The first 19 locomotives ordered by

Isambard Kingdom Brunel Isambard Kingdom Brunel (; 9 April 1806 – 15 September 1859) was a British civil engineer who is considered "one of the most ingenious and prolific figures in engineering history," "one of the 19th-century engineering giants," and "one ...

for the

Great Western Railway The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835 and ran ...

included two unusual Haigh Foundry locomotives. ''Snake'' and ''Viper'' were built at the

Haigh Foundry Haigh Foundry was an ironworks and foundry in Haigh, Lancashire, which was notable for the manufacture of early steam locomotives. Origins Haigh Foundry was established in the Douglas Valley in Haigh around 1790 by Alexander Lindsay, 6th Earl ...

and delivered in September 1838. They had

cylinders A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infini ...

and the

driving wheels On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled tog ...

geared 2:3 to keep the cylinder stroke speed low while allowing high track speed, in line with Brunel's specifications. The boiler had a diameter of and was long. Both locomotives became only really useful after modifications in the years 1839 till 1840 they had been rebuilt with and conventional drive. Most probably they received their driving wheels at the same time. They were later converted to

2-2-2 Under the Whyte notation for the classification of steam locomotives, 2-2-2 represents the wheel arrangement of two leading wheels on one axle, two powered driving wheels on one axle, and two trailing wheels on one axle. The wheel arrangement both ...

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 a more traditional tender. Most tank engines also have bunkers (or fuel tanks) to hold fuel; in a tender-tank locom ...

s, possibly when they were sent to work the South Devon Railway in 1846, where they got the names ''Exe'' and ''Teign''. The locomotives returned 1851. ''Snake'' operated till November 1869, ''Viper'' till January 1868. The boiler of ''Viper'' was afterwards used as stationary boiler in

Shrewsbury Shrewsbury ( , also ) is a market town, civil parish, and the county town of Shropshire, England, on the River Severn, north-west of London; at the 2021 census, it had a population of 76,782. The town's name can be pronounced as either 'Sh ...

Names

* ''Snake'' (Haigh Foundry 25; 1838–1869) :Between 1846 and 1851 it carried a different name, ''Exe'', while working on the South Devon Railway, after the

River Exe The River Exe ( ) in England rises at Exe Head, near the village of Simonsbath, on Exmoor in Somerset, from the Bristol Channel coast, but flows more or less directly due south, so that most of its length lies in Devon. It flows for 60 mile ...

; it reverted to ''Snake'' when it returned to the Great Western Railway. * ''Viper'' (Haigh Foundry 26; 1838–1868) :Between 1846 and 1851 it carried a different name, ''Teign'', while working on the South Devon Railway, after the

River Teign The River Teign is a river in the county of Devon, England. It is long and rises on Dartmoor, becomes an estuary just below Newton Abbot and reaches the English Channel at Teignmouth. Toponymy The river-name 'Teign' is first attested in an An ...

; it reverted to ''Viper'' when it returned to the Great Western Railway.

References

Sources

* * {{GWR Locomotives

Broad gauge (7 feet) railway locomotives 2-2-2 locomotives Early steam locomotives Steam locomotives of Great Britain Railway locomotives introduced in 1838