SR Class W
Encyclopedia
The SR Class W were 3-cylinder 2-6-4T tank engines designed in 1929 by Richard Maunsell
for use on the Southern Railway . They were introduced in 1932 and constructed at Eastleigh and Ashford. The class was intended for short distance, inter-company/regional freight traffic transfer in London
, and were standardised with parts from the N, N1, U and U1 classes.
was surrounded by a number of large freight Marshalling yards, where long distance freight was brought and re-organised into new trains for onward transmission to its destination. Three of these yards, at Feltham
, Norwood
and Hither Green
were operated by the Southern Railway
. The requirement for a fast freight transfer locomotive between these yards, and across London to other railway yards provided a challenge for Richard Maunsell. The electrified suburban lines were busy with commuter traffic that took priority over freight workings, and the London network abounded in junctions and signal stops. The design brief called for a powerful locomotive with good acceleration and adhesion. One that was able to climb the steep gradients over the flying junctions that were to be found all over the Southern Railway's London network. The ability to operate over tight curves and be able to move from a standstill on the aforementioned gradients were also key considerations that needed to be incorporated into the design. A tank locomotive
design was also preferable since the journeys were relatively short, and the work would involve frequent changes in direction.
was considered at first, but due to the specialist characteristics of the design as a yard engine for marshalling freight, they were not deemed fit for the purpose of hauling loads under the tight timings of London's railway system. The solution was a smaller wheeled version of the ill-fated K1 class with three cylinders to allow for better acceleration, with three sets Walschaerts valve gear.
The resultant W Class, was designed in 1929.As a result of the rebuilding of the 'River' K1 class 2-6-4 tank engines following the Sevenoaks rail crash
, the surplus bogies and leading wheels were earmarked for the new design. The 2-6-4 wheel arrangement was settled upon as being ideal for intensive suburban routes, and the use of parts from the K Class and the same boiler as used on the N, N1 and U1 classes enabled the standardization of Southern locomotives to continue. The locomotives were provided with heavy braking equipment to cater for freight wagons with or without continuous brakes that were in circulation at the time. With this in mind, the class were unusually provided with extra braking on the bogies and trailing wheels.
and the boilers at Brighton railway works
. However by the time that Ashford had delivered the first five sets of frames in early 1930 a severe trade recession
meant that they were no longer needed. The frames were stored and the boilers used as spares for the N and U class locomotives. By mid 1931 trade had recovered to allow construction of the initial five to be completed. These were delivered during January and February 1932. The components for the remaining five locomotives still on order were gathered at Eastleigh during 1932, but once again their construction was delayed pending a more sustained economic recovery, and the boilers were used elsewhere.
A second batch consisting of these five locomotives together with a further five ordered in March 1930 were eventually delivered between April 1935 and April 1936. Eastleigh works was then committed to the construction of the Schools class and so the order was transferred to Ashford.
to Old Oak Common
, Willesden
, Cricklewood
and Ferme Park marshalling yards.
The class was generally well liked by their crews apart from the fact that the driver was on the right hand side of the Eastleigh batch, which made accurate stopping difficult when signalling was predominantly on the left on the Southern network. This would have meant that the fireman was frequently utilised as lookout on the left hand side.
In 1948 there was a chronic shortage of large passenger tank locomotives on the un-electrified lines of the former London Brighton and South Coast Railway. As a result, trials of the class were made with passenger stock between Victoria railway station and Tunbridge Wells West railway station
via the Oxted Line
. However, the like the K & K1 classes the W class were found to be unstable at speed and were banned from use on passenger trains.
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....
for use on the Southern Railway . They were introduced in 1932 and constructed at Eastleigh and Ashford. The class was intended for short distance, inter-company/regional freight traffic transfer in 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...
, and were standardised with parts from the N, N1, U and U1 classes.
Background
From the 1920s, 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...
was surrounded by a number of large freight Marshalling yards, where long distance freight was brought and re-organised into new trains for onward transmission to its destination. Three of these yards, 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...
, Norwood
Norwood Junction railway station
Norwood Junction railway station is in South Norwood in the London Borough of Croydon in south London, in Travelcard Zone 4.The station is managed by London Overground and trains operated by Southern and London Overground .-History:...
and Hither Green
Hither Green railway station
Hither Green is a railway station located in Hither Green in the London Borough of Lewisham, in southeast London, United Kingdom. Hither Green is a busy commuter station with services to several London termini and destinations to the southeast Hither Green is a railway station located in Hither...
were operated by 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...
. The requirement for a fast freight transfer locomotive between these yards, and across London to other railway yards provided a challenge for Richard Maunsell. The electrified suburban lines were busy with commuter traffic that took priority over freight workings, and the London network abounded in junctions and signal stops. The design brief called for a powerful locomotive with good acceleration and adhesion. One that was able to climb the steep gradients over the flying junctions that were to be found all over the Southern Railway's London network. The ability to operate over tight curves and be able to move from a standstill on the aforementioned gradients were also key considerations that needed to be incorporated into the design. A tank locomotive
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...
design was also preferable since the journeys were relatively short, and the work would involve frequent changes in direction.
