Dambusters - the history thread (a bit long)

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Soldato
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A TARGET FOUND AND A WEAPON CONCEIVED

At the out break of the Second World War, Dr. Barnes Wallis, designer of the Vicker's Wellington Bomber began to consider how he could help shorten the war. Although, engaged at the time in the design of the Vicker's Warwick, the planned replacement for the Wellington. Dr. Wallis began, in his spare time, to study the German industrial machine. These studies lead him to conclude that aerial bombardment of Germany's industrial system had some serious short comings. The most alarming of which was that no matter how many times a factory was attacked; it was merely a simple process to either rebuild it or better still, to disperse it over a wide area. The later making the task of permanently destroying the factory that more difficult. One thing did however, begin to become clear to Wallis. There was one area of German Industry that was impossible to relocate or disperse and that was his power sources: Coal Mines, Rumanian Oil Fields, Hydroelectric Dams.

After further investigation, Dr. Wallis quickly rejected the Coal Mines for these were to easily repaired. The Oil Fields too were also rejected simply because the the Royal Air Force did not possess an aircraft with the range to attack these distant targets. The hydroelectric dams however were different story.

Located in the heart of Germany's Industrial center, the Ruhr Valley, these dams supplied the majority of the electrical power and also controlled the water levels in canals that transported materials to and from the factories. Of the seven dams in the region, three stood out from the rest: the Moehne, the Eder, and the Sorpe. By breaching one or more of these not only would Germany's steel industry be seriously effected. But so too would his tank, locomotive, aircraft and gun manufacturing processes.

With the target now clear in his mind Wallis soon concluded that an attack using a conventional bomb was out of the question. A new and specialized weapon would be required.

By January 1943, Dr. Wallis had designed, tested and managed convince both the government and the Air Ministry that his weapon, now code named "Upkeep"; could effectively breach a dam.

Weighing almost 9500 lbs, Upkeep, was cylindrical in shape and was unique in the fact that it rotated backwards at 500 rpm during its release. The speed and altitude of the aircraft was also critical; these having to be maintained at precisely 220 m.p.h. and sixty feet respectively. If these requirements were meet and the weapon was released between 400 and 450 yards away from the dam wall. Then the weapon would literally skip across the surface of the water and over any torpedo nets until it struck the dam wall. With its forward momentum lost, the backwards rotation then forced the weapon to roll down the side of the dam wall; where it was detonated by a hydrostatic fuse at a predetermined depth. The actual breach was made by the combination of the shock wave generated by the explosion; followed by the immense weight of the water pressing against the weakened wall.



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THE FINAL PROBLEMS

Two major problems now remained before any attack could be mounted. The first was how to transport Upkeep to the target, whilst the second, was how to train a squadron sufficiently to give the best possible chance of success.

The first was easily solved. The RAF's champion in shear bomb lifting capacity, the Avro Lancaster - which had only twelve months earlier entered active service - was the obvious, indeed the only choice.

However, even though the Lancaster would have little trouble with the weight of Upkeep; modifications were required to the aircraft to allow the weapon to be carried. These were devised by Mr. Roy Chadwick, designer of the Lancaster, and resulted in the removal of both the bomb bay doors and mid upper turret. In addition, special fairings were installed at each end of the bomb bay to maintain smooth air flow over the aircraft. The changes to the standard Lancaster resulted in a new variant of the aircraft: the Lancaster Mk. BI Special or type 464 Provisioning Lancaster.

Side View Of Mk. BI Special Lancaster
View Of Lancaster With Upkeep Bomb Loaded

The second problem, was not as easily resolved. Upon being requested that he release an entire Lancaster Squadron for special training. Air Chief Marshall Harris, Commander of Bomber Command, claiming that his Lancaster Squadron's were far to valuable to be wasted on such unimportant targets as Dams, flatly refused.

Instead on March 21, 1943, the Air Ministry authorized that a new unit, initially known as "X" Squadron, but soon after renumbered No. 617 Squadron was to be formed at Scampton, Lincolnshire and be attached to No. 5 Group. The new squadron it was decided would be lead by Wing Commander Guy Gibson, DSO and Bar, DFC and Bar.

With only the knowledge that their target would require low level flying over water at night. Gibson and his hand picked and much decorated crews, began low flying four engine aircraft like never before. Training continued even during the hours of daylight; with moonlight conditions being simulated by means of coloured cockpit windows and special goggles.

The crews soon had little difficulty flying at the required 220 mph; but the critical height of sixty feet became a growing concern amongst them. The normal pressure altimeter lacked the accuracy; whilst the radio altimeter, although better, also failed to give sufficiently accurate readings to be relied upon. The problem was eventually solved by fitting two Adlis lamps to the underside of the aircraft; one the nose and the other in the rear section of the bomb bay. It was then a fairly simple process to align each beam in such a way that they would converge on the water at exactly sixty feet below the aircraft.

