LSWR N15 class
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 Preserved 30777 Sir Lamiel is part of the National Collection. |
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| Power type | Steam |
|---|---|
| Designer | Robert Urie Richard Maunsell (redesign) Oliver Bulleid (modifications) |
| Builder | SR Eastleigh Works (44) North British (30) |
| Build date | 1919–1926 |
| Total production | 74 |
| Configuration | 4-6-0 |
| Gauge | 4 ft 8½ in (1,435 mm) |
| Leading wheel size | 3 feet 1 inch (0.94 m) |
| Driver size | 6 feet 7 inches (2.0 m) |
| Length | 66 feet 5.75 inches (20.263 m) |
| Locomotive weight | 80 tons 19 cwt (82.2 tonnes) (Nos. 448–452 and 763–792) 79 tons 18 cwt (81.2 tonnes) (Nos. 793–806) |
| Fuel type | coal |
| Fuel capacity | 5 tons (5.1 tonnes) (Urie outside-frame bogie tender) |
| Water capacity | 5,200 imp gal (23,600 l) (Urie outside-frame bogie tender) 5,000 imp gal (22,700 l) (Six-wheel tender) |
| Boiler pressure | 180 psi (1.24 MPa) (Urie batch) 200 psi (1.38 MPa) (Eastleigh/Scotch batches) |
| Cylinders | 2 |
| Cylinder size | 22in × 28in (560mm × 710mm) (Urie batch – as built) 21in × 28in (530mm × 710mm) (Eastleigh/Scotch batches ) |
| Tractive effort | 23,900 lbf (106.31 kN) (Maunsell batch) |
| Career | London & South Western Railway, Southern Railway (Great Britain), British Railways (Southern Region) |
| Class | LSWR: N15 SR: King Arthur BR: 5P |
| Locale | Great Britain |
| Retired | 1953–1962 |
| Preserved | One, No. 777 |
The LSWR N15 class were British 2-cylinder 4-6-0 express passenger steam locomotives designed by Robert W. Urie. The class had a complex build history spanning several years of construction from 1919. The first examples were constructed for the London and South Western Railway (LSWR), where they worked heavy express trains to the South Coast ports and further west to Exeter.
Following the Grouping of railway companies in 1923, the LSWR became part of the Southern Railway. The Southern Railway's publicity department gave the locomotives names associated with Arthurian legend, becoming the King Arthur Class.[2] The Chief Mechanical Engineer (CME) of the newly formed Southern Railway, Richard Maunsell, increased class strength to 74 locomotives. Maunsell incorporated several improvements, notably to the steam circuit (the route steam travels to the cylinders).
The new locomotives were built in batches at Eastleigh and Glasgow, leading to the nicknames of 'Eastleigh Arthurs' and 'Scotch Arthurs' when in service. Maunsell's successor Oliver Bulleid further improved performance in some examples by altering exhaust arrangements. The locomotives continued operating with British Railways until the end of 1962. One example, 30777 Sir Lamiel, is preserved as part of the National Collection and can be seen on mainline railtours.
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[edit] Background
The management of the LSWR saw the need for a modern, standard express passenger locomotive to work from London to the South-West of England, hauling the heavy boat trains to the South Coast ports of Portsmouth, Weymouth and Southampton.[3] Robert Urie found that his H15 4-6-0 showed considerable speed potential on the Western Section of the LSWR from Basingstoke westwards,[4] and could be further developed into a new class of 4-6-0 express passenger locomotives with 6 ft 7 in (2.0 m) driving wheels.[5]
[edit] Design details and construction history
[edit] Urie N15s
The first locomotives, known as the "Urie N15s", were built in two batches of 10 engines by the London and South Western Railway's Eastleigh Works between 1918–19 and 1922–23.[6] The first batch was a direct development of Urie's H15 locomotive design, incorporating a Drummond-style cab, Urie's 'stovepipe' chimney and Urie's new version of Drummond's bogie tender with outside plate frames over the wheels.[7] The Urie-designed chimney was to cause draughting problems in service, which arose during an intensification of the LSWR timetables, when the locomotives gained a reputation for being poor steamers on long runs, as crews reported steadily falling steam pressure.[8] From 1928, all but one had their cylinder diameter reduced from 22 inches (560 mm) to 21 inches (530 mm), improving efficiency as it used less steam to move the piston.[9]
[edit] Modifications, naming and Maunsell's 'Eastleigh' Arthurs
At the 'Grouping' of 1923, the LSWR became part of the new Southern Railway, whose Chief Mechanical Engineer (CME) was Richard Maunsell. Maunsell planned to introduce his own new designs into the express passenger stable, one of which was to become the future Lord Nelson Class. However, there was a pressing need to maintain existing services, necessitating the modification of weaker aspects of Urie's original N15 design as an interim solution.[10] A larger diameter chimney and blast-pipe were two of Maunsell's improvements to the steam circuit, which resulted in a fast, free-steaming locomotive.[11] From 1925 a new series was built at Eastleigh with improved valve events (the timing of valve movements with the piston), boiler pressure increased to 200 psi (1.38 MPa) and cylinder diameter reduced to 20.5 inches (520 mm) equipped with Maunsell's smaller version of the Urie 8-wheel bogie tender with a capacity of 5,000 imperial gallons (23,000 l/6,000 US gal) of water and 5 tons (5.1 tonnes) of coal.[12] This was sufficient to achieve extended running on the Southern's Western section, where there were no water troughs to replenish water in the tender.
