Alexander Allan (locomotive engineer)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Alexander Allan
Born 1809
Montrose, Angus
Died 2 June 1891
Scarborough, Yorkshire
Nationality Scottish
Citizenship British
Engineering career
Discipline Mechanical engineering
LNWR No. 3074, Allan's 'Crewe' goods engine designed for the GJR, introduced 1845 and claimed to be the first 2-4-0[1]
Allan's 2-2-2 Columbine, GJR No. 49, LNWR No. 1868 with cab, built 1845 withdrawn 1902

Alexander Allan was a Scottish mechanical engineer. He was born at Montrose, Angus, in 1809 and died at Scarborough, Yorkshire on 2 June 1891.[2]


From 1843 to 1853 he was Works Manager at the Crewe Works of the Grand Junction Railway, later London and North Western Railway, under Francis Trevithick. He later claimed the credit for designing the Crewe type locomotive with inclined cylinders and double frames, but this claim has been challenged.[3] From 1853 to 1865 he was Locomotive Superintendent of the Scottish Central Railway. Allan was an original member of the Institution of Mechanical Engineers in 1847.


Allan made a number of inventions, including a balanced slide valve, but the best-known is his straight-link valve gear of 1855.

See also[edit]


Allan valve gear, seen here fitted to an early Austrian locomotive
  1. ^ "Steam engine locomotive, built at the Crewe works, for the Grand Junction Railway.". flickr. 5 December 2009. Retrieved 29 April 2016. 
  2. ^ "Alexander Allan and other Crewe locomotive designers". 16 September 2008. Retrieved 19 June 2012. 
  3. ^ "The Crewe Type" by D H Stuart & Brian Reed, 1971


Preceded by
Robert Sinclair
Locomotive Superintendent of Scottish Central Railway
Succeeded by
Post abolished when S.C.R. absorbed by Caledonian Railway