LSWR Class S15
Encyclopedia
The LSWR S15 class was a British 2-cylinder 4-6-0
freight steam locomotive
designed by Robert W. Urie, based on his H15 class and N15 class
locomotives. The class had a complex build history, spanning several years of construction from 1920 to 1936. The first examples were constructed for the London and South Western Railway
(LSWR), where they hauled freight trains to the south coast ports and further west to Exeter
, as well as occasional passenger work in conjunction with their larger-wheeled N15 class counterparts.
Following the Grouping of railway companies
in 1923, the LSWR became part of the Southern Railway
, and the Chief Mechanical Engineer
(CME) of the newly formed company, Richard Maunsell
, increased the S15 class strength to 45 locomotives. Maunsell incorporated several improvements, notably to the steam circuit and the locomotive's loading gauge
, allowing it to operate on routes with height and width restrictions.
The new locomotives were built in three batches at Eastleigh
, and were in service with the Southern Railway for 14 years. The locomotives continued in operation with the Southern Region of British Railways
until 1966. Seven examples have been preserved for use on heritage railways, and are currently in varying states of repair.
's freight yards to the southwest of England
. As the LSWR lacked existing freight designs capable of undertaking this task, a new design was needed to serve the south coast ports of Portsmouth
, Weymouth and Southampton
. The design was also to power traffic including milk trains, which required fast transit to the dairies in London. Robert Urie used this opportunity to develop his recent H15 class design further, applying the 4-6-0 locomotive concept to a purpose-built freight design built to order number S15. It was this order number that gave the class the name "S15".
in three discrete batches between February 1920 and December 1936.
, the two-cylinders
and valve gear
were standardised between the classes, although a taper boiler was used on the S15 and N15 classes, as opposed to the parallel boiler of the H15 class. The only other major difference was the smaller diameter of the driving wheels. Smaller diameter wheels gave better traction
, essential for a fast freight locomotive.
By May 1921 sixteen were in service, and were mostly allocated to the London area, including the new marshalling yard at Feltham
. Despite being mechanically sound, changes were made to Urie's original design after the Grouping of railway companies
in 1923.
Urie retired as Locomotive Superintendent when the LSWR was amalgamated into the Southern Railway in 1923. Richard Maunsell was given the newly created post of CME to the Southern Railway, and decided to revise the cylinder arrangement of the locomotive. In doing so, he delayed the construction of further locomotives until the modifications had been made. When the modifications were trialled in service, it became evident amongst locomotive crews that Maunsell had taken a sound design and made it better, achieving a consistent locomotive capable of undertaking all the tasks for which it was intended. With the successful implementation of the modifications, permission was given by the management of the Southern Railway for a second batch of locomotives to be constructed.
was also modified for operation on the Southern's new composite loading gauge
, and differed from previous batches in having the Ashford-style cab, which was usually fitted to LBSCR locomotives. Unlike the original Drummond cab that was also favoured by Urie, the Ashford-style cab was of an all-steel
construction and had a roof that was flush with the cab sides. 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 Maunsell's chief draughtsman James Clayton, who transferred to Ashford Works in 1914 from the Midland Railway. Variants of this cab became standard for all new Southern Railway locomotives and converted tank engines
.
Other modifications included the lengthening of valve travel, and fitting larger outside steam pipes to streamline the flow of steam into the cylinders. Fifteen locomotives of this revised design were built in 1927, and some were given 4000 gallons (18,184.4 l) six-wheeled tenders for use on the Southern Railway's Central section. This allowed the locomotive to be turned on the shorter turntables found on this part of the network. From new, the rest of the class was equipped with the Urie 5000 gallons (22,730.5 l) eight-wheel bogie tender, which allowed the class to operate on the extended freight routes of the Southern Railway's Western section. The standardisation measures undertaken by both Urie and Maunsell were soon vindicated by the fact that tenders and other parts were swapped with those of other classes on the Southern Railway when locomotives were under overhaul.
to improve visibility from the footplate when travelling at speed. This modification was a feature that became common to most Maunsell-influenced designs.
, Southampton
and Nine Elms. The S15s were also vary capable passenger engines, being able to deputise in situations where there was a shortage of passenger locomotives during peak holiday periods. Both Urie and Maunsell S15s spent most of their working lives on the Southern Railway's Western section, although they were sometimes used on inter-regional freights. In order to increase maintenance efficiency, all Urie S15 locomotives (which had the lower boiler pressure) were concentrated at the Southern Railway's London
freight depot at Feltham. This yard also featured the Maunsell S15s, which were allocated to Exmouth Junction
, Hither Green
and Salisbury
, demonstrating the "go anywhere" nature of the class. Despite the design being only a year newer, the S15s outlasted their N15 King Arthur class counterparts because of their dual freight/passenger abilities, though they were retired between 1962 and 1966 as part of the British Railways Modernisation Plan. Maunsell S15 number 30837 became the final member of the class in operation, returning to Feltham in January 1966 to work a farewell rail tour.
