Hi,
The big 16" battleship guns (New Jersey, Missouri, etc) were supposedly said to be shifted some 20-odd feet when all nine barrles were fired in a single broadside.
I guess the RH&D had to be going full speed and the guns firing in line with the track to push the train back 10 feet - otherwise it would be pushed off the rails????
As I recall, the Tilden Park (California) 4-4-0 made a visit to RH&D about 10-15 years ago. I recall the story ib Live Steam. A US styled NG American 4-4-0 seemed to overpower the RH&D rolling stock.
Doug vV