The Glasgow Subway is an underground light metro system in Glasgow , Scotland. Opened on 14 December , it is the third-oldest underground metro system in the world after the Metropolitan Railway in London, , and the Budapest Metro , Originally a cable railway , the subway was later electrified , but the double-track circular line was never expanded. The line was originally known as the Glasgow District Subway , and was thus the first mass transit system to be known as a "subway"; it was later renamed Glasgow Subway Railway.
In it was renamed the Glasgow Underground. Despite this rebranding, many Glaswegians continued to refer to the network as "the Subway". The system is not the oldest underground railway in Glasgow: that distinction belongs to a three-mile five-kilometre section of the Glasgow City and District Railway opened in , now part of the North Clyde Line of the suburban railway network, which runs in a tunnel under the city centre between High Street and west of Charing Cross.
Another major section of underground suburban railway line in Glasgow is the Argyle Line , which was formerly part of the Glasgow Central Railway. The tracks have the unusual narrow gauge of 4 ft 1, mm and a nominal tunnel diameter of 11 ft 3. The system is described as two lines, the Outer Circle and Inner Circle, which simply refers to the double track, having trains running clockwise and anticlockwise respectively around the same route in separate tunnels.
Stations use a variety of platform layouts including single island platforms, opposing side platforms and in some stations such as Hillhead one side and one island platform. The subway's running lines are entirely underground, although the maintenance depot at Broomloan Road located between the Govan and Ibrox stations is above ground, as was the earlier depot, also at Govan. Prior to modernisation, trains used to be lifted by crane onto and off the tracks.
In the event of maintenance or repair work, the system can operate a full service six trains per circle with one of the sub-stations inoperative. The Glasgow District Subway Company began construction of the underground in and it opened on 14 December The cable was driven from a steam-powered plant between West Street and Shields Road stations.
