As World War 2 reached its blistering zenith, a depleted and overextended Nazi
Germany began to pin its hopes of victory on its secret super weapon programs.
As such, the relentless ingenuity of German engineering gave birth
to the Vergeltungswaffen initiative, which loosely translates to "reprisal weapons."
The program resulted in the creation of the V-1 flying bomb and the V-2
missile, the precursor to modern intercontinental ballistic missiles.
The weapons were used to rain destruction over Britain and to inflict terror among the
confident Allies, but the V rockets had limited success in halting their ability to wage war.
However, a secret V-weapon was already in the works, and if successful, it would far surpass
the others in raw power. The V-3 was a massive 430-foot-long super cannon capable of thrusting
150-millimeter caliber shells, each weighing 140 kilograms at a rate of 600 shells per minute.
Adolf Hitler's plan was to have 50 super cannons launching
3,000 rounds at London every day, and it was up to the Allies to stop the
production of the world-shattering wonder weapon before it began its lethal barrage…
An Old Idea
Back in the 19th century, American engineers toyed with the idea of creating a massively long
cannon whose projectiles would be propelled by a sustained chain of detonations as they traveled
along the gun barrel. Each detonation was meant to add thrust to the shell,
achieving unparalleled speeds and ranges by the time it left the barrel.
The design depicted a series of propellant stages positioned at
intervals along the barrel to deliver extra acceleration. These stages were
activated by the hot gasses that pushed the projectile forward.
Early experimentation, however, could never properly synchronize the subsequent detonations
with the projectile's movement, leading to unintended explosions and collateral damage.
In 1880, a prototype underwent testing at the Frankford Arsenal in Philadelphia but
was deemed unsuccessful. The projectile could not seal properly, causing the flash from the primary
propellant charge to bypass it and ignite the secondary charges prematurely. As a result, the
shell's velocity was reduced instead of increased, and the idea was promptly abandoned in the US.
Decades later, as World War 1 raged over the European continent,
France was threatened by the fearsome Paris gun, a colossal 34-meter German
siege weapon that could punish the French capital from over 75 miles.
Horrified and enraged by the German weapon,
the French military began planning and developing its own super cannon in 1918.
French engineers revisited the idea first concocted by the Americans and
modernized the design, creating a blueprint for an artillery weapon of unfathomable scale and power.
But the need for the super cannon soon vanished with the retreat of the German
armies and the end of the war, and the prototype phase of the project was indefinitely postponed.
Little did the French know that their idea would soon
be made a reality by the nation it was designed to keep at bay.
A New Design
One decade after the production of the French cannon was halted,
a new conflict took France by storm. Amid the breakneck speeds of the Wehrmacht invasion,
the nation failed to secure or destroy its secret military schematics,
and the designs of the long-range gun soon fell into the hands of the German troops.
In 1942, August Cönders, the chief engineer of "Röchling Stahlwerk AG" in Wetzlar, Germany,
and developer of the revolutionary bunker-busting Röchling shell, took notice of the patent.
Cönders believed that the gradual acceleration of the shell,
achieved by a series of small charges arranged along the barrel's length,
could be a potential solution to the challenge of designing long-range guns.
German engineers eventually revamped the concept of traditional guns and
solved the decades-long problem of relying on a highly explosive
charge by using electrically activated charges to eliminate premature ignition.
With this new perspective and using machinery already in use to produce
20-millimeter tubes for the Flak 38 anti-aircraft guns, Cönders constructed
a 20-millimeter multi-chamber gun prototype at the Wetzlar plant.
Initial testing showed encouraging results. However, to secure the support of the Ministry
of Arms, Hermann Röchling had to present Cönders' project to Albert Speer. The hook they used was
that of a cannon capable of bombarding London from the Pas-de-Calais coastline.
Once Speer was onboard, he had to persuade Hitler to approve the ambitious and expensive
venture. The Royal Air Force had recently bombed the Peenemünde rocket center,
a massive testing facility for German missiles, and Hitler was eager to make the British pay.
As Speer informed him of the V-3 project, the Further was more than happy to listen…
Making The Super-Cannon a Reality
By August 17, Hitler had approved the immediate construction of the
gun without any further testing or prototypes.
