SR Lord Nelson class

Infobox Locomotive
powertype=Steam
name = SR Lord Nelson class Herring, pp. 110-111]

---

caption = No. 850 "Lord Nelson" as preserved
designer = Richard Maunsell
builder = SR Eastleigh Works
builddate = 1926–1929
totalproduction = 16
whytetype = 4-6-0
gauge = RailGauge|ussg
leadingsize = 3 ft 1 in (0.94 m)
driversize = 6 ft 7 in (2.01 m)
length = 69 ft 9¾ in (21.27 m)
weight = 142 tons 6 cwt (144.5 tonnes)
fueltype = coal
fuelc

waterc

cylindercount = 4
cylindersize = 16½ in × 26 in (41.9 cm × 66 cm)
firearea = 33 ft² (3.07 m²)
boilerpressure = 220 lbf/in² (1,500 kPa)
tractiveeffort = 33,500 lbf (149 kN)
railroad = Southern Railway (Great Britain), Southern Region of British Railways
locale=Great Britain
railroadclass=7P|

The SR class LN or "Lord Nelson" class is a class of 4-6-0 steam locomotive designed for the Southern Railway by Richard Maunsell. They were intended for express passenger work to the South-West of England. Sixteen of them were constructed, representing the ultimate in Southern 4-6-0 design. They followed Southern Railway practice of naming their express passenger types, in this case after famous admirals.

The class continued to operate with British Railways until withdrawn in 1961/62. Only one example of the class – the first engine, "Lord Nelson" itself – has been saved from scrapping. "Lord Nelson" can be seen running on mainline tours and preserved railways throughout Britain.

Background

The requirement to secure a more modern and powerful replacement for the N15 Class led to Maunsell considering a larger 4-6-0 design with a larger boiler and firebox. Swift, p. 9 ] The new design was intended for heavy express passenger work between London and South-West England. Sixteen locomotives were constructed and they proved to be the ultimate in 4-6-0 steam locomotive design on the Southern Railway.

Construction history

Production began in 1926 at Eastleigh when the prototype, "Lord Nelson", was constructed. The locomotives were nominally an improvement on Robert Urie's N15 "King Arthur" class, able to pull heavier loads at sustained speeds of convert|55|mph|abbr=on. Maunsell developed the prototype over two years, with production beginning in 1928, and ending in 1929 with the 16th class member. The heavy loads envisaged for this class failed to materialise, with subsequent economic consideration ending the production run.Haresnape, section: "Lord Nelson class"]

An unusual feature of the "Lord Nelson" class of locomotives was the setting of the crank axles at 135°, rather than the standard 90° of other locomotive types. This gave eight beats per revolution, rather than the usual four of other locomotives, a feature which was designed to give a more even draw on the fire.

Due to the long distance running expected of the class, locomotives working on the Western section of the Southern Railway were provided with a modified "watercart" design of bogied tender with high coal and water capacity. Locomotives allocated to the Eastern section were provided with smaller, six-wheeled tenders. Other features were in common with the "King Arthur" class, the boiler being the same length, as well as the use of a Belpaire firebox.

Modifications

The "Lord Nelson" class locomotives gained a reputation for being poor steamers, prompting Oliver Bulleid, Maunsell's replacement as CME of the Southern, to modify the class in 1938. The modifications consisted of larger diameter chimneys and Lemaître multiple jet blastpipes, which effectively transformed their performance.

Naming the locomotives

The locomotives were named after famous Royal Navy admirals, with the doyen of the class being named "Lord Nelson". As a result the rest of the locomotives belonged to the "Lord Nelson" (LN) class.Burridge, pp. 54-55]

Operational details

For a period after its introduction to the Southern Railway network, the "Lord Nelson" class held the title of "most powerful locomotive in Britain" – a claim based on its tractive effort. The advanced design of the locomotive led to the GWR introducing the GWR 6000 Class in order to regain the title lost by their GWR Castle class locomotives when the "Lord Nelsons" were constructed. One member of the "Lord Nelson" class was involved in what could have been a major accident on 23 January 1930. This entailed the leading driving wheels jumping off the track, though the locomotive ran for many yards before they re-railed themselves over a point.Anderson, E.P.: "Report on the partial derailment of the engine of an express passenger train that occurred on the 23 January, near Kent House", Introduction]

The "Lord Nelsons" were notoriously difficult for inexperienced crews to fire properly, due to their long firebox.Swift, pp. 9-10] To circumvent such problems, specific crews who had proven experience in firing the locomotives were allocated.Sawford, p. 30] The cause of this problem was that there were relatively few locomotives in the class for crews to train on. They were, however, highly respected, and were a good deputy for the Bulleid pacifics, which later superseded them on top link expresses.Whitehouse, & Thomas, p. 47] The LMS "Royal Scot" Class was loosely based on this design. [ Southern E-Group (2004) [http://www.semgonline.com/steam/lnclass_1.html] , Retrieved 3 May 2007. For information on influence.]

