The Dambusters Raid Explained

In May 1943, the RAF launched one of the Second World War’s most audacious missions: the Dambusters Raid. Today, we follow the raid as it unfolded, hearing about the remarkable people involved and examining its lasting impact. Produced by Mariana Des Forges and edited by Dougal Patmore. Dan Snow's History Hit is now available on YouTube! Check it out at: https://www.youtube.com/@DSHHPodcast Sign up to History Hit for hundreds of hours of original documentaries, with a new release every week and ad-free podcasts. Sign up at https://www.historyhit.com/subscribe. We'd love to hear your feedback - you can take part in our podcast survey here: https://insights.historyhit.com/history-hit-podcast-always-on. You can also email the podcast directly at [email protected] mailto:[email protected]. Hosted on Acast. See acast.com/privacy https://acast.com/privacy for more information.

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• 0:00Dan Snow?

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• 1:56Dan Snow?

  On the night of the 16th and 17th of May 1943, there was a full moon. It was an unusual night for a bombing raid. Usually, British bombers avoided a full moon because they could be seen, but this was a highly unusual raid. 133 men in 19 heavily modified aircraft, carrying huge, untested bombs that bounced. The target was some of the biggest and most important dams in Germany.

• 2:28Dan Snow?

  In today's episode, I'm going to tell you the story of the Dam Busters, one of the greatest British stories from the Second World War. The so-called Dam Busters raid, or Operation Chastised, to give it its official name, was vital for the British. Not just because it disrupted German war production, but predominantly, I think, for morale. It came at a time when the Allies were really on their back foot, and the bravery and ingenuity of this raid gave a much-needed boost to the public and the fighting forces. It was also important because it's a turning point, I think, in strategic warfare. It shows that bombs were no longer a clumsy area weapon, but they could be dropped from fast-moving aircraft with extraordinary precision. For all those reasons, this was a raid that mattered. An extraordinary tale.

• 3:13Dan Snow?

  You're listening to Dan Snow's History, and this is my version of the Dam Busters story.

• 3:24Dan Snow?

  It's the 16th of March 1943, about two months before the Dam Busters raid. A 24-year-old pilot was summoned to the headquarters of RAF Bomber Command's 5 Group in Lincolnshire. It's a funny-looking building. It's called St Vincent's Hall. I've been there, and it's a sort of Gothic Revival mansion in Grantham. Today, it's in private hands, but much of the downstairs still feels like a slightly strange 19th-century stately home. It was the nerve center of Britain's bombing effort against occupied Europe. As I sat there in the echoing, columned, high-ceilinged marble hall,

• 4:04Dan Snow?

  I could imagine that young man, also sitting there, waiting to be summoned to see a bigwig. I think mostly, he was wondering, why the hell was he there? That young pilot was called Guy Gibson. He'd already survived two tours of duty. He'd flown over 150 missions. So the fact that he's still alive at this point in the war is pretty surprising. He's finally called in to meet probably the second most important RAF Bomber Command Officer in the country, Sir Ralph Cochrane, who says, "How do you feel about one more flight?" Gibson replied, "What kind of trip, sir?" And Cochrane said simply, "A very important one. Possibly the most devastating raid of all time.

• 4:48Dan Snow?

  I can't tell you any more." So it's like the beginning of every single heist film, one last gig. Gibson noted down later that he thought he was being asked to go on a raid that night. And so despite all his reservations and concerns, he just said simply, "I haven't got my flying kit with me." Cochrane said, "No, it's not tonight. You've got two months and you have to form your own squadron." Gibson asked about the target and Cochrane replied, "I can't tell you any more than that at the moment, I'm afraid." So Guy Gibson now had a mission. He just needed planes and he needed men. Three days later, Gibson arrived at the RAF base at Scampton in Lincolnshire.

• 5:33Dan Snow?

  Now, I've been there many times. It's closed now unfortunately and it has changed a lot recently. It was one of those heritage sites that at the time I just took for granted. I was able to see Gibson's office, it was still there. Now it's been demolished. But it had the same sort of wartime construction that you can recognise on airfields right across the UK, those same moed lawns, those same iconic type of hangars. And that's the place where Gibson had to build his squadron. 21 aircraft, 21 crews, that's 147 aircrew. It was so secret, it didn't have a name. It was known simply as Squadron X. One of the myths about the Dam Busters is that it was a sort of elite unit.

• 6:15Dan Snow?

  It was a sort of Avengers end game of all the best crews in the RAF. And that's not exactly true. Some of them were certainly elite, no question. Les Munro, he was a New Zealander with seventeen missions under his belt. He arrived and he looked at all the gallantry medals on people's chests and he saw that there were a lot of very good aviators there. But lots of people, well, they didn't necessarily want to sign up. Their jobs were dangerous enough without volunteering for a super special secret mission. And so some other squadrons sent crews that they were actually trying to get rid of. They were volunteered by their squadron leaders and so you get a bit of a mix. Some of them, like George Leonard Johnson, known in classic RAF fashion as Johnny Johnson, he had plenty of operational experience.

