Glasgow & South Western Railway Co (railway company: 1850-1923: Scotland)

The Ardrossan & Johnstone Railway , North Ayrshire, Scotland was authorised in July 1827 by an Act of Parliament to engineer a line between Ardrossan harbour to the Glasgow, Paisley & Ardrossan canal at Johnstone, Renfrewshire, Scotland. The line was only completed between Ardrossan and Kilwinning, North Ayrshire, with a 4ft 6in gauge. The Glasgow, Paisley, Kilmarnock & Ayr Railway Act of 1837 authorised the making of a line from Glasgow to Ayr, South Ayrshire, with a connection to the Ardrossan & Johnstone Railway at Kilwinning, effectively making the Ardrossan Railway a branch line. The Ardrossan Railway Act of 1840 changed the name of the company to the Ardrossan Railway, doubled the line and introduced the 4ft 8in gauge making it suitable to carry locomotives. In 1854, the Ardrossan Railway Transfer Act vested the Ardrossan Railway in the Glasgow & South Western Railway Co .

The Glasgow & South Western Railway Co was formed in 1850 by the amalgamation of the Glasgow, Paisley, Kilmarnock & Ayr Railway and the Glasgow, Dumfries & Carlisle Railway. The main line linked Glasgow with Carlisle, England via Paisley, Dalry, Kilmarnock, Dumfries and Annan, joining the Caledonian Railway at Gretna, Dumfries & Galloway, Scotland. This was a rather round about route, and, in 1865, the company was allowed to build a cut-off between Glasgow and Kilmarnock via Cathcart on the south side of Glasgow.

Competition between the three big Scottish railway companies, i.e. the Caledonian Railway, North British Railway and the Glasgow & South Western Railway, was fierce and each guarded their territory whilst building branch lines that encroached on the others' territory.

The company went on to expand its control by purchasing other lines, such as the Greenock & Ayrshire in 1879. The company merged in 1923 with the Caledonian Railway , the Highland Railway, the London & North Western Railway, and the Midland Railway to form the London, Midland & Scottish Railway Co. This company was nationalised as part of British Rail in 1948.

John Kellet, Railways and Victorian Cities (London, 1979)

David Thomas, A Regional History of the Railways of Great Britain: Scotland (Newton Abbot, 1971)