History has a weird way of remembering the terrifying stuff that actually worked, like the V-2 rocket, while burying the truly bizarre failures. The V3 nazi super gun is exactly that—a weapon so ambitious it bordered on science fiction, yet so flawed it was basically a steel-and-concrete death trap for its own builders.
You’ve probably heard of the "V" weapons. The V-1 was the buzzing "doodlebug" cruise missile. The V-2 was the world's first long-range ballistic rocket. But the V-3? It wasn't a rocket at all. It was a 430-foot-long cannon buried deep inside a French hillside, designed to rain 1,500 shells a day on London until the city was nothing but rubble.
Honestly, the tech behind it was kind of brilliant, in a terrifyingly "mad scientist" way.
The Centipede Gun: How the V3 Actually Worked
The biggest problem with traditional artillery is physics. If you want to shoot a shell 100 miles, you need a massive explosion. But if you put all that powder in the breech at once, the pressure is so high it just blows the gun apart. To get around this, a German engineer named August Cönders reached back into the 19th century for a forgotten idea: the multi-charge principle.
Basically, the V3 nazi super gun wasn't just one big tube with a bang at the bottom. It had dozens of side chambers branching off the main barrel like the legs of a millipede—which is why the Germans nicknamed it the Tausendfüßler (centipede).
Here is how a firing sequence was supposed to go:
- The main charge at the bottom fires, starting the shell's journey.
- As the shell passes the first pair of side chambers, they trigger, adding more gas pressure.
- This happens again and again, dozens of times, kicking the shell faster and faster as it moves up the 140-meter barrel.
- By the time it exits the muzzle, it’s traveling at over 1,500 meters per second.
It was designed to hit London from Mimoyecques, France, which is about 100 miles away. If they had finished it, the Germans planned to have 25 of these barrels lined up in a single underground fortress.
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Why the Super Gun Was a Technical Nightmare
While it sounds good on paper, the V3 nazi super gun was a disaster in practice. During testing at Misdroy in Poland, the barrels kept exploding. Turns out, timing the side charges is incredibly hard. If a charge fires a millisecond too early, it hits the shell from the front and slows it down or causes the whole section to burst.
And then there was the "droop" problem. A 440-foot steel barrel is heavy. Even when supported, the sheer length caused the tube to sag slightly under its own weight, which isn't great when you're trying to fire a high-speed projectile through it.
The Germans also struggled with the shells. They were long, arrow-shaped fin-stabilized projectiles. Because the gun was smoothbore (no rifling), the fins had to do all the work to keep the shell from tumbling. In early tests, the fins often ripped off the moment they hit the air, leaving the shell to wobble uselessly into the sea.
The Fortress of Mimoyecques
The site itself was a marvel of slave labor and engineering. The Germans chose a chalk hill near Calais because chalk is easy to tunnel through but stays stable. They dug a massive railway tunnel into the hill and then angled five shafts up toward the surface at exactly 50 degrees—the perfect angle to hit the heart of London.
Construction was handled by the Organization Todt, using thousands of forced laborers. It was meant to be "bomb-proof," covered by a concrete slab 18 feet thick. But they underestimated just how much the British wanted to stop them.
Operation Crossbow and the Tallboy Bombs
The Allies didn't actually know what the V-3 was at first. From aerial reconnaissance, they just saw a massive construction site with strange railway sidings. They assumed it was a V-2 launch site and put it on the priority list for Operation Crossbow.
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The site was hammered with thousands of tons of conventional bombs, but the underground tunnels stayed safe. That changed on July 6, 1944.
The RAF's 617 Squadron—the famous "Dambusters"—showed up with Tallboy bombs. These were 12,000-pound "earthquake bombs" designed by Barnes Wallis. They weren't meant to blow up on the surface; they were designed to penetrate deep into the earth before detonating, sending shockwaves that would collapse tunnels.
It worked. Three Tallboys hit the Mimoyecques site directly. The shockwaves collapsed the shafts and buried hundreds of workers alive. The project was effectively killed that day.
The Ardennes Version: The Gun That Actually Fired
Most people think the V-3 never saw combat, but that’s not quite true. After the Mimoyecques site was abandoned, the Germans built two smaller, "short" versions of the gun. These weren't buried in hills; they were basically slapped together on hillsides using whatever parts were left.
During the Battle of the Bulge in late 1944, these guns were used to shell Luxembourg. They fired about 183 rounds total.
Was it effective? Not really. It killed about 10 people and wounded 35. For a weapon that cost millions of Reichsmarks and years of development, it was a total tactical failure. The barrels on these smaller versions also tended to crack after just a few shots, making them as dangerous to the crews as they were to the targets.
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Why We Should Still Care About the V3
The V3 nazi super gun is a classic example of Hitler's obsession with "Wunderwaffen" or wonder weapons. He spent massive amounts of resources on "big" solutions that didn't actually solve the problems he was facing. While the Allies were building thousands of reliable tanks and planes, the Nazis were digging holes in hills for guns that didn't work.
However, the technology didn't die in 1945. In the 1960s, a Canadian engineer named Gerald Bull became obsessed with the same "super gun" concept. He eventually tried to build a version for Saddam Hussein in Iraq, called Project Babylon. Bull was assassinated in 1990, and the project was seized, but it shows that the dream of a "space gun" or a long-range cannon is still floating around in the world of ballistics.
Visiting the Site Today
If you're ever in northern France, you can actually visit the Forteresse de Mimoyecques. It’s a museum now. You can walk through the tunnels and see a replica of the barrel sections. It’s a damp, eerie place that serves as a tomb for the slave laborers who died there and a monument to the hubris of the Third Reich.
The site is also, weirdly enough, a nature preserve for bats. They hibernate in the cool, quiet tunnels where the super guns were supposed to sit. It’s a fittingly quiet end for a weapon meant to scream across the English Channel.
Next Steps for History Buffs:
If you want to understand the full scale of the V-weapon program, you should look into the V-2 rocket facility at La Coupole, which is only about a 30-minute drive from the V-3 site. It offers a much broader look at how the Nazis pioneered rocket science while simultaneously committing horrific human rights abuses. You can also research Gerald Bull and Project Babylon to see how the V-3's technical DNA almost resurfaced in the late 20th century.