Class 126 diesel multiple units were introduced to Scotland from 1956. Initially, they were diagrammed to work between Edinburgh Waverley and Glasgow Queen Street. In 1959, a second batch was introduced with slight design changes, and these were used on the Glasgow St Enoch to Ayr and Stranraer Harbour workings. The Edinburgh units were always based at Leith Central and the later builds were based at Ayr Depot. They became known as Inter City units as they initially connected up Edinburgh and Glasgow with faster end-to-end journey times compared with their steam forerunners. The Ayr-based units were later moved to work from Glasgow Central. Both fleets have worked charters on to the West Highland Lines and other routes. This book illustrates the class from their introduction in the mid-1950s until their withdrawal from British Rail in 1983.

Four coaches have been preserved at the Bo'ness and Kinneil Heritage Railway.