Although overshadowed by the later and more famous steam locomotives that John G. Robinson would go on to design, the Great Central Railway Class 11B 4-4-0 Express Passenger engines were a successful class which totalled 40. Built from 1901 to 1903, in later rebuilt form as 11D, some 11Bs would last in service until 1950. Railwaymen continued to refer to the class as "11B" even after all were rebuilt to 11D. Being contemporary with and to some extent the 4-4-0 version of Robinson's much more numerous 0-6-0 goods class 9J, which were known as "Pom-Poms", the 11Bs acquired the nickname "Pom-Pom Bogies". The London & North Eastern Railway classified the 11Bs, along with their 11C and 11D rebuilds, as Class D9.