The Prince of Wales class was a 4-6-0 express locomotive designed by Charles Bowen Cooke with inside cylinders and drivers with a diameter of 6 ft 3 in (1,905 mm). Essentially it was a superheated version of Whale's Experiment class with larger cylinders. A 4-6-2T tank locomotive built at the same time was called “Prince of Wales Tank”.
130 were built by the LNWR at Crewe, but also 20 more were contracted out to North British and 91 to Beardmore. Starting in 1924, they received Belpaire fireboxes. Four received Walschaerts valve gear for trials, but these remained the only ones. Withdrawals started in 1933 and at the beginning of World War II, only 22 were still in service. Six were passed over to British Railways, but all were gone before the actual renumbering could take place.