Design
The SR Z ClassSR Z Class
The SR Z class was an 0-8-0T 3-cylinder tank engine designed by Richard Maunsell and intended for heavy shunting on the Southern Railway, the first eight entering into service in 1929...
was considered at first, but due to the specialist characteristics of the design as a yard engine for marshalling freight, they were not deemed fit for the purpose of hauling loads under the tight timings of London's railway system. The solution was a smaller wheeled version of the ill-fated K1 class with three cylinders to allow for better acceleration, with three sets Walschaerts valve gear.
The resultant W Class, was designed in 1929.As a result of the rebuilding of the 'River' K1 class 2-6-4 tank engines following the Sevenoaks rail crash
Sevenoaks railway station
Sevenoaks railway station serves the town of Sevenoaks in Kent. Train services are provided by Southeastern.Trains from the station run northbound to London Bridge, Cannon Street , Waterloo East and London Charing Cross via Orpington, to London Blackfriars via Swanley and Catford, and southbound to...
, the surplus bogies and leading wheels were earmarked for the new design. The 2-6-4 wheel arrangement was settled upon as being ideal for intensive suburban routes, and the use of parts from the K Class and the same boiler as used on the N, N1 and U1 classes enabled the standardization of Southern locomotives to continue. The locomotives were provided with heavy braking equipment to cater for freight wagons with or without continuous brakes that were in circulation at the time. With this in mind, the class were unusually provided with extra braking on the bogies and trailing wheels.
Construction history
An initial order was place with Eastleigh railway works for ten locomotives, with the frames to be constructed at Ashford railway worksAshford 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...
and the boilers at Brighton railway works
Brighton railway works
Brighton railway works was one of the earliest railway-owned locomotive repair works, founded in 1840 by the London and Brighton Railway in Brighton, England, and thus pre-dating the more famous railway works at Crewe, Doncaster and Swindon...
. However by the time that Ashford had delivered the first five sets of frames in early 1930 a severe trade recession
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
meant that they were no longer needed. The frames were stored and the boilers used as spares for the N and U class locomotives. By mid 1931 trade had recovered to allow construction of the initial five to be completed. These were delivered during January and February 1932. The components for the remaining five locomotives still on order were gathered at Eastleigh during 1932, but once again their construction was delayed pending a more sustained economic recovery, and the boilers were used elsewhere.
A second batch consisting of these five locomotives together with a further five ordered in March 1930 were eventually delivered between April 1935 and April 1936. Eastleigh works was then committed to the construction of the Schools class and so the order was transferred to Ashford.
Variations
The two batches differed from each other because the Eastleigh batch had gravity sanding capability and steam regulators on the right hand side, whilst the Ashford batch had steam sanding and regulators on the left, as was common on most other classes of Southern locomotives.Modifications
The first batch was modified between 1959 and 1960 to incorporate steam sanding, as this was already present on the Ashford batch. The right hand driving, however, remained.Southern
The first batch was turned out in black livery with green lining, and were numbered 1911–1915 with 'Southern' in yellow on the water tanks. The Ashford batch was outshopped in unlined black livery, and the initial batch were also converted to this new livery. These locomotives were numbered 1916–1925.Post-1948 (nationalisation)
The locomotives retained their freight black liveries, and the BR crest was placed on the water tank sides. Numbering was per the BR standard numbering system, in the range 31911–31925.Operational details
The class was mainly used around London working from Hither Green, Norwood and Feltham yards. They were also used on inter-company/regional transfer freight duties over the West London LineWest London Line
The West London Line is a short railway in inner West London which links lines at in the south to lines near Willesden Junction in the north. It has always been an important cross-London link especially for freight services...
to Old Oak Common
Old Oak Common
Old Oak Common is an area of London between Harlesden and Acton known for its railway depots, particularly Old Oak Common TMD. Further south lies an open area, Wormwood Scrubs Park, and Wormwood Scrubs prison...
, Willesden
Willesden Junction station
Willesden Junction station is a Network Rail station in Harlesden, northwest London, UK. It is served by both London Overground and the Bakerloo line of the London Underground.-History:The station developed on three contiguous sites:...
, Cricklewood
Cricklewood railway station
Cricklewood railway station is in the London Borough of Barnet in North London. The station lies on the north-south Midland Main Line where it crosses Cricklewood Lane. It is served by First Capital Connect services as part of the Thameslink service...
and Ferme Park marshalling yards.
The class was generally well liked by their crews apart from the fact that the driver was on the right hand side of the Eastleigh batch, which made accurate stopping difficult when signalling was predominantly on the left on the Southern network. This would have meant that the fireman was frequently utilised as lookout on the left hand side.
In 1948 there was a chronic shortage of large passenger tank locomotives on the un-electrified lines of the former London Brighton and South Coast Railway. As a result, trials of the class were made with passenger stock between Victoria railway station and Tunbridge Wells West railway station
Tunbridge Wells West railway station
Tunbridge Wells West is a railway station located in Royal Tunbridge Wells, Kent. It is one of two railway stations in Tunbridge Wells constructed by rival companies. The other, Tunbridge Wells Central was opened in 1845 by the South Eastern Railway . Tunbridge Wells West was closed to mainline...
via the Oxted Line
Oxted Line
The Oxted Line is a railway line in southern England. It was originally operated jointly by the London, Brighton and South Coast Railway and the South Eastern Railway. It is now part of the Southern franchise....
. However, the like the K & K1 classes the W class were found to be unstable at speed and were banned from use on passenger trains.