the
Dambusters
The
Dambusters have been immortalised in World War Two folklore
as a result of their attack on the dams of the Ruhr. As part
of the Allies bombing campaign against Germany during the
war, the Dambusters wa an elite Lancaster bomber unit and
the raid was led by Wing Commander Guy Gibson VC. How much
impact the Dambusters raid had is still debated but what
cannot be denied is the bravery of the men involved in the
raid and the unique contribution made by Dr.Barnes Wallis
who developed the unique bouncing bomb that was used on the
raid. If the raid did not have a long term impact, it did
have enormous propaganda value for the Allies.
Dr Barnes Wallis
Barnes
Wallis was an employee of the Vickers Aircraft Company. In
March 1941, he completed a piece of work entitled "A note on
the method of attacking the Axis powers." Wallis had
envisaged the Allies using a huge bomb against the Germans –
ten tons in weight so that any building/object was
vulnerable to an aerial attack even if it was built
underground.
This fifty-page piece of work stated that the Allies had to
develop a new form of bombing if massive concrete structures
were to be destroyed. He wanted much larger bombs built so
that the area surrounding where the bombs were dropped would
be so massively shaken as to create enough jarring pressure
to shake a target to pieces. Therefore, pinpoint precision
bombing would no longer be necessary as physics would take
over once a bomb had exploded.
"To
attack these targets successfully it is necessary to inject
the largest possible charge to the greatest possible depth
in the medium (earth or water) that surrounds or is in
contact with the target." (Wallis)
Wallis
proved that a 10 ton bomb dropped at 40,000 feet would go
135 feet into a normal surface and would create no crater as
all energy would be directed into an earthquake effect with
potentially devastating consequences. However, no one was
particularly interested in what Wallis had written and many
felt that his ideas were just ‘pie-in-the-sky’. No one had
ever built a bomb that was 10 tons; no bomber had ever been
built that could carry such a bomb and no plane flying then
could fly at 40,000 feet. Some saw Wallis as an eccentric.
However, one part of his paper did attract attention. Wallis
believed that Germany’s industrial heart could be destroyed
– literally drowned – if the huge dams in the Ruhr were
destroyed unleashing vast quantities of water into the Ruhr
industrial sector. An ‘Air Attack on Dams Committee’ was
formed in 1941 under the chairmanship Dr. Pye. The committee
decided that the primary target should be the Möhne Dam
which enclosed the Möhne and Hedve rivers. The dam was 130
feet high and 112 feet thick at its base. Even the top was
25 feet thick making it a formidable target to destroy.
The first idea Wallis had was to attack the dam with a
series of very large bombs in a conventional manner. He
quickly dropped this idea as the accuracy required for such
an aerial attack was simply beyond the capacity for a bomb
aimer at several thousand feet. A bomb would need to land
within 50 feet of the dam’s wall for it to be effective and
in July 1941, the Air Attack on Dams Committee concluded
that:
"There
seems to be no doubt that an attack on the Möhne Dam is
impracticable with existing weapons."
A torpedo type bomb was out of the question as the Germans
had already thought of that as a way of attacking the dam.
Anti-torpedo nets protected the dam. Wallis came up with an
idea he called "childishly simple". He believed that you
could use a bouncing bomb that would clear the protective
nets, that would smash into the dam wall, stay intact and
then sink to a depth of 30 feet before exploding using a
hydrostatic fuse (similar to the ones found in depth
charges). To ensure that the bomb went down the dam wall,
Wallis planned for the bomb to spin forwards after it had
hit the wall – despite the fact that it would be dropped by
a bomber spinning backwards.
Wallis received permission to develop the bomb – code-named
‘Upkeep’. The bomb was 50 inches in diameter, 60 inches long
and weighed 9250 lbs. Of this weight, 6,600 lbs was powerful
RDX explosive. The bomb was designed to be mounted across
the bomb bay of a Lancaster bomber. It was spun using a
system of V-shaped pivots to which was attached a small
motor built into the bomb bay.
Upkeep was not an easy bomb to deliver and the elite of
Bomber Command joined a brand new squadron called 617 in
March 1943. The crew had to release the bomb while flying at
exactly 220 mph and at a height of exactly 60 feet above the
water. If the Lancaster was forced into a tight turn at this
height, one of its wing tips would barely be above the
surface of the water. Precision flying at its best was
needed just to get the bomb in motion. To add to the
difficulties, the crew had to drop the bomb at exactly 425
yards from the dam wall. There could only be 25 yards either
side of this figure – a tiny amount of seconds given the
speed the Lancaster's would be flying at – and the fact that
German guns would be targeting them. To add to the task, the
attack was also scheduled to be carried out at night.
617 Squadron
was lead by Wing Commander Guy Gibson and he was allowed to
select the men who were to be on the attack.
Guy Gibson, centre, with fellow flyers
The whole
attack was given the code-name ‘Chastise’. Gibson was
ordered by ‘Bomber’ Harris, head of Bomber Command, to pick
men who had survived near enough 60 bombing raids as these
men would have the necessary experience needed for the
attack. 617 squadron started extensive sessions of low
flying but none of them knew the target they were practising
for – this they were only told at the last minute.
On the night of May 16th, 1943, nineteen Lancaster bombers
took off from Scampton in Lincolnshire. They had three
primary targets: the Möhne, Eder and Sorpe dams and two
secondary ones, the Lister and the Eneppe dams. Of the
nineteen planes, five would be held in reserve during the
attacks.
Gibson led the first attack. At 00.56 hours, the Möhne Dam
was breached and by 01.54 hours so was the Eder Dam. The
Sorpe Dam was attacked by planes from the reserve force but,
though hit, it held out.
Just how low the Lancasters flew during the attack is shown
by the fact that one Lancaster had to turn back as it had
hit the sea on the journey to mainland Europe and lost its
bomb.
The attack had huge propaganda value and made Gibson a
national hero. Of the nineteen Lancasters that took part in
the attacks with 133 crew, eight planes were lost with the
loss of 56 men; three of these men survived to become
prisoners-of-war. Gibson was awarded the Victoria Cross for
bringing round his Lancaster to give covering fire to the
Lancasters that were following up his attack on the Möhne
Dam. 33 others members of 617 squadron were also decorated.
How successful was the raid?
Severe flooding occurred where the Möhne Dam was breached.
1,200 people were killed including nearly 600 forced
labourers from Eastern Europe who were housed in a labour
camp near Neheim. Six small electricity works were damaged
and rail lines passing through the Möhne Valley were
disrupted. But industrial production was not affected in the
long-term. When the Eder Dam broke, there were similar
results. Kassel, an important arms producing town, was
reached by the floodwater, but little actual damage was
done. Had the Sorpe Dam been breached, then the damage would
have been much greater. The potential for a major disaster
was recognised by Albert Speer who commented that:
"Ruhr
production would have suffered the heaviest possible blow."
In the short
and long term, the damage done by 617 squadron was repaired
quite quickly. But the most important impact of the raid was
that 20,000 men working on the Atlantic Wall had been moved
to the Ruhr to carry out repairs to the damaged and breached
dams. This work was completed before the rains of the autumn
appeared.
The bombing of specific military and strategic targets
became more important as the war progressed, as the raid on
Schweinfürt demonstrated. The raid by 617 Squadron was part
of this approach. |