The LSWR X6 class was a class of express passenger 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...

 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...

s designed 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...

 by William Adams

William Adams (locomotive engineer)

William Adams was the Locomotive Superintendent of the North London Railway from 1858 to 1873; the Great Eastern Railway from 1873 until 1878 and the London and South Western Railway from then until his retirement in 1895...

. Ten were constructed at Nine Elms Locomotive Works

Nine Elms Locomotive Works

Nine Elms locomotive works were built in 1839 by the London and South Western Railway adjoining their passenger terminus near the Vauxhall end of Nine Elms Lane, in the district of Nine Elms in the London Borough of Battersea. They were rebuilt in 1841 and remained the principal locomotive...

 between 1885–1886.

The class were numbered 657–666, and just as the T3 class

LSWR T3 class

The LSWR T3 class was a class of express passenger 4-4-0 steam locomotives designed for the London and South Western Railway by William Adams. Twenty were constructed between 1892–1893....

 were a smaller-wheeled version of the X2 class

LSWR X2 class

The LSWR X2 class was a class of express passenger 4-4-0 steam locomotives designed for the London and South Western Railway by William Adams. Twenty were constructed at Nine Elms Locomotive Works between 1880–1882....

, the X6 class were a smaller-wheeled version of the T6 class

LSWR T6 class

The LSWR T6 class was a class of express passenger 4-4-0 steam locomotives designed for the London and South Western Railway by William Adams. Ten were constructed at Nine Elms Locomotive Works between 1885–1886....

. The boiler was identical to that used the T6 class. Some of the engines were subsequently fitted with a Drummond boiler, including N°658 which was the last Adams 4-4-0 to remain in service.

Table of locomotive orders

Year	Order	Quantity	LSWR Numbers	Notes
1895	X6	10	657–666

All passed to 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...

 at 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...

in 1923. Withdrawals started in 1933, and by the start of World War II, only six remained. Five were retired during the war, leaving only No. 658, which was withdrawn in December 1946. All were scrapped.