THE ATTACK PLAN

Operation "Chastise" called for nineteen Lancaster's, flying in three waves and in order to avoid detection at low level to avoid detection; to attack the primary targets of: the Moehne, the Eder and the Sorpe Dams:

The first wave comprising of nine aircraft and led by Gibson, would attack the Moehne and if successful they would continue on to attack the Eder.

The second wave comprising of five aircraft would attack the Sorpe.

The third wave, also comprising of five aircraft would act as an airborne reserve. This reserve, would attack either the Moehne or Eder dams, if not breached. Or if they had been successfully breached, would attack the alternate targets: the Diemal, Ennepe and Lister dams.

View list of aircraft and aircrew's by wave.

View Route Map



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CHASTISE IS LAUNCHED

At 9:30 pm on 16th May, 1943, only eight weeks after No. 617 Squadron had been formed, the first wave took off from RAF Scampton. The second and third waves soon followed.

THE FIRST WAVE:

At midnight eight of the nine Lancaster's in the first wave arrived over the Moehne Dam. The ninth, AJ-B, flown by Flight Lieutenant Astell, had crashed near Dorsten after being hit by flak.

Gibson, in AJ-G, opened that attack by accurately placing his weapon; but failed to breached the wall.

After waiting for the water to settle. Flight Lieutenant Hopgood in AJ-M, began his run in, but was hit by flak and released his weapon late, causing it to bounced over the dam wall and explode harmlessly. His aircraft crashed soon after; only two crew members survived.

Having seen that the the German gunners had now identified the target and means of attack. Gibson in an attempt to confuse the gunners, escorted Flight Lieutenant Martin, in AJ-P, into the target. Martins' run however, was not accurate and his weapon exploded short of the wall.

Squadron Leader Young, in AJ-A, was next to make his run. Escorted by both Gibson and Martin, he managed to accurately place his weapon; but again the explosion failed to generate a breach.

Flight Lieutenant Maltby, in AJ-J, who like the remaining members of the first wave, had been circling the area waiting for his turn. He accurately placed his weapon with the aid of an escorted run. The explosion, proved too much for the Moehnes' wall, which was finally breached.

With only three "Upkeep's" remaining, Gibson ordered these aircraft to follow him to attack the Eder Dam. While the others began their return to base. With the exception of Squadron Leader Young, who was shot down by the coastal defences over Holland with all crew members killed. All returned safely to Scampton.

Arriving over the Eder. The target was found to be undefended and so the attack runs were made unescorted and without interference from flak.

Flight Lieutenant Shannon, in AJ-L, opened the attack and after several dummy runs, successfully placed his weapon. As the water settled a slight breach was noticeable, but was not sufficient to cause the dam to fail.

As was the case with Shannon's attack; Squadron Leader Maudsley, in AJ-Z, made several dummy attacks before releasing his weapon. His timing however was off and the late release of the weapon caused it to strike the parapet and explode on impact at almost the same time as his aircraft passed over head. Maudsley's aircraft was seriously damaged by the blast and it is reported that he may have actually received earlier damage to his aircraft by flak during the flight to the target. Once he had regained control, he immediately set course for Scampton. He would be shot down by light flak east of Emmerich, there were no survivors.

Pilot Officer Knight, in AJ-N, who carried the last of the first waves "Upkeep's". Accurately placed his weapon and the already weakened wall was breached.

THE SECOND WAVE:

Even before launching any attacks, the second wave of five aircraft had been seriously depleted.

Two aircraft had aborted and returned to base during the outward bound flight. Pilot Officer Rice, in AJ-H, being forced to do so; after flying so low that his aircraft actually struck the sea which in turn resulted in his weapon being torn off. While Flight Lieutenant Munro, in AJ-W, returned early after his crew intercom system was damaged by flak.

A further two aircraft, AJ-E and AJ-K, flown by Flight Lieutenant Barlow and Sergeant Byers respectively; crashed after being hit by flak. There were no survivors from either aircraft.

The sole remaining aircraft, AJ-T, flown by Flight Lieutenant McCarthy, continued on and successfully attacked, but failed to breach, the Sorpe Dam.

THE THIRD WAVE:

The third wave, also consisted of five aircraft, suffered the loss of three aircraft before reaching their respective targets.

Pilot Officer Ottley, in AJ-C, while enrolee to attack the Lister Dam. Crashed, four kilometres north of Hamm after being hit by flak. All but one of the crew were killed.