Cönders began his massive endeavor by building a full-caliber gun at
the Hillersleben proving ground near Magdeburg. But as 1943 drew to a close,
he realized the project would be much more difficult to materialize than he previously
anticipated as he now faced a series of challenges in both implementing the gun's
fundamental principles and developing a viable design for the shells it was intended to fire.
Little by little, the undeterred engineer honed the design parameters and adjusted
his gun accordingly. But even when everything was working as intended,
the muzzle velocity was just over 1,000 meters per second,
much less than they had promised Hitler and not nearly enough to reach London from France.
Germany then poured more money and engineers into the project,
delegating the projectile issue to several German companies which competed fiercely to
develop an adequate shell for the massive cannon.
Meanwhile, Cönders solved the pestering issue of obturation by inserting a sealing
piston between the projectile and the initial propellant charge.
This effectively prevented the flash from the charge from advancing beyond the projectile
and resolved the challenge of managing the ignition of the secondary charges.
By the end of 1943, everything appeared on track to build 50 super cannons to
obliterate Britain from the French coast, and Major Bock of Festung Pioneer-Stab 27
was tasked with finding a suitable site to position the V-3 batteries.
The location had to be within the operational range of the guns but
not so close to the channel that the facilities could be targeted by the Royal Navy's warships.
The chosen site was a limestone hill near Mimoyecques in northern France,
which had a rock core suitable for excavating gun shafts. The place was named Wiese and
consisted of two parallel facilities, each with five drifts holding 50 HDP gun tubes.
The plans were to have the first battery of five-gun tubes ready by March of 1944.
The clock was ticking, and Germany was not precisely winning the war. If they
did not finish their guns as soon as possible, it might be too late to raze London into oblivion.
The Debacle
The urgency was overwhelming. As the construction of the Mimoyecques facility
was put into overdrive, Cönders oversaw a crucial series of trials held from May
20 to 24 in which the colossal weapon shattered records with incredible ranges of up to 55 miles.
Then, on July 4, the Misdroy gun took aim and unleashed eight rounds, one of which
traveled a formidable 59 miles. Even so, it fell short of the 120 miles needed to reach London.
To make matters worse, disaster struck as the tests neared their climax. With
a deafening roar, the gun burst and the barrel shattered into pieces,
putting an abrupt and fiery end to Cönders’ ambitions.
After the massive failure at Misdroy, the Mimoyecques project was scaled back from five
guns to three, and Hitler began doubting the capabilities of the wonder weapon.
The question of whether the V-3 would be able to reach London would remain unanswered as
the notorious RAF 617 Squadron, also known as "Dambusters," unleashed their 5,400-kilogram
"Tallboy" bombs over Wiese on July 6, obliterating the site and rendering it completely inoperable.
A Final Push
By the final months of 1944, a paranoid and shattered Hitler gave control of all the
V-weapon programs to SS General Hans Kammler to defend Germany from the invading Allies.
Kammler hastily built a last V-3 super cannon placed in the hands of the army artillery unit
Artillerie Abteilung 705 under Hauptman Patzig. The battery was strategically positioned in a
wooded ravine of the Ruwer River at Lampaden, Germany, around 8.1 miles southeast of Trier.
Soon after, a second cannon started construction,
and Kammler was ordered to aim both of them toward the recently liberated Luxembourg by December 30.
On that date, the V-3 gun sprang into action with a flurry of warm-up rounds
followed by a rapid succession of five high-explosive shells.
The shells were fired at an impressive velocity of approximately 3,070 feet per second.
The second gun was also brought into action on January 11, 1945, and by February 22,
a total of 183 rounds had been fired, with a confirmed 44 hits in the urban area.
But time had sealed the fate of the V-3 super cannon. When American troops were
just a few kilometers from the cannons, Kammler ordered his men to take them apart.
The sites were abandoned, and the Americans seized the gun equipment.
As with the remaining Vergeltungswaffen weapons, the V-3 came too late to shift the tides of war in
Germany's favor, remaining as an ineffective yet impressive show of German engineering…
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