75th Anniversary of The Dambusters

This year, 2018, marks not only a 100 years of the RAF but also the 75th anniversary of Operation CHASTISE, the legendary Dams Raid, one of the most famous RAF’s raids. This daring raid resulted in a tremendous success for the Allies and it is often considered as one of the first real signs of the tide turning against the German war machine during the Second World War.

On 17 May 1943, the Air Ministry published the press release stating the following:

‘In the early hours of this (Monday) morning a force of Lancasters of Bomber Command led by Wing Commander G. P. Gibson, D.S.O, D.F.C., attacked with mines the dams at the Möhne and Sorpe reservoirs. These control two-thirds of the water storage capacity of the Ruhr basin. Reconnaissance later established that the Möhne Dam had been breached over a length of 100 yards and that the power station below had been swept away by the resulting floods. The Eder Dam, which controls head waters of the Weser and Fulda valleys and operates several power stations, was also attacked and was reported as breached…’

Avro Lancaster at the RAF Museum, London

The idea to target the dams rather than other military facilities first appeared in 1938, when war with Germany already seemed unavoidable. Destroying the dams would most-likely damage or even paralyse German industry and cause havoc due to a significant flood. It was seen equal to ‘the destruction of a considerable number of targets further down the chain of the industrial energy system’. However, this brilliant idea had a long list of obstacles, including the very limited accuracy of strategic bombing at that time.

In 1940 Barnes Wallis, a Vickers aircraft company designer, who had designed many aircraft including the Wellington bomber, joined the project.

The aerial assault on most German dams was quite difficult due to the anti-aircraft gun batteries defending them. Breaching a dam from the air would require a large explosive charge dropped from a great height. But Wallis worked on the principle that a smaller charge might successfully breach a dam if it was detonated close to the dam’s wall at very low level. That is how the idea of the ‘bouncing bomb’ also known by the code name ‘UPKEEP’ came into being.

The diagram illustrating how the bouncing bomb was used to attack the Möhne and Eder dams and the ultimate design of what had became known as the UPKEEP mine

The bombs detonate when they hit the target. The ‘bouncing bomb’ was in fact a mine. Once dropped, it would bounce across the dam’s waters, roll down the wall and sink below the surface to a given depth which was the triggering event for the explosion.

Testing proved successful and alongside the modification of Lancaster the project finally progressed to the stage of actual raid planning in early 1943.

The Operation was called CHASTISE. A new secret Special Duties squadron, initially called Squadron X, and later renamed to No 617 Squadron was formed within the RAF. The aircrew was assembled from various RAF Squadrons, with each individual recruited for their degree of experience and from varying ranks.

Wg Cdr Guy Penrose Gibson

On 15 March 1943, 24-years old Wing Commander Guy Penrose Gibson, DFC and bar, was transferred from No 107 Squadron to become the Commander of new No 617 Squadron. Guy Gibson had already earned himself a reputation first in Bomber Command and then in Fighter Command piloting Beaufighter Night Fighters, but the information about his first secret mission was quite vague.

At first, he feared that the target would be the warship Tirpitz. Tirpitz indeed became one of 617 Squadrons later missions. But their first target was Möhne, Eder and Sorpe Dams.

Target photos of Mohne and Eder Dams

On 16 May 1943 at 9.39pm Gibson and the first flight of three Lancasters set off from RAF Scampton, forming the first attack wave for Möhne and Eder Dams. The other two waves took off shortly afterwards.

One of the Lancasters piloted by Flight Lieutenant William Astell, was shot at north-west of Dorsten and crashed killing all 7 members of the crew.

The first wave arrived at the Möhne Dam shortly followed by the second. Guy Gibson (“G for George”) flew the first attack and the first ‘UPKEEP’ was dropped at 12.28am on 17 May. It exploded close to the dam and caused damage but didn’t breach it.

The Second attack was led by Flight Lieutenant Hopgood (“M for Mother”), the second ‘UPKEEP’ was dropped late, bouncing over the dam. The Lancaster was shot at and went down in flames.

Flight Lieutenant Martin (“P for Popsie”) flew the third attack with Guy Gibson flying alongside and drawing some fire away. Their ‘UPKEEP’ was deployed but failed to breach the dam also.

The fourth attack led by Squadron Leader Young (“A for Apple”) didn’t breach the dam, but most probably damaged the structure. And finally, Squadron Leader David Maltby (“J for Johnny”) breached the dam in the fifth attack, when this ‘UPKEEP’ was dropped as planned.

Richard Todd as Guy Gibson at RAF Scampton during the filming of ‘The Dambusters’, April 1954

The remaining aircraft turned to Eder Dam which was just 60 miles away. The Eder Dam was breached on the third attempt by Pilot Officer Lesley Knight.

The second attack wave lost two of their aircraft on the way. They were damaged and returned to RAF Scampton. The remaining aircraft attacked the Sorpe Dam, caused some damage but 617 Squadron was not successful in breaching it.

Two out of five aircraft in the third attack wave crashed on their way and one was forced to return to base because of the technical issues. The two remaining aircraft deployed their mines, but no damage was done.

Reconnaissance Photos of the Damaged Dams

The breach of Möhne Dam resulted in a 20 mile flood and 1,200 people German, military, and European prisoners of war, died. The breach of the Eder Dam caused a 30-foot tidal wave, which swept away power stations and pumping stations. Water supplies and transport were severely effected by flooding but the results were not as disruptive as the Air Ministry had hoped. However, it was a successful strike seen as ‘the greatest and the most far-reaching destruction yet wreaked on Germany in a single night’.

Next morning the newspapers published the dramatic images of the breached dams, praising the fearless pilots. 34 survivors were decorated and Guy Gibson was awarded with Victoria Cross. 617 Squadron was established as the ‘Special Operation’ Squadron and took as its motto the phrase : “après moi le deluge” (After me the flood).

A menu from the celebratory dinner hosted by A.V. Roe & Co. Ltd. at the Hungaria Restaurant on 22 June 1943. The menu is signed by 19 members of 617 Squadron including Guy Gibson twice. Note the title!

The legendary Dams Raid, the impossible mission which was achieved due to unprecedented courage and sacrifice, was immortalised by much-loved movie The Dam Busters starring Michael Redgrave as Dr. Barnes Wallis and Richard Todd as Wing Commander Guy Gibson. The film was a major success and featured the enormously popular and powerful Dambusters March.

This week to commemorate the 75th anniversary of the Dambusters the RAF Museum will host a very special outdoor film screening of this very film provided by The Luna Cinema at our London site.

The screening will be the culmination of a week of events celebrating the Dams Raid including talks and lectures sharing the Dambusters legacy, family workshops on dams’ building, plus the rare opportunity to marvel at the flypast of the amazing Dambusters’ aircraft, the Avro Lancaster as it passes over the Museum. Details of these events can be found at www.rafmuseum.org/whatson

If you would like to learn more about the history of Operation CHASTISE and 617 Squadron you can also explore our Online Exhibition and three commissioned podcasts devoted to the Dams Raid.

In the meantime, we look forward to welcoming you to our London site this weekend as we celebrate and commemorate one the most epic aerial campaigns of the Second World War and of RAF history.

About the Author

Tatiana Timoshina: Communications Executive

I am responsible for all of the Museum's Social Media and Digital communications. As a recent joiner to the Museum I look forward to discovering amazing stories and sharing them with you.