• 6:59Dan Snow?

  He'd completed a tour of thirty flights. He'd been given time off after that, but during those flights, he had experienced engine failure, enemy night interceptions, and of course, anti-aircraft fire. So many of these men had been through a lot, they'd seen it all. The RAF did eventually assign a number to this new squadron, six one seven. It was about to become the most famous squadron number in RAF history. Gibson, like his squadron, has become the stuff of legends. He was definitely an extraordinary aviator, but he was a very hard man as well. He seemed to manage up slightly better than he managed down.

• 7:44Dan Snow?

  People above him, well, they loved him, commanders, politicians. But some of those who worked for him thought he could be an overly harsh taskmaster. One veteran reported that he was the sort of little bugger who was always jumping out from behind a hut to tell you your buttons are undone. Another described to me once that they were on a drunken night and sometimes Gibson would get bundled out of the bar in a kind of military form of industrial action. He'd had a very difficult childhood, to be fair to him. He'd been abandoned by his father, his mother was an addict. She was imprisoned briefly and she died when he was pretty young, in a terrible alcohol-related death.

• 8:24Dan Snow?

  But his single-mindedness was clearly vital to the formation of this squadron and their ability to carry out that raid. Six days after agreeing to lead this mission, and with no idea still about where he was heading off to, Gibson was driven to a golf course in a requisitioned vehicle. There he met a scientist. He was one of Britain's most respected aircraft designers, just a classic archetypal boffin. His name was Barnes Wallace. He was in his 40s and he'd made a career working first on airships and then on aircraft. Now, he was particularly interested in bombs and Gibson reports that Barnes Wallace sort of looked around to make sure no one was listening.

• 9:08Dan Snow?

  And then he said, "But I'm very glad you've come. I don't suppose you know what it's for?" Gibson replied, "No idea, I'm afraid." To which Barnes Wallace said, "What? Do you mean you haven't been told the target? Well, that makes things awkward, very awkward." So Guy Gibson cannot be told what the target is, but he does have the security clearance to learn about the weapon he's going to use. Barnes Wallace tells him about that weapon. He thinks he's invented a new kind of bomb. He shows Gibson some film. It shows a bomb skimming across the surface of a lake before coming to a stop next to its intended target.

• 9:49Dan Snow?

  Barnes Wallace has watched his kids skimming stones on a beach and then the idea struck him. He'd taken his kids back home and he'd done some experiments with them. One of the classic experiments, in fact, in British history, he'd skimmed marbles along the surface of a paddling pool. The problem he faced is that those marbles, and indeed his prototype bomb, had been launched from surface level, from a static platform. They'd been shot or fired from elastic bands, for example. He now had to deal with the fact that he had to get an aircraft to deliver that bomb. And that meant getting the aircraft ridiculously low. Wallace asked Gibson if he could do it.

• 10:32Dan Snow?

  And Gibson said, "It was difficult, but it was worth a try." Gibson left that meeting assuming that there was going to be an attack against the fortified U-boat pens on the French coast where German submarines were operating from with such devastating effect in the Atlantic. Or perhaps the target might be the mighty well-defended battleship Tirpitz in the Norwegian fjords. Either of those operations would be very dangerous indeed. Gibson got back to Scampton. He jumped on the bonnet of a car, he gathered his men around him, and he announced that they had been chosen for a very dangerous mission. Anyone who didn't want to come was free to pull out.

• 11:13Dan Snow?

  They could return to their own squadrons, there'd be no stigma at all attached to it. Not a soul moved. They all stayed where they were. Shortly after this, Gibson was summoned back to Cochrane's headquarters at Bomber Command. He found three large crates in Cochrane's office. In them, he was told, are models of the target. So they all got their screwdrivers out and they opened up the crates. Gibson actually says he experienced a wave of relief when he found not models of the Tirpitz, but of some dams. He reports, "Six-one-seven squadron were going after the dams of the Ruhr Valley, Germany's industrial heartland." And that's because that industrial heartland with its factories, it needed lots and lots

• 11:58Dan Snow?

  of water and lots of power. Those reservoirs, held in place by those hydroelectric dams, provided both. The biggest was called the Mona Dam, 130 feet high, half a mile long. It had been the biggest dam in Europe when it was built just before the First World War. The problem with those dams is that they might be very long, but they're very, very thin indeed. They're very hard to hit if you're flying a bomber horizontally from thousands of feet up in the air, which is traditionally how you bomb targets on the ground in this period. And that's why an entirely new approach had to be invented for this raid, and invented fast. They had to strike them in May, just under two months away.

• 12:40Dan Snow?

