Of all the attempts to militarize railways, perhaps the most absurd was the 19th- and early 20th-century quest to mount massive artillery on the rails. This ill-fated pursuit began as far back as the American Civil War, where both sides experimented with rail-mounted guns: the Union fielded a 13-inch siege mortar dubbed the Dictator on a flatbed car, while Confederates repurposed Brooke naval rifles on railcars in hopes of gaining a battlefield edge.

The trend continued across Europe and the world. French engineers were drafting plans for railway cannons as early as the 1870s. By World War I, America and Britain were testing and fielding numerous models. In many cases, they were little more than cannons scavenged from the bones of battleships and mounted on train cars—a lethal recycling campaign.

The trend was not to last, however. These weapons reached their peak—and swift decline—in the days which made and followed World War II, when the quest for ever-larger cannonry led Hitler’s Germany to expend massive resources to build the two heaviest and largest-caliber rifled guns ever fielded. Of the two, one fired a mere handful of shells while the other was destroyed by Allied forces before it could fire a single shot. This monumental waste of military resources was the final gasp for railway cannonry.