View source for SR Leader class

{{Short description|Prototype dual cab steam locomotive}}
{{Use dmy dates|date=November 2016}}
{{Use British English|date=November 2016}}
{{Infobox locomotive
| powertype = Steam
| name = SR/BR Leader class<ref name=Bulleid>{{Harvtxt|Bulleid|1977|p=143}}</ref>
| alt = A side-and-front view of an 0-6-0+0-6-0 tank steam locomotive travelling towards the cameraman. The locomotive is a cuboid that contains boiler, fuel and cabs. The cuboid sits on two 0-6-0 bogies. It is hauling a train of around seven carriages past a signal box in the background.
| image = Leader-05.jpg
| caption = Leader locomotive 36001 with test train at Oxted
| designer = [[Oliver Bulleid]]
| builder = SR Brighton Works
| builddate = 1946&ndash;1949
| totalproduction = 5 (only one completed)
| whytetype = {{whyte|0-6-0+0-6-0|T}}
| uicclass = C′C′ h6t
| gauge = {{Track gauge|ussg|allk=on}}
| driverdiameter = {{convert|5|ft|1|in|m|3|abbr=on}}
| length = {{convert|67|ft|m|2|abbr=on}}
| locoweight = {{convert|150|LT|ST t|0|abbr=off}}
| fueltype = [[Coal]]
| fuelcap = {{convert|4|LT|ST t|abbr=off|lk=on}}
| watercap = {{convert|4000|impgal|abbr=on}}
| cylindercount = Six (Three in each bogie)
| cylindersize = {{convert|12+1/4|x|15|in|mm|0|abbr=on}}
| valvegear = [[Bulleid chain driven valve gear]]
| firearea = {{convert|25.5|sqft|m2|abbr=on}}
| boilerpressure = {{convert|280|lbf/in2|MPa|2|abbr=on}}
| tractiveeffort = {{convert|26300|lbf|kN|2|abbr=on}}
| operator = {{ubl|[[Southern Railway (UK)|Southern Railway]]|→ [[British Railways]]}}
| operatorclass = SR / BR: Leader
| powerclass = SR / BR: Unknown
| nicknames = The Chinese Laundry
| locale = [[Southern Region of British Railways|Southern Region]]
| withdrawndate = 1951
| disposition = All [[scrap]]ped
}}
The '''Leader''' was a class of experimental {{whyte|0-6-0+0-6-0|T}} steam locomotive, produced in the [[United Kingdom]] to the design of the innovative engineer [[Oliver Bulleid]]. The Leader was an attempt to extend the life of steam traction by eliminating many of the operational drawbacks associated with existing steam locomotives. It was intended as a replacement for the ageing fleet of [[LSWR M7 class|M7 class]] tank engines still in operation on the [[Southern Railway (UK)|Southern Railway]] (SR).<ref name= Bulleid1/> Design work began in 1946 and development continued after the nationalisation of the railways in 1948, under the auspices of [[British Railways]] (BR).

The Leader project was part of Bulleid's desire to modernise the steam locomotive based on experience gained with the Southern Railway's fleet of electric stock.<ref name=Bulleid1>{{Harvtxt|Bulleid|1977|p=135}}</ref> Bulleid considered that attitudes towards the labour-intensity of steam operation had changed during the post-war period, favouring [[Diesel locomotive|dieselisation]] and [[Electric locomotive|electrification]]. In an effort to demonstrate the continued potential of steam, Bulleid pushed forward the boundaries of steam-power, hoping it could compete with diesel and electric locomotives in terms of labour-saving and ease of operation.<ref name=Day-Lewis/>

The design incorporated many novel features, such as the use of [[thermic siphon]]s, [[bogies]] and cabs at either end of the locomotive, resulting in its unique—for a steam locomotive—modern diesel-like appearance. Several of its innovations proved to be unsuccessful however, partly accounting for the project's cancellation in the early 1950s. Five Leader locomotives were started, although only one was completed. The operational locomotive was trialled on the former Southern Railway network around [[Brighton]]. Problems with the design, indifferent reports on performance and political pressure surrounding spiralling development costs, led to all locomotives of the class being scrapped by 1951.

