The LSWR D15 class

4-4-0 4-4-0, in the Whyte notation, denotes a steam locomotive with a wheel arrangement of four leading wheels on two axles (usually in a leading bogie), four powered and coupled driving wheels on two axles, and no trailing wheels. First built in the ...

was the last

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

design by

Dugald Drummond Dugald Drummond (1 January 1840 – 8 November 1912) 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. He was the older brother of the eng ...

for the

London and South Western Railway The London and South Western Railway (LSWR, sometimes written L&SWR) was a railway company in England from 1838 to 1922. Originating as the London and Southampton Railway, its network extended to Dorchester and Weymouth, to Salisbury, Exete ...

in 1912. By 1912, Dugald Drummond had built several classes of unsuccessful

4-6-0 A 4-6-0 steam locomotive, under the Whyte notation for the classification of steam locomotives by wheel arrangement, has four leading wheels on two axles in a leading bogie and six powered and coupled driving wheels on three axles with the abs ...

express passenger locomotives. The result of these failures was that when he designed what was to be his last class in 1911, a new 4-4-0 design emerged from

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 LSWR The London and South Western Railway (LSWR) opened a carriage and wagon works at Eas ...

in February 1912, with what was to be the first of his D15 class.

Technical details

Boiler

In line with the typical Drummond layout, the D15s had a short

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 ...

with wing plates. The

boiler A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, centra ...

was based on that fitted to the 1905 rebuild of his first double-single, T7 class number 720 of 1897; and had a long firebox with a sloping grate. This resulted in the boiler being pitched higher than usual to allow clearance over the trailing axle.

Water feed

An exhaust steam

feedwater heater A feedwater heater is a power plant component used to pre-heat water delivered to a steam generating boiler. Preheating the feedwater reduces the irreversibilities involved in steam generation and therefore improves the thermodynamic efficiency o ...

was provided and the boiler fed by duplex pumps located on the frames, between the coupled wheels.

Tenders

The class was initially given the "intermediate" type of eight-wheel, double bogie tender with inside bogie frames carrying of coal and of water, due to the lack of water troughs on the line. By 1923, the eight-wheeled tenders had been replaced by six-wheeled versions transferred from K10 and L11 locomotives.

Superheaters

After Drummond's death,

Robert Urie Robert Wallace Urie (22 October 1854 – 6 January 1937) was a Scottish locomotive engineer who was the last chief mechanical engineer of the London and South Western Railway. Career After serving an apprenticeship with and working for vario ...

, his successor, fitted the class with Eastleigh

superheater A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, in some steam engines, and in processes such as steam reforming. ...

s. These had a very small superheating surface so they were replaced by Maunsell superheaters, when

Richard Maunsell Richard Edward Lloyd Maunsell (pronounced "Mansell") (26 May 1868 – 7 March 1944) was an Irish Locomotive Engineer who held the post of chief mechanical engineer (CME) of the South Eastern and Chatham Railway from 1913 until the Railways A ...

was appointed

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 locomotive ...

of the Southern Railway after the

grouping Grouping generally refers to the creation of one or more groups, or to the groups themselves. More specifically, grouping may refer to: * Shot grouping in shooting sports and other uses of firearms * the use of symbols of grouping in mathemati ...

of 1923.

Construction history

Operational details

Contrary to Drummond's previous 4-6-0 designs, the D15s performed exceptionally well and were put to work on trains to

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, where many drivers noted their superior operational characteristics when compared to the T14 class 4-6-0s. This was due to a marked reduction in

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

and

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...

consumption, and easier maintenance. However, with the succession of Urie, no further D15s were constructed, as he preferred to concentrate on 4-6-0 designs. These successful locomotives worked, in the main, out of

Waterloo Waterloo most commonly refers to: * Battle of Waterloo, 1815 battle where Napoleon's French army was defeated by Anglo-allied and Prussian forces * Waterloo, Belgium Waterloo may also refer to: Other places Australia * Waterloo, New South Wale ...

and for a period prior to electrification had a virtual monopoly of the

Portsmouth Portsmouth ( ) is a port city status in the United Kingdom, city and unitary authority in Hampshire, England. Most of Portsmouth is located on Portsea Island, off the south coast of England in the Solent, making Portsmouth the only city in En ...

expresses, until the

Schools A school is the educational institution (and, in the case of in-person learning, the building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of ...

class were introduced. Until the advent of the Bulleid Light Pacifics, a D15 was usually to be found working the

Brighton Brighton ( ) is a seaside resort in the city status in the United Kingdom, city of Brighton and Hove, East Sussex, England, south of London. Archaeological evidence of settlement in the area dates back to the Bronze Age Britain, Bronze Age, R ...

Plymouth Plymouth ( ) is a port city status in the United Kingdom, city and unitary authority in Devon, South West England. It is located on Devon's south coast between the rivers River Plym, Plym and River Tamar, Tamar, about southwest of Exeter and ...

service. Number 468 differed from the rest of the class in that it had the

safety valve A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds ...

s mounted on the firebox, with Urie N15 style dome and safety valve casings, whilst the others had Drummond direct-loaded safety valves on their domes. As built, number 463 was fitted with a hooter rather than a

whistle A whistle is a musical instrument which produces sound from a stream of gas, most commonly air. It is a type of Fipple, fipple flute, and may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a s ...

, which it kept until the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. The class continued into

British Railways British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most rail transport in Great Britain from 1948 to 1997. Originally a trading brand of the Railway Executive of the British Transport Commis ...

service in 1948 but were gradually withdrawn in the early 1950s. This meant that none survived to be preserved.

Accidents and incidents

*In August 1949, locomotive No. 467 was hauling a train which overran signals at station,

Hampshire Hampshire (, ; abbreviated to Hants.) is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Berkshire to the north, Surrey and West Sussex to the east, the Isle of Wight across the Solent to the south, ...

and was derailed by trap points. The derailment caused a set of points to move, causing a boat train to be diverted. This avoided a more serious accident as No. 467 was foul of the line it should have been on.Bishop, Bill (1984) p. 53.

Livery and numbering

LSWR and Southern

Under the LSWR, the D15s were outshopped in the LSWR Passenger Sage Green livery with purple-brown edging, creating panels of green. This was further lined in white and black with 'LSWR' in gilt on the tender tank sides. They were numbered 463–472 in a continuous block. When transferred to Southern Railway ownership after 1923, the locomotives carried Richard Maunsell's darker version of the LSWR livery.Swift, Peter (2006). The LSWR standard gilt lettering was changed to yellow with 'Southern' on the water tank sides. The locomotives also featured black and white lining.Haresnape & Rowledge (1982). p. 91.

Post-1948 (nationalisation)

Livery after Nationalisation was initially Southern freight livery with 'British Railways' on the tender, and an 'S' prefix on the number. The class was subsequently outshopped in BR Mixed Traffic Black with red and white lining, with the BR crest on the tender.Longworth, Hugh (2005). Locomotive numbering was per BR standard practice, with all 10 locomotives passing into

ownership in 1948. BR numbers were 30463-30472.''Ian Allan ABC of British Railways Locomotives'', 1949 edition, part 2, p. 12.

References

Notes

Bibliography

* * * * {{DEFAULTSORT:Lswr D15 Class D15 4-4-0 locomotives 2′B h2 locomotives Railway locomotives introduced in 1912 Scrapped locomotives Standard-gauge steam locomotives of Great Britain