Until the advent of the Class 800 bi-mode units, DMUs were never very common on the Great Western Mainline (apart from the short lived Oxford to Bristol experiment). However, in 1989 there was a diagrammed out and back working for a Class 155, the purpose of which was a little unclear. 155325 is seen here passing Bourton on 22 December 1989 with the 2A26 12:40 Oxford to Swindon Regional Railways service. It would return a little later as the 2A70 13:45 Swindon to Oxford. Unlike the later Class 165 operated Oxford to Bristol trains, these non-stop Class 155s used the normally freight only Didcot North Junction to Foxhall Junction curve.