==Background==

The basis of the Leader originated from a 1944 review of the Southern Railway's steam locomotive fleet, resulting in a Southern Railway design brief which called for a high-powered locomotive requiring little maintenance to replace the ageing fleet of M7 class tank engines.<ref name= Bulleid1/> The brief also stipulated that the locomotive would be used on both passenger and freight trains, requiring high route availability. Bulleid proposed an initial design based on his [[SR Q1 class]] locomotive, which had proved easy to maintain in service.<ref name=Day-Lewis>Day-Lewis (1964), ''The Leader locomotive''</ref> As the proposal progressed, Bulleid saw that certain tasks required with conventional steam locomotives could be eliminated by adopting some of the features of the contemporary Southern [[electric locomotives]].<ref name=Bulleid1/> However, one of the subsequent designs of a [[0-4-4-0]] wheel arrangement had an unacceptably high axle-loading of {{convert|20|LT|t ST|1|abbr=off}}, which increased the risk of damaging the Southern Railway's track.<ref name=Bulleid2>{{Harvtxt|Bulleid|1977|p=129}}</ref> By developing the proposal further, Bulleid settled for a {{whyte|0-6-0+0-6-0|T}} design of bogie locomotive, which spread the weight more evenly over the rails and reduced the axle-loading.<ref name=Bulleid3>{{Harvtxt|Bulleid|1977|p=136}}</ref>

==Design==
[[File:Bulleid Leader.jpg|thumb|alt=A line diagram of an 0-6-0+0-6-0 tank steam locomotive showing side and front profiles. It includes principal dimensions and weights.|left|350px|Works diagram of the Leader]]
A series of initial ideas were presented to the Southern Railway management by Bulleid that incorporated double-ended running, giving the locomotive driver maximum visibility in either direction without a [[boiler]] or [[Tender (rail)|tender]] obscuring his view. The need for a [[Turntable (railroad)|turntable]] to turn the locomotive was therefore eliminated, although the initial designs were rejected by the operating department because of problems with welding technique.<ref name=Haresnape>{{Harvtxt|Haresnape|1979}} Section 4</ref> The accepted design included two [[0-6-0]] steam [[bogies]] with weight-saving [[sleeve valve]]s and chains to couple the driving axles. The boiler was offset to provide space for a communication corridor, allowing the driver to access both cabs without leaving the locomotive, an arrangement which led to later problems.<ref name=Robertson1>{{Harvtxt|Robertson|2007|p=116}}</ref> The firebox, near the centre of the locomotive, was fed by the fireman from a third cab, linked to both driving cabs by the communication corridor.<ref name=Harris>{{Harvtxt|Harris|1994|p=115}}</ref> The entire ensemble was placed on a common frame and thus often referred to as an {{whyte|0-6-6-0|T}}, even though the actual notation is {{whyte|0-6-0+0-6-0|T}} since both engine units pivoted as on a [[Garratt locomotive|Garratt]], [[Fairlie locomotive#Double Fairlie locomotive|Double Fairlie]] or [[Meyer locomotive]].<ref name=Robertson2>{{Harvtxt|Robertson|2007|p=42}}</ref><ref name="SAR&H Aug 1943">Espitalier, T.J.; Day, W.A.J. (1943). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter II - The Adoption of the 3 ft. 6 in. Gauge on the Cape Government Railways'' (Continued). South African Railways and Harbours Magazine, August 1943. p. 592.</ref><ref name="Holland 1">{{Holland-Vol 1|page=25}}</ref><ref name="Dulez 150">{{Dulez 150|page=21}}</ref>

The Leader prototype was constructed at [[Brighton railway works]], work beginning in 1946.<ref name=Haresnape/> An initial order for five locomotives was placed straight from the drawing board in 1946 and a further 31 were ordered in 1947, although, with nationalisation looming, this was merely a gesture.<ref name=Robertson3>{{Harvtxt|Robertson|2007|p=46}}</ref> The latter order was cancelled after the Southern Railway was taken into public ownership, to allow trials to be carried out on the prototype.<ref name=Robertson3/>

