story relates the unique and unforgettable attack of the Möhne
and Eder dams by squadron 617 in May 1943. The raid was conducted
by Wing Commander Guy Gibson, an old hand of Bomber Command, who
had been in command of squadron 106, equally equiped with Lancaster,
before creating Squadron 617 composed of bomber aces only. Before
the raid on the dams, Guy Gibson had completed three operational
terms totalizing 173 bombing missions. Aged 25, he had been awarded
DFC and DSO*. He disappeared piloting a Mosquito as master bomber
during an attack on Rheydt in September 1944. (After Paul Brickhill's
book "The Dam Busters", ed. Flammarion, Paris).
felt like scening the scale model : the same basin filled
with water, the same fields around, the same massive wall
crowned with two towers closing the end of the lake.
Faintly lighted, the rampart looked like a hideous floating
fortress, a battleship fastened between two moorings.
"Good Lord", somebody murmured. "Do you think
we can demolish that one ?". Suddenly the dam livened
up. Beams of tracer bullets spouted from the towers sweeping
across the sky in all directions.
"Rather agressive, those Fritz !" Trevor Roper remarked.
The three pilots skillfully cleared off and started to round
the lake, making sure they stayed out of reach of the flak.
Gibson tried to count the guns. There were at least one at
each side of the lake close to the dam and at least four in
each tower. He called the machines of the next wave and they
answered one after another except for Astell. Gibson
repeated his call again and again
but Astell was dead since an hour. Finally, seeing that insisting
was useless, Gibson told his crew, "let's go !".
Then switching to the radio, he called the others saying :
- "Take care everybody, I'm attacking, be ready for charging.
Hello Mother, take command if something happens to me.
- OK chief, good luck !" went the calm voice of Hopgood.
Gibson flew away as far as the hills at the east end of the
lake. Then, turning gradually, he rushed with the full power
of his four engines. Slowly the machine lined up till, straight
ahead, at some 5 km, the dam with its towers suddenly appeared.
Emerging over the water at 400 kph, Gibson bellowed his last
order : "Check altitude ! Control speed ! Ready machine
guns, lights on !"
The navigator turned on the searchlight under the belly of
the machine and waiting for the light beams to cross at the
water surface, started his refrain : "lower, lower, a
bit higher, good, perfect..."
When the Lancaster stabilized at exactly 20 meters above the
lake, the German gunners saw the lights. Immediately, beams
of tracers focused the target previously invisible. The bullets
seemed slow at first, but increasingly faster while the machine
closed in on the dam.
Gibson, perfectly calm, piloted the Lancaster straight between
the two towers. Spafford, looking through the hole in the
plywood visor, waited with his hand on the launching button.
Suddenly, a terrible noise bursted from the nose when the
front gun opened fire on the two towers. Gibson felt like
the dam, giant wall with scattered will'-o'-the-wisp, was
going to crush him. The smell of powder and overheated metal
got in his throat and he thought : "in a minute we're
Then Spafford cried out "Bomb launched", the machine
entered between the two towers and Hutchinson launched a red
flare signaling the others they were safe.
perfectly calm, piloted the lancaster straight between the
two towers... Illustration : Benjamin Freudenthal - 70 x 50
cm poster avalaible - To order,
moment later, Trevor Roper, from the back-turret sprayed the
German gunners with fourfold bursts. They regained self-control
while the Lancaster dived staggering along the valley, skimming
the floor for dodging the Flak. When out of its reach, Gibson
pulled up over the hills, turned sharply and looked at the
dam. At first he didn't see anything. Then, suddenly, the
water surface, cut by the towers outline, lifted. An enormous
white cone broke the surface and spouted skywards. The lake
bubbled and while the column reached its highest point and
hovered like a ghost over three hundred meters high the rumbling
of the explosion catched up with the plane. Terror stricken,
the men saw a waterfall spill over the dam. A moment they
thought the wall had burst. Little by little the water quietened
and they noticed that the dam was still in place. Had it been
shaken only ?
Some minutes later, while the Lancaster was circling over
the hills, Gibson thought the water sufficiently calm to give
it a second try.
-"Hello Mother, your turn and good luck.
-Ok chief, here we go" sounded the always nonchalant
voice of Hopgood.
Emerging from a gap in the hills, he piloted straight to the
dam. The other creaws observed him anxiously. The searchlights
under the machine belly went on, and two light circles slided
over the water till they united. Hence, Hopgood had reached
the right height but at the same time, the Flak started firing.
Unruffled, he continued the charge. At 500 meters from the
wall, the machine got into a swirl of tracers ; a red glow
appeared around the tank of the interior starboard engine,
and next the tail emited a long flame. The bomb was launched
a split second too late and fell over the parapet on the power
station at the base of the dam.
"Mother" got over the dam and immediately nosed
up. Hopgood tried to pull up so the crew could parachute.
