LSWR N15 Class
Encyclopedia
The LSWR N15 class was a British 2–cylinder 4-6-0
express passenger steam locomotive
designed by Robert W. Urie. The class has a complex build history spanning three sub-classes and eight years of construction from 1919 to 1926. The first batch of the class was constructed for the London and South Western Railway
(LSWR), where they hauled 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
(SR) and its publicity department gave the N15 locomotives names associated with Arthurian legend; the class hence becoming known as King Arthurs. The Chief Mechanical Engineer
(CME) of the newly formed company, Richard Maunsell
, modified the Urie locomotives in the light of operational experience and increased the class strength to 74 locomotives. Maunsell and his Chief Draughtsman James Clayton incorporated several improvements, notably to the steam circuit and valve gear
.
The new locomotives were built over several batches at Eastleigh and Glasgow
, leading to the nicknames of "Eastleigh Arthurs" and "Scotch Arthurs" in service. The class was subjected to smoke deflection experiments in 1926, becoming the first British class of steam locomotive to be fitted with smoke deflectors
. Maunsell's successor, Oliver Bulleid
, attempted to improve performance by altering exhaust
arrangements. The locomotives continued operating with British Railways (BR) until the end of 1962. One example, 30777 Sir Lamiel
, is preserved as part of the National Collection and can be seen on mainline railtour
s.
mixed-traffic
4-6-0 design in 1913 and the prototype was built in August 1914. It showed a marked improvement in performance over Dugald Drummond
’s LSWR T14 class
4-6-0 when tested on local and express passenger trains. The introduction of ten H15 engines into service coincided with the outbreak of the First World War, which prevented construction of further class members. Despite the interruption caused by the conflict, Urie anticipated that peacetime increases in passenger traffic would necessitate longer trains from London
to the south-west of England. Passenger loadings on the heavy boat trains to the London and South Western Railway
’s (LSWR) ports of Portsmouth
, Weymouth and Southampton
had been increasing prior to the war, and was beginning to overcome the capabilities of the LSWR’s passenger locomotive fleet. His response was to produce a modern, standard express passenger design similar to the H15.
Trials undertaken in 1914 with the H15 class prototype had demonstrated to Urie that the basic design showed considerable speed potential on the Western section of the LSWR from Basingstoke
westwards, and could form the basis of a powerful new class of 4-6-0 express passenger locomotive with larger 6 in 7 in (2.01 m) driving wheels. The LSWR required such a locomotive, which would need to cope with increasing train loads on this long and arduous route to the West Country
. The result was the N15 class design, completed by Urie in 1917. It incorporated features from the H15 class, including eight-wheel double bogie
tenders with outside plate frames
over the wheels and exposed Walschaerts valve gear. High running plates along the boiler were retained for ease of oiling and maintenance.
Despite the similarities, the N15 class represented a refinement of the H15 template. The cylinders were increased in size to 22 × in diameter, the largest used on a British steam locomotive at that time. The substantial boiler
design was also different to the parallel version used on the H15, and became the first tapered types to be constructed at Eastleigh Works. Contrary to boiler construction practices elsewhere where tapering began near the firebox, it was restricted to the front end of the N15’s barrel to reduce the diameter of the smokebox
, and consequently the weight carried by the front bogie. The design also featured Urie’s design of narrow-diameter "stovepipe" chimney, a large dome cover on top of the boiler, and his "Eastleigh" superheater.
A shortage of copper delayed completion of Nos. 741–745, and the last of the batch emerged from Eastleigh in November 1919. After the running-in of Nos. 736–745 and an intensification of the LSWR timetable to the West Country, a second batch of ten was ordered in October 1921. They entered service over the period June 1922–March 1923, and were numbered in the series 746–755.
At "Grouping
" in January 1923, the LSWR became part of the new Southern Railway
, whose Chief Mechanical Engineer
was Richard Maunsell
. Maunsell planned to introduce his own designs of express passenger locomotive, one of which was to become the future Lord Nelson class
. Despite this, there was a short-term need to maintain existing services that required modification and expansion of Urie's N15 design.
, G14
and P14 classes
4-6-0s into 2–cylinder H15 class locomotives. Only the five F13s were converted to H15s; the remaining ten G14 and P14s (Nos. 448–457, renumbered E448–E457) were rebuilt as N15s, implementing modifications to Urie’s original design.
The modifications are attributed to Maunsell’s Chief Draughtsman James Clayton, who had transferred to Ashford railway works
in 1914 from Derby works
. They were the result of cooperation between the South Eastern and Chatham Railway
(SECR) and the Great Western Railway
(GWR) when Maunsell was seconded to the Railway Executive Committee during the First World War. The aim was to create a series of standard freight and passenger locomotives for use throughout Britain, and meant that Clayton was privy to the latest GWR developments in steam design. These included streamlined steam passages, long-travel valves, the maximisation of power through reduced cylinder sizes and higher boiler pressure.
Maunsell initiated trials with Urie N15 No. 442 in 1924, and proved that better performance could be obtained by altering the steam circuit, valve travel and draughting arrangements. As a result, Clayton reduced the N15 cylinder diameter to 20.5 inches (520.7 mm) and replaced the safety valves with Ross pop valves set to 200 psi (1.38 MPa) boiler pressure. The Urie boiler was retained, though the Eastleigh superheater was replaced by a Maunsell type with 10 per cent greater superheating surface area. This was supplemented by a larger steam chest
and an increased-diameter chimney casting specially designed for the rebuilds. It incorporated a rim and capuchon
to control exhaust flow into the atmosphere. Valve events (the timing of valve
movements with the piston) were also revised to promote efficient steam usage and the wheels were re-balanced to reduce hammerblow.
When rebuilding was complete, only the numbers, smokebox doors with centre tightening handles and the flat-sided cabs remained of the G14 and P14 classes. The rebuilds retained their distinctive Drummond "watercart" tenders, which were modified with the removal of the complex injector feedwater heating equipment. The "watercart" tenders were of 4300 imp gal (19,548.2 l) water and 5 LT (5.1 t) coal capacity. The ten rebuilds became the first members of the King Arthur class upon entering service.
in 1924. The company had under-quoted to gain the contract, which meant that production of the batch was rushed. The necessity to maintain an intensive timetable on the Southern Railway’s Western section prompted an increase of the order to 30 locomotives (Nos. E763–E792). Their construction in Glasgow
would gain them the "Scotch Arthurs" nickname in service. They were all delivered to the Southern Railway by October 1925, and featured the front-end refinements used on the Drummond rebuilds.
The North British batch was built to the Southern's new composite loading gauge
and differed from previous batches in having an Ashford-style cab based upon that used on the N class. Unlike the Drummond cab retained by Nos. 448–457 and E741–E755, the Ashford cab was of an all-steel construction and had a roof that was flush with the cab sides, allowing it to be used on gauge-restricted routes in the east of the network. It was inspired by the standard cab developed in 1904 by R. M. Deeley
for the Midland Railway
, and was one of a number of Midland features introduced by Clayton to the SECR and subsequently the Southern Railway. The smokebox door was revised to the Ashford pattern, which omitted the use of central tightening handles in favour of clamps around the circumference. The batch was fitted with the Urie-designed, North British-built 5000 imp gal (22,730.5 l) capacity double-bogie tenders.
The Operating Department intended to equip Nos. E793–E807 with six-wheel, 4000 imp gal (18,184.4 l) capacity tenders for use on the former SECR lines of the Eastern section. These were to replace Scotch Arthurs Nos. E763–E772 on boat train duties. This was because the 5000 imp gal (22,730.5 l) tenders attached to Nos. E763–E772 were better suited to the longer routes of the Western section. The final ten engines (Nos. E808–E817) were for the former LBSCR routes of the Central section, where short turntables restricted tender size to the 3500 imp gal (15,911.3 l) Ashford variety used on the N class. After the order was changed to the Lord Nelson class design, 14 N class tenders were fitted to Nos. E793–E806 for use the Central section. The high draw-gear (the link between locomotive and tender) of the N class tenders necessitated modification to the frames beneath the cab.