===Bogie and cylinder design===
Each of the two [[bogies]] had three cylinders, with the driving wheels connected by chains enclosed in an oil-bath, based upon Bulleid's [[Bulleid chain-driven valve gear|chain-driven valve gear]] on his Pacific locomotives.<ref name=Tuplin>{{Harvtxt|Tuplin|1965|p=413}}</ref> The [[valve gear]] used the unusual [[sleeve valve]] arrangement that was also tested on the ex-[[LB&SCR H1 class]] ''Hartland Point'' in parallel with the construction of the first Leader locomotive.<ref name=Tuplin/> The Leader was the first steam locomotive to use a form of sleeve valve since [[Cecil Paget]]'s [[Midland Railway Paget locomotive|locomotive of 1908]] and the concurrent testing of the principle on ''Hartland Point'' hints at the rushed nature of the locomotive's conception.<ref name=Robertson4>{{Harvtxt|Robertson|2007|p=47}}</ref> The locomotive sat on the unusual [[Bulleid Firth Brown wheel]]s, which were lighter, yet stronger, than the spoked equivalent.

The use of sleeve valves and oil baths to lubricate the moving parts of the engine units was inspired by contemporary [[internal combustion engine]] practice.<ref name=Haresnape/> This included oscillating gear that gave a 25-degree axial movement to the sleeves, allowing even lubrication of the moving parts.<ref name=Tuplin1>{{Harvtxt|Tuplin|1965|p=414}}</ref> However, this resulted in an over-complicated mechanism that was difficult to maintain, perpetuating the seizures it was meant to eradicate. This feature was removed from both bogies of the prototype as the trials progressed.<ref name=Robertson5>{{Harvtxt|Robertson|2007|p=77}}</ref> Another innovative feature of the steam bogie assembly was the ability to interchange them when faults occurred, an easy operation for maintenance staff when compared to the complexities of overhauling a regular steam locomotive's motion.<ref name=Bulleid2/>

The three cylinders of each bogie were cast in mono-block format, each surrounded by two annular inlet steam chests and a single large outlet steam chest.<ref name=Tuplin1/> These had the added function of keeping the cylinder heated by hot steam to maintain the temperature and pressure of steam entering the cylinders. However, these castings were difficult to machine accurately.<ref name=Tuplin1/> The steam-sealing arrangements needed for this system were also complex, with each of the six cylinders and valve sleeves requiring 24 sealing rings.<ref name=Robertson4/>

===Boiler, firebox, smokebox and casing design===
[[File:Leader boiler under construction.jpg|thumb|alt=A picture of a steam locomotive boiler under construction. The firebox is a cube with curved top and is in pieces ready for welding. Various components are scattered about the floor of a boilershop at a locomotive works site.|right|250px|The Leader boiler and firebox, showing the offset firehole door position (dotted). Also visible are two of the four thermic siphons.]]
The boiler was the culmination of lessons learned with the Pacifics and was a prolific steam-raiser. All Leader boilers were constructed at [[Eastleigh]], and proved to be the least problematic area of the entire design.<ref name=Tuplin/> The boiler pressure was set at {{convert|280|psi|kPa|abbr=on}} and each was fitted with four [[thermic siphon]]s within the [[firebox (steam engine)|firebox]], both to increase the rate of evaporation and improve water circulation.<ref name=Robertson6 /> These had been used previously to great effect on Bulleid's [[SR Merchant Navy class|Merchant Navy]] and [[SR West Country and Battle of Britain classes|West Country and Battle of Britain class]] designs.<ref name=Robertson6>{{Harvtxt|Robertson|2007|p=25}}</ref>

The Leader had a "dry lining" firebox. It was not surrounded on top and sides by a "jacket" of water as in normal practice,<ref name=Harris1>{{Harvtxt|Harris|1994|p=116}}</ref> but was constructed of welded steel and used firebricks instead of water for insulation, a novel but troublesome solution.<ref name=Haresnape/> Using firebricks reduced the grate area from {{convert|47|ft2|m2}} to {{convert|25.5|ft2|m2}} and concentrated the fire in a smaller area.<ref name=Harris1/> The firehole door was offset to the left of the boiler backhead, which created difficulties for the fireman when adding coal to the fire.<ref name=Bulleid4>{{Harvtxt|Bulleid|1977|p=145}}</ref> The firebox was not initially equipped with a firebrick arch, although one was retro-fitted during the summer of 1950.<ref name=Harris2>{{Harvtxt|Harris|1994|p=117}}</ref> The arch was problematic because it led to a tendency for flames to enter the cab at high outputs, a situation made worse by the narrowing of the firebox area.<ref name=Harris2/>

