The legacy of the Dambusters

With the film’s help, the raid became part of the tapestry of British life for generations of schoolchildren – seen as one of the great boy’s own adventures. And then, of course, there was Eric Coates’s heroic title theme, which is still a staple of orchestra evenings and football terraces today.

The actual Operation Chastise was the RAF’s attempt in 1943 to breach dams, and so “deprive Ruhr industry, and the Mittelland Canal of water, over the longest period of time possible”. A special method of attack using a cylindrical mine, known as Upkeep, was evolved to do this. If Upkeep was released over water, with backspin, from a height of 60 feet, at a given distance and speed, it would bounce across the surface, sink against the dam wall and explode at a pre-determined depth.

On the evening of Sunday 16 May 1943, 19 rigorously trained bomber crews of No 617 Squadron, 5 Group, Bomber Command, took off from Scampton, Lincolnshire, to put Upkeep to the test. Their targets were in a region of steep-sided valleys in North Rhine-Westphalia and Hesse.

The raid’s planners were especially keen to release the waters held by three of the dams. Top of their list was the Möhne, which held over a quarter of the storage capacity of the Ruhr basin. Next was the Eder, which impounded 202 million tonnes of water and assisted inland water transport by helping to regulate the depth of water in the river Weser and the Mittelland Canal. Third was the Sorpe, which stored water to assist continuity of supply to other reservoirs. By removing this reserve capacity, the British hoped to intensify and prolong the consequences of a successful attack on the Möhne. Unlike the other dams, the Sorpe was an embankment dam and regarded by the RAF as “incapable of being directly breached”. The British hoped, therefore, to cause enough damage to force the Germans to drain the Sorpe in order to carry out repairs.

The crews flew along precisely mapped routes to avoid known defences. Such airmanship called for exceptional skill and navigational precision: eight aircraft failed to return.

Aside from the losses, flak damage forced one aircraft to turn back, another returned early having hit the sea and lost its load, and a third failed to find its target. It was all the more remarkable, then, that the raid accomplished two of its three main objectives, breaching the Möhne and Eder.

News of the Dambusters’ success thrilled the public. “With one single blow,” The Daily Telegraph told its readers on its front page on 19 May, “the RAF has precipitated what may prove to be the greatest industrial disaster yet inflicted on Germany in this war.” “Ruhr dam floods spreading… damage 60 miles down stream,” declared The Times on the following day. “Flood ruin widens in Reich valleys,” echoed The New York Times. The havoc seemed almost biblical, and, as it spread, so did press stories about the raid’s effects and the bravery with which it had been undertaken. Readers were told about the courage of Chastise’s leader, Wing Commander Guy Gibson, who at the Möhne had shielded several attacking aircraft by interposing his own machine between them and the more heavily defended bank of the reservoir. Gibson was awarded the Victoria Cross for his bravery and became a national hero. Publicity continued with press coverage of a royal visit to Scampton.

Chastise epitomised a feeling that the war had passed a turning point. Axis forces in north Africa had surrendered four days beforehand. “One continent at least has been cleansed,” Churchill told the joint session of Congress two days after the raid. Earlier in his speech, the prime minister said: “You have just read of the destruction of the great dams which feed the canals and provide power in the enemy’s munition works. This was a gallant operation… it will play a very far-reaching part . . .”

Gibson completed his wartime autobiography, Enemy Coast Ahead, just before his death in action in 1944. The book was published in 1946 but for security reasons it did not reveal Upkeep’s technical secrets or the identity of its inventor – the engineer Barnes Wallis. For an introduction to Wallis, the public had to wait for Paul Brickhill’s book The Dam Busters (1951), while full details of Upkeep were not revealed until 1962.

Operation Chastise took a terrible toll. Over 1,300 people perished, while of 133 young men who flew to the dams, only 77 returned (three were captured). Wallis was shaken by the losses. His wife wrote to a friend the next day: “Poor B. didn’t get home till 5 to 12 last night… & was awake till 2.30 this morning telling me all about it… he woke at 6 feeling absolutely awful: he’d killed so many people.”

Since the 1960s, some historians have questioned the raid’s military value. Yet public fascination has grown rather than slackened. Each year brings more books, new documentaries. There’s been talk of another film. There have been Dambuster commemorative mugs, Royal Worcester plates, stamps. Macallans distilled a limited edition Dambusters whisky; the Cheese Society sells Dambuster cheese; Amber Ales brew Dambuster IPA.

And though Eric Coates’s title theme continues to be hummed and played everywhere, triumphalist renditions on football terraces belie its use during some of the film’s most introspective moments, as when it underscores the uneasy calm that pervades the airfield on the eve of the raid.

Perhaps this is the nub: while the dams raid has become one of history’s feats of arms, it is tinged by melancholy. Towards its end the film verges on the wordless: an empty room, a ticking clock, an envelope containing a last letter. With the number of UK military deaths in Afghanistan now equivalent to losses from more than eight dams raids, the story of Chastise has become part of the flow from then to now.

Richard Morris is a research professor specialising in battlefield archaeology and aviation history at the University of Huddersfield