When the former Drummond G14 and P14 4-6-0s were rebuilt to Maunsell’s N15 specification in February 1925, the Southern Railway decided to give names to all express passenger locomotives. Because of the railway's association with the West of England, the Public Relations Officer, John Elliot suggested that members of the N15 class should be named after characters and places associated with the legend of King Arthur
. 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". Walker was the General Manager of the Southern Railway, who had told Elliot that Maunsell's permission was required. The first G14 to be rebuilt, No. E453, was given the first name and christened King Arthur. The Urie locomotives (hitherto referred as N15s rather than King Arthurs) were also given names connected with Arthurian legend and were referred to as "Urie Arthurs"; the Maunsell batches of N15s were nicknamed the "Eastleigh" and "Scotch Arthurs".
between , Weymouth
, Exeter
and Plymouth
. Locomotives were changed at before the upgrading of the South Western Mainline in 1922, when fast running through to Exeter was possible. The Southern Railway's motive power re-organisation following the Grouping
of 1923 saw the class allocated to sheds across the network and used on to cross-country trains. Operations were expanded to more restricted Central and Eastern section mainlines in 1925, and suitably modified class members hauled commuter and heavy boat trains from to and expresses to . In 1931, No. E780 Sir Persant hauled the inaugural Bournemouth Belle
Pullman
train from Waterloo to .
In peacetime, the class was occasionally used on fast freights from Southampton Docks, although it was common to see them at the head of freight and troop trains during the Second World War. Ten "Urie Arthurs" were transferred to the London and North Eastern Railway
(LNER) in October 1942, and were based at Heaton shed for use on freight and occasional passenger trains in the north east and southern Scotland
. They returned to the Southern Railway in July 1943 after the introduction of United States Army Transportation Corps
S160 class
2-8-0
s into service. From 1945 the King Arthur class regularly deputised for Bulleid’s new Pacifics, which were experiencing poor serviceability due to mechanical failures. The entire class came into British Railways ownership in 1948: they could be found in most areas of the Southern Region
on medium-length expresses and stopping trains on the ex-LSWR mainline.
in staging wind tunnel tests
. These resulted in a standard plate design (illustrated in the infobox), which was gradually fitted to the class from late 1927 onwards.
Another criticism from locomotive crews concerned the exposed cab in bad weather, which necessitated the installation of a tarpaulin
sheet over the rear of the cab and the front of the tender, restricting rearward vision. The 1921 Coal Miners’ strike meant that two class members (Nos. 737 and 739) were converted to oil-burning. One of the modified locomotives subsequently caught fire at Salisbury shed, and both were reverted to coal firing by the end of the year. When the LSWR was amalgamated into the Southern Railway in 1923, Urie had done little to remedy the shortcomings of the N15s, and it fell to his successor to improve the class.
When Maunsell inherited the design as CME of the Southern Railway, he began trials using the weakest N15 (No. 442) in 1924. The results indicated that better performance could be obtained by altering the steam circuit, valve travel and draughting arrangements, although the first two recommendations were deemed too costly for immediate implementation by the Locomotive Committee. Eight extra King Arthur-type boilers were ordered from North British and fitted to N15s Nos. 737–742 by December 1925 in an effort to improve steaming. The remaining Urie boilers were fitted with standard Ross pop safety valves to ease maintenance. Maunsell also addressed draughting problems caused by the narrow Urie "stovepipe" chimney. The exhaust arrangements were modified on No. 737 using the King Arthur chimney design and reduced-diameter blastpipe
s. This proved successful, and all "Urie N15s" were modified over the period 1925–1929. The oil-burning equipment was refitted to Nos. 737 and 739 during the 1926 General Strike
and removed in December of that year.
Beginning in 1928, all but No. 755 had their cylinder diameter reduced from 22 inches (558.8 mm) to 21 inches (533.4 mm) when renewals were due, improving speed on flat sections of railway, but affecting their performance on the gradients west of Salisbury. No. 755 The Red Knight was modified in 1940 by Maunsell’s successor, Oliver Bulleid
with his own design of 21 inches (533.4 mm) cylinders and streamlined steam passages. This was married to a Lemaître
multiple-jet blastpipe
and wide-diameter chimney, allowing the locomotive to produce performances akin to the more powerful Lord Nelson class. Four other N15s were so modified with four more on order, though the latter was cancelled due to wartime shortages of metal. The soft exhaust of the Lemaître multiple-jet blastpipe precipitated an adjustment to the smoke deflectors on three converted locomotives, with the tops angled to the vertical in an attempt to improve air-flow along the boiler cladding. This failed to achieve the desired effect, and the final two modified locomotives retained the Maunsell-style deflectors.
The final modifications to the "Urie N15s" involved the conversion of five locomotives (Nos. 740, 745, 748, 749 and 752) to oil-firing in 1946–1947. This was in response to a government scheme to address a post-war coal shortage. The oil tanks were fabricated from welded steel and fitted within the tender coal space. After initial problems with No. 740 Merlin were rectified, the oil-fired locomotives proved good performers on Bournemouth services. A further addition to the oil-fired locomotives was electric headcode and cab lighting, which was retained when reverted to coal-firing in 1948.
Despite the successful use of modified N15 components to rebuild Nos. E448–E457, the mechanically similar "Scotch Arthurs" proved disappointing when put into service from May 1925. The performance of those allocated to the Eastern section was indifferent, and failed to improve upon the double-headed
ex-SECR 4-4-0
s they were to replace. Reports of poor steaming and hot driving and tender wheel axleboxes were common from crewmen and shed fitters. After investigation, the problems were attributed to poor workmanship during construction as the North British Locomotive Company underquoted production costs to gain the contract. Defects were found in boiler construction across the batch, and necessitated six replacement boilers, re-riveting, re-fitting of tubes and replacement of firebox stays. The hot driving wheel axleboxes were caused by the main frames being out of alignment. A 1926 report suggested that all affected locomotives should be taken to Eastleigh for repair. Once repaired, the "Scotch Arthurs" proved as capable as the rest of the class in service.
"Scotch Arthurs" Nos. E763–E772 received new tenders between 1928 and 1930 in a series of tender exchanges with the Lord Nelson and LSWR S15 classes. This ensured that they could exchange their Urie 5000 imp gal (22,730.5 l) bogie tenders with the 4000 imp gal (18,184.4 l) Ashford design for use on the shorter Eastern section routes. Whilst useful for the roster clerks at Battersea shed, any transfer to the Western section was hampered because of their shorter range. By 1937, all had reverted to the Urie 5000 imp gal (22,730.5 l) bogie tenders, though Nos. E768–E772 were attached to new Maunsell flush-sided tenders with brake vacuum reservoirs fitted behind the coal space. These were again swapped with Maunsell LSWR-style bogie tenders fitted to the Lord Nelson class.
The second batch of "Eastleigh Arthurs" displaced the ex-K class tanks and ex-LBSCR H2 "Atlantic"
4-4-2
locomotives on the and routes respectively. They were well liked by crews and used on this part of the network until the arrival of electrification. No. E782 Sir Brian was used on the former Great Northern
main line for performance trials against the SECR K and K1 class tanks following a railway accident at Sevenoaks, Kent
in 1927. The tests were supervised by the London and North Eastern Railway
's CME, Sir Nigel Gresley
, who commented that the class was unstable at high speeds. The instability was caused by motion hammerblow and exacerbated by irregularities in track-work. This caused excessive stress to the axleboxes and poor riding characteristics on the footplate
. Despite this, the class benefited from an excellent maintenance regime.
Maunsell’s replacement Oliver Bulleid
believed that there was little need to improve draughting on this series. However, reports of poor steaming with No. 792 Sir Hervis de Revel gave him an opportunity to trial a Lemaître multiple-jet blastpipe and wide-diameter chimney on a Maunsell Arthur in 1940. This did not enhance performance to the extent of No. 755 The Red Knight. Under British Railways ownership, the locomotive was re-fitted with the Maunsell chimney in March 1952 with no further problems reported. In another wartime experiment, Bulleid fitted No. 783 Sir Gillemere with three thin "stovepipe" chimneys in November 1940. These were set in a triangular formation to reduce visibility of exhaust from the air in response to attacks made by low-flying aircraft on Southern Railway trains. The "stovepipes" were reduced to two, producing a fierce exhaust blast that dislodged soot inside tunnels and under bridges. The experiment was discontinued in February 1941 and the locomotive re-fitted with a Maunsell King Arthur chimney. The last experiment was with spark-arresting equipment in response to lineside fires caused by poor quality coal. Nos. 784 Sir Nerovens and 788 Sir Urre of the Mount were fitted with new wide-diameter chimneys in late 1947. Test-trains showed mixed results and the trials were stopped in 1951 after improvements in coal quality and the fitting of internal smokebox spark-arrestors.
locomotives allocated to the Southern Region between 1959–1962.