The [[smokebox]] had an inherent problem in maintaining a constant [[vacuum]]. This was a result of another Bulleid labour-saving innovation, a sliding hatch controlled from the front cab, that enabled ash to be cleaned out via a chute onto the track when the locomotive was on the move.<ref name=Tuplin2>{{Harvtxt|Tuplin|1965|p=415}}</ref> The problem lay with ash gathering around the edges of the slide, allowing air to leak into the smokebox, thereby reducing the overall efficiency of the locomotive.<ref name=Harris1/> The fierce blast from the exhaust also meant that ash and embers were ejected into the atmosphere, creating a potential lineside fire hazard.<ref name=Robertson7>{{Harvtxt|Robertson|2007|p=95}}</ref>

For ease of maintenance, the boiler, firebox and smokebox were encased in steel sheeting, which meant that the engine's shape resembled that of a modern [[diesel locomotive]]. That was a major departure from traditional steam locomotive design, allowing the engine to be cleaned using a carriage-washing plant.<ref name=Bulleid5>{{Harvtxt|Bulleid|1977|p=125}}</ref> The locomotive was designed to carry 4 tons (4.06 tonnes) of coal and {{convert|4000|impgal}} of water, and the coal bunker was covered by a tarpaulin to prevent water ingress into the fireman's cab.<ref name=Bulleid>{{Harvtxt|Bulleid|1977|p=143}}</ref> Entry into the locomotive was by way of ladders leading up to sliding doors, although, due to the bogie design, the climb into the fireman's cab necessitated clambering over the oilbath casing.<ref name=Harris1/>

==Construction==
Construction of the first five Leader locomotives began at the Southern Railway's [[Brighton railway works]] in July 1947.<ref name=Bulleid13>{{Harvtxt|Bulleid|1977|p=140}}</ref> British Railways inherited the Leader project upon nationalisation in 1948, which was far enough advanced to continue constructing the prototype, as Bulleid was still chief mechanical engineer of the newly formed [[Southern Region of British Railways]].<ref name=Bulleid14>{{Harvtxt|Bulleid|1977|p=141}}</ref> Although work on the other four locomotives stalled, the prototype Leader emerged from Brighton as locomotive No. 36001 in June 1949.

The other four members of the initial order made by the Southern Railway, Nos. 36002&ndash;5, were at varying stages of construction by the end of the development period. No. 36002 was almost complete, No. 36003 was without its outer casing, and Nos. 36004&ndash;5 were little more than sets of frames, although most of their major components had been constructed at Eastleigh and Brighton and were stored ready for fitting.<ref name=Haresnape/> With no prospect of further money being allocated by the Railway Executive for their completion, the unfinished locomotives were put into store at various depots around the former Southern Railway network pending a decision on their future.<ref name=Haresnape/>

==Operation==
With a calculated tractive effort of 25,350&nbsp;lb, the Leader was given the [[British Rail locomotive and multiple unit numbering and classification|power classification]] of 5.<ref name=world>{{cite magazine| last = Townroe| first = S. C.|title = More light on the Leader Class| magazine = [[Railway World]]| location = Shepperton| publisher = Ian Allan| publication-date = October 1971| volume = 32| issue = 377| pages = 436–438}}</ref> This was considerably lower than the contemporary [[SR West Country and Battle of Britain classes|WC/BB]] pacifics which were rated as class 7, and this meant that the Leader had to be able to have an axle loading that would allow it to operate over secondary routes and on branch lines where the double-ended design would be of most benefit, something that was not likely with the weight inherent in the design.

