LSWR S11 class

The problem of uniting both power and traction in a compact express passenger locomotive design had taxed the Locomotive Superintendents of the LSWR for many years.Burtt (1949).{{page needed|date=October 2016}} Joseph Beattie was the first to establish the LSWR's policy of using smaller wheeled locomotives to handle these steep gradients.{{page needed|date=October 2016}}

Dugald Drummond attempted to grasp the nettle by utilising his new T9 class over the arduous route. It soon became clear that despite the merits of the T9s for fast running on the various express passenger services to the west of England, the large wheels of the class were not suited for the task in hand. A new design of locomotive was needed that incorporated the desired improvements to enable fast running on gradients.{{page needed|date=October 2016}}

Drummond decided to construct a new class of ten 4-4-0s specifically for this part of the LSWR network. The class incorporated the same frames as the T9 but with smaller {{convert|6|ft|1|in|m|3}} driving wheels and balanced crank axles.Morrison & Whitely (1989).{{page needed|date=October 2016}} The boiler was also {{convert|5|ft|m|2}} in diameter, also different from the T9s, and capped with a dome and stovepipe chimney. Production began at Nine Elms in 1903 and all ten were finished by the end of the year.{{page needed|date=October 2016}} All examples were fitted with Drummond's "watercart" eight-wheel tender for longer nonstop running.

The class was fitted with cross-water tubes in the firebox as on the T9 class, although feedwater tubes were not fitted.Herring (2000). Section "T9 Class". This was done to increase the water's heating surface, which although successful made the boiler more complex. The class was superheated between 1920 and 1922 by Drumond's successor Robert Urie.Swift, Peter H. (2006). Railway Archives 13: pp. 40–53

Under the LSWR, the class was outshopped in the LSWR Passenger Sage Green livery with purple-brown edging, creating panels of green.{{page needed|date=October 2016}} This was further lined in white and black with 'LSWR' in gilt on the tender tank sides.

When transferred to Southern Railway ownership after 1923, the locomotives were outshopped in Richard Maunsell's darker version of the LSWR livery.Swift, Peter (2006). Maunsell 4-6-0 King Arthur Class.{{page needed|date=October 2016}} The LSWR standard gilt lettering was changed to yellow with 'Southern' on the water tank sides. The locomotives also featured black and white lining.Haresnape & Rowledge (1982).{{page needed|date=October 2016}}

However, despite Bulleid's experimentation with Malachite Green livery on express passenger locomotive, the Maunsell livery was continued with the S11s, though the 'Southern' lettering on the tender was changed to the 'Sunshine Yellow' style. During the Second World War, members of the class outshopped form overhaul were turned out in wartime black, and some of the class retained this livery to Nationalisation.{{page needed|date=October 2016}}

Livery after Nationalisation was initially Southern Wartime Black livery with 'British Railways' on the tender, and an 'S' prefix on the number, until superseded by the Standard BR 30xxx series.

The S11s were well regarded on expresses around the ports served by the LSWR.{{page needed|date=October 2016}} The class was initially used in the West Country to handle the steep gradients they were designed for. However, it was found that their smaller wheels and larger boilers were not as successful as was hoped. The class was slower and more cumbersome then the T9s, leading to crews preferring the latter's higher speed both on downhill and level stretches of railway.{{page needed|date=October 2016}}

Another issue with the class was the fact that they consumed more water with their larger boilers, which was a major issue for a railway with no water troughs to refill while running, and therefore skilled use of the injectors was required.{{page needed|date=October 2016}} The boiler was mounted higher above the frames which led to ride instability at high speeds{{page needed|date=October 2016}} and required more care by crewmen in approaching junctions and speed restrictions. 9 members of the class were withdrawn in 1951, with the last member scrapped in 1954.

{{reflist|2}}

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• {{cite book |last=Bradley |first=D. L. |year=1986 |title=LSWR Locomotives: The Drummond Classes |location=Didcot, Oxon |publisher=Wild Swan Publications |isbn=0-906867-42-8}}
• {{cite book |last=Burtt |first=F. |year=1949 |title=L. & S.W.R. Locomotives: 1872–1923 |location=London |publisher=Ian Allan}}
• {{cite book |last1=Haresnape |first1=B. |last2=Rowledge |first2=P. |name-list-style=amp |year=1982 |title=Drummond Locomotives: A Pictorial History |location=Hinckley |publisher=Ian Allan Publishing |isbn=0-7110-1206-7}}
• {{cite book |last=Herring |first=Peter |year=2000 |title=Classic British Steam Locomotives |location=London |publisher=Abbeydale Press |isbn=1-86147-057-6}}
• {{cite book |last1=Morrison |first1=G. W. |last2=Whitely |first2=J. S. |name-list-style=amp |year=1989 |title=The Big Four Remembered |location=Sparkford |publisher=Haynes Publishing Group |isbn=1-85648-179-4}}
• {{cite journal |last=Swift |first=Peter H. |title=The Drummond 'S11' Class 4-4-0s of the London & South Western Railway |journal=Railway Archives |year=2006 |volume=13 |pages=40–53}}
• {{cite book |last=Swift |first=Peter |year=2006 |title=Maunsell 4-6-0 King Arthur Class |series=Locomotives in Detail, volume 4 |location=Hinckley |publisher=Ian Allan Publishing |isbn=0-7110-3086-3}}

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{{LSWR Locomotives}}

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Category:4-4-0 locomotives

Category:2′B n2 locomotives

S11

Category:Railway locomotives introduced in 1903

Category:Scrapped locomotives

Category:Standard-gauge steam locomotives of Great Britain

Category:Passenger locomotives in the United Kingdom