The Maunsell King Arthur class also faced a decrease in suitable work on the Central and Eastern sections following the introduction of BR Standard class 5 and BR Standard class 4
4-6-0s in 1955. The gradual withdrawal of the "Urie N15s", H15s and SR N15x classes presented an opportunity to replace the ageing Drummond "watercart" tenders fitted to Nos. 448–457 with Urie 5000 imp gal (22,730.5 l) bogie tenders. This coincided with a 1958 programme to similarly change the 3500 imp gal (15,911.3 l) Ashford tenders fitted to eight of the second batch "Eastleigh Arthurs". The class remained intact until the completion of the Eastern section electrification
when 17 were made redundant in 1959. More withdrawals took place in 1960 when an increase in Bulleid Pacifics allocated to the Western section reduced available work. The ranks thinned to 12 in 1961, and further withdrawals reduced the class to one, No. 30770 Sir Prianius. The class outlasted the newer – but less numerous – Lord Nelson
class by one month when No. 30770 was withdrawn from Basingstoke Shed in November 1962.
for passenger locomotives. This was distinct from Drummond’s sage green because it was more olive in colour, and yellowed with cleaning and weathering. Black and white lining decorated the boiler bands and borders of the sage green panels. The lettering was in gilt: the initials "LSWR" located on the side of the tender, the locomotive number on the cabside.
The first Southern livery continued that of the LSWR, though with primrose yellow transfers
showing "Southern" and the locomotive number, placed on the tender. The lining separating the black border on tender and cab side panels was changed to yellow. Primrose yellow transfers
, showing "Southern" and the locomotive number, were placed on the tender. An "E" prefix was located above the tender number (e.g. E749), denoting that the class was registered for maintenance at Eastleigh works. The gilt numerals on the cabside and tender rear were replaced by a cast oval plate with "Southern Railway" around the edge and the number located in the centre. Yellow numerals were painted onto the front buffer-beam to ease identification. In February 1925 Maunsell developed a deeper green with black and white lining. This was applied to his new King Arthur class locomotives and the "Urie N15s" were similarly painted when overhauls were due. Wheels were olive-green with black tyres. From 1929 the "E" prefix was removed and the cast numerals on the tender rear were removed and replaced with yellow transfers (e.g. 749).
In May 1938, after Bulleid's appointment as CME, No. 749 Iseult was trialled in bright unlined light green with yellow-painted block numerals replacing the cast numberplates. The tender was given two designs of lettering, with "Southern" on one side and the initials "SR" on the other. The Board of Directors disapproved and Bulleid repainted the locomotive in darker malachite green
with black and white lining (this would later be applied to his Pacifics). The legend "Southern" in block-lettering remained on the tender, though the number was relocated to the cabside on one side and the smoke deflector on the other. Both were painted in a light "sunshine yellow". No. 749 was returned to Maunsell’s green livery.
Several variations of the Maunsell green, Urie sage green and Bulleid malachite green
liveries were tried with black, white/black, and yellow lining, some sporting a green panel on the smoke deflectors. However from 1942 to 1946, during the Second World War, members of the class under overhaul were turned out in unlined-black livery as a wartime economy measure, with green-shaded sunshine yellow lettering. The final Southern livery used from 1946 reverted to malachite green, with yellow/black lining, and sunshine yellow lettering. Some of the class (Nos. 782 and 800, Sir Brian and Sir Persant) did not receive this livery.
Numbering was initially a continuation of the Southern Railway system, though an 'S' prefix was added to denote a pre-nationalisation locomotive, so that No. 448 would become No. s448. As each locomotive became due for overhaul and received its 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.
After the poor steaming of the Urie batch was addressed, the class proved popular amongst crews, mechanically reliable and capable of high speeds. However, their heavy hammerblow at speed meant that they were prone to rough riding and instability. The two Maunsell batches with their streamlined steam passages and better draughting arrangements were superior in performance, and were a popular choice when Bulleid’s locomotives were unavailable. Their use of standard parts considerably eased maintenance, and the fitting of different tender and cab sizes meant few operational restrictions for the class on mainline routes. The class gave many years of service, and were noted for their ability to "do the job". The electrification of the Eastern and Central sections and the increasing number of Bulleid Pacifics in service meant the lack of a suitable role for the class under British Railways ownership. In spite of the reduction in work, high mileages were obtained with No. 30745 Tintagel achieving 1464032 miles (2,356,125.3 km) in service.
The decision to preserve a member of the class was made in November 1960. It was first intended to preserve the King Arthur class doyen No. 453 King Arthur, and it was stored for a time after withdrawal in 1961 pending restoration to museum condition. However, it was decided to restore the preserved locomotive to as-built condition, and the lack of a suitable Drummond "watercart" tender precluded this consideration. No. 453 was subsequently scrapped and it was decided to preserve one of the North British-built batch, No. 30777 Sir Lamiel
, withdrawn in October 1961, instead. Sir Lamiel was named after a character in Thomas Malory
's Le Morte d'Arthur
, Sir Lamiel of Cardiff. This locomotive was restored to Maunsell livery as No. E777, and became part of the National Collection. It was restored to the later British Railways livery in 2003, and No. 30777 can be seen at the Great Central Railway
and on the railway network hauling mainline railtours as of 2010.
4-6-0
Under the Whyte notation for the classification of steam locomotives, 4-6-0 represents the wheel arrangement of four leading wheels on two axles in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This wheel arrangement became the second-most popular...
express passenger steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
designed by Robert W. Urie. The class has a complex build history spanning three sub-classes and eight years of construction from 1919 to 1926. The first batch of the class was constructed for the London and South Western Railway
London and South Western Railway
The London and South Western Railway was a railway company in England from 1838 to 1922. Its network extended from London to Plymouth via Salisbury and Exeter, with branches to Ilfracombe and Padstow and via Southampton to Bournemouth and Weymouth. It also had many routes connecting towns in...
(LSWR), where they hauled heavy express trains to the south coast ports and further west to Exeter
Exeter
Exeter is a historic city in Devon, England. It lies within the ceremonial county of Devon, of which it is the county town as well as the home of Devon County Council. Currently the administrative area has the status of a non-metropolitan district, and is therefore under the administration of the...
.
Following the grouping of railway companies
Railways Act 1921
The Railways Act 1921, also known as the Grouping Act, was an enactment by the British government of David Lloyd George intended to stem the losses being made by many of the country's 120 railway companies, move the railways away from internal competition, and to retain some of the benefits which...
in 1923, the LSWR became part of the Southern Railway
Southern Railway (Great Britain)
The Southern Railway was a British railway company established in the 1923 Grouping. It linked London with the Channel ports, South West England, South coast resorts and Kent...
(SR) and its publicity department gave the N15 locomotives names associated with Arthurian legend; the class hence becoming known as King Arthurs. The Chief Mechanical Engineer
Chief Mechanical Engineer
Chief Mechanical Engineer and Locomotive Superintendent are titles applied by British, Australian, and New Zealand railway companies to the person ultimately responsible to the board of the company for the building and maintaining of the locomotives and rolling stock...
(CME) of the newly formed company, Richard Maunsell
Richard Maunsell
Richard Edward Lloyd Maunsell held the post of Chief Mechanical Engineer of the South Eastern and Chatham Railway from 1913 until the 1923 Grouping and then the post of CME of the Southern Railway in England until 1937....
, modified the Urie locomotives in the light of operational experience and increased the class strength to 74 locomotives. Maunsell and his Chief Draughtsman James Clayton incorporated several improvements, notably to the steam circuit and valve gear
Valve gear
The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle...
.
The new locomotives were built over several batches at Eastleigh and Glasgow
North British Locomotive Company
The North British Locomotive Company was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp Stewart and Company , Neilson, Reid and Company and Dübs and Company , creating the largest locomotive manufacturing company in Europe.Its main factories were...
, leading to the nicknames of "Eastleigh Arthurs" and "Scotch Arthurs" in service. The class was subjected to smoke deflection experiments in 1926, becoming the first British class of steam locomotive to be fitted with smoke deflectors
Smoke deflectors
Smoke deflectors are vertical plates attached to the front of a steam locomotive on each side of the smokebox. They are designed to lift smoke away from the locomotive at speed so that the driver has better visibility unimpaired by drifting smoke....
. Maunsell's successor, Oliver Bulleid
Oliver Bulleid
Oliver Vaughan Snell Bulleid was a British railway and mechanical engineer best known as the Chief Mechanical Engineer of the Southern Railway between 1937 and the 1948 nationalisation, developing many well-known locomotives.- Early life and Great Northern Railway :He was born in Invercargill,...
, attempted to improve performance by altering exhaust
Steam locomotive exhaust system
The Steam locomotive exhaust system consists of those parts of a steam locomotive which together discharge exhaust steam from the cylinders in order to increase the draught through the fire...
arrangements. The locomotives continued operating with British Railways (BR) until the end of 1962. One example, 30777 Sir Lamiel
LSWR N15 Class 30777 Sir Lamiel
Southern Railway 777 Sir Lamiel is an N15 “King Arthur” class 4-6-0 steam locomotive built for the Southern Railway by the North British Locomotive Company in June 1925, and withdrawn from service in October 1961. It is now preserved and used on the Network Rail infrastructure in association with...