Maunsell's projected new design of express passenger locomotive would not be ready in time for the summer timetable of 1925, leading to a third batch of 10 locomotives constructed at Eastleigh in 1925. This batch used the tenders and running numbers of the withdrawn Drummond LSWR G14 and P14 classes, and differed from the original Urie batch in their use of higher boiler pressure and smaller cylinders.[12]
When the third batch was under construction, the decision was taken by the Southern Railway to name all express passenger locomotives. The N15 class was subsequently named after characters and places associated with the legend of King Arthur, because of the Southern's association with the West of England.[10] The first name was applied to one of the G14 replacements, E453, which became King Arthur. The Urie N15s were also given names connected with Arthurian legend, and were referred to as 'Urie Arthurs'. Finally, the Maunsell batch of N15s were nicknamed the 'Eastleigh Arthurs'. When Maunsell was told of the decision to name the locomotives, he replied: "Tell [Sir Herbert Walker] I have no objection, but I warn you, it won't make any difference to the working of the engines".[13]
[edit] 'Scotch' Arthurs and Bulleid's modifications
At the same time as the construction of the 'Eastleigh Arthurs', Maunsell ordered a further batch of 20 locomotives from the North British Locomotive Company in 1924 for delivery in 1925.[14] This order was increased to thirty locomotives, and their construction in Glasgow gained them the 'Scotch Arthurs' nickname in service.[10] These were built to the Southern's new composite loading gauge, differing from previous batches in having the Ashford-style cab, which was usually fitted to LBSCR locomotives.[10] The Ashford-style cab differed from the Drummond version in that it was of all-steel construction and had a roof that was flush with the cab sides. It was inspired by the standard cab developed from 1904 by R.M. Deeley for the Midland Railway, and was one of a number of Midland features introduced by Maunsell's chief draughtsman James Clayton, who transferred to Ashford in 1914 from the Midland Railway. Variants of this cab became standard for all new locomotives and converted tank engines.
A final batch of 14 engines was ordered for use on the Central section of the Southern Railway, the former LBSCR network. These were equipped with a smaller capacity 6-wheel, 3,500 imp gal (16,000 l) tender.[10] These were built at Eastleigh in 1926, the smaller tender allowed those fitted to turn on the shorter turntables found in this part of the Southern Railway. In 1926 the N15 class became the first in Britain equipped with smoke deflectors; several designs were tried, with 772 initially fitted with those of the German style.[15] When Oliver Bulleid was appointed CME in 1937, five locomotives were modified with Lemaître's multiple-jet blastpipe and wide-diameter chimney, resulting in further improvements in performance that enabled these locomotives to operate more efficiently.[16]
[edit] Operational details and preservation
- For class details and current status of the preserved locomotive, see: List of King Arthur class locomotives
The locomotives were well received by their crews and were noted for their ability to 'do the job', and for putting in many years' reliable, although unspectacular, service.[17] However, a common criticism from locomotive crews concerned the exposed nature of the cab in bad weather, which necessitated the installation of a tarpaulin sheet over the rear of the cab and the front of the tender. Another criticism was the lack of stability at high speeds, which was commented upon by Nigel Gresley when they were used on the former Great Northern main line for trials against the class A1s during the 1920s.[7] Instability at speed is a frequent issue with two-cylinder locomotives, where there is a greater tendency to 'waddle' along the track, which is perpetuated by the piston movement. This coincided with the visit of number 449 Sir Torre to the Darlington Railway Centenary celebrations in July 1925.[18]
The class was found in most areas of the British Railways Southern Region's network on medium-length expresses and stopping trains on the ex-LSWR mainline, though the detail variations across the class meant that the Urie Arthurs began to be withdrawn as early as 1953 for reasons of standardisation.[7] The first withdrawal, 30754 The Green Knight began the slow running down of the class, but because so many were constructed, they outlasted the Lord Nelson class by one month.[10] The last withdrawal was 30770 Sir Prianius from Basingstoke shed in November 1962.[10]
The number of batches constructed at different locations and times inevitably meant detail differences between members of the class. "Arthur" No. 755 was unique in having a different cylinder bore to the rest of the class at 22 inch (559 mm).[19] Further detail differences comprised weight variation: 80 tons 19 cwt (82.2 t) for Nos. 448–452 and 763–792, 79 tons 18 cwt for Nos 453–457, and 81 tons 17 cwt (82.1 t) for Nos. 793–806.[20]
Because of the relatively early withdrawal of the class by the end of 1962, only one was saved for posterity, and as of 2008, the National Collection's 30777 Sir Lamiel can be seen on the railway network hauling mainline railtours. Sir Lamiel was named after a character in Thomas Malory's Le Morte d'Arthur, Sir Lamiel of Cardiff.[21]
[edit] Livery and numbering
[edit] LSWR and Southern Railway
Under LSWR ownership, the Urie 'Arthurs' were painted in the late LSWR Sage Green livery, with black and white lining. These were used to edge the panels of Sage Green, with gilt lettering and numbering located on the tender and cabside respectively.[22] The initials 'LSWR' were located on the tender.
