[5] The units run on 25 kV AC overhead line supply via a Brecknell Willis high speed pantograph, using four Brush TM2141B traction motors.

With much shorter passenger journeys in mind, the Class 320 units originally lacked the toilets of the Class 321 units and also began life with a lower speed capability (75 mph or 121 km/h) due to the much closer spacing of stations on the North Clyde Line.

However, yaw dampers were fitted across the class in 2010,[citation needed] allowing them to run at 90 mph (145 km/h).

Their interior design includes paintings of various landmarks and famous sights along the various SPT rail routes on the car ends.

In September 2008 the Scottish Government's agency Transport Scotland announced that all ScotRail trains would eventually be repainted in a new, blue livery with white Saltire markings on the carriage ends.

[citation needed] The refurbishment work included: The first unit to be completed was 320314, which headed south to Wabtec Doncaster on 14 February 2011 and returned on 6 June 2011.

The first three converted units, 320411, 320412 and 320416, entered service in March 2016, initially retaining their London Midland livery.

[12] The first of the five additional units, 320404, was released from Wabtec and moved to Glasgow Shields Road TMD on 8 August 2018.