Hay Festival 2012: stop this Dam Busters nonsense There is a myth, James Holland told us in a vigorous Hay lecture, that the May 1943 "bouncing bomb" raid on the Ruhr was a handy bit of Allied propaganda and not much more. It is one that the military historian is determined to dispel. "One of the things that really annoys me about the historiography of the Second World War is the way the British do down our role - "Oh, we were a bit rubbish ... hanging on the coat-tails of the Americans ... the raid was a good PR coup to show the Americans what we could do but it wasn't significant because the dams were rebuilt five months later anyway." That is absolute nonsense of the first order," Holland told the audience. The destruction of the dams created a tsunami that took out over 100 factories, with bridges, roads and railways washed away. The Germans were forced to divert 70,000 workers to the rebuilding effort at a moment when the tide was turning against them. It was a PR coup but that was the least significant effect of the raid. For Nazi Germany this was a huge blow," insisted Holland. In his book, The Dam Busters: The True Story of the Legendary Raid on the Ruhr, Holland introduces us to the men of 617 Squadron - some of whom never made it back. The story is familiar to most, not least because it was immortalised in the 1955 film with Richard Todd as Wing Commander Guy Gibson, but the author said it was almost impossible to grasp the heroism of their actions. The mission was technically difficult and was carried out by men who had never attempted such a task before, Holland said. Rushing over the earth at 250mph, at night, in the heart of enemy territory, at less than 100ft, on a route you've never flown in your life when you can't see what's coming up against you, then dropping a bomb on a sixpence so that it bounces across the water and hits in exactly the right place or the dam won't blow up - I can't stress enough how difficult that is. They were an experienced crew but not well-trained on this mission. There is no way on earth an operation on this scale would be carried out today with a crew being that undercooked. The raids claimed the lives of 53 of the 133 airmen who took part. Of the 19 aircraft that took off, 11 made it back. The Lancaster Bombers flew at just 60ft above ground level - the wing of the plane measured 50ft - and the crews successfully breached the Mohne and Eder dams.