  Because that's when they'd be absolutely full after the winter rains. And breaching them any later just wouldn't have the same effect. Barnes Wallace was certain these dams were the choke point of the German war industry. He calculated that it took 150 tonnes of water to create a tonne of steel. So he thought, let's go for the water, not the steel. Now, one of the most remarkable dambuster related adventures that I ever went on was when I was staggering through some reasonably thick woodland in Hertfordshire. I was looking for an extraordinary wartime relic. It had been built in the winter of 1940 to 41. And all I had to do was listen for running water, and I found it.

• 13:24Dan Snow?

  It is a miniature dam blocking a stream. And it's still doing that job today, little pond behind it. Amazingly, that dam is a perfect scale model. It's one fiftieth of the size of one of those target dams. And then through that winter of 1940-41, they tried blowing it up over and over again. And they calculated that 30,000 pounds of high explosives near the dam wall might do the job. The only problem was that the heaviest bomber then in service in operation, the Lancaster bomber, could only carry about 4,000 pounds worth of bombs at that point in the war. So way off. But the scientists discovered that if the bomb could be delivered at the right place,

• 14:08Dan Snow?

  snug against the wall of the dam, 30 feet down underwater, then 7,000 pounds of explosives might do the trick. And now you're getting nearer what the Lancaster could conceivably carry. The problem though, is you've got to get that bomb right next to the wall of the dam. And the Lancaster's accuracy at this point of the war, well, it is, it's not good. So Barnes Wallace had to come up with a way of getting that bomb to exactly the right place. He created a four-tonne bomb. Three of those tonnes were high explosives. It would be the heaviest bomb ever dropped from an aircraft.

• 14:50Dan Snow?

  But now, he'd have to modify the Lancaster to carry it. He'd have to strip a lot of weight out. And you'd have to sling that bomb beneath the Lancaster because it wouldn't fit up inside the bomb bay. They got rid of the upper turret. They had to strip away a lot of armour plating, which the crews were absolutely thrilled about, as you can imagine. The bomb, codenamed upkeep, was so big that half of it actually hung outside the fuselage. Now, the man actually in charge of the strategic bombing campaign, the commander in chief, was Arthur Harris, Bomber Harris. He was sick of scientists coming up to him, promising him silver bullets to win the war. Shortcuts, clever little hacks. And he wasn't actually super impressed with this raid.

• 15:32Dan Snow?

  It was a suggestion for a raid, using a bomb that hadn't been fully tested, that didn't really yet exist, carried from an aircraft that hadn't really been designed for that purpose. And he called the Dam Busters plan tripe beyond description, and said there was not the smallest chance of it working. But in the end, he was talked into giving it a go. Gibson, for his part, well, he didn't have to worry too much about that high politics. But he did have to worry about how his crews were going to get this bomb to the target dropped in exactly the right place. They would have to learn to fly the Lancaster, not at 20,000 feet, but at treetop height. And they started this process on the 31st of March, 1943.

• 16:16Dan Snow?

  There are just endless stories of close scrapes, of farmers going crazy as animals go mad in the fields below with terror. Aircraft arriving back at the base with undercarriages festooned with the branches of trees. By early April, the crews were practicing over water. And they chose the Derwent reservoir in Derbyshire, in particular because it was similar to the dams and some of the topography of the German targets. The locals were in for quite a shock. It was a quiet part of the world, and suddenly they found their roof tiles were coming dislodged. A drop in milk and egg production happened because animals got spooked. And of course, no one could tell them anything. About why their little valley, their reservoir and dam had been selected for

• 17:01Dan Snow?

  this training purpose. Now, I've been lucky enough to fly from bomber country, sorry, flat Lincolnshire, up to the Derwent water, I've flown at very low level. And you move from very flat east coast country, and you suddenly hit the uplands, the so-called peak district. That's at the southern extremity of the Pennines, which I can tell you is a sort of range of mountains, we could say, well, certainly very hilly country that divides England in half, like a spine. And the big challenge back then, and the big challenge for me when I was in the small aircraft, was navigation. Because when you're very low down, you can't see very much. The towns and the lakes and the roads, the features, they actually blast past you. They come and then they're gone. So you have to keep your finger right on the map all the time, and your eye constantly on the ground. Otherwise,

• 17:46Dan Snow?

  you just lose touch of where you are. That's one of the great advantages of flying high. You can see more of the earth below you. So, the job of these air crews was to try and find their way there. And then to try and hit a raft in the lake. And largely, they failed to do so. Their bomb aiming gear is set to work for horizontal bombing from 20,000 feet. It's pretty useless when you're blasting along at 240 miles an hour on the surface of a lake, you try and release your bomb on top of a small raft bobbing about below you. It's hard. It's very, very hard. And it was about to get much harder, because they were going to switch to doing it at night. Guy Gibson went first. He always led

• 18:30Dan Snow?

  by example. He navigated his way to Derbyshire. He did a few runs down the valley. He couldn't tell where the water was. He very nearly crashed. He had to pull up at the last minute. Had Gibson crashed, it would have been, I think, clear the raid would have been pulled off. It would have had huge repercussions. So, we got six weeks to go until the raid. Guy Gibson's almost killed himself and his crew. And really, no one has any idea how they're going to pull this off. Then in early April, Gibson gets a knock on the door. It's another boffin, a scientist who's come to help, Wing Commander Charles Dan. He says he's got a way of helping with aiming, trying to get the bouncing bombs to really work. Not only would they have to be dropped from a height of 150 feet, according to Barnes

• 19:14Dan Snow?

