The Dambusters at 75

Last night marked the 75th anniversary of Operation Chastise, the legendary Dambusters Raid, which occurred on the night of 16/17 May, 1943.

19 Avro Lancaster bombers, led by Wing Commander Gibson with British, Canadian, Australian and New Zealand crews, departed from England on a daring nighttime bombing mission code named “Operation Chastise.”

Their goal was to strike German dams in the Ruhr valley, with the result of disrupting water supplies and industrial production and diverting resources from other aspects of the German war effort.


Barnes Wallis, a scientist for Vickers-Armstrong, had come up with the concept of a bomb which, when dropped whilst spinning, would produce the physical effect of impacting against a dam at a point below the water line–thus allowing the dam to be breached.

The trick was to find the right height and speed from which to drop the special bomb. Additionally, the Lancasters had to be modified in order to carry the weighty munition. Unfortunately, this meant removing much of the armour meant to protect it against enemy fire.

Air Chief Marshal Harris entrusted the formation of the squadron, the Royal Air Force’s 617 Squadron, to two-tour veteran Wing Commander Guy Gibson.

Twenty-one crews assembled in Scampton, England to prepare. Given the individual and cumulative experience of the crews, their new training was specialized and focused on the mission at hand.

The focus was on low-level flying at specific speeds–something that was tricky enough to do over the tranquil English countryside, never mind over enemy territory where attack by anti-aircraft artillery or enemy aircraft was expected.

By the time the mission was ready to start in May 1943, 19 crews were set to participate in the raids. Each Avro Lancaster had a crew of seven: pilot, navigator, flight engineer, front and rear gunner, bomb aimer, and wireless operator.

Of the total of 133 crew members who flew on May 16, 30 were members of the Royal Canadian Air Force.

The Lancasters proceeded in three waves–the first wave of nine, a second wave of five, and a third reserve wave of five.

The first wave, commanded by Wing Commander Gibson, led the attacks on the Möhne and Eder Dams. The second wave, under the command of Flight Lieutenant Joseph Charles McCarthy of the RCAF, headed for the Sorpe Dam.

The reserve flight of five would head for the Sorpe Dam, or in the event it was breached, divert towards the Ennerpe or Bever Dam.

At least, that was the plan. But fate had other ideas. Flight Lieutenant McCarthy had to swap his plane due to mechanical issues and lagged behind his wave.

Two aircraft had to abort the mission during the opening leg of the mission. In the end, only 17 travelled to the Ruhr along three different flight paths.

This was to ensure the Luftwaffe was not alerted to the presence of the entire Squadron, so that at least some of the bombers would be able to get through to the intended target region.

Upon reaching the intended target, Wing Commander Gibson’s aircraft, marked “G – George,” made the first dive, levelling off at 20 metres above the Möhne River at a cruising speed of 384 kilometres per hour.

His bomb detonated but did not breach the dam. The next four aircraft followed suit, with Wing Commander Gibson flying alongside to help divert enemy anti-aircraft fire.

The bomb from the fifth Lancaster finally achieved the intended result, and the dam broke open and unleashed its deluge into the valley below. Wing Commander Gibson turned with the remaining three aircraft in his flight towards the Eder Dam, and following the same method, had similar success.

The Möhne and Eder dams were both breached with the surrounding areas flooded. An estimated 1,600 civilians were killed in the flooding.

The Sorpe and Ennerpe dams were damaged but not enough for the waters to break through. German assets were diverted to the region to aid in the clean-up and restoration of services.

In the eyes of the Bomber Command, the mission was a success, even at the high price of 40 per cent casualties. Five aircraft crashed or were shot down on their way to the valley.

Two were destroyed while attacking the dams, and one was shot down on the return flight. In total eight aircraft and 56 crew were lost on the raid.

Wing Commander Gibson was recognized for his leadership and abilities with the Victoria Cross. Of the other 33 who were decorated for their contributions to the raid, seven were members of the Royal Canadian Air Force.


The May 1943 Dambusters raids had a tremendous impact on morale, both at home and in Germany.

In Britain and throughout the Empire, Wing Commander Gibson and the men of 617 Squadron had demonstrated what could be done on a daring midnight raid, giving people hope at a desperate and trying time during the Second World War.

As retired LCol David Bashow says in his history of Canadians in Bomber Command, No Prouder Place: “Its very audacity and innovativeness gave hope for the future and a sense of purpose to many.”

More here: The Dambusters



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