The "Iron Duke" locomotives were designed for the Great Western Railway by Daniel Gooch,and originally had a 2-2-2 wheel arrangement.This was later altered to 4-2-2.The locos were designed for fast passenger work,and were broad gauge (7 foot,or 2.140m).The original "Iron Duke" engine was built in 1847,and withdrawn in 1871.In 1985,as part of the 150th celebrations of the Great Western Railway,a replica was built,and ran on a specially constructed track in London.Unfortunately,the locos boiler certificate has now expired,and the engine is static display only.It is currently on show in the car park at Toddington,on the Gloucestershire and Warwickshire Railway.It's quite a sobering thought that,even with an open driving area,these locos regularly reached speeds of 80 m.p.h.