GWR Iron Duke class

[1] The remainder of the class entered service between April 1847 and July The Iron Duke locomotives were fast for their time, and were recorded reaching 78.2 mph (125.9 km/h).

In May to July 1870, three locomotives (Great Britain, Prometheus and Estaffete) were extensively rebuilt with new frames and boilers, but retaining their original names.

Lord of the Isles (the last to be withdrawn) was initially preserved by the GWR at Swindon Works, but was scrapped in January 1906 owing to the pressure of space.

Named after the railway, it was designed to show how the 2-2-2 express engines could be improved; its 8-foot-diameter (2.438 m) driving wheels were one foot (305 mm) larger than those of the successful Fire Fly class.

After withdrawal in 1884, the locomotive was stored at Swindon Works until 1906; during this time it was exhibited at Edinburgh in 1890, Chicago in 1893, and Earl's Court, (London) in 1897.