Pilot Officer Burpee, in AJ-S, after straying slightly off track, quickly fell victim to the flak defences over the Gilze Rijen night fighter airfield. Once again all of the crew were killed.

While Flight Sergeant Anderson, in AJ-Y, was forced to abort the operation after the rear gun turret proved unserviceable.

The remaining two aircraft, AJ-O and AJ-F, flown by Flight Sergeants Townsend and Brown respectively; continued.

Flight Sergeant Townsend was ordered to attack the Ennepe Dam. Which he successfully located and attacked. He failed to generate a breech however, after his weapon exploded short of the dam.

Flight Sergeant Brown, after attacking a train enroute and flying through heavy flak. Finally, arrived at the Sorpe Dam only to find it almost completely hidden by mist. Numerous attack runs were made, only to be called off at the last possible moment for one reason or another. Finally, through the skill of the pilot and the crew, the bomb aimer successfully dropped his weapon and achieved a direct hit. The dam wall held however, and all that the crew of AJ-F could do was head for home.



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THE AFTERMATH

With the breaching of two of the primary targets; Operation Chastise was undoubtedly a success.

As Barnes Wallis had predicted, wide spread damage was caused by flooding and Germany's manufacturing industry, communications and various other services were also interrupted.

But perhaps the most important consequences of the raid were not to be measured in material damage, but in the effect the raid had on the war as a whole: For Germany, the raid forced the redeployment of troops and weapons desperately needed on the Russian Front, to repair and then permanently defend the dams. While on the home front, the news of the raid gave a much needed boost to the morale of the British people; who had had their backs to the wall for three long years.



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THE SACRIFICE

Of the one hundred and thirty-three aircrew flying in nineteen aircraft. Fifty-three or forty percent lost their lives, while an additional three became prisoners of war. Eight aircraft or forty-two percent of the force failed to return.



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THE RECOGNITION

In recognition of their achievement. Queen Elisabeth, on the behalf of King George VI, who was out of the country at the time, presented the thirty-four of the survivors with the decorations and medals of gallantry.

Victoria Cross:

Wg Cdr. G.P. Gibson, DSO and Bar, DFC and Bar

Distinguished Service Order:

Flt Lt. J.C. McCarthy, DFC, Flt Lt. D.J.H. Maltby, DFC, Flt Lt. H.B. Martin, DFC,

Flt Lt. D.J. Shannon, DFC, Plt Off. L.G. Knight

Bar to Distinguished Flying Cross:

Flt Lt. R.C Hay, DFC, Flt Lt. R.E.G. Hutchison, DFC, Flt Lt. J.F. Leggo, DFC, Flg Off. D.R. Walker, DFC

Distinguished Flying Cross:

Flt Lt. R.D. Trevor-Roper, DFM, Flg Off. J. Buckley, Flg Off. L. Chambers,

Flg Off. H.S. Hobday, Flg Off. E.C. Johnson,

Plt Off. F.M. Spafford, DFM, Plt Off. J. Fort, Plt Off. C.L. Howard,

Plt Off. G.A. Deering, Plt Off. H.T. Taerum

Conspicuous Gallantry Medal (Flying):

Flt. Sgt. K.W. Brown, Flt. Sgt. W.C. Townsend, DFM

Bar to Distinguished Flying Medal:

Sgt. C.E. Franklin, DFM

Distinguished Flying Medal:

F/Sgt. G.A. Chalmers, F/Sgt. D.A. MacLean, F/Sgt. Simpson, F/Sgt. L.J. Sumpter,

Sgt. V. Nicholson, Sgt. G.L. Johnson, Sgt. D.P. Heal, Sgt. S. Oancia, Sgt. J. Pulford,

Sgt. D.E. Webb, Sgt. Wilkinson
 
Squadron Leader Young's nickname was 'dinghy' - because he often came home in his rubber dinghy.


Did you see the prog. on C4 last night? - 2nd part next week.


edit - bonus question for 50 points - what was Sqn Leader Gibson's dog called?
 
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Originally posted by Sleepy
The trick with the 2 spotlights was allegedly thought up after a visit to a strip joint. :p

Not according to the book i read. That was thought up to integrate it into the film - one of very few inaccuracies.

It was really thought up at farnborough out of desperation as there was no altimeter that could acurately measure 200 feet never mind 60 especially over water.
 
The Dambusters (Paul Brickhill) is a very good read despite being a bit 'jolly hockey sticks' & not 100% factually correct. It also documents what 617 Sqn did after the Dambusters raid.

Leonard Cheshire's biography is also worth a look - he commanded 617 Sqn after Gibson & was the British observer when the 2nd atom bomb was dropped.

Apparently the effect of the raid on Germany's industry was enormously exagerrated according to modern historians, although the effect on German morale cannot be denied.
 
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