  Wallace, but they had to be exactly 1,350 feet from the dam. But fear not, says Wing Commander Charles Dyer, he'd invented a new site, and it's an extraordinarily simple invention. It's really just a few bits of woods knocked together. You can make one at home for yourself, if you like, if you find yourself needing one, who knows? It's a sort of Y shape, and then at the end of each branch of the Y, there's an upright, so that when you look along it and you line up those two uprights with the towers of the dam, well, that means at that exact second, you're in the right place and you have to drop the bomb. Now, I had been flown down that reservoir by a former RAF Red Arrows pilot at about

• 19:58Dan Snow?

  180 miles an hour, so slower than the Lancasters were going. And actually, even a muppet like me, I was able to use that wooden site and I was able to drop my notional bomb correct to within about 10 metres of exactly where it needed to be dropped. So in terms of getting the bombs to drop at exactly the right distance from the dam, that site did go a long way to solving that particular problem. There were more problems, though. The next one was even trickier. How on earth do you judge when you're flying 150 feet above the surface, above the water, when all your instruments have that lack of precision? They cannot possibly give you that level of accuracy. Again, they came up with a very elegant, simple, clever solution to their seemingly insuperable problem.

• 20:39Dan Snow?

  So although in this story, we sort of remember the air crew, their tenacity, their heroism, their sacrifice, we do also need to remember the scientists, the engineers, who made this possible, and we need to celebrate something in that human spirit that allows us to turn our brain to problems and overcome them, something we need plenty of today. A scientist from the Ministry of Aircraft Production came up with a neat idea. Two spotlights mounted on either side of the Lancaster at very carefully calculated angles, and that meant as the plane got lower and lower to the ground, they would form a figure of eight when the plane was exactly 150 feet off the water, which was the altitude they thought they needed to drop the bomb at. It worked.

• 21:24Dan Snow?

  So you've got the height sorted, they've got the distance from the dam at which they need to drop the bomb sorted, but they don't actually have a bomb that works yet. On the 13th of April, there was a test at Culver in Kent. I've been to that spot. I stood on the beach where Barnes, Wallace and Gibson watched in a state of nervous tension as a prototype bomb was dropped from an aircraft. Would it hit the white floating buoys, or buoys as you might say in North America, as it bounced along the sea? No, it didn't. The bomb completely shattered on impact. Wallace groaned. A few days later, they were back on that same stretch of beach on the north coast of Kent. There's actually the remains of a 12th century church there. It's rather handsome and some of it's eroded into the sea.

• 22:09Dan Snow?

  But that church was built itself within the confines of Roman fort. And there's a Saxon enclosure there as well. So it's a great place to go. So as they made history on that day, they were standing in the shadow of millennia of history. But this time, they made history in the wrong way. Again, the bombs all went wrong. They either sank immediately or their casings shattered.

• 22:32Dan Snow?

  But there was some hope. On one of the bombs, the cylindrical core of the bomb skimmed. And that gave Wallace an idea. Originally, he thought the bomb would have to be a perfect sphere like his children's marbles. But now he thought he would try and work with this cylindrical shape. It might skim more easily when it was dropped from an aircraft. There was another test in mid-April. A cylinder was dropped this time and it sunk immediately. There were 23 days until the raid. Wallace asked Gibson for a meeting. Wallace has got a further request and it can't have been easy for him to ask this. He shows Gibson some maths that he's been doing. He's come to some shocking conclusions.

• 23:17Dan Snow?

  For the bomb to skim properly, it can't be dropped from 150 feet. That's too high. It has to be dropped instead from 60 feet.

• 23:28Dan Snow?

  He says to Gibson, can you fly 60 feet from the water? Gibson thought about it. He knew that this was ridiculously low. I mean, just one false move and they would be straight in the water. But he replied coolly, we'll have a crack at it tonight. So this is probably the bit where we remind ourselves that the Lancaster had a wingspan of around 100 feet. So this is a crazy flying height. Gibson uses those spotlights. They're set up to optimize for 60 feet and he discovers that the system still works. So he thinks his men can fly at 60 feet over the surface of the reservoirs. The plan can be made to work if the bomb responds better to being dropped from that height.

• 24:12Dan Snow?