The "Lord Nelson" class locomotives frequently deputised for stricken Bulleid "Pacific"s throughout the 1950s.Townroe, section: "Lord Nelson class"] They remained in the top link until the rebuilding and subsequent increased reliability of the "Pacific"s rendered the "Lord Nelson" class superfluous to operational requirements, when they were gradually phased out of service. Swift, p. 59 ] All "Lord Nelson" class locomotives had been withdrawn by 1962.

Livery and numbering

Southern Railway

Livery was Southern Railway malachite green with sunshine yellow lining on the boiler rings. During the war years the locomotives were outshopped in wartime black livery, though retained the word "Southern" in yellow on the tender. Swift, p. 40 ]

Numbers allocated to the locomotives were a variation of LSWR practice, and being constructed at Eastleigh were given the prefix "E" before the number to distinguish from the locomotives of other pre-grouping railway companies that also carried the same number. Swift, p. 39 ] In the case of the "Lord Nelson" class the numbering ranged from E850 to E865. This was eventually superseded by numbers without the "E" prefix, becoming 850 to 865 from 1931. [ Maunsell Society Newsletter (1980) [http://www.maunsell.ndo.co.uk/newsletter/archive/newsletter5.htm] Retrieved 16 May, 2007. For information on the "E" numbering system.]

Post-1948 (nationalisation)

The initial livery applied following the nationalisation of the railways in 1948 was modified Southern malachite green and sunshine yellow with "British Railways" on the tender, and the Southern numbering system was temporarily retained with an "S" prefix (such as S850) until superseded by the British Railways numbering system.Scott-Morgan, p. 44] The locomotives then carried British Railways Brunswick green livery with orange and black lining.Scott-Morgan, p. 43] By this stage the locomotives were renumbered under standard British Railways procedure, from 30850 to 30865."Ian Allan ABC", 1958–59]

Preservation

:"For location details and current status of the preserved locomotive, see: List of Lord Nelson Class Locomotives"The only survivor, the class doyen (30)850 "Lord Nelson", has been preserved as part of the National Collection, and is now running on the national network.

See also

*List of Lord Nelson class Locomotives

Footnotes

Bibliography

*Anderson, E.P.: "Report on the partial derailment of the engine of an express passenger train that occurred on the 23rd January, near Kent House"; "Ministry of Transport: Railway accidents ... which occurred during the three months ending 31st March, 1930" (London: HMSO, 1930)
*Burridge, Frank: "Nameplates of the Big Four" (Oxford Publishing Company: Oxford, 1975) ISBN 0902888439
*Haresnape, Brian: "Maunsell Locomotives - a pictorial history" (Ian Allan Ltd, 1977)
*Herring, Peter: "Classic British Steam Locomotives" (Abbeydale Press: London, 2000) ISBN 1861470576
*"Ian Allan ABC of British Railways Locomotives", Winter 1958–59 edition
*Sawford, Eric: Southern Steam in Retrospect (Alan Sutton: Stroud, 2007) ISBN 9780750946279
*Scott-Morgan, John: "Maunsell Locomotives" (Ian Allan Publishing: Hinckley, 2002), ISBN 0711028729
*Swift, Peter: "Maunsell 4-6-0 Lord Nelson Class (Locomotives in Detail series volume 8)" (Hinckley: Ian Allan Publishing, 2007), ISBN 0711032475
*Townroe, S.C.: "'Arthurs', 'Nelsons' & 'Schools' at work" (London: Ian Allan, 1973)
*Whitehouse, Patrick & Thomas, David St.John: SR 150: A Century and a Half of the Southern Railway (Newton Abbot: David and Charles, 2002) ISBN 0715391488

External links

* [http://www.semgonline.com/steam/lnclass_1.html SEMG page]