[2][3][4][5] Unlike other Metro systems in the United Kingdom, the Subway has a running gauge of 1,220 mm (approximately 4 ft).

This rolling stock was converted from cable to electric traction in 1935 and finally withdrawn from service in 1977 upon the closure of the railway for modernisation.

[14] Originally after the 1977–1980 modernisation the trains carried a light orange livery with a white stripe and stylised 'Trans-Clyde' branding.

This livery was also used on SPTE buses and on suburban and commuter trains operated by ScotRail within the Strathclyde region.

[18] Car 122 was withdrawn in October 2015 and stripped of usable equipment in order to provide spare parts for the remaining fleet, being scrapped soon after.

[24] In July 2024, SPT announced that old Subway carriages would be given away to charities or sold off for £5,000, potentially to be re-used as glamping pods or other buildings.

Strathclyde Partnership for Transport (SPT) unveiled a £280 million contract with Stadler and Ansaldo STS in 2016 for modernisation of the Subway, including new rolling stock and signalling.

Trains feature the potential for driverless operation, an open-gangway design, space for wheelchairs, and compatibility with platform screen doors.