[2] The Class 314 fleet was used to operate inner-suburban services on the Strathclyde Partnership for Transport rail network in and around Glasgow, most typically on the Argyle, North Clyde, Cathcart Circle, Paisley Canal and Inverclyde lines.

Although the fleet had undergone a number of life-extension overhauls and upgrades, it was withdrawn from service in 2018–2019 as a result of non-compliance with the requirements of the Persons with Reduced Mobility Technical Specification for Interoperability (PRM-TSI),[a] which became legally binding at the end of December 2019.

[1] The 25 kV supply collected from the overhead lines by the pantograph was passed from the transformer in the intermediate trailer to four 110 horsepower (82 kW) direct current traction motors mounted under each driving car.

The sixteen-strong Class 314 fleet had been acquired for the main purpose of operating the newly-opened Argyle Line, which they did—along with the North Clyde Line—from introduction in late 1979[6] until October 1999.

[citation needed] The increasing age of the Class 314 units, along with their failing to comply with the PRM-TSI requirements, made it unlikely that they would remain in service into the 2020s without further costly refurbishment.

[13][5] The project was initially handled primarily by a workgroup at the University of St Andrews, before a request for tenders was issued in September 2020 seeking a commercial partner for the full design, installation, and demonstration of a hydrogen fuel system using the Class 314 unit.

[5] Arcola's A-Drive fuel cell powertrain forms the core of the new traction system, with hydrogen tanks and battery modules installed underneath all three vehicles.

[5] The intent is for the demonstrator to remain reasonably similar to a "standard" Class 314 unit, so that it can be run under its existing certificates of conformity for the general railway network.