3777 at the Northampton & Lamport Railway in December 2013. ©Dan Adkins
Following the modernisation plan of 1955 British Railways identified a need for faster, higher capacity wagons to cater for rapidly growing petroleum traffic. Working with Esso, Charles Roberts Ltd developed a new design with a capacity of 35t – the result the 35t Class A and Class B tank wagons. The wagons were designated Class A and Class B (depending on the contents) and hundreds were built. As well as petroleum products they were also used for chemicals and molasses. From 1960 a modified suspension was introduced, and examples of the wagons remained in service into the 1990s. They operated in long block trains and also as smaller cuts in mixed freight trains, and were hauled by anything from 9Fs, 8Fs or Black 5s to pairs of BRCW Type 3s, Sulzer Type 4s or EE Type 3s.
(Information provided by Revolution Trains)