On completion, No. 36001 was immediately put into service trials using empty passenger carriage stock in the south-east of England.<ref name=Haresnape/> The official trial records kept at Brighton works reported varying degrees of success and failure on the runs undertaken.<ref name=Cox>{{Harvtxt|Cox|1966|p=18}}</ref> However, the results of the trials as reported to [[British Railways]] headquarters at [[Marylebone]] were "conspicuous by the absence of praise" for the strengths of the Leader, namely the boiler, braking system and total adhesion provided by the two bogies.<ref name=Cox2>{{Harvtxt|Cox|1966|p=19}}</ref> Several theories have been put forward regarding this state of affairs, the most plausible being that the more conservative members of the railway workforce at Brighton and the [[Railway Executive]] felt that the Leader was too revolutionary and were keen to maintain the status quo.<ref name=Robertson8>{{Harvtxt|Robertson|2007|p=151}}</ref>


[[File:Leader at Brighton.jpg|thumb|alt=A picture of a locomotive under construction. The cuboid box containing cabs and boiler is being lowered onto the two bogies by a crane inside a locomotive works. Various components are scattered in the foreground.|right|The Leader being lifted onto its power bogies at Brighton, May 1949. The casing allowed the locomotive to be put through a carriage-washing plant.]]
Following trials that lasted over a year, No. 36001 was shown to have several flaws, including heavy coal and water consumption, mechanical unreliability, untenable working conditions for both fireman and driver, loss of steam through the cylinder rings and uneven weight distribution on the bogies. After renewing the cylinder assembly, it was tested around [[Brighton]] and [[Eastleigh]] using an [[London and North Eastern Railway|LNER]] [[Dynamometer car]], where good running was experienced at high costs in fuel and effort on the part of the fireman. For a period of two weeks the Leader was tested against the performance of a [[SR U class|U class]] locomotive<ref name=world /> which indicated that the brake release was too slow in service for use on tight schedules despite the brake application being noted as the best used on a Bulleid design.<ref name=Bulleid6>{{Harvtxt|Bulleid|1977|p=151}}</ref> These trials were interrupted by breakage of the crank axles, these being replaced by axles from 36002 only for these to break in turn at approximately the same mileage as the originals.<ref name=world />

Throughout No. 36001's trials, the firebrick lining provided a constant problem by continually collapsing into the fire.<ref name=Harris/> The firebricks were then replaced with [[cast iron]] substitutes that melted in the intense heat of the firebox, which were in turn replaced by thicker {{convert|9|in|mm|adj=on}} firebricks.<ref name=Haresnape/> Some of the firemen allotted to the Leader complained about cramped conditions in the centre cab of the locomotive, a situation made worse by flames entering the cab from the firebox at high outputs.<ref name=Robertson7/> It was an enclosed space that was constantly hot and the single fireman's entrance door on the side of the locomotive was left open during travel to promote ventilation.<ref name=Harris/> The door into the fireman's cab also attracted criticism, as it would have been blocked in the event of the locomotive overturning on that side, preventing the fireman's escape, so that members of the railway trade union [[Associated Society of Locomotive Engineers and Firemen|ASLEF]] threatened to stop their crews from operating the Leader.<ref name=Harris1/> Measurements in the fireman's cab showed temperatures could reach {{convert|120|°F|°C|-1}} earning the locomotive the nickname of ''The Chinese Laundry'' due to the heat and humidity.<ref name=world />

During work on the crank axles at Eastleigh Works the opportunity was taken to place the locomotive on the weighbridge which showed that the offset boiler and coal bunker caused the locomotive's centre of gravity to be shifted to one side.<ref name=world /> Experiments had to be undertaken to balance the locomotive by filling the linking corridor with large quantities of scrap metal, replaced in a re-design by a raised floor, covering the weighted material. These modifications resulted in the engine exceeding the total weight limit of 150 tons (151 tonnes), severely limiting the design's route availability during testing.<ref name=Cox3>{{Harvtxt|Cox|1966|p=16}}</ref> A related problem was that despite being a tall locomotive, at {{convert|12|ft|11|in|m}}, the cab ceilings were relatively low. The cab at the smokebox end of the locomotive suffered from the same excessive heat as did the fireman's cab. To circumvent this problem the locomotive was used in reverse, as the rear cab was next to the water tank and coal chute and therefore away from the hot gases circulating inside the smokebox.<ref name=Robertson14>{{Harvtxt|Robertson|2007|p=87}}</ref>