, although some have yet to be restored to working order as of February 2009:
The first Southern Railway livery continued that of the LSWR, but with the number displayed on the tender. However, from 1925, a darker Olive-type green was substituted, and the entire class was so painted.
Wheels were green with black tyres, and the cabside numbers were replaced by a cast oval plate with "Southern Railway" around the edge and the number in the centre. Primrose Yellow "Southern" and locomotive number transfers were placed on the tender tank. From 1927 the Maunsell locomotives were given black livery with green lining, and remained in that guise with little modification until nationalisation.
The only slight livery modification occurred before the Second World War, when Oliver Bulleid
introduced the "Sunshine Yellow" lettering and numbering. A further modification was the application of a green shaded "Sunshine" lettering during the war. This was finally reverted to "Sunshine Yellow" lettering and numbering after the war. Nos.496–515 were built between 1919 and 1921, Nos.823–837 were delivered from Eastleigh during 1927 and 1928 and a further ten, No.838–847, were authorised in 1931.
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...
freight 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, based on his H15 class and N15 class
LSWR N15 Class
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...
locomotives. The class had a complex build history, spanning several years of construction from 1920 to 1936. The first examples were 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 freight 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...
, as well as occasional passenger work in conjunction with their larger-wheeled N15 class counterparts.
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...
, and 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....
, increased the S15 class strength to 45 locomotives. Maunsell incorporated several improvements, notably to the steam circuit and the locomotive's 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...
, allowing it to operate on routes with height and width restrictions.
The new locomotives were built in three batches at Eastleigh
Eastleigh Works
Eastleigh Works is a locomotive, carriage and wagon building and repair facility in the town of Eastleigh in the county of Hampshire in England.-History under the LSWR:...
, and were in service with the Southern Railway for 14 years. The locomotives continued in operation with the Southern Region of British Railways
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...
until 1966. Seven examples have been preserved for use on heritage railways, and are currently in varying states of repair.
Background
During the First World War, the LSWR management wished to address the requirement for a modern, standard heavy freight locomotive to work from LondonLondon
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...
's freight yards to the southwest of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. As the LSWR lacked existing freight designs capable of undertaking this task, a new design was needed to serve the south coast 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...
. The design was also to power traffic including milk trains, which required fast transit to the dairies in London. Robert Urie used this opportunity to develop his recent H15 class design further, applying the 4-6-0 locomotive concept to a purpose-built freight design built to order number S15. It was this order number that gave the class the name "S15".
Construction history
The S15 class were all built by Eastleigh WorksEastleigh Works
Eastleigh Works is a locomotive, carriage and wagon building and repair facility in the town of Eastleigh in the county of Hampshire in England.-History under the LSWR:...
in three discrete batches between February 1920 and December 1936.
| Year | Order | Quantity | LSWR / SR numbers | Notes |
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Final batch of 4-6-0 locomotives built by the Southern Railway. |
First batch – Urie 1920-21
This was the third design by Robert Urie for the LSWR. The outline was made during the First World War, and incorporated lessons learned from the operation of his H15 class, a design that was to provide the basis for future standardisation on the LSWR. To economise on maintenance, the S15 class had interchangeable components that could be used on a similar design, the N15 class passenger locomotive, which had the same overall appearance. Details such as the boilerBoiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...
, the two-cylinders
Cylinder (steam locomotive)
The cylinders of a steam locomotive are the components that convert the power stored in the steam into motion.Cylinders may be arranged in several different ways.-Early locomotives:...
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...
were standardised between the classes, although a taper boiler was used on the S15 and N15 classes, as opposed to the parallel boiler of the H15 class. The only other major difference was the smaller diameter of the driving wheels. Smaller diameter wheels gave better traction
Traction (engineering)
Traction refers to the maximum frictional force that can be produced between surfaces without slipping.The units of traction are those of force, or if expressed as a coefficient of traction a ratio.-Traction:...
, essential for a fast freight locomotive.
By May 1921 sixteen were in service, and were mostly allocated to the London area, including the new marshalling yard at Feltham
Feltham marshalling yard
Feltham marshalling yard, also known as Feltham hump yard, was a large railway marshalling yard designed for the concentration of freight traffic to and from South West London, and for transfer to other marshalling yards in London. It was built on the Waterloo to Reading Line...
. Despite being mechanically sound, changes were made to Urie's original design after 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.
