14-Inch Naval Guns
Long range German artillery was quite effective during World War I, especially in Belgium where it put allied port operations at risk.
Unfortunately, allied counter fires were insufficient in range to counter the threat. After considering the problem, the Navy Department approved mounting 14-inch naval guns to railway cars.
The result was a railroad gun, manned by U.S. Navy Sailors, that could hit well behind the German lines with devastating results.
Credit : Daniel Garas