Despite its problems, the locomotive displayed outstanding steaming characteristics and total traction from the two [[power bogie]]s on its trial runs.<ref name=Robertson11>{{Harvtxt|Robertson|2007|p=158}}</ref> When properly fired, the Leader was capable of keeping up with the schedules, even running ahead on occasions. However, operational difficulties were encountered when stopping for water - not only did the locomotive use water at a rapid rate, requiring frequent stops but the all-enclosed casing and the overall height of the locomotive meant that many of the [[water crane|water cranes]] were too low to feed directly into the water tank, thus requiring either an improvised arrangement of scoops and hoses or filling the tank from a standpipe and hose - both options greatly extended the amount of time needed to take on water. These delays tended to lose any time advantages gained when the locomotive performed well and affected the published performance figures.<ref name=Robertson12>{{Harvtxt|Robertson|2007|p=156}}</ref> Despite hauling test trains over the Central Section of the former Southern Railway, the Leader prototype was never used on a revenue-earning service because of the risk of failure of the valve gear and the adverse publicity this would cause for British Railways.<ref name=Robertson13>{{Harvtxt|Robertson|2007|p=150}}</ref>

==Livery and numbering==
===Southern Railway===
When the project was under the auspices of the Southern Railway, No. 36001 would have been numbered CC101.<ref name=Bulleid/> Bulleid advocated a continental style of locomotive nomenclature, based upon his experiences at the French branch of [[Westinghouse Electric]] before the [[First World War]]. The Southern Railway number followed an adaptation of the [[UIC classification]] system where "C" refers to the number of driving axles – in this case three on each bogie.<ref name=Burridge>{{Harvtxt|Burridge|1975|p=60}}</ref> Since the design has six driving axles, the numbering would have been CC101&ndash;CC105 for the initial batch, the final number being the locomotive identifier.

===British Railways===
[[File:Leader1949.jpg|Leader 36001 outside Brighton works in 1949|thumb|right]]
Operational livery was photographic grey with red and white lining.  The British Railways "Cycling Lion" crest was also used, though after the works photograph this was painted over without explanation.<ref name=Haresnape/> Numbering was the British Railways standard system, in the 36001 series.<ref name=Haresnape/> If the class had gone into full production, the locomotives would have been painted in British Railways mixed traffic/freight black livery with red, grey and cream lining. 36001 was initially painted in this livery but this preceded the official works photograph and was subsequently repainted in photographic grey.<ref name=Robertson9>{{Harvtxt|Robertson|2007|p=37}}</ref>

==Operational assessment==

Production of the Leader demonstrated the inherent unsuitability of encasing a steam boiler in an enclosed superstructure. The environment inside was highly unsuitable, the weight was prohibitive, and necessary maintenance such as boiler washouts could only be achieved by a major dismantling of the locomotive.<ref name=world />

Despite the high expectations attached to the Leader, it was not the motive power revolution that Bulleid intended it to be. No part of the Leader design was perpetuated on the [[BR standard classes|British Railways Standard class locomotives]] by [[Robert Riddles]], nor did it find favour internationally, with the [[Garratt locomotive]]s providing a similar function for less maintenance.<ref name=Day-Lewis/> The whole concept was quietly dropped in 1951 after Bulleid left British Railways to become [[Chief Mechanical Engineer]] of [[Córas Iompair Éireann]] (where he produced [[CIÉ No. CC1]], a [[peat]]-burning locomotive to a similar design) and all five were scrapped.<ref name=Day-Lewis/> The culmination of the project was a £178,865 5s 0d (equivalent to £{{formatnum:{{Inflation|UK|178865.25|1950|{{Inflation-year|UK}}|r=0}}}} as of {{Inflation-year|UK}}{{Inflation-fn|UK}}) bill for the taxpayer though, when the press reported the story as late as 1953, it was claimed that £500,000 (equivalent to £{{formatnum:{{Inflation|UK|500000|1950|{{Inflation-year|UK}}|r=0}}}} as of {{Inflation-year|UK}}) was wasted on the project.<ref>''Sunday Dispatch'', 18 January 1953</ref> [[R. G. Jarvis]], who was placed in charge of the project after Bulleid's departure, insisted that the locomotive required an entire re-design to solve the problems of the original concept.