Urie retired as Locomotive Superintendent when the LSWR was amalgamated into the Southern Railway in 1923. Richard Maunsell was given the newly created post of CME to the Southern Railway, and decided to revise the cylinder arrangement of the locomotive. In doing so, he delayed the construction of further locomotives until the modifications had been made. When the modifications were trialled in service, it became evident amongst locomotive crews that Maunsell had taken a sound design and made it better, achieving a consistent locomotive capable of undertaking all the tasks for which it was intended. With the successful implementation of the modifications, permission was given by the management of the Southern Railway for a second batch of locomotives to be constructed.
Second batch – Maunsell 1927–28
Maunsell's modifications included increasing the boiler pressure from 180 psi (1.24 MPa) to 200 psi (1.38 MPa), and the reduction of the cylinder bore by half an inch. The footplateFootplate
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...
was also modified for operation on 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 the Ashford-style cab, which was usually fitted to LBSCR locomotives. Unlike the original Drummond cab that was also favoured by Urie, the Ashford-style cab was of an all-steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
construction and had a roof that was flush with the cab sides. 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 Maunsell's chief draughtsman James Clayton, who transferred to Ashford Works in 1914 from the Midland Railway. Variants of this cab became standard for all new Southern Railway locomotives and converted tank engines
Tank locomotive
A tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of pulling it behind it in a tender. It will most likely also have some kind of bunker to hold the fuel. There are several different types of tank locomotive dependent upon...
.
Other modifications included the lengthening of valve travel, and fitting larger outside steam pipes to streamline the flow of steam into the cylinders. Fifteen locomotives of this revised design were built in 1927, and some were given 4000 gallons (18,184.4 l) six-wheeled tenders for use on the Southern Railway's Central section. This allowed the locomotive to be turned on the shorter turntables found on this part of the network. From new, the rest of the class was equipped with the Urie 5000 gallons (22,730.5 l) eight-wheel bogie tender, which allowed the class to operate on the extended freight routes of the Southern Railway's Western section. The standardisation measures undertaken by both Urie and Maunsell were soon vindicated by the fact that tenders and other parts were swapped with those of other classes on the Southern Railway when locomotives were under overhaul.
Third batch – Maunsell 1936
The benefits gained by Maunsell's modifications showed in the improved performance of the first batch of Maunsell S15s over their Urie-built predecessors. A third batch was ordered in 1931, coinciding with a downturn in the volume of freight due to the economic depression. This meant that the last of the S15 class was not completed until 1936, although weight-saving modifications were undertaken to this batch. A final modification was also applied to the class at this time, when all locomotives were equipped with smoke deflectorsSmoke 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....
to improve visibility from the footplate when travelling at speed. This modification was a feature that became common to most Maunsell-influenced designs.
Operational details
After modification by Maunsell, the S15 class was regarded by locomotive crews as an excellent goods engine best known for working heavy night express goods trains between ExeterExeter
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...
, 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...
and Nine Elms. The S15s were also vary capable passenger engines, being able to deputise in situations where there was a shortage of passenger locomotives during peak holiday periods. Both Urie and Maunsell S15s spent most of their working lives on the Southern Railway's Western section, although they were sometimes used on inter-regional freights. In order to increase maintenance efficiency, all Urie S15 locomotives (which had the lower boiler pressure) were concentrated at the Southern Railway's 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...
freight depot at Feltham. This yard also featured the Maunsell S15s, which were allocated to Exmouth Junction
Exmouth Junction
Exmouth Junction is the railway junction where the Exmouth branch line diverges from the London Waterloo to Exeter main line in Exeter, Devon, England. It was for many years the location for one of the largest engine sheds in the former London and South Western Railway...
, Hither Green
Hither Green
Hither Green is a district in south east London, England, located in the London Borough of Lewisham. It is situated 6.6 miles south east of Charing Cross, and on the Prime Meridian....
and Salisbury
Salisbury
Salisbury is a cathedral city in Wiltshire, England and the only city in the county. It is the second largest settlement in the county...
, demonstrating the "go anywhere" nature of the class. Despite the design being only a year newer, the S15s outlasted their N15 King Arthur class counterparts because of their dual freight/passenger abilities, though they were retired between 1962 and 1966 as part of the British Railways Modernisation Plan. Maunsell S15 number 30837 became the final member of the class in operation, returning to Feltham in January 1966 to work a farewell rail tour.
Preservation
Seven S15s have been preserved, two Urie examples and five by Maunsell, and can be seen at several heritage railways around the country. All surviving members of the class were purchased from Woodham Brothers scrapyard in Barry, Vale of Glamorgan, South WalesSouth Wales
South Wales is an area of Wales bordered by England and the Bristol Channel to the east and south, and Mid Wales and West Wales to the north and west. The most densely populated region in the south-west of the United Kingdom, it is home to around 2.1 million people and includes the capital city of...