, is preserved as part of the National Collection and can be seen on mainline railtour
Railtour
A railtour is a special train which is run in order to allow people to experience rail travel which is not available using timetabled passenger services...
s.
Background
Robert Urie completed his H15 classLSWR Class H15
The LSWR/SR H15 class was a class of 2-cylinder 4-6-0 steam locomotives designed by Robert Urie for mixed-traffic duties on the LSWR. Further batches were constructed by Richard Maunsell for the SR.- Construction history :...
mixed-traffic
Mixed-traffic locomotive
A mixed-traffic locomotive is one designed to be capable of hauling both passenger trains and freight trains. The term is mostly used in the United Kingdom and those nations following British practice...
4-6-0 design in 1913 and the prototype was built in August 1914. It showed a marked improvement in performance over Dugald Drummond
Dugald Drummond
Dugald Drummond was a Scottish steam locomotive engineer. He had a career with the North British Railway, LB&SCR, Caledonian Railway and London and South Western Railway...
’s LSWR T14 class
LSWR T14 class
The LSWR Class T14 was a class of ten 4-6-0 locomotives designed by Dugald Drummond for express passenger use on the London and South Western Railway and constructed at Eastleigh in 1911–12 .- Background :...
4-6-0 when tested on local and express passenger trains. The introduction of ten H15 engines into service coincided with the outbreak of the First World War, which prevented construction of further class members. Despite the interruption caused by the conflict, Urie anticipated that peacetime increases in passenger traffic would necessitate longer trains from London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to the south-west of England. Passenger loadings on the heavy boat trains to the London and South Western Railway
London and South Western Railway
The London and South Western Railway was a railway company in England from 1838 to 1922. Its network extended from London to Plymouth via Salisbury and Exeter, with branches to Ilfracombe and Padstow and via Southampton to Bournemouth and Weymouth. It also had many routes connecting towns in...
’s (LSWR) ports of Portsmouth
Portsmouth
Portsmouth is the second largest city in the ceremonial county of Hampshire on the south coast of England. Portsmouth is notable for being the United Kingdom's only island city; it is located mainly on Portsea Island...
, Weymouth and Southampton
Southampton
Southampton is the largest city in the county of Hampshire on the south coast of England, and is situated south-west of London and north-west of Portsmouth. Southampton is a major port and the closest city to the New Forest...
had been increasing prior to the war, and was beginning to overcome the capabilities of the LSWR’s passenger locomotive fleet. His response was to produce a modern, standard express passenger design similar to the H15.
Design and construction
- For detailed information on numbering variations, see: Livery and numbering
Trials undertaken in 1914 with the H15 class prototype had demonstrated to Urie that the basic design showed considerable speed potential on the Western section of the LSWR from Basingstoke
Basingstoke railway station
Basingstoke railway station, in the town of Basingstoke in the county of Hampshire in England, is on the South Western Main Line from London Waterloo, with local and fast services operated by South West Trains. It is also the terminus of First Great Western local services on the Reading to...
westwards, and could form the basis of a powerful new class of 4-6-0 express passenger locomotive with larger 6 in 7 in (2.01 m) driving wheels. The LSWR required such a locomotive, which would need to cope with increasing train loads on this long and arduous route to the West Country
West Country
The West Country is an informal term for the area of south western England roughly corresponding to the modern South West England government region. It is often defined to encompass the historic counties of Cornwall, Devon, Dorset and Somerset and the City of Bristol, while the counties of...
. The result was the N15 class design, completed by Urie in 1917. It incorporated features from the H15 class, including eight-wheel double bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
tenders with outside plate frames
Locomotive frame
A locomotive frame is the structure that forms the backbone of the railway locomotive, giving it strength and supporting the superstructure elements such as a cab, boiler or bodywork. The vast majority of locomotives have had a frame structure of some kind...
over the wheels and exposed Walschaerts valve gear. High running plates along the boiler were retained for ease of oiling and maintenance.
Despite the similarities, the N15 class represented a refinement of the H15 template. The cylinders were increased in size to 22 × in diameter, the largest used on a British steam locomotive at that time. The substantial boiler
Fire-tube boiler
A fire-tube boiler is a type of boiler in which hot gases from a fire pass through one or more tubes running through a sealed container of water...
design was also different to the parallel version used on the H15, and became the first tapered types to be constructed at Eastleigh Works. Contrary to boiler construction practices elsewhere where tapering began near the firebox, it was restricted to the front end of the N15’s barrel to reduce the diameter of the smokebox
Smokebox
A smokebox is one of the major basic parts of a Steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is exhausted to the atmosphere through the chimney .To assist...
, and consequently the weight carried by the front bogie. The design also featured Urie’s design of narrow-diameter "stovepipe" chimney, a large dome cover on top of the boiler, and his "Eastleigh" superheater.
"Urie N15s"
The N15 design was approved by the LSWR management committee, though the order for construction was postponed until wartime control of raw materials was relaxed. Government approval was obtained in mid–1918, and Eastleigh Works began to produce the LSWR’s first new locomotive class since 1914. The first locomotives, later known by crewmen as the "Urie N15s", were built in two ten-engine batches by the LSWR's Eastleigh Works between 1918–19 and 1922–23. Of the first batch, the prototype, No. 736 entered service on 31 August 1918, with four more appearing between September 1918 and April 1919. They shared a similar profile to Urie's H15 class with the use of flat-sided Drummond-style cabs with gently curving roofs. The double bogie tenders were outwardly similar in appearance to those used on the H15s, although strengthened during construction with extra internal bracing to hold 5000 gallons (22,730.5 l) of water.A shortage of copper delayed completion of Nos. 741–745, and the last of the batch emerged from Eastleigh in November 1919. After the running-in of Nos. 736–745 and an intensification of the LSWR timetable to the West Country, a second batch of ten was ordered in October 1921. They entered service over the period June 1922–March 1923, and were numbered in the series 746–755.
At "Grouping
Railways Act 1921
The Railways Act 1921, also known as the Grouping Act, was an enactment by the British government of David Lloyd George intended to stem the losses being made by many of the country's 120 railway companies, move the railways away from internal competition, and to retain some of the benefits which...
" in January 1923, the LSWR became part of the new Southern Railway
Southern Railway (Great Britain)
The Southern Railway was a British railway company established in the 1923 Grouping. It linked London with the Channel ports, South West England, South coast resorts and Kent...
, whose Chief Mechanical Engineer
Chief Mechanical Engineer
Chief Mechanical Engineer and Locomotive Superintendent are titles applied by British, Australian, and New Zealand railway companies to the person ultimately responsible to the board of the company for the building and maintaining of the locomotives and rolling stock...
was Richard Maunsell
Richard Maunsell
Richard Edward Lloyd Maunsell held the post of Chief Mechanical Engineer of the South Eastern and Chatham Railway from 1913 until the 1923 Grouping and then the post of CME of the Southern Railway in England until 1937....
. Maunsell planned to introduce his own designs of express passenger locomotive, one of which was to become the future Lord Nelson class
SR Lord Nelson Class
The SR class LN or Lord Nelson class is a type of 4-cylinder 4-6-0 steam locomotive designed for the Southern Railway by Richard Maunsell in 1926. They were intended for Continental boat trains between London and Dover harbour, but were also later used for express passenger work to the South-West...
. Despite this, there was a short-term need to maintain existing services that required modification and expansion of Urie's N15 design.
Maunsell’s "Eastleigh Arthurs": Drummond rebuilds
Maunsell's projected design of express passenger locomotive was not ready for introduction during the summer timetable of 1925, so a third batch of ten N15s was ordered for construction at Eastleigh. This batch was part of an outstanding LSWR order to rebuild 15 of Drummond’s unsuccessful 4-cylinder F13LSWR F13 class
The London and South Western Railway F13 class was a class of 4-6-0 locomotives designed by Dugald Drummond for the London and South Western Railway .- Background :...
, G14
LSWR G14 class
The LSWR G14 class was a class of 4-6-0 locomotive designed by Dugald Drummond for the London and South Western Railway.- Background :The continuing need to grasp the nettle in terms of Drummond's first two 4-6-0 classes meant that he went back to the drawing board to create yet another design...
and P14 classes
LSWR P14 class
The LSWR P14 class was a class of 4-6-0 locomotive designed by Dugald Drummond for the London and South Western Railway.- Background :The continuing need to grasp the nettle in terms of Drummond's first two 4-6-0 classes meant that he went back to the drawing board to create another design...
