The Subway Line (10.4 km), nicknamed Clockwork Orange, was already built in 1896, so it's one of the oldest metros in the world. Originally operated by steam engines via cable traction, the line was electrified in 1935. From 1977 to 1979 the whole line was thoroughly reformed and reopened in 1980.
Trains take approximately 24 minutes for an entire circle. Most stations have quite narrow central platforms long enough for a 3-car-train. Between Govan and Ibrox, on the south bank of the river Clyde, a tunnel exit leads to the Subway's depot. Directions are indicated as "Outer Circle" (clockwise) and "Inner Circle" (anti-clockwise).
In 2003, the Underground was renamed Subway, which was actually its original name. A new automatic control system has been installed and the old system removed. Some stations have a narrow island platform between the tracks but now used for one direction of travel only, since a new side platform has been created to one side. For safety reasons a barrier is being erected along the platform edge next to the track whose trains do not use the island platform.