It’s 1943 and Germany believes its dams- critically important for its war effort-
are invulnerable to British bombs. Then a single Lancaster bomber drops to sixty feet
and unleashes a strange, tumbling barrel out of its bomb bay. In astonishment,
German soldiers watch this barrel bounce right over the torpedo nets protecting one
of the biggest dams in Germany, then run up the side of the dam before falling back down.
The explosion is tremendous, and British dam busters are about to
turn the tide of the war with the weirdest weapon of World War 2.
Thanks to the entry of the United States into the war, the British army had backup,
but breaking through the German defenses was proving challenging. The Nazis were
relying heavily on the Ruhr Valley, a heavily industrialized region where the waters were kept
in check by a series of dams. These dams not only kept the area safe from flooding, but they were
also key sources of hydroelectric power for the region and provided drinking water. They were also
key to the canals running through the region. Any failure in the dams could be devastating.
That was exactly what the British were counting on.
Even before the war, the British had set their sights on the Ruhr Valley as a potential target
in the event of a conflict. Now, with the Nazis threatening to conquer the British isles,
they knew that this might be a way to turn the tides There was just one problem - they didn’t
have a weapon that was capable of breaking through those defenses. The dams were heavily fortified,
too strong to be attacked from the air. Their only vulnerable spots
were their base - but the Germans knew that. The dams were protected
by underwater torpedo nets that would stop the bombs short of their targets.
This would be one of the trickiest missions of the war - and it would require a new type of weapon.
The beginnings of Operation Chastise were found in the notes of Barnes Wallis,
a weapons designer at the British engineering firm Vickers. He had designed some of the Royal
Air Force’s most powerful bombers and was working on anti-ship weapons when he was
called back into service to figure out how to destroy the dams. His first idea?
A much bigger bomb, one of the most powerful conventional weapons ever created. If it
hit its target, it would break through the fortifications and shatter the dam.
There was just one problem with this plan.
The British had some big bombers, but none were equipped to carry a bomb of that size. Also,
their planes weren’t designed to fly at the altitude needed to deliver the weapon,
nicknamed an Earthquake Bomb because of its high-speed, high-altitude delivery. He proposed
a bigger bomber, but the time and money needed were unacceptable. So the plan was scrapped, and
Wallis started to focus on the dam’s weak point. Getting to it from the top was impractical, but
if he could figure out a way around the torpedo nets, it would be easy to cause massive damage.
It was a new kind of war, and it was time to throw out all previous thinking about bombs.
Wallis’ next design took everyone by surprise. It was almost a third of the size of the previous
model, only about nine thousand pounds. But it actually wasn’t a bomb at all - it was a mine
shaped like a cylinder that would work like a depth charge. Instead of being
dropped from a high height, it only needed to be launched sixty feet above the water.
Sent flying towards the target at two hundred and forty miles an hour, it would speed towards
the target and skip across the water. The backspin would then cause the bomb to run
across the side of the dam before hitting the base, detonating with a massive impact.
It looked more like an oil drum than a high-tech bomb - but it packed a punch.
Now it was time to test this new concept, and the first task was blowing up a scale model dam.
After this passed with flying colors, the British military tested it on an abandoned
dam in Wales and determined that they needed a charge of 7,500 pounds to breach the dam.
This brought the bomb within the levels that could be carried by the popular Avro Lancaster airplane.
As the military conducted airdrop trials and the airplanes were adapted to carry the massive bomb,
a new stumbling block emerged in the mission.
It was the worst nightmare of designers everywhere - bureaucracy.
Air Vice-Marshall Francis Linnell of the Ministry of Aircraft Production was not
pleased. He wanted Wallis focused on developing new aircraft, and Wallis was pressured to resign
after the head of bomber command denied the allocation of the bombers.
The whole project was in danger - until the Chief of the Air Staff heard about the
project. The higher-ups were convinced of the mission’s necessity, Wallis got his bombers,
and the design of what would be known as the Upkeep mines continued. The mission was scheduled
for May 1943, when the high waters would make it easier to deliver the payload underwater.
It was eight weeks to the mission, and there was a lot of work to be done.
The modifications to the Lancasters still needed to be completed and the mine had to be perfected,
but there was one other piece to the mission - someone needed to take on the incredibly
dangerous mission into enemy territory. They’d be delivering a payload to one of
the most closely guarded locations in the Nazi regime, at serious risk of capture or death,
and they had to pull off a military maneuver never before attempted in combat.
The wrong team being selected could turn the tide of the war against the British.
And it all fell on No. 5 Group RAF.
The elite unit was one of Britain’s best - but it wasn’t only British. It contained allied soldiers
from Canada, Australia, and New Zealand. They were briefed on their mission and would target
a pair of dams - the Mohne and the Sorpe, both upstream from the Ruhr industrial area. They had
a secondary target, the Eder Dam if things went south. The goal? To deliver a devastating blow to
German infrastructure, cut off their hydroelectric power, and disrupt the flow of water to factories,
cities, and canals. The hit could also cause major flooding if the damage was serious enough.
The entire war could hinge on this one bombing raid.
