The Glasgow Subway rolling stock serves the Glasgow Subway, the third-oldest underground metro system in the world. The first 33 cars of the current rolling stock was built by Metro Cammell between 1977 and 1979. Eight additional trailer cars were built in 1992. The rolling stock entered service when the subway re-opened after modernisation work on 16 April 1980. The rolling stock is being refurbished ahead of new rolling stock being acquired as part of the upgrade to the subway.