After the problems during the trials in 1950, in November of that year 36001 and the four other Leader locomotives then in various stages of assembly were all cut up for scrap.<ref name=world /> Only the numberplates of No. 36001 and No. 36002 are known to exist.<ref name=Robertson15>{{Harvtxt|Robertson|2007|p=110}}</ref> The numberplate for No. 36001 is in the [[National Railway Museum]]; a locomotive builder's plate intended for the locomotive, but never fitted in service, was auctioned for £1050 in 2008.<ref>
Great Central Railwayana Auctions (2007) [http://www.gcrauctions.com/sale113/all-lots.html Auction Catalogue: Great Central Railwayana, 6 October 2007] {{Webarchive|url=https://web.archive.org/web/20110711081037/http://www.gcrauctions.com/sale113/all-lots.html |date=11 July 2011 }}, Retrieved 17 February 2009. Sold for £1050, see Lot 24.
</ref> The Leader was a bold attempt at pushing back the boundaries of contemporary steam locomotive design and, if successful, might have prolonged the life of steam on British Railways.<ref name=Day-Lewis/>

==References==
;Notes
{{Reflist|colwidth=30em}}

;Bibliography
{{Refbegin}}
*{{cite book|last=Bulleid|first=H.A.V|title=Bulleid of the Southern|year=1977|publisher=Ian Allan Publishing|isbn=0-7110-0689-X }}
* {{cite book |last=Burridge |first=Frank |title=Nameplates of the Big Four |publisher=Oxford Publishing Company |location=Oxford |year=1975 |isbn=0-902888-43-9 }}
* {{cite book |last=Cox |first=E.S. |title=Locomotive Panorama, volume 2 |location=London |publisher=Ian Allan |year=1966 }}
* {{cite book| last=Day-Lewis| first=S.| title=Bulleid, ''Last Giant of Steam''| location=London| publisher=George Allen & Unwin| year=1964}}
* {{cite book |last=Haresnape |first=Brian |title=Bulleid Locomotives: A Pictorial History |location=London |publisher=Ian Allan |year=1979 }}
* {{cite magazine |last=Harris |first=Michael |title=Firing Bulleid's 'Leader' |magazine=Steam Days |issue=66 |year=1994 }}
* {{cite book |last=Robertson |first=Kevin |title=The Leader Project: Fiasco or Triumph? |location=Oxford |publisher=Oxford Publishing Company |year=2007 |isbn=978-0-86093-606-0 }}
* {{cite magazine |last=Tuplin |first=W.A. |title=The ill-fated 'Leader' |magazine=Railway World |volume=26 |year=1965 }}
{{Refend}}

==Further reading==
* {{cite book| title=Ian Allan ABC of British Railways Locomotives| edition=1950}}
* {{cite book| last=Carter| first=Ernest F.| title=Unusual Locomotives| publisher=Frederick Muller Ltd.| year=1960}}
* {{cite book| last=Nock| first=O.S.| title=Southern Steam| location=Newton Abbot| publisher=David and Charles| year=1972}}
* {{cite book| last=Robertson| first=Kevin| title=Leader and Southern Experimental Steam| location=Stroud| publisher=Alan Sutton Publishing| year=1990}}
* {{cite book| last=Tufnell| first=Robert| title=Prototype Locomotives| location=Newton Abbot| publisher=David and Charles| year=1985}}

==External links==
{{Commons category|SR Leader class}}
* [http://www.semgonline.com/steam/leader_01.html "Leader" class locomotive] ''Southern E-Group''

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[[Category:Southern Railway (UK) locomotives|Leader]]
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[[Category:Railway locomotives introduced in 1949]]
[[Category:Scrapped locomotives]]
[[Category:Standard-gauge steam locomotives of Great Britain]]