The first Southern livery was that of the LSWR, though with the number displayed on the tender. However from 1925, a darker Olive-type green was substituted, and the entire class was modified.[22] Wheels were green with black tyres, whilst the cabside numerals were replaced by a cast oval plate with 'Southern Railway' around the edge and the number located in the centre. Primrose Yellow 'Southern' and locomotive number transfers were placed on the tender tank.[22] In 1939, after Bulleid's appointment as CME, the locomotives were subjected to livery experimentation. 'Southern' remained on the tender, though the number transfer was moved back to the cabside, both in 'Sunshine Yellow' lettering. Several variations of the Maunsell Green and Bulleid Malachite Green liveries were used with black, white/black and yellow lining, with some sporting a green panel on the smoke deflectors.[23] However from 1942 to 1946, the class was turned out in unlined black livery with green shaded 'Sunshine' lettering. The final Southern livery used from 1946 reverted to Malachite Green, with yellow and black lining, and 'Sunshine Yellow' lettering and numbering. However, some of the class (Numbers 792 and 800 Sir Brian and Sir Persant) did not receive this livery.[24]
[edit] Post-1948 (nationalisation)
British Railways gave the class the power classification of 5P after nationalisation in 1948.[25] After 18 months in transitional British Railways Malachite Green livery, the class was released with British Railways Brunswick Green livery with orange and black lining as each member of the class became due for a heavy general overhaul. Initially, the British Railways 'Cycling Lion' crest was located on the tender, replaced from the mid-1950s by the late 'Ferret and Dartboard' crest.[25]
Numbering was originally that of the Southern Railway, though an 'S' prefix was added, so that number 448 would become s448. Once again, as each locomotive became due for overhaul and received their new livery, the numbering was changed to the British Railways standard numbering system, in the series 30448–30457 for the first ten and 30736–30806 for the rest.[26]
[edit] Footnotes
- ^ Swift, pp. 84–91
- ^ Nock, p. 241
- ^ Swift, p. 9
- ^ Nock, pp. 142–144
- ^ Swift,p. 92
- ^ Swift, p. 14
- ^ a b c Clarke, p. 48
- ^ Clarke, p. 49
- ^ Ian Allan Abc 1956 "N15"
- ^ a b c d e f g Herring, pp. 110–111
- ^ Swift, p. 38
- ^ a b Haresnape, Section "N15 class"
- ^ Nock, p. 241
- ^ Swift, pp. 19–25
- ^ Swift, p. 32
- ^ Bulleid, for information on Oliver Bulleid's modifications
- ^ Banks, p. 50
- ^ Casserley, p. 77
- ^ Clarke, p. 50
- ^ Bradley, N15 class details
- ^ Burridge, Section "King Arthur class Names"
- ^ a b c Swift, p. 50
- ^ Swift, p. 56
- ^ Swift, p. 64
- ^ a b Swift, p. 65
- ^ Ian Allan Abc 1958–59 "N15"
[edit] References
- Ian Allan ABC of British Railways Locomotives, 1956 edition (Hinckley: Ian Allan Publishing, 1959)
- Ian Allan ABC of British Railways Locomotives, winter 1958–59 edition (Hinckley: Ian Allan Publishing, 1956)
- Banks, Chris: BR Locomotives 1955 (Oxford Publishing Company: Oxford, 2001), ISBN 0860935604
- Bradley, D. L.: LSWR Locomotives - the Urie classes (Wild Swan Publications, 1987), ISBN 090686755X
- Bulleid, H. A. V.: Bulleid of the Southern (Ian Allan Publishing: Hinckley, 1979)
- Burridge, Frank: Nameplates of the Big Four (Oxford Publishing Company: Oxford, 1975) ISBN 0-90288-843-9
- Clarke, Jeremy: 'The Locomotives of R. E. L. Maunsell' (Steam World: 250, April 2008)
- Haresnape, Brian: Maunsell Locomotives - a pictorial history (Ian Allan Ltd, 1977), ISBN 0711007438
- Herring, Peter: Classic British Steam Locomotives (Abbeydale Press: London, 2000) Section "King Arthur & Lord Nelson Classes" ISBN 1-86147-057-6
- Nock, O.S.: British Locomotives of the 20th Century, Vol. 1 (Book Club Associates, 1983)
- Swift, Peter: Maunsell 4-6-0 King Arthur Class (Locomotives in Detail series volume 4) (Hinckley: Ian Allan Publishing, 2006), ISBN 0711030863
[edit] See also
[edit] External links
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