4-6-0s into 2–cylinder H15 class locomotives. Only the five F13s were converted to H15s; the remaining ten G14 and P14s (Nos. 448–457, renumbered E448–E457) were rebuilt as N15s, implementing modifications to Urie’s original design.
The modifications are attributed to Maunsell’s Chief Draughtsman James Clayton, who had transferred to Ashford railway works
Ashford railway works
Ashford railway works was in the town of Ashford in the county of Kent in England.-South Eastern Railway:Ashford locomotive works was built by the South Eastern Railway on a new site in 1847, replacing an earlier locomotive repair facility at New Cross in London...
in 1914 from Derby works
Derby Works
The Midland Railway Locomotive Works, known locally as "the loco" comprised a number of British manufacturing facilities in Derby building locomotives and, initially, rolling stock in Derby, UK.-Early days:...
. They were the result of cooperation between the South Eastern and Chatham Railway
South Eastern and Chatham Railway
The South Eastern and Chatham Railway Companies Joint Management Committee , known by its shorter name of the South Eastern and Chatham Railway was a working union of two neighbouring rival railways, the South Eastern Railway and London, Chatham and Dover Railway , that operated services between...
(SECR) and the Great Western Railway
Great Western Railway
The Great Western Railway was a British railway company that linked London with the south-west and west of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament in 1835 and ran its first trains in 1838...
(GWR) when Maunsell was seconded to the Railway Executive Committee during the First World War. The aim was to create a series of standard freight and passenger locomotives for use throughout Britain, and meant that Clayton was privy to the latest GWR developments in steam design. These included streamlined steam passages, long-travel valves, the maximisation of power through reduced cylinder sizes and higher boiler pressure.
Maunsell initiated trials with Urie N15 No. 442 in 1924, and proved that better performance could be obtained by altering the steam circuit, valve travel and draughting arrangements. As a result, Clayton reduced the N15 cylinder diameter to 20.5 inches (520.7 mm) and replaced the safety valves with Ross pop valves set to 200 psi (1.38 MPa) boiler pressure. The Urie boiler was retained, though the Eastleigh superheater was replaced by a Maunsell type with 10 per cent greater superheating surface area. This was supplemented by a larger steam chest
Steam locomotive components
A listing of the components found on typical steam locomotives.center|720px|Schematic steam locomotiveGuide to steam locomotive components .A listing of the components found on typical steam...
and an increased-diameter chimney casting specially designed for the rebuilds. It incorporated a rim and capuchon
Capuchon (chimney)
A capuchon is a raised lip at the front of a ships funnel or railway steam locomotive chimney. It is intended to prevent down draughts when in motion and encourage smoke to rise. When fitted to ships' funnels the intention is to keep the after decks clear of exhaust smuts...
to control exhaust flow into the atmosphere. Valve events (the timing of valve
Valve gear
The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle...
movements with the piston) were also revised to promote efficient steam usage and the wheels were re-balanced to reduce hammerblow.
When rebuilding was complete, only the numbers, smokebox doors with centre tightening handles and the flat-sided cabs remained of the G14 and P14 classes. The rebuilds retained their distinctive Drummond "watercart" tenders, which were modified with the removal of the complex injector feedwater heating equipment. The "watercart" tenders were of 4300 imp gal (19,548.2 l) water and 5 LT (5.1 t) coal capacity. The ten rebuilds became the first members of the King Arthur class upon entering service.
"Scotch Arthurs"
As the Drummond G14 and P14 4-6-0s were rebuilt to the N15 specification at Eastleigh, a lack of production capacity due to repair and overhaul meant that Maunsell ordered a further batch of 20 locomotives from the North British Locomotive CompanyNorth British Locomotive Company
The North British Locomotive Company was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp Stewart and Company , Neilson, Reid and Company and Dübs and Company , creating the largest locomotive manufacturing company in Europe.Its main factories were...
in 1924. The company had under-quoted to gain the contract, which meant that production of the batch was rushed. The necessity to maintain an intensive timetable on the Southern Railway’s Western section prompted an increase of the order to 30 locomotives (Nos. E763–E792). Their construction in Glasgow
Glasgow
Glasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands...
would gain them the "Scotch Arthurs" nickname in service. They were all delivered to the Southern Railway by October 1925, and featured the front-end refinements used on the Drummond rebuilds.
The North British batch was built to the Southern's new composite loading gauge
Loading gauge
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures...
and differed from previous batches in having an Ashford-style cab based upon that used on the N class. Unlike the Drummond cab retained by Nos. 448–457 and E741–E755, the Ashford cab was of an all-steel construction and had a roof that was flush with the cab sides, allowing it to be used on gauge-restricted routes in the east of the network. It was inspired by the standard cab developed in 1904 by R. M. Deeley
Richard Deeley
Richard Mountford Deeley was a British engineer, chiefly noted for his five years as Chief Mechanical Engineer of the Midland Railway....
for the Midland Railway
Midland Railway
The Midland Railway was a railway company in the United Kingdom from 1844 to 1922, when it became part of the London, Midland and Scottish Railway....
, and was one of a number of Midland features introduced by Clayton to the SECR and subsequently the Southern Railway. The smokebox door was revised to the Ashford pattern, which omitted the use of central tightening handles in favour of clamps around the circumference. The batch was fitted with the Urie-designed, North British-built 5000 imp gal (22,730.5 l) capacity double-bogie tenders.
Maunsell's "Eastleigh Arthurs": second batch
With the "Scotch Arthurs" in service, the Southern Railway had an ample fleet of express passenger locomotives for its Western section routes. As part of a process of fleet standardisation, the Operating Department expressed a desire replace obsolescent locomotives on the Eastern and Central sections with the King Arthur class. In May 1925, a batch of 25 locomotives (Nos. E793–E817) based upon the Scotch Arthurs was ordered for construction at Eastleigh with smaller firebox grates and improved water heating surfaces. After the first 14 (Nos. E793–E806) were built, it was decided to discontinue construction in favour of Maunsell’s new 4-cylinder Lord Nelson class design in June 1926.The Operating Department intended to equip Nos. E793–E807 with six-wheel, 4000 imp gal (18,184.4 l) capacity tenders for use on the former SECR lines of the Eastern section. These were to replace Scotch Arthurs Nos. E763–E772 on boat train duties. This was because the 5000 imp gal (22,730.5 l) tenders attached to Nos. E763–E772 were better suited to the longer routes of the Western section. The final ten engines (Nos. E808–E817) were for the former LBSCR routes of the Central section, where short turntables restricted tender size to the 3500 imp gal (15,911.3 l) Ashford variety used on the N class. After the order was changed to the Lord Nelson class design, 14 N class tenders were fitted to Nos. E793–E806 for use the Central section. The high draw-gear (the link between locomotive and tender) of the N class tenders necessitated modification to the frames beneath the cab.
Naming the locomotives
- For class details, see: List of King Arthur class locomotives
When the former Drummond G14 and P14 4-6-0s were rebuilt to Maunsell’s N15 specification in February 1925, the Southern Railway decided to give names to all express passenger locomotives. Because of the railway's association with the West of England, the Public Relations Officer, John Elliot suggested that members of the N15 class should be named after characters and places associated with the legend of King Arthur
King Arthur
King Arthur is a legendary British leader of the late 5th and early 6th centuries, who, according to Medieval histories and romances, led the defence of Britain against Saxon invaders in the early 6th century. The details of Arthur's story are mainly composed of folklore and literary invention, and...
. When Maunsell was told of the decision to name the locomotives, he replied: "Tell Sir Herbert [Walker
Herbert Ashcombe Walker
Sir Herbert Ashcombe Walker, KCB was a British railway manager.-Early life:Walker was born in London 15 May 1868. He was educated at the North London Collegiate School and at Bruges.-Career:...
] I have no objection, but I warn you, it won't make any difference to the working of the engines". Walker was the General Manager of the Southern Railway, who had told Elliot that Maunsell's permission was required. The first G14 to be rebuilt, No. E453, was given the first name and christened King Arthur. The Urie locomotives (hitherto referred as N15s rather than King Arthurs) were also given names connected with Arthurian legend and were referred to as "Urie Arthurs"; the Maunsell batches of N15s were nicknamed the "Eastleigh" and "Scotch Arthurs".
