In March 2016 Strathclyde Partnership for Transport (SPT) awarded a joint venture of Stadler Bussnang and Ansaldo STS a £203.2m contract to modernise electrical and mechanical systems on the Subway. In addition to rolling stock, the contract included CBTC and automation technology, communications systems, a new operational control centre and a 760m-long test track for the new fleet at Broomloan.

The contract is a key component of SPT’s £288m Subway Modernisation Programme, which also includes the refurbishment of the circular line’s 15 stations as well as track and tunnel upgrades.

The 1219mm-gauge trains are equipped for Unattended Train Operation. Assembly is being carried out at Stadler’s Altenrhein plant in eastern Switzerland and two more trains are due to arrive in Glasgow by the end of the summer for the first phase of testing.

The four-car trains accommodate 118 seated passengers including 12 on tip-up seats and 204 standees (at 6 p/m2) and will also accommodate wheelchairs, a first for the Subway. At 39.25m, the new trains will be 1.51m longer than the existing three-car trains, which date from 1977-1992.