, although some have yet to be restored to working order as of February 2009:
- 30499 Watercress LineWatercress LineThe Watercress Line is the marketing name of the Mid-Hants Railway, a heritage railway in Hampshire, England, running from New Alresford to Alton where it connects to the National Rail network. The line gained its popular name in the days that it was used to transport locally grown watercress to...
; still in scrapyard condition, owned by Urie Locomotive Society. - 30506 Watercress LineWatercress LineThe Watercress Line is the marketing name of the Mid-Hants Railway, a heritage railway in Hampshire, England, running from New Alresford to Alton where it connects to the National Rail network. The line gained its popular name in the days that it was used to transport locally grown watercress to...
; owned by Urie Locomotive Society. - 30825 North Yorkshire Moors RailwayNorth Yorkshire Moors RailwayThe North Yorkshire Moors Railway is a heritage railway in North Yorkshire, England. First opened in 1836 as the Whitby and Pickering Railway, the railway was planned in 1831 by George Stephenson as a means of opening up trade routes inland from the then important seaport of Whitby. The line...
; currently the only operational class member in 2009. - 30828 Watercress LineWatercress LineThe Watercress Line is the marketing name of the Mid-Hants Railway, a heritage railway in Hampshire, England, running from New Alresford to Alton where it connects to the National Rail network. The line gained its popular name in the days that it was used to transport locally grown watercress to...
; given the name Harry A. Frith in preservation. - 30830 North Yorkshire Moors RailwayNorth Yorkshire Moors RailwayThe North Yorkshire Moors Railway is a heritage railway in North Yorkshire, England. First opened in 1836 as the Whitby and Pickering Railway, the railway was planned in 1831 by George Stephenson as a means of opening up trade routes inland from the then important seaport of Whitby. The line...
; this locomotive has been a source of spares for the other class members on this railway. However it must be restored as 830, a condition of sale, restoration under way. 830 was based at the Bluebell Railway where 847 is, for a number of years before moving to the North Yorkshire Moors Railway. - 30841 North Yorkshire Moors RailwayNorth Yorkshire Moors RailwayThe North Yorkshire Moors Railway is a heritage railway in North Yorkshire, England. First opened in 1836 as the Whitby and Pickering Railway, the railway was planned in 1831 by George Stephenson as a means of opening up trade routes inland from the then important seaport of Whitby. The line...
; parts used on 30825. This locomotive was the NYMR main locomotive in the 1990s and has appeared in a number of 'Heartbeat' episodes. - 30847 Bluebell RailwayBluebell RailwayThe Bluebell Railway is a heritage line running for nine miles along the border between East and West Sussex, England. Steam trains are operated between and , with an intermediate station at .The railway is managed and run largely by volunteers...
; this locomotive was the last S15 constructed, built in 1936, owned by Maunsell Locomotive Society.
LSWR and Southern Railway
Under LSWR ownership the S15s were painted in the late LSWR dark Holly Green livery, with the same black and light green lining applied to most of the LSWR's freight designs. Gilt lettering and numbering was located on the tender and cabside respectively. The initials "LSWR" were located on the tender.The first Southern Railway livery continued that of the LSWR, but with the number displayed on the tender. However, from 1925, a darker Olive-type green was substituted, and the entire class was so painted.
Wheels were green with black tyres, and the cabside numbers were replaced by a cast oval plate with "Southern Railway" around the edge and the number in the centre. Primrose Yellow "Southern" and locomotive number transfers were placed on the tender tank. From 1927 the Maunsell locomotives were given black livery with green lining, and remained in that guise with little modification until nationalisation.
The only slight livery modification occurred before the Second World War, when 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,...
introduced the "Sunshine Yellow" lettering and numbering. A further modification was the application of a green shaded "Sunshine" lettering during the war. This was finally reverted to "Sunshine Yellow" lettering and numbering after the war. Nos.496–515 were built between 1919 and 1921, Nos.823–837 were delivered from Eastleigh during 1927 and 1928 and a further ten, No.838–847, were authorised in 1931.
British Railways
After a period in British Railways transitional livery the entire class was painted in British Railways Goods Black livery with no lining, the numbering located on the cabsides and the British Railways crest on the tender sides. Numbering was initially as per Southern Railway with an "s" prefix, but the locomotives were eventually re-numbered under the British Railways standard numbering system according to batch. They were numbered in the series of 30496–30515 for the Urie batch, 30823–30837 for the second batch, and 30838–30847 for the third.External links
- SEMG gallery
- Railuk database
- http://www.bluebell-railway.co.uk/bluebell/loco_overhaul.html#847