Operational details
The N15 class was intended to haul heavy expresses over the long LSWR mainlinesSouth Western Main Line
The South Western Main Line is a railway line between London Waterloo and Weymouth on the Dorset coast, in the south of England. It is a major railway which serves many important commuter areas, as well as the major settlements of Southampton and Bournemouth...
between , Weymouth
Weymouth railway station
Weymouth railway station is a railway station serving the town of Weymouth, Dorset, England. The station is the terminus of both the South Western Main Line from London Waterloo and the Heart of Wessex Line from and .-History:...
, Exeter
Exeter Central railway station
Exeter Central railway station is the most centrally located of the railway stations in Exeter, Devon, England. It is smaller than St Davids which is on the west side of the city but it is served by trains on the London Waterloo to Exeter main line, and is also by local services to , and . From...
and Plymouth
Plymouth Friary railway station
Plymouth Friary railway station was the London and South Western Railway terminus in Plymouth, Devon, England.-History:London and South Western Railway trains first arrived at Plymouth on 17 May 1876, entering the town from the east...
. Locomotives were changed at before the upgrading of the South Western Mainline in 1922, when fast running through to Exeter was possible. The Southern Railway's motive power re-organisation following the Grouping
Railways Act 1921
The Railways Act 1921, also known as the Grouping Act, was an enactment by the British government of David Lloyd George intended to stem the losses being made by many of the country's 120 railway companies, move the railways away from internal competition, and to retain some of the benefits which...
of 1923 saw the class allocated to sheds across the network and used on to cross-country trains. Operations were expanded to more restricted Central and Eastern section mainlines in 1925, and suitably modified class members hauled commuter and heavy boat trains from to and expresses to . In 1931, No. E780 Sir Persant hauled the inaugural Bournemouth Belle
Bournemouth Belle
The Bournemouth Belle was a named train run by the Southern Railway from 1931 until nationalisation in 1948 and subsequently by British Railways until it was withdrawn on 9 July 1967....
Pullman
Pullman train (UK)
Pullman trains in Great Britain were mainline luxury railway services that operated with first-class coaches and a steward service, provided by the British Pullman Car Company.-Origins:...
train from Waterloo to .
In peacetime, the class was occasionally used on fast freights from Southampton Docks, although it was common to see them at the head of freight and troop trains during the Second World War. Ten "Urie Arthurs" were transferred to the London and North Eastern Railway
London and North Eastern Railway
The London and North Eastern Railway was the second-largest of the "Big Four" railway companies created by the Railways Act 1921 in Britain...
(LNER) in October 1942, and were based at Heaton shed for use on freight and occasional passenger trains in the north east and southern Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
. They returned to the Southern Railway in July 1943 after the introduction of United States Army Transportation Corps
United States Army Transportation Corps
The Transportation Corps was established 31 July 1942 by Executive Order 9082. The Transportation Corps is a combat service support branch of the U.S. Army, and was headquartered at Fort Eustis, Virginia, but has now moved to Fort Lee, Virginia. The Transportation Corps is responsible for the...
S160 class
USATC S160 Class
The United States Army Transportation Corps S160 Class is a class of 2-8-0 Consolidation steam locomotive designed for use in Europe during World War II for heavy freight work...
2-8-0
2-8-0
Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and no trailing wheels...
s into service. From 1945 the King Arthur class regularly deputised for Bulleid’s new Pacifics, which were experiencing poor serviceability due to mechanical failures. The entire class came into British Railways ownership in 1948: they could be found in most areas of the Southern Region
Southern Region of British Railways
The Southern Region was a region of British Railways from 1948. The region ceased to be an operating unit in its own right in the 1980s and was wound up at the end of 1992. The region covered south London, southern England and the south coast, including the busy commuter belt areas of Kent, Sussex...
on medium-length expresses and stopping trains on the ex-LSWR mainline.
Smoke deflector experiments
In 1926 the N15 class became the first in Britain equipped with smoke deflectors, with several designs tested. Experiments were undertaken throughout 1926 and included the fitting of a curved plate above the smokebox of No. E753 Melisande to channel air from below the chimney to lift the exhaust above the locomotive when on the move. Nos. E450 Sir Kay and E753 Sir Gillemere had air scoops attached to the chimney, whilst E772 Sir Percivale was fitted with large, square German-type smoke deflectors. Finally, No. E453 King Arthur was fitted with small, rectangular smoke deflectors fitted to the handrails on the smokebox sides. The experiments produced mixed results, and Maunsell requested the assistance of the University of LondonUniversity of London
-20th century:Shortly after 6 Burlington Gardens was vacated, the University went through a period of rapid expansion. Bedford College, Royal Holloway and the London School of Economics all joined in 1900, Regent's Park College, which had affiliated in 1841 became an official divinity school of the...
in staging wind tunnel tests
Wind tunnel
A wind tunnel is a research tool used in aerodynamic research to study the effects of air moving past solid objects.-Theory of operation:Wind tunnels were first proposed as a means of studying vehicles in free flight...
. These resulted in a standard plate design (illustrated in the infobox), which was gradually fitted to the class from late 1927 onwards.
Performance of the Urie batch and modifications
Under LSWR ownership, the N15s were initially well-received by crews, though the batch soon gained a reputation for poor steaming on long runs. Through running of the class into Exeter was stopped in favour of engine changes at Salisbury, and Urie attributed the problem to poor driving technique. A series of trial runs changed this assumption, and demonstrated that steam pressure gradually decreased on the flat. The trials also revealed that the robust construction of the motion produced the heaviest hammerblow of any British locomotive class, and had caused cracked frames on the test locomotive.Another criticism from locomotive crews concerned the exposed cab in bad weather, which necessitated the installation of a tarpaulin
Tarpaulin
A tarpaulin, colloquially tarp, is a large sheet of strong, flexible, water-resistant or waterproof material, often cloth such as canvas or polyester coated with urethane, or made of plastics such as polyethylene. In some places such as Australia, and in military slang, a tarp may be known as a...
sheet over the rear of the cab and the front of the tender, restricting rearward vision. The 1921 Coal Miners’ strike meant that two class members (Nos. 737 and 739) were converted to oil-burning. One of the modified locomotives subsequently caught fire at Salisbury shed, and both were reverted to coal firing by the end of the year. When the LSWR was amalgamated into the Southern Railway in 1923, Urie had done little to remedy the shortcomings of the N15s, and it fell to his successor to improve the class.
When Maunsell inherited the design as CME of the Southern Railway, he began trials using the weakest N15 (No. 442) in 1924. The results indicated that better performance could be obtained by altering the steam circuit, valve travel and draughting arrangements, although the first two recommendations were deemed too costly for immediate implementation by the Locomotive Committee. Eight extra King Arthur-type boilers were ordered from North British and fitted to N15s Nos. 737–742 by December 1925 in an effort to improve steaming. The remaining Urie boilers were fitted with standard Ross pop safety valves to ease maintenance. Maunsell also addressed draughting problems caused by the narrow Urie "stovepipe" chimney. The exhaust arrangements were modified on No. 737 using the King Arthur chimney design and reduced-diameter blastpipe
Blastpipe
The blastpipe is part of the exhaust system of a steam locomotive that discharges exhaust steam from the cylinders into the smokebox beneath the chimney in order to increase the draught through the fire.- History :...
s. This proved successful, and all "Urie N15s" were modified over the period 1925–1929. The oil-burning equipment was refitted to Nos. 737 and 739 during the 1926 General Strike
1926 United Kingdom general strike
The 1926 general strike in the United Kingdom was a general strike that lasted nine days, from 4 May 1926 to 13 May 1926. It was called by the general council of the Trades Union Congress in an unsuccessful attempt to force the British government to act to prevent wage reduction and worsening...
and removed in December of that year.
Beginning in 1928, all but No. 755 had their cylinder diameter reduced from 22 inches (558.8 mm) to 21 inches (533.4 mm) when renewals were due, improving speed on flat sections of railway, but affecting their performance on the gradients west of Salisbury. No. 755 The Red Knight was modified in 1940 by Maunsell’s successor, Oliver Bulleid
Oliver Bulleid
Oliver Vaughan Snell Bulleid was a British railway and mechanical engineer best known as the Chief Mechanical Engineer of the Southern Railway between 1937 and the 1948 nationalisation, developing many well-known locomotives.- Early life and Great Northern Railway :He was born in Invercargill,...
with his own design of 21 inches (533.4 mm) cylinders and streamlined steam passages. This was married to a Lemaître
Lemaître exhaust
The Lemaître exhaust is a type of Steam locomotive exhaust system developed by the Belgian engineer Jean Lemaître.-Construction:The Lemaître exhaust featured a blastpipe with 5 nozzles in a circular pattern exhausting up a large-diameter chimney stack, with a variable area nozzle exhausting up the...
multiple-jet blastpipe
Blastpipe
The blastpipe is part of the exhaust system of a steam locomotive that discharges exhaust steam from the cylinders into the smokebox beneath the chimney in order to increase the draught through the fire.- History :...
and wide-diameter chimney, allowing the locomotive to produce performances akin to the more powerful Lord Nelson class. Four other N15s were so modified with four more on order, though the latter was cancelled due to wartime shortages of metal. The soft exhaust of the Lemaître multiple-jet blastpipe precipitated an adjustment to the smoke deflectors on three converted locomotives, with the tops angled to the vertical in an attempt to improve air-flow along the boiler cladding. This failed to achieve the desired effect, and the final two modified locomotives retained the Maunsell-style deflectors.