  On the 29th of April, with just 18 days to go before the May full moon, the date on which the raid was supposed to take place, Gibson and Wallace go back to North Kent. They stand on that beach, just a stone's throw away from that Roman fort, and they watch the Lancaster coming in at 60 feet. The bomb is released and it bounces. It bounces six times. It travels 2,000 feet. Barnes Wallace, the quiet, staid British engineer, goes absolutely bonkers. He stops waving his handkerchief around and dancing. Gibson is so surprised, he decides to join in the dancing too. The bomb works.

• 24:56Dan Snow?

  Now they have to build enough of them. More Dam Busters coming up after this.

• 25:11Dan Snow?

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• 25:53Dan Snow?

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• 26:36Dan Snow?

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• 28:34Dan Snow?

  With just six days to go before the raid, the bombs arrive at RAF Scampton. Bear in mind, the men at this point still have no idea where they're heading for. Then the Air Ministry gets in touch. Now, if Guy Gibson was worried he wouldn't have enough time to nail this, the raid was suddenly brought forward by 24 hours. They have even less time to prepare. And the preparation did not go smoothly. The day before they were about to fly, Guy Gibson was rocked by a personal tragedy. His dog was run over. Now, this, to many of you out there, might seem a bit weird, but it did seem to have a profound impact on Gibson. Barnes Wallace thought that Gibson might not be able to go on the raid because he was so distraught.

• 29:17Dan Snow?

  And it makes me think that we don't really understand what it takes to survive in your early twenties, so many brushes with death. He was in a very unhappy marriage. He'd had a traumatic childhood. That dog meant a huge amount to him. And the death of his dog was seen as something that could seriously derail the successful execution of this raid. On the morning of the 16th of May 1943, Gibson was feeling terrible. He was miserable. He'd been unable to sleep. A terrible mixture of stress and all the emotions and the loss of his dog. And he also had savage gout in his feet that meant he'd slept very, very badly indeed. He refused to go to the doctor to take medication for it because he was worried that it would shave a little bit off his reaction time. He just couldn't risk taking any medication.

• 30:03Dan Snow?

  That morning, he attended the burial of his dog outside his office. And then he went to check out the loading of the bombs onto the Lancaster bombers. The aircraft were all in the hangars. The enormous bombs were being ratcheted up into the bomb base. Each of the Lancaster had been designated with code names. For example, P for Poxey or F for Freddie. The crew of P for Poxey were on board their aircraft, doing their last minute checks. One of them pressed the bomb release button and the calipers holding onto the bomb, which had three tonnes of high explosives in it, snapped back and the bomb smashed into the floor of the hangar. People ran for their lives and fortunately, the bomb didn't detonate.

• 30:44Dan Snow?

  At 6pm on the 16th of May 1943, Gibson called his men together, 133 of them. Barnes Wallace was there and that was the first time he'd actually met the men. He turned to Gibson and said, "I hope they all come back." And Gibson, who knew very well that they weren't going to all come back, replied, "It won't be your fault if they don't." Gibson briefed them there and then on what they had to do. The plan was for 19 aircraft to fly in three waves. The first wave, led by Gibson, would fly to the Mona Dam. Joe McCarthy, known as Big Joe, was an American aviator. He'd signed up to serve in the Royal Canadian Air Force before the USA had joined the Second World War. He would lead the second wave.

• 31:28Dan Snow?

  He would take a slightly shorter route and he'd attack the Sauber Dam. A reserve of five aircraft was going to meet any survivors of the first two and head for the third dam, the Eda Dam. After that briefing, they were given a luxurious breakfast by wartime standards, a meal of bacon and eggs, both in very short supply at the time. At 8pm that May evening, the men lounged on the grass outside the hangars for a few precious moments. Somebody went up to Gibson and asked if he needed anything and he replied, "A lot of beer when we get back." And then he added grimly, "Hopefully."

• 32:10Dan Snow?

  The aircraft revved their engines, they moved into their positions at the end of the strip, and they took off. Operation Chastise had begun. The bombers headed out into the gathering darkness, out across the North Sea at ultra-low level to avoid radar. They maintained strict radio silence. The navigators, can you imagine? They were trying to calculate wind speed, bearing, trying to use the star's dead reckoning to work out exactly where the aircraft were. One of the pilots, New Zealander Les Munro, crossed the Dutch coast successfully, but he looked south and saw a burst of anti-aircraft fire and an explosion. One of the aircraft had drifted too far south and crossed the coast at the wrong spot.

• 32:53Dan Snow?

  We now know it was Vernon Byers, the squadron's least experienced pilot. It was only his sixth mission. His whole crew was killed. Then suddenly Munro felt his fuselage shake with incoming fire. His communications were shot through. He couldn't talk to the bomb-aimer. He couldn't talk to the rear gunner. He couldn't talk to the navigator. There was no way he could continue the mission. He turned for home. Meanwhile, another pilot, Jeff Rice, flying an aircraft codenamed H for Harry, misjudged it over the North Sea. He hit the surface of the sea itself and flooded the aircraft tail. He managed to lift the plane off the water. The tail gun had almost been submerged in the back of the aircraft.

