British Rail Standard class 6 “Clan”

The BR Standard class 6 Pacific was designed after the Standard class 7 “Britannia”. Since the Britannia was too heavy for many lines in Scotland, a new type of locomotives with a better route availability had to be ordered. Trials with the SR Bulleid Light Pacific on the line to Inverness had shown that a light Pacific would be optimal for this task. So Riddles took the frames of the Britannia and mounted a smaller boiler with a pressure of 225 instead of 250 psi and smaller cylinders.

This resulted in a locomotive that could be used on most lines in Scotland due to its low axle load, but still had many common parts with the Britannia, facilitating maintenance. The new locomotive was quickly rushed into production so that ten could be completed between December 1951 and March 1952. Their numbers were 72000 to 72009. The Highland Railway Clan class had recently been withdrawn, and so five of the new class received names from Scottish clans previously carried by the old locomotives.

Service showed that many crews less familiar with the class had difficulties in steaming, what reduced their power. This was attributed to a insufficient diameter of the single chimney, what had to be modified afterwards. Additionally, there were some frame cracks. A planned second batch of 15 locomotives was not built, on the one hand this could be explained by steel shortages, but the 1955 Modernisation Plan was already being worked out and it became foreseeable that no more express steam locomotives would be needed.

Today an eleventh one is under construction that is scheduled to be completed by 2030. It will be numbered 72010 and since the second batch was to be used in the Southern Region and the first of this batch was to be named “Hengist”, the new locomotive will receive this name. After 999 standard locomotives had been built between 1951 and 1960, it will be the 1000^th standard steam locomotive in Britain.