No. 789 was a class M15 2-4-2 steam locomotive that was built for the Great Eastern Railway by Stratford Works in 1904. No. 789 and its siblings were used on branchline trains.
Rebuilding[]
789 was one of the 32 M15s to be rebuilt with the fitting of a higher pressure boiler, and also involved replacing Joy valve gear with Stephenson valve gear thus forming the M15R class.