• 33:35Dan Snow?

  He shook himself off and went to check, but the bomb hanging below the fuselage was gone. It had been torn off. So that aircraft too was forced to turn for home. They'd hardly reached the coast of Europe and three crews had dropped out. Only 16 remained. Gibson, the 24-year-old in command of this raid, also hit the coast over some strong German defences, but miraculously he was able to carry on. Just after midnight on the 17th of May, Guy Gibson's group crossed into Germany. A navigational error unfortunately put them about six miles off course, so much closer to the heavily defended industrial Ruhr Valley. One of the aircraft was lit up by searchlights. It was sprayed with anti-aircraft fire.

• 34:17Dan Snow?

  The rear gunner was wounded, the wireless operator very badly wounded, and the front gunner killed. One engine was on fire. Yet the pilot managed to get hold of it, close the engine down, and continue towards the dams. It is quarter past midnight. Gibson arrives above his dam, the Mona, and he can see it clearly in the moonlight. He said later, "It looked unconquerable, squat, massive", but he didn't have much time to make a leisurely reconnaissance. Anti-aircraft fire opened up from positions on the dam and around it. He has fewer aircraft than he'd hoped. By now, 21 men were already dead. He only had 14 Lancasters left. Gibson has a quick look at the dam and then he just goes for it. He breaks radio silence.

• 35:01Dan Snow?

  He notifies the other aircraft nearby him. He says, "Well, boys, I suppose we'd better get the ball rolling. I'm going into attack." He leads the only way he knows how: from the front. He goes first. Now, those Lancasters are carrying bombs so new that they've never been dropped on an operational mission ever before. And I probably should have mentioned one more thing. You also have to put backspin on the bomb. So they have to start spinning the bomb at about 500 revolutions per minute. The machines crank into action, shaking the fuselage as Gibson dives to low level and off they go. The navigator is calling Gibson down, down, down, using the beams of light fixed on the outside of the fuselage.

• 35:46Dan Snow?

  Lower, lower, until they're 60 feet above the surface of the reservoir. Anti-aircraft fire comes screaming horizontally past his cockpit. The guns on the dam open up. Gibson's bomb-aimer is looking through the primitive wooden sight, which proves so effective in training at dropping the bomb in just the right place. But will it work in practice? A little left, a little right, steady, steady, then comes- The call, bomb's gone. Gibson pulls up so it doesn't hit the dam and soars into the sky. The bomb below them bounces, skims across the surface, doesn't quite make it to the dam, sinks and explodes, sending a plume of water a thousand feet into the air.

• 36:28Dan Snow?

  It was like an earthquake and it was followed by a tsunami of water, but the dam held firm. For now. The first coded message was sent back, it was received in Lincolnshire. It was a fail. Scientist Barnes Wallace groans. Another Lancaster flown by Flight Lieutenant John Veer Hopgood, Hoppy Hopgood, as he was known, it goes in, half his crew wounded or dead, himself badly injured. He's flying on three engines. Now he goes in for his bomb run. The anti-aircraft fire is accurate now, his aircraft is peppered with holes. His bomber releases a second, a fragment of a second too late and the bomb bounces over the dam and explodes beyond. Hopgood's plane is on fire.

• 37:12Dan Snow?

  He roars over the intercom screaming at his crew to get out. He climbs as high as he can to give them a chance. The tail gunner drags the terribly wounded radio operator to the door, throws him out, pulling his chute. Then he jumps out too. The bomber is so low that he hits the trees hard, but survives albeit with a broken back and eventually finds himself in German captivity. Hoppy Hopgood stays rooted to his seat, fighting with the controls desperately giving the rest of his crew the best possible odds of survival. There's no chance of him parachuting out of this broken plane. And shortly after, his Lancaster, the aircraft M for mother, smashes into the valley below

• 37:55Dan Snow?

  and Hopgood is killed instantly. There was no time to mourn him. The climax of the Dam Busters, coming up, don't go away.

• 38:14Speaker 01

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• 38:44Speaker 02

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• 39:26Speaker 02

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• 39:42Dan Snow?

  Next up came the Australian Mickey Martin. This man was as wild on the ground as he was in the air. And at this point, Gibson also does something wild. He does something extraordinary. He dives down to fly alongside Martin's Lancaster to draw enemy fire away from them and no doubt, provide encouragement to Martin. Martin gets his bomb away cleanly. It explodes, but the dam remains intact. Three of the best pilots in the squadron have gone, and there's been no dam break. Next up, aircraft A for Apple. It also failed. Then came the Lancaster J for Johnny, 23-year-old David Maltby at the controls.

• 40:26Dan Snow?

