The LNWR Teutonic class was a class of 10 passenger three-cylinder

compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with defensive struct ...

2-2-2-0 locomotives designed by F. W. Webb for the

London and North Western Railway The London and North Western Railway (LNWR, L&NWR) was a British railway company between 1846 and 1922. In the late 19th century, the L&NWR was the largest joint stock company in the United Kingdom. In 1923, it became a constituent of the Lo ...

, and manufactured by them in their

Crewe Works Crewe Works is a British railway engineering facility located in the town of Crewe, Cheshire. The works, which was originally opened by the Grand Junction Railway in 1840, employed around 7,000 to 8,000 workers at its peak. In the 1980s, a lot ...

between 1889 and 1890.

Design

The design featured a boiler pressed to delivering saturated steam to two outside high-pressure cylinders, which exhausted to one low-pressure cylinder inside the frames. All three cylinders had a stroke of ; the high-pressure cylinders drove the rear wheels, while the low-pressure drove the leading driving wheels. As the two pairs of driving wheels were not connected, the locomotives were "

duplex drive DD or Duplex Drive tanks, nicknamed "Donald Duck tanks", were a type of amphibious swimming tank developed by the British during the Second World War. The phrase is mostly used for the Duplex Drive variant of the M4 Sherman medium tank, that was ...

" or "double-singles". They were a development of Webb's Dreadnought class; they had larger driving and leading wheels, and the additions of cylinder tail rods (which were later removed). There were also further modifications to the Joy valve gear, but the seven locomotives built in 1890 had the inside cylinder worked by

slip-eccentric 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. It can also serve as a reversing g ...

instead from new. Of the ten locomotives, nine were named after ships of the

White Star Line The White Star Line was a British shipping company. Founded out of the remains of a defunct packet company, it gradually rose up to become one of the most prominent shipping lines in the world, providing passenger and cargo services between t ...

, the exception was named after a character in a

Walter Scott Sir Walter Scott, 1st Baronet (15 August 1771 – 21 September 1832), was a Scottish novelist, poet, playwright and historian. Many of his works remain classics of European and Scottish literature, notably the novels ''Ivanhoe'', ''Rob Roy (n ...

novel, as it was exhibited at the Edinburgh International Exhibition of 1890.

Decline

When

George Whale George Whale (7 December 1842 – 7 March 1910) was an English locomotive engineer who was born in Bocking, Essex, and educated in Lewisham, London. He worked for the London and North Western Railway (LNWR). Career In 1858 he entered the LNWR' ...

become chief mechanical engineer of the LNWR in 1903, he started a programme of eliminating Webb's over-complicated duplex compound locomotives. Consequently, the class was scrapped between October 1905, and July 1907, having been replaced by Whale's Experiment class.

References

* {{LNWR Locomotives Teutonic 2-2-2-0 locomotives Railway locomotives introduced in 1890 Compound locomotives Standard gauge steam locomotives of Great Britain Duplex locomotives