The rise of air power was the last nail in the war train’s coffin.
The Heavy Gustav fired a total of 48 shots at Sevastopol, mostly on Soviet forts. It never fired in anger again. Berlin blew more than 1,000 tons of steel, thousands of man-hours and millions of Reichsmarks for just 48 shots in a war where steel, labor and treasure were in limited supply. In other words, it was a technical marvel but a military folly. In the years to come, rockets, atomic weapons and heavy bombers would offer the same functions as the Gustav with greater mobility, range and firing rates.
War trains dominated combat for more than 100 years. Massive railborne artillery shelled the enemy while trains unloaded troops and supplies. For a brief moment, the terrifying machines were the most powerful weapon on the battlefield. But technology advanced.
Improvements to tanks, cars and planes during World War II marked the twilight of the war train. The great trains of the First World War still dominated the imagination, however, and the Nazis built impressive — but impractical — railborne cannons.
The German Heavy Gustav was the largest gun ever built. It was more than 150 feet long, 40 feet tall and weighed almost 1,500 tons. The steel giant Krupp A.G. made only two, and neither worked well.
The weapon derived from experience. After witnessing the success of other railway guns, the German High Command asked Krupp’s engineers to design a weapon to destroy the French border fortifications along the Maginot Line.
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The Gustav’s barrel alone was more than 100 feet long and fired 31-inch-wide, 12-foot-long shells at an effective ranges of 20 miles. The ammo came in two varieties — a five-ton explosive round and a seven-ton armor piercer.