  This time Gibson decided to circle the dam to use his machine guns on board his Lancaster to try and suppress the fire of the anti-aircraft guns on the dam. And he has some success at doing this. Maltby experiences less anti-aircraft fire. As he makes his approach and goes screaming over the dam, he sees the top is already crumbling. A previous effort has weakened it, done some good. Meanwhile, his bomb is skimming over the water. It comes to rest, striking the dam. It sinks dead centre and then it explodes. Gibson paused. He was about to order another aircraft to go and attack, but suddenly he saw something. He saw a breach.

• 41:05Dan Snow?

  Millions of gallons of water now surging over a hundred-metre-long stretch of broken dam, right in the centre. His crew started screaming in celebration. The water crashed down into the valley below, and this is something we often forget about in this Dam Busters raid. It would be the costliest raid to that point of the war for the civilian population because those bombs unleashed a tidal wave, in some places 40 feet high. It swept down with an astonishing primal force and floods would extend hundreds of miles beyond, destroying factories and villages and houses and farms. There would be a terrible human cost on both sides this night.

• 41:50Dan Snow?

  Back in Lincolnshire, the news of the success transforms what must have been a fairly grim operations room. Bomber Harris, who'd been extremely pessimistic, as you'll remember, about the outcome of this raid, he walks up to Barnes Wallace and said, "When you first came to me this idea, I didn't believe it for a moment. Now you could sell me a pink elephant." Back over Germany, Gibson was rallying his men after destruction of the Mona Dam. But as he was doing so, a little way away, a lone aircraft was trying to hit another dam, the Sauber Dam. Now, interestingly, the topography was simply too difficult for a Lancaster to weave its way and skim a bomb at low level towards the dam. So on this occasion, they were using a slightly more conventional way of bombing.

• 42:34Dan Snow?

  The Sauber was an earthwork embankment type of dam, and the bouncing bomb wasn't designed for that type of structure. So the idea when attacking the Sauber was to fly along it and just drop the weapon in a conventional manner with the hope it might just crack the watertight concrete core and start a leak that would in time blow up the dam. Joe McCarthy was the first to attack. He dropped the bomb accurately on his 10th attempt. I've talked to someone aboard that aircraft, and they went round and they went round and round. Joe McCarthy was getting pretty unpopular by the end of that. Minor damage was done to the dam, but it held firm.

• 43:16Dan Snow?

  This almost leisurely attack on the Sauber Dam has always struck me as strange. It's a sort of isolated aircraft, disconnected from the rest of the story, as if it's disconnected from the war itself. There was no anti-aircraft fire, no enemy fighters, it was just a Lancaster going round again and again, just trying to drop a huge bomb on a rural dam. It's such a strange aspect of this dramatic night. Back with the main group of aircraft, Guy Gibson had wrangled the three bombers that hadn't yet dropped those bombs and headed for the mighty Eder Dam. 138 feet high, 120 feet thick at its base, it is a monster. He arrived at about 1.30 in the morning, it was getting foggy, the dam was becoming obscured. Now, there were no anti-aircraft guns here either, because the Germans just thought it

• 44:00Dan Snow?

  was inconceivable that the Brits would attempt to attack it. There was a really narrow approach, and having dropped the bomb, having skimmed that bomb, the pilots would have to pull up in a frenzied attempt to avoid hitting a giant cliff of rock. The aircraft L for leather made multiple attempts. Then, once it was happy, it dropped the bomb, which exploded, but the dam wasn't destroyed. The next aircraft up seemed to have an issue seemingly with its release gear, it jammed and it dropped the bomb late. The bomb smashed into the parapet and it blew up and damaged the aircraft. Forty minutes later, that limping bomber was shot down over the Dutch border as it was heading for home. The last available aircraft on this dam was N for nuts.

• 44:43Dan Snow?

  The pilot was the 22-year-old Australian Methodist Les Knight. On the ground, he was rather quiet. He avoided the big drinking sessions. He lined up N for nuts. He released the bomb and he climbed hard. Behind him, there was a mighty explosion. Gibson was watching. He reports that he saw what looked like a fist punching through cardboard. The dam disintegrated. A giant wall of water gouged its way down the valley. Again, as with the Mona Dam, hundreds of people were killed, drowned. Many of them were slave labourers, imported workers from Hitler's conquests in the East. It was a humanitarian catastrophe. Two of the dams on the Ruhr had been destroyed. There was some hope that the Sauber Dam might yet be breached,

• 45:28Dan Snow?

  but the reserve wave of five aircraft, well, it was a bit of a disaster. One tried to drop a bomb on the Sauber. It didn't achieve much. And two of those five ended up getting shot down. So the Sauber Dam remained intact. Just 12 crews were left in the air, still with a long journey back to England. Around 3:00 or 4:00 in the morning, the first aircraft lands back at Scampton. The atmosphere is mixed. There's jubilation, there's excitement, there's pride, but there's deep, deep sadness for those that were lost. It's almost impossible, I think, for us to empathise with those two extreme emotions being felt at the same time, simultaneously. They went out drinking. They went to the officers' mess, then they went to the station commander's house. Barnes Wallace was there in his dressing gown.

