Or: Size Matters.

Nazi Germany, during World War II, came up with a whole litany of ideas for reducing London to smoldering rubble. You've probably heard of the V-1 and V-2 rockets, used with some success (from the German viewpoint), and the basis of much subsequent rocket science in the United States and Soviet Union.

Of slightly less renown, however, is the V-3 Hochdruckpumpe.

Sounds Neat. What's it mean?

So many names, depending on whose side you were on. This particular weapon came under the following designations:

What is it?

Another attempt at a so-called supergun. The V-3 was designed as a massive long-range projectile weapon, designed to fire across the English Channel from occupied France.

A multi-chambered, breech loading, 6 inch caliber weapon, the barrel was 150 meters long--well over a modern American football field, so it wasn't exactly subtle.

The scientists of the time were certainly fantastic engineers, making huge strides in the advancement of all technologies, but this thing was really a beast, despite the simplicity of the concept, which is more or less this, on a reduced scale:

You have a gun. You pull the trigger, the firing pin ignites the powder in the shell, bullet shoots out. Fine.

Now, add additional charges as the bullet is traveling through the barrel, timed to go off just after it passes, thus increasing its velocity.

The theory behind this monstrosity is that your initial blast can only be so big; enormous shells are impractical, and might blow the weapon apart anyway. So--do it in stages. Simple.

Of course, if you want to get your bullet into the stratosphere (which they did, knowing that the thinner air would further increase the range), and if you want to make more than a pinprick in the face of London, everything will have to be dramatically increased in size.

To accomplish this, supplementary chambers were constructed and attached to the main barrel at 45 degree angles, spaced four meters apart along its length. The projectile got stabilizing fins attached to aid its flight, and at the end of the day, the Nazis had quite the potential party popper, predicting muzzle velocities of about 5000ft/sec, and a range of 175 miles for a 140 kilogram explosive projectile.

Whose idea was this?

The supergun was already an old idea in 1943; this one was designed by Saar Roechling, based on the work of a Baron von Pirquet, who had done some tinkering in the field himself years before, redesigning the Moon Gun conceived by author Jules Verne. He took additional cues from two Americans, Lyman and Haskell, who built a small prototype weapon for the U.S. Army way back in the 1880s.

Of course, previous models were either much smaller, or tended to explode. There were three main problems:

  1. The timing was imprecise, resulting in an inefficient launch
  2. The initial blast would sneak up the pipe, and start setting off the supplementary charges, thus slowing the projectile down, or blowing the barrel apart.
  3. The lateral chambers exploded after just a few shots.

Numbers one and two were the real deal-breakers. The third hiccup was seen as a necessary evil, tolerable only because the chambers were somewhat more easily replaced. But an engineer at Saar Roechling, Herr Conders, came up with the solution that, to Hitler, made the whole thing truly worth investigating: electrically triggered detonations of the lateral chambers.


The project didn't really get underway until 1943, when a 20mm prototype was successfully demonstrated at Miedzyzdroje, in Poland. Going against the advice of his military commanders, Hitler himself ordered the construction of no less than fifty of the guns, to be placed in strategically located underground bunkers along France's coast.

At only 165 km away from London, the town of Mimoyecques, near Calais, was chosen as the initial deployment site under Operation Wiese.

Slave labor--favorite of many an oppressive regime--began sinking the bores 30 meters into a chalk hill, at fixed angles. The sites were then covered with 5 meters of reinforced concrete.

By 1944, everything was nearly ready to go.

Why Don't I Remember Hearing about This Before?

They never got a decent shot off. The French Resistance leaked word to the Allies almost as soon as construction began; it's not easy to conceal such a massive undertaking, especially when the main compononent is 150 meters long.

Bombing runs began in early 1944, when Allied planes started dropping 5400kg "Tallboy" bombs, designed to penetrate the bunkers. All attempts were unsuccessful until three managed to drop right in the pickle barrel: the gun shaft openings.

The bombs rode all the way down, 30 meters, to the main floor of the complex. Anyone working at the time was killed. Hitler, rushing whatever he had left into service, managed to get two smaller versions operational to no avail. No results were recorded.

By the time the Allies overran Calais, production had been abandoned.

Thanks to:
www.geocities.com/pentagon/2833/ wonder/supergun/v-3/v-3.html