 In terms of familial relationships, Prince of Wales Tank was both a superheated and extended version of the Precursor Tank, and a version of the Prince of Wales Class 4-6-0 steam locomotive with side tanks and a bunker which necessitated an extension to the frames and trailing pony truck.They were used on suburban services out of Euston station and from an early date also used on passenger services between Shrewsbury and Swansea (Victoria) over the steeply-graded Central Wales line, a journey of some 120 miles.The LNWR built 47 of the superheated tanks between 1910 and 1916 under Charles Bowen-Cooke.