• 46:11Dan Snow?

  He'd been crying about the losses of the young men who never came back. And Gibson tried to comfort him. And you can understand why Barnes Wallace was so moved. It had been his plan. It's his idea. It's his bomb. He was the reason that 133 men had flown out on this raid. Only 80 survived. Three of them were prisoners in German hands. 53 young men had been killed that night. I'll talk about that a bit more in a second, but first of all, let's talk about the damage. Let's talk about the impact on the war. A photo reconnaissance Spitfire flew over and early the next morning, the pilot reported, "I looked down into the deep valley, which had seemed so peaceful three days before, but now it was a wide torrent."

• 46:53Dan Snow?

  The whole of the valley of the river was inundated with only patches of high ground and tops of trees and church steeples showing above the flood. I was overcome by the immensity of it. On the face of it, the damage was astonishing. Albert Speer was the man appointed by Hitler to boost Germany's munitions productions through the extensive use of appalling slave labour and shocking working additions, but he did achieve some extraordinary results. He talks about the huge success of this raid and he had to move several thousand construction workers to repair these dams. They were workers who would otherwise strengthen the construction of Germany's Atlantic Wall, the defences on the beaches of France and Belgium, which would eventually face the Allied invasion of Western Europe on D-Day.

• 47:36Dan Snow?

  There were hundreds of factories that were destroyed and disrupted. Industrial output was disrupted, but here's the key thing. Speer points out that the British didn't follow up on that success. They allowed the reconstruction of those dams to go on all through the summer without any further bombing raids. And I think that that British reluctance does have to do a lot with Arthur Harris. He was sceptical that dams were a kind of silver bullet, that they were a shortcut to victory. He believed that what was required was a massive campaign of destruction of Germany's industrial areas. That was how disrupt industry. And that was the way to bring the war to an end, by undermining support for Hitler's Nazi regime. It is very interesting to think what would have happened if those dams had been the target of sustained further bombing.

• 48:19Dan Snow?

  But irrespective of that, what it was, was a gigantic victory in terms of morale, nationally and internationally. It was famous, it was deemed a stunning success. The Dam Busters immediately became world famous. The men themselves, well, they were given a whole week off, but they were soon flying again operationally. And that's what's so tragic. Of the 77 men who came home from the Dam Busters raid, 32 of them would be killed before the end of the war. In the immediate aftermath, Gibson was turned into a reluctant celebrity. He was awarded the Victoria Cross for gallantry, the highest gallantry award that you can receive as a Briton. Dozens of other men that night also received gallantry decorations. They'd all gone to Buckingham Palace together to pick up those medals. Gibson, though, remained very upset by the loss of his dog.

• 49:04Dan Snow?

  He would lie in bed, moaning about how much he missed the dog. He didn't really celebrate his Victoria Cross. Winston Churchill, the Prime Minister, met him and Churchill's wife was annoyed he was married. She rather fancied him to marry one of her daughters. He went on desert island discs and his last pick was Ride of the Valkyries.

• 49:23Dan Snow?

  But Gibson wasn't really happy when he wasn't on frontline duties. I'm not sure where he was happy, really. On the 19th of September 1944, he insists on leading a raid over Holland, and he crashed and was killed. It's thought that he was unfamiliar with that particular type of aircraft, and that may have led to him making a mistake. He'd taken part in 172 missions. He was 26 years old when he died. Winston Churchill wrote, "What we've lost in this officer is one of our most splendid of all of our fighting men. His name will not be forgotten. It will forever be enshrined in the most wonderful records of our country." Splendid Churchillian stuff from the big man there, but Barnes Wallace, I think, was more perceptive. He wrote, "For some men of great courage and adventure,

• 50:07Dan Snow?

  inactivity was a slow death. Would a man like Gibson ever have adjusted back to a peacetime life? One can imagine it would have been a somewhat empty existence. After all he'd been through, facing death had become his drug. He'd seen countless friends and comrades perish in the Great Crusade. Perhaps something in him even welcomed the inevitability. He'd always felt that before the war ended, he would join them in their bomber command Valhalla. He'd pushed his luck beyond all limits, and he knew it. But that was the kind of man he was, a man of great courage, inspiration and leadership. They all were." Thanks so much for listening, folks. As I've, I'm sure you can understand now why it's one of my favourite stories,

• 50:52Dan Snow?

  and I'm very lucky to have met the men involved in this raid. It seems like a great privilege now they've all passed away. If you've enjoyed this, I'd love for you to leave us a review wherever you get your pods. It helps others discover this great thing we've got going on here at Dan Snow's History. Thanks so much. See you next time.

• 51:19Speaker 02

  This is a paid partnership with Apple Card. The coolest flex at brunch these days is not the Bloody Mary with the bottomless gold flake caviar topping. It's