The mission would take place at night for the maximum chance for success, and the team quickly
began training in low-light and low-altitude flying. The technical advisors struggled to solve
issues such as the visibility of the target and determining the aircraft’s altitude. Every little
detail of the mission could be the difference between success and failure, and some spotlights
attached to the plane promised to solve the altitude problem. But the mission would also need
brains in the cockpit, and the Royal Air Force chose one of their best men to lead the charge.
And he was only twenty-five years old.
Guy Penrose Gibson was already one of the best pilots in the Royal Air Force,
and they trusted him with maybe their most critical mission yet. Security was tight
on the mission, and early on only Wallis and Gibson knew the details of the mission. They
briefed the other soldiers down the line as needed, and on May 13th, 1943 they received
the bombs. Three days later, they would take flight, divided into three formations that
would each hit one target - either the primary ones or falling back to hit the secondary ones.
They ran into a last-second disruption - two crew members were sick and scrapped from the mission.
But nothing would stop Operation Chastise from taking aim.
The routes to the targets were well-scouted, and the planes avoided the areas with known
anti-aircraft guns. One bomber was late due to a coolant leak, but two and a half hours
before midnight, they started taking off. Soon, all three formations were in the air,
flying low to avoid German radar. One radio operator tracking them observed a plane and
was shocked by what he saw - one of the pilots was flying so low, he was actually below tree level!
But it wouldn’t be long before the planes hit rough waters.
Formation No. 2 was the first to hit trouble. Some bombers were damaged and lost their
radio or bombs, while others crashed or were forced to bail out. But Formation No. 1 fared
differently - and soon the Mohne Dam was in site. They took heavy anti-aircraft fire,
but ultimately delivered a devastating hit to the Mohne and the massive structure was breached.
But the allies weren’t done yet.
Next up was the Eder Dam, and the pilots soon realized there would be trouble - the valley was
extremely foggy. But this actually turned into an advantage - the geography and fog made it harder
to defend the dam with anti-aircraft guns, and they didn’t take as many hits as they did in the
first strike. But that didn’t mean it wouldn’t be challenging - it took one plane six tries
to try to find the target, and another bomb struck the top of the dam and damaged the aircraft.
Ultimately, the final bomb of the formation hit its target and shattered the dam’s defenses.
The next test would be the hardest yet.
The Sorpe Dam was the mission’s reach goal - it was much hardier than the other two,
made of earthen material rather than concrete and steel. By the time the squadron was ready
to attack it, only two planes remained. A close call with a church steeple in
the region nearly took out one plane, and there was no time for the bomb aimer to get
a perfect shot. It took nine failed bombing runs before the bomb was finally dropped,
and it hit - but not perfectly. The top of the dam was damaged, but the core structure was intact.
Now there was just one challenge left - get home.
Two more planes were lost on the way back, but back at the base in Scampton, the mission
commanders waited anxiously to see who would return. Ultimately, eleven bombers returned, with
mission commander Guy Gibson returning over an hour after the first survivor. The last survivors
of this extremely dangerous mission arrived two hours later. In total, eight of the nineteen
planes that took off to deliver a devastating blow to the German war machine were lost.
But the punch they delivered to the enemy was far more devastating.
The bomber command had put a lot into this mission, and the costs in human life were
harsh. But the results were worth it. Two massive dams had been breached,
and soon afterward huge floods laid waste to the region. A pilot that scouted the area observed
that he could only see treetops and church steeples poking above the floodwaters. It
took a long time for the full damage to be assessed, but now it’s believed that around
sixteen hundred people in the region died in the floods and the financial cost was incalculable.
The unit’s bravery, and Barnes Wallis’ ingenuity, had paid off.
80 of the 153 Dambusters survived the mission, and they were all highly honored for their service.
Guy Gibson in particular became the most decorated soldier in British history at
the time before returning to the war. But as time went on, a debate began.
It was a highly effective mission - maybe too effective. In harnessing the forces
of nature to devastate a German region, the British unleashed mass casualties.
Most of the victims of the flood were civilians, many of them foreign workers and prisoners of war.
To honor the heroes, or mourn the victims? This question would be debated for decades.
The war was eventually won, and the story of the Dambusters passed into history.
It wouldn’t be long before the silver screen came calling, and in 1955 a movie was made based on a
series of books about the raid. Not only was it the most popular film of the year in Britain,
but its depiction of the pinpoint strike against a massive structure’s
most vulnerable point reportedly inspired the iconic strike on the Death Star in Star Wars.
But it would have a different impact on the future of war.
In 1977, an amendment to the Geneva Convention outlawed attacking dams if it could cause
severe losses among the civilian population. An exception was made for if the Dam is critical to
military operations and there’s no other way to neutralize it, but the shock and awe of Operation
Chastise had horrified enough people that they wanted to make sure it would never happen again.
One figure of the strike, though, couldn’t be reached for comment.
Like so many other war heroes, Guy Gibson returned to combat after his most heroic
mission. He took tours of Canada and the US first, but eventually returned to service.
Over a year after the Dambusters mission, he would be involved in an attack on Bremen when
his plane crashed for unknown reasons, and he became one of the many fallen of World War II.
For more on WW2 artillery, check out “How Close Did Nazis Come to Creating the Atomic Bomb?”
or watch “Worst War Crimes Committed by the United States During WW2”
for some other controversial missions.