Suddenly the tanks exploded, a wing broke off and the condemned
Lancaster spinned down in a rain of white-hot debris. While
it crashed, the powerstation blew up in a profusion of lights.
10 seconds later it was all over. "Poor Hoppy !"
murmured some voice. Gibson, his face rigid like a mask, called
"- Hello, Popsie, you're ready ?
- Fully ready chief, I'm going".
- While you attack, I'll fly over the dam to lure away the
- Ok Chief, thanks a lot !"
When Martin appeared from over the hills Gibson rushed over
the lake parallelly aligned with the dam but outside Flak's
range. The six beams of tracers that focused the towers distracted
the Germans who didn't remark Martin's machine before it was
at 800 meters from the dam. Nevertheless, three guns managed
to draw an iron curtain between the towers, a deadly curtain
that Martin inevitably had to clear. Exactly when Bob Hay
pronounced "bomb launched !", the machine gave a
sudden jolt. Two shells had hit the port side wing, and one
had exploded in the interior tank.
machine cleared the dam and dived down the valley. The crew
anxiously observed the damaged wing. Suddenly, noting the
absence of flames, the navigator started to scream : "That
was a lucky strike, the tank was empty !". Martin smiling,
rubbed his chin before crying into the mike : "bomb launched,
chief ! ".
-"Well done, Popsie. hello "Apple", are you
- Yes sir.
- So go ahead ! Warn me when you're in position so I can divert
these Flak people. Hello Popsie, are you hurt ?
- Yes, two holes in the port side wing, but everybody unscathed.
We'll make it back I think".
victorious attack of Maltby
lake started bubbling again, the same
white column spouted hundreds meters
high, the same waterfall spilled over
the dam. But when the water furor
quietened, the dam was still there.
Even after a third bomb launched by
"Apple" with wonderfull
precision, it was still standing.
Again Gibson waited for the white
column to subside, then ordered Maltby
to give a try. This time, both Gibson
and Martin rushed simultaneously from
opposite sides over the lake, firing
with all their guns and turning on
their sidelights to distract the Flak.
Once more, the enormous eruption shook
up the black surface of the Möhne.
Once more a geyser spouted from close
to the wall. Presently, the water
vapor covered the entire valley and
it was difficult to judge the result
of the explosion.
Gibson, slightly unnerved, just ordered
Shannon to lauch his bomb, when a rapturous
voice screamed in his headphones : "that's
it ! The dam is down ! look at that
It was martin, who, turning over the
valley, had assisted in the collapse
of the rampart. The huge mass of concrete
had suddenly exploded, and an entire
section had collapsed under the water
pressure. A gap measuring 100 meters
wide by 30 meters high opened the
middle of the construction. And a
wild flood of 134 millions cubic meters
entered between its ragged flanks.
Gibson had to rescind his order to
Shannon. One after the other, the
machines flew over the defeated dam.
Under the indifferent moon light a
liquid wall 7 meters high gushed down
the shope. A German, possibly the
sole survivor of the towers, started
suddenly firing at the bombers ; a
few well targeted bursts silenced
him quickly. Little by little, their
common emotion transformed into unbriddled
joy ; Hutchinson was the only one
not participating in the lively, rather
desultory and very loud exchange.
Sitting at his manipulator he sent
by morse, very slowly and clearly
a significance - weighty words : "Nigger",
the name of Gibson's New Foundland
terrier, And also the code word signifying
the complete success of the operation.
In the meantime the water and vapor
wisp rendered the valley unrecognizable.
Gibson ordered Martin and Maltby to
go home. Then he lead the other crews
to the east over the Eder. They were
going to try finishing the job they
extraordinary weapon that enabled
the Lancasters of Squadron 617
to break the Ruhr dams had been
conceived by a civil engineer,
Barnes Wallis. despite the lack
of enthusiasm at the staff during
preliminary studies, Wallis
continued to experiment and
demonstrate the feasibility
of his project. The process
included a variety of tests
like catapulting marble blocks
encased in metal containers
in the water, shooting blazing
projectiles at a lake or blasting
small charges along the inlet
of a water reservoir. During
the 1942-1943 winter a Wellington
bomber equipped with a special
dropping mechanism made a series
of tests with dummy
cylinders at Chesil Beach, near
Weymouth. A real charge was tested
afterwards and the RAF got the
famous bomb in April 1943. Unfortunately,
the exercise bombs broke at impact
or veered off course.
Wallis reinforced the
outer casing, making the
bombs operational. Code
named Upkeep, the final
version was a 4190 kg
cylinder, 1,52 meter long
and 1,27 meter in diameter.The
explosive charge consisting
of 2290 kg torpex was
set off by three hydrostatic
guns triggered at 9 meter
water depth. A self-destructive
device started 90 seconds
after dropping. The Germans
analysed one of theses
weapons recovered from
a downed Lancaster qualified
it as a "spinning
depth bomb". This
label is rather pertinent,
yet the invention of Wallis
entered history as the