The main line ran from Glasgow along the west coast and to Gretna. The railway also served Paisley, Greenock, Ardrossan, Troon and the ports on the west coast, between which it had regular steamer services. It also owned the harbours at Troon and Ayr. The headquarters were at St Enoch Station, Glasgow. In 1921 the railway comprised 1,128 miles of line and the company’s capital was about £19 million.1
The G&SWR, in association with the Midland Railway, provided a third Anglo-Scottish route, intermediate between the West Coast and East Coast routes. It was as a result of the Midland connection that Glasgow St Enoch station was designed in a style heavily influenced by London St Pancras.
The Prince's Pier, Greenock, in use today as a shipping terminus
Ardrossan: The Ardrossan Railway was built by the Glasgow, Paisley and Ardrossan Canal company. The canal, opened in 1810, was intended to connect Glasgow to Ardrossan by canal, but linked Glasgow and Paisley only as far as Johnstone.3 The final link was to be made by the canal-owned Ardrossan to Johnstone Railway, incorporated on 14 June1827. Work started at Ardrossan but it reached only Kilwinning, in 1831, when the company ran out of money. In 1840 the railway was separated from canal company ownership and on 20 August1840 it reopened as a standard gauge, double-track, line connected to the GPK&AR at Kilwinning. Ardrossan henceforth developed as a shipping port; later the line was extended to Largs.
St Enoch Station no longer exists, it closed in 1966 and it became a car park; the roof was demolished in 1975. In the mid 1980s, the site was redeveloped as the St Enoch Centre, opening in May 1989.
The Bridge of Weir Railway and the Greenock and Ayrshire Railway to Greenock Princes Pier was closed between Princes Pier and Kilmacolm in 1966. However, in 1971 the Princes Pier stub was connected to the Inverclyde Line, at Cartsburn junction, in order to serve the Clyde Port Authority container terminal. The Paisley Canal Line closed completely in January 1983, and the original Paisley Canal station, on the east side of Causeyside Street, became a steak house. In the 1980s / 1990s the course of the line beyond Paisley was made into a footpath and cycle path. This connects Lady Octavia Park in Greenock, through upper Port Glasgow, Kilmacolm, past Quarrier's Village, and on to Paisley. It forms a section of the Sustrans scheduled National Cycle Route from Edinburgh to Gourock.5
The G&SWR Castle Douglas and Dumfries Railway closed in June 1965, as did the joint G&SWR/Caledonian Railway owned line between Castle Douglas and Challoch Junction (between Dunragit and Glenluce). The Dalry Junction to Kilmarnock portion of the Carlisle main line lost it's local passenger service in 1966 and was closed completely in October 1973 (following the completion of WCML electrification work), all services to Glasgow henceforth running over the Glasgow, Barrhead and Kilmarnock Joint Railway via Stewarton.
In 1990 the Paisley Canal Line reopened from Glasgow Central station as far as a new Paisley Canal railway station on the west side of Causeyside Street.
Thomas, John; Paterson, Rev A.J.S. (1984). A Regional History of the Railways of Great Britain. Volume VI Scotland: The Lowlands and the Borders, 2nd edition, Newton Abbott, Devon: David & Charles. ISBN 0-9465-3712-7. OCLC12521072.