The Improved Director class (LNER class D11) was designed by John G. Robinson for express passenger work on the Great Central main line between London Marylebone and Sheffield and Manchester. An improved version of the 11E Director class (LNER class D10). No. 508 was built in March 1920 as the third member of the class. It had an operational life of over 40 years, being withdrawn in 1960. One member of the class, no. 506 Butler Henderson, is fortunately preserved, but unfortunately in static condition, at Barrow Hill.