The final modifications to the "Urie N15s" involved the conversion of five locomotives (Nos. 740, 745, 748, 749 and 752) to oil-firing in 1946–1947. This was in response to a government scheme to address a post-war coal shortage. The oil tanks were fabricated from welded steel and fitted within the tender coal space. After initial problems with No. 740 Merlin were rectified, the oil-fired locomotives proved good performers on Bournemouth services. A further addition to the oil-fired locomotives was electric headcode and cab lighting, which was retained when reverted to coal-firing in 1948.
Performance of the Maunsell batches and modifications
The improved front-end layout applied to the first batch of "Eastleigh Arthurs" (Nos. E448–E457) ensured continuous fast running on flat sections of track around London, although their propensity for speed was sometimes compromised over the hilly terrain west of Salisbury. The inside bearings of the Drummond "watercart" tenders proved problematic, as they were too small for the load carried and suffered from water ingress. The retention of the tall Drummond cab prevented use away from the Western section of the Southern Railway. Despite these problems, their operational reliability prompted the management to arrange the visit of No. E449 Sir Torre to the Darlington Railway Centenary celebrations in July 1925. No. E449 also recorded speeds of up to 90 mph (40.2 m/s) on the South West Mainline near in 1929. This proved that with the right components, Urie’s original design could perform well.Despite the successful use of modified N15 components to rebuild Nos. E448–E457, the mechanically similar "Scotch Arthurs" proved disappointing when put into service from May 1925. The performance of those allocated to the Eastern section was indifferent, and failed to improve upon the double-headed
Double-heading
In railroad terminology, double-heading or double heading indicates the use of two locomotives at the front of a train, each operated individually by its own crew. The practice of triple-heading involves the use of three locomotives....
ex-SECR 4-4-0
4-4-0
Under the Whyte notation for the classification of steam locomotives, 4-4-0 represents the wheel arrangement of four leading wheels on two axles , four powered and coupled driving wheels on two axles, and no trailing wheels...
s they were to replace. Reports of poor steaming and hot driving and tender wheel axleboxes were common from crewmen and shed fitters. After investigation, the problems were attributed to poor workmanship during construction as the North British Locomotive Company underquoted production costs to gain the contract. Defects were found in boiler construction across the batch, and necessitated six replacement boilers, re-riveting, re-fitting of tubes and replacement of firebox stays. The hot driving wheel axleboxes were caused by the main frames being out of alignment. A 1926 report suggested that all affected locomotives should be taken to Eastleigh for repair. Once repaired, the "Scotch Arthurs" proved as capable as the rest of the class in service.
"Scotch Arthurs" Nos. E763–E772 received new tenders between 1928 and 1930 in a series of tender exchanges with the Lord Nelson and LSWR S15 classes. This ensured that they could exchange their Urie 5000 imp gal (22,730.5 l) bogie tenders with the 4000 imp gal (18,184.4 l) Ashford design for use on the shorter Eastern section routes. Whilst useful for the roster clerks at Battersea shed, any transfer to the Western section was hampered because of their shorter range. By 1937, all had reverted to the Urie 5000 imp gal (22,730.5 l) bogie tenders, though Nos. E768–E772 were attached to new Maunsell flush-sided tenders with brake vacuum reservoirs fitted behind the coal space. These were again swapped with Maunsell LSWR-style bogie tenders fitted to the Lord Nelson class.
The second batch of "Eastleigh Arthurs" displaced the ex-K class tanks and ex-LBSCR H2 "Atlantic"
LB&SCR H2 class
The London, Brighton and South Coast Railway H2 class was a class of 4-4-2 steam locomotives for express passenger work. They were designed when D. E. Marsh was officially Locomotive Superintendent, and were built at Brighton Works in 1911 and 1912...
4-4-2
4-4-2 (locomotive)
Under the Whyte notation for the classification of steam locomotives, 4-4-2 represents the wheel arrangement of four leading wheels on two axles , four powered and coupled driving wheels on two axles, and two trailing wheels on one axle...
locomotives on the and routes respectively. They were well liked by crews and used on this part of the network until the arrival of electrification. No. E782 Sir Brian was used on the former Great Northern
Great Northern Railway (Great Britain)
The Great Northern Railway was a British railway company established by the Great Northern Railway Act of 1846. On 1 January 1923 the company lost its identity as a constituent of the newly formed London and North Eastern Railway....
main line for performance trials against the SECR K and K1 class tanks following a railway accident at Sevenoaks, Kent
Sevenoaks railway accident
The Sevenoaks railway accident occurred on 24 August 1927 between Dunton Green railway station and Sevenoaks railway station. The Southern Railway's afternoon express from Cannon Street to Deal left London at 5pm, in charge of River Class tank engine No 800 River Cray. Several passengers later...
in 1927. The tests were supervised by the London and North Eastern Railway
London and North Eastern Railway
The London and North Eastern Railway was the second-largest of the "Big Four" railway companies created by the Railways Act 1921 in Britain...
's CME, Sir Nigel Gresley
Nigel Gresley
Sir Herbert Nigel Gresley was one of Britain's most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer of the London and North Eastern Railway . He was the designer of some of the most famous steam locomotives in Britain, including the LNER Class A1 and LNER Class A4...
, who commented that the class was unstable at high speeds. The instability was caused by motion hammerblow and exacerbated by irregularities in track-work. This caused excessive stress to the axleboxes and poor riding characteristics on the footplate
Footplate
The footplate of a steam locomotive is a large metal plate that rests on top of the frames and is normally covered with wooden floorboards. It is usually the full width of the locomotive and extends from the front of the cab to the rear of cab or coal bunker just above the buffer beam. The...
. Despite this, the class benefited from an excellent maintenance regime.
Maunsell’s replacement Oliver Bulleid
Oliver Bulleid
Oliver Vaughan Snell Bulleid was a British railway and mechanical engineer best known as the Chief Mechanical Engineer of the Southern Railway between 1937 and the 1948 nationalisation, developing many well-known locomotives.- Early life and Great Northern Railway :He was born in Invercargill,...
believed that there was little need to improve draughting on this series. However, reports of poor steaming with No. 792 Sir Hervis de Revel gave him an opportunity to trial a Lemaître multiple-jet blastpipe and wide-diameter chimney on a Maunsell Arthur in 1940. This did not enhance performance to the extent of No. 755 The Red Knight. Under British Railways ownership, the locomotive was re-fitted with the Maunsell chimney in March 1952 with no further problems reported. In another wartime experiment, Bulleid fitted No. 783 Sir Gillemere with three thin "stovepipe" chimneys in November 1940. These were set in a triangular formation to reduce visibility of exhaust from the air in response to attacks made by low-flying aircraft on Southern Railway trains. The "stovepipes" were reduced to two, producing a fierce exhaust blast that dislodged soot inside tunnels and under bridges. The experiment was discontinued in February 1941 and the locomotive re-fitted with a Maunsell King Arthur chimney. The last experiment was with spark-arresting equipment in response to lineside fires caused by poor quality coal. Nos. 784 Sir Nerovens and 788 Sir Urre of the Mount were fitted with new wide-diameter chimneys in late 1947. Test-trains showed mixed results and the trials were stopped in 1951 after improvements in coal quality and the fitting of internal smokebox spark-arrestors.
Withdrawal
The detail variations across the class meant the "Urie N15s" were placed into store over the winters of 1949 and 1952. The Maunsell King Arthur examples were easier to maintain, and the large number of modern Bulleid Pacific and British Railways Standard classes were able to undertake similar duties. The "Urie N15s" were brought into service during the summer months, although their deteriorating condition was demonstrated when No. 30754 The Green Knight was withdrawn with cracked frames in 1953. The slow running-down of the "Urie N15s" continued between 1955–1957, and several were stored prior to withdrawal. The last three were withdrawn from Basingstoke shed, with No. 30738 "King Pellinore" the final example to cease operation in March 1958. All were broken up for scrap, though their names were given to 20 BR Standard class 5BR standard class 5
The British Railways Standard Class 5MT 4-6-0 was one of the standard classes of steam locomotives built by British Railways in the 1950s. 172 were built, essentially being a development of the LMS Stanier Class 5 4-6-0 .- Background :...
locomotives allocated to the Southern Region between 1959–1962.
