike the Merchant Navy Class, which was initially turned out in British Railways Experimental Express Passenger Blue livery. By this stage, the Southern Railway-built locomotives were renumbered and re-liveried under standard British Railways procedure within the 34xxx series, from 34001–34070. The rebuilt locomotives were also painted in British Railways Brunswick Green with orange and black lining, and crest on the tender side, whilst the nameplates were placed on a custom-made mounting on the running plate due to the absence of a flat surface.

Preservation

Twenty of these locomotives escaped scrapping, and all still exist in varying states of preservation. However, it is not certain that all of them will eventually be restored due to the very poor condition some of them were in when purchased by various preservation societies. Exactly half of those preserved are in original condition, whilst the other ten are rebuilds. Had it not been for Woodham's Scrapyard in South Wales, no rebuilt "Light Pacifics" would have been preserved. Other relics of both classes have survived in the guise of locomotive nameplates, which were taken from their locomotives towards the end of steam on the British Railways Southern Region in the 1960s. As a result, many exist in private collections, and several have been seen at auction, selling for several thousands of pounds. "The Railway Magazine" (May, 2007), p. 85]

Preserved "Light Pacifics"

:"For location details and current status of the preserved locomotives, see: List of SR West Country and Battle of Britain Class locomotives. Preserved locomotives are un-rebuilt, except where stated otherwise:"

;West Country Class

*34007 "Wadebridge"
*34010 "Sidmouth" - Rebuilt
*34016 "Bodmin" - Rebuilt
*21C123 (34023) "Blackmoor Vale"
*34027 "Taw Valley" - Rebuilt
*34028 "Eddystone" - Rebuilt
*34039 "Boscastle" - Rebuilt
*34046 "Braunton" - Rebuilt
*34092 "City of Wells"
*34101 "Hartland" - Rebuilt
*34105 "Swanage"

;Battle of Britain Class

*34051 "Winston Churchill"
*34053 "Sir Keith Park" - Rebuilt
*34058 "Sir Frederick Pile" - Rebuilt
*34059 "Sir Archibald Sinclair" - Rebuilt
*34067 "Tangmere"
*34070 "Manston"
*34072 "257 Squadron"
*34073 "249 Squadron"
*34081 "92 Squadron"

Footnotes

Bibliography

*Arlett, Mike: "The Train Now Departing: Personal memories of the last days of steam" (London: BBC Books, 1989) ISBN 0563206969

*"Bulleids in Retrospect", Transport Video Publishing, Wheathampstead, Hertfordshire

*Burridge, Frank: "Nameplates of the Big Four" (Oxford Publishing Company: Oxford, 1975) ISBN 0902888439

*Creer, S. & Morrison, B.: "The Power of the Bulleid Pacifics" (Oxford Publishing Company: Oxford, 2001) ISBN 0860930823

*Derry, Richard: "The Book of the West Country and Battle of Britain Pacifics" (Irwell Press, 2004) ISBN 1903266238

*Fairclough, T. & Wills, A.: "Southern Steam Locomotive Survey: Bulleid Light Pacifics" (Kings Langley: Enterprise Transport Books Ltd., 1970) ISBN 0851532721

*Harvey, R. J.: "Bulleid 4-6-2 Merchant Navy Class" (Locomotives in Detail series volume 1) (Hinckley: Ian Allan Publishing, 2004), ISBN 0711030138

*Herring, Peter: "Classic British Steam Locomotives" (Abbeydale Press: London, 2000) Section "WC/BB Class" ISBN 1861470576

*"Ian Allan ABC of British Railways Locomotives", winter 1958–59 edition

*"The Railway Magazine" (May, 2007), p. 85
*Whitehouse, Patrick & Thomas, David St.John: "SR 150: A Century and a Half of the Southern Railway" (Newton Abbot: David and Charles, 2002)

Further reading

* Bulleid, H. A. V.: "Bulleid of the Southern" (Hinckley: Ian Allan Publishing, 1977) ISBN 071100689X

* Day-Lewis, S.: "Bulleid, Last Giant of Steam" (1964)

*"Ian Allan ABC of British Railways Locomotives", winter 1955–56 edition

ee also

* List of SR West Country and Battle of Britain Class locomotives

External links

* [http://www.semgonline.com/steam/blp01.html Southern E-group (1)] – "un-rebuilt 'Light Pacifics' "
* [http://www.semgonline.com/steam/blp51.html Southern E-group (2)] – "rebuilt 'Light Pacifics' "
* [http://www.watercressline.co.uk/tw/pics/wc-valve.jpgDiagram showing arrangement of the chain-driven valve gear]
* [http://www.locos-in-profile.co.uk/Bulleid_Society/master_frames/master_ovsb.html Bulleid Society: WC/BB locomotive summary] – "Table showing key dates, mileages, running numbers, etc for all class members"