The Class 3031 of the Great Western Railway, also known as the “Dean Single”, was created from the conversion of 30 examples of the Class 3001, which had been built by William Dean in the 7 feet 1/4 inch broad gauge and were converted to standard gauge a short time later. Since an increase in power through a wider boiler was impossible with the standard gauge due to the limited space between the large wheels, the boiler was extended to the front. After the leading axle derailed in the middle of the box tunnel due to the increased weight, it was replaced with a bogie, resulting in the class 3031. Since the cylinders were located below the smoke box in class 3001, a special bogie had to be constructed. This could be pulled out after loosening four screws and slightly lifting the front part of the locomotive to ensure uncomplicated maintenance of the smoke box and cylinders.

No. 3050 “Royal Sovereign”

J.R. Howden, The Boys' Book of Locomotives

First, two class 3001 locomotives were converted in March 1894, the remaining 28 were converted between June and December of the same year. A total of 50 more were factory built between 1894 and 1899. In use, the class 3031, like other locomotives with a 4-2-2 wheel arrangement, excelled with high sustained speeds. On May 9, 1904, a mail train was able to travel the 117 miles from Bristol to London-Paddington in just under 100 minutes for the first time, which corresponds to an average speed of around 70 mph. However, since one driven axle was soon no longer sufficient, they were decommissioned between 1908 and 1915. Today there is a replica of No. 3041 “The Queen”, which was completed in 1982.