The Maunsell King Arthur class also faced a decrease in suitable work on the Central and Eastern sections following the introduction of BR Standard class 5 and BR Standard class 4
BR standard class 4 4-6-0
The British Railways Standard Class 4 4-6-0 is a class of steam locomotives, 80 of which were built during the 1950s. Six have been preserved.-Background:...
4-6-0s in 1955. The gradual withdrawal of the "Urie N15s", H15s and SR N15x classes presented an opportunity to replace the ageing Drummond "watercart" tenders fitted to Nos. 448–457 with Urie 5000 imp gal (22,730.5 l) bogie tenders. This coincided with a 1958 programme to similarly change the 3500 imp gal (15,911.3 l) Ashford tenders fitted to eight of the second batch "Eastleigh Arthurs". The class remained intact until the completion of the Eastern section electrification
Railway electrification system
A railway electrification system supplies electrical energy to railway locomotives and multiple units as well as trams so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world...
when 17 were made redundant in 1959. More withdrawals took place in 1960 when an increase in Bulleid Pacifics allocated to the Western section reduced available work. The ranks thinned to 12 in 1961, and further withdrawals reduced the class to one, No. 30770 Sir Prianius. The class outlasted the newer – but less numerous – Lord Nelson
SR Lord Nelson Class
The SR class LN or Lord Nelson class is a type of 4-cylinder 4-6-0 steam locomotive designed for the Southern Railway by Richard Maunsell in 1926. They were intended for Continental boat trains between London and Dover harbour, but were also later used for express passenger work to the South-West...
class by one month when No. 30770 was withdrawn from Basingstoke Shed in November 1962.
LSWR and Southern Railway
Under LSWR ownership, the "Urie N15s" were painted in Urie’s LSWR sage green liveryLivery
A livery is a uniform, insignia or symbol adorning, in a non-military context, a person, an object or a vehicle that denotes a relationship between the wearer of the livery and an individual or corporate body. Often, elements of the heraldry relating to the individual or corporate body feature in...
for passenger locomotives. This was distinct from Drummond’s sage green because it was more olive in colour, and yellowed with cleaning and weathering. Black and white lining decorated the boiler bands and borders of the sage green panels. The lettering was in gilt: the initials "LSWR" located on the side of the tender, the locomotive number on the cabside.
The first Southern livery continued that of the LSWR, though with primrose yellow transfers
Decal
A decal or transfer is a plastic, cloth, paper or ceramic substrate that has printed on it a pattern or image that can be moved to another surface upon contact, usually with the aid of heat or water. The word is short for decalcomania...
showing "Southern" and the locomotive number, placed on the tender. The lining separating the black border on tender and cab side panels was changed to yellow. Primrose yellow transfers
Decal
A decal or transfer is a plastic, cloth, paper or ceramic substrate that has printed on it a pattern or image that can be moved to another surface upon contact, usually with the aid of heat or water. The word is short for decalcomania...
, showing "Southern" and the locomotive number, were placed on the tender. An "E" prefix was located above the tender number (e.g. E749), denoting that the class was registered for maintenance at Eastleigh works. The gilt numerals on the cabside and tender rear were replaced by a cast oval plate with "Southern Railway" around the edge and the number located in the centre. Yellow numerals were painted onto the front buffer-beam to ease identification. In February 1925 Maunsell developed a deeper green with black and white lining. This was applied to his new King Arthur class locomotives and the "Urie N15s" were similarly painted when overhauls were due. Wheels were olive-green with black tyres. From 1929 the "E" prefix was removed and the cast numerals on the tender rear were removed and replaced with yellow transfers (e.g. 749).
In May 1938, after Bulleid's appointment as CME, No. 749 Iseult was trialled in bright unlined light green with yellow-painted block numerals replacing the cast numberplates. The tender was given two designs of lettering, with "Southern" on one side and the initials "SR" on the other. The Board of Directors disapproved and Bulleid repainted the locomotive in darker malachite green
Malachite green
Malachite green is an organic compound that is used as a dyestuff and has emerged as a controversial agent in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper...
with black and white lining (this would later be applied to his Pacifics). The legend "Southern" in block-lettering remained on the tender, though the number was relocated to the cabside on one side and the smoke deflector on the other. Both were painted in a light "sunshine yellow". No. 749 was returned to Maunsell’s green livery.
Several variations of the Maunsell green, Urie sage green and Bulleid malachite green
Malachite green
Malachite green is an organic compound that is used as a dyestuff and has emerged as a controversial agent in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper...
liveries were tried with black, white/black, and yellow lining, some sporting a green panel on the smoke deflectors. However from 1942 to 1946, during the Second World War, members of the class under overhaul were turned out in unlined-black livery as a wartime economy measure, with green-shaded sunshine yellow lettering. The final Southern livery used from 1946 reverted to malachite green, with yellow/black lining, and sunshine yellow lettering. Some of the class (Nos. 782 and 800, Sir Brian and Sir Persant) did not receive this livery.
British Railways
British Railways gave the class the power classification of 5P after nationalisation in 1948. For the first 18 months the locomotives sported a transitional livery: Southern Railway malachite green with "British Railways" on the tender in sunshine yellow lettering. As each member of the class became due for a heavy general overhaul, they were repainted in the new standard British Railways express passenger livery of Brunswick green with orange and black lining from April 1949. Initially, the British Railways "Cycling Lion" crest was located on the tender, replaced from the 1957 by the later "Ferret and Dartboard" crest.Numbering was initially a continuation of the Southern Railway system, though an 'S' prefix was added to denote a pre-nationalisation locomotive, so that No. 448 would become No. s448. As each locomotive became due for overhaul and received its 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.
Operational assessment and preservation
- For class details and current status of the preserved locomotive, see: List of King Arthur class locomotives
After the poor steaming of the Urie batch was addressed, the class proved popular amongst crews, mechanically reliable and capable of high speeds. However, their heavy hammerblow at speed meant that they were prone to rough riding and instability. The two Maunsell batches with their streamlined steam passages and better draughting arrangements were superior in performance, and were a popular choice when Bulleid’s locomotives were unavailable. Their use of standard parts considerably eased maintenance, and the fitting of different tender and cab sizes meant few operational restrictions for the class on mainline routes. The class gave many years of service, and were noted for their ability to "do the job". The electrification of the Eastern and Central sections and the increasing number of Bulleid Pacifics in service meant the lack of a suitable role for the class under British Railways ownership. In spite of the reduction in work, high mileages were obtained with No. 30745 Tintagel achieving 1464032 miles (2,356,125.3 km) in service.
The decision to preserve a member of the class was made in November 1960. It was first intended to preserve the King Arthur class doyen No. 453 King Arthur, and it was stored for a time after withdrawal in 1961 pending restoration to museum condition. However, it was decided to restore the preserved locomotive to as-built condition, and the lack of a suitable Drummond "watercart" tender precluded this consideration. No. 453 was subsequently scrapped and it was decided to preserve one of the North British-built batch, No. 30777 Sir Lamiel
LSWR N15 Class 30777 Sir Lamiel
Southern Railway 777 Sir Lamiel is an N15 “King Arthur” class 4-6-0 steam locomotive built for the Southern Railway by the North British Locomotive Company in June 1925, and withdrawn from service in October 1961. It is now preserved and used on the Network Rail infrastructure in association with...
, withdrawn in October 1961, instead. Sir Lamiel was named after a character in Thomas Malory
Thomas Malory
Sir Thomas Malory was an English writer, the author or compiler of Le Morte d'Arthur. The antiquary John Leland as well as John Bale believed him to be Welsh, but most modern scholars, beginning with G. L...
's Le Morte d'Arthur
Le Morte d'Arthur
Le Morte d'Arthur is a compilation by Sir Thomas Malory of Romance tales about the legendary King Arthur, Guinevere, Lancelot, and the Knights of the Round Table...
, Sir Lamiel of Cardiff. This locomotive was restored to Maunsell livery as No. E777, and became part of the National Collection. It was restored to the later British Railways livery in 2003, and No. 30777 can be seen at the Great Central Railway
Great Central Railway (preserved)
The Great Central Railway is a heritage railway split into two adjacent sections, one in Leicestershire and the other Nottinghamshire.The Leicestershire section is currently Britain's only double track mainline heritage railway, with of working double track, period signalling, locomotives and...
and on the railway network hauling mainline railtours as of 2010.