Top - The Great Western Railway Iron Duke class 4-2-2 was a 7 foot and 1/4 inch broad gauge steam locomotive designed by Daniel Gooch in 1846 for express passenger train service. The Iron Duke class were extremely fast with an estimated top speed of 80 mph but typically averaged 60 mph between London and Swindon. This is a replica locomotive built in 1985 - Date unknown Amy Adams.Middle - The Great Western Railway Iron Duke class 4-2-2 replica locomotive - Date unknown Rob Speare.Bottom - Broad gauge trains at Kingswear - Date unknown Anonymous Photographer.