Alexander Allan was a Scottish

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 mechanical engineer. He was born at Montrose

Montrose, Angus

Montrose is a coastal resort town and former royal burgh in Angus, Scotland. It is situated 38 miles north of Dundee between the mouths of the North and South Esk rivers...

, Angus

Angus

Angus is one of the 32 local government council areas of Scotland, a registration county and a lieutenancy area. The council area borders Aberdeenshire, Perth and Kinross and Dundee City...

, in 1809 and died on 2 June 1891.

From 1843 to 1853 he was Works Manager at the Crewe Works

Crewe Works

Crewe railway works is a British railway engineering facility built in 1840 by the Grand Junction Railway. It is located in the town of Crewe, in the county of Cheshire....

 of the Grand Junction Railway

Grand Junction Railway

The Grand Junction Railway was an early railway company in the United Kingdom, which existed between 1833 and 1846 when it was merged into the London and North Western Railway...

, later London and North Western Railway

London and North Western Railway

The London and North Western Railway was a British railway company between 1846 and 1922. It was created by the merger of three companies – the Grand Junction Railway, the London and Birmingham Railway and the Manchester and Birmingham Railway...

, under Francis Trevithick

Francis Trevithick

Francis Trevithick , from Camborne, Cornwall, was one of the first locomotive engineers of the London and North Western Railway .- Life :...

. Here he was responsible for designing the Crewe type (locomotive)

Crewe type (locomotive)

The Crewe type locomotive was a design of steam locomotive designed by Alexander Allan and William Buddicom during the 1840s. It was widely copied elsewhere, particularly in France.-History:...

 with inclined cycliners and double frames. From 1853 to 1865 he was Locomotive Superintendent of the Scottish Central Railway

Scottish Central Railway

The Scottish Central Railway was formed in 1845 to link the Caledonian Railway near Castlecary to the Scottish Midland Junction Railway at Perth...

. Allan was an original member of the Institution of Mechanical Engineers

Institution of Mechanical Engineers

The Institution of Mechanical Engineers is the British engineering society based in central London, representing mechanical engineering. It is licensed by the Engineering Council UK to assess candidates for inclusion on ECUK's Register of professional Engineers...

 in 1847.

Inventions

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

Sources

• London and North Western Railway Society