The British Railways Modernisation Plan of 1955 proposed the electrification of the Glasgow suburban system. This was achieved when electric train services began on the north side of the city in 1960 and in 1967 on the south side. "Glasgow Electric" was a high profile modern brand, and the new rolling stock was carefully designed to achieve an attractive "modern" look, and quickly acquired iconic status as "Blue Trains".
Ninety-one 3-car units were built by Pressed Steel at Linwood, near Paisley, from 1959-1961, and a further nineteen near-identical Class 311 units were built in 1967 for the south side electrification. These were built by Cravens in Sheffield as Pressed Steel had closed in the meantime.
One complete Linwood-built unit has been saved for preservation. It is a hybrid unit consisting of the driving vehicles from set 303032 and the motor coach from 303023, which replaced 303032's own motor coach, the HT transformer of which was damaged by an electrical flash over.
The driving trailer cars are painted in Strathclyde Passenger Transport Executive colours of orange and black. These SPTE colours replaced the Blue Train blue and the green/orange/cream livery of the Glasgow Corporation buses. Unit 303023 was one of only four sets to carry the later Strathclude Passenger Transport carmine/cream livery.
The set is in rebuilt condition, with replacement interiors and altered driving cabs to block the passenger forward view which was a feature of the original construction. It thus demonstrates the compromises necessary to keep cars in traffic during 40 years daily service to the city.
| Number | Description | Date Built |
| 75597 | DTSO Driving Trailer Second Open coach | 1959 |
| 61503 | MBSO Motor Brake Second Open coach | 1959 |
| 75632 | BDTSO Battery Driving Trailer Second Open coach | 1959 |
