Railroad Gun
From NSwiki, the NationStates encyclopedia.
IRL, railroad or railway guns were used with limited success by several powers in the first and second second world wars. They consist of a large [usually naval-sized] cannon or array of cannons designed to be moved by rail. A few NS nations use them; Some fire nuclear shells and all are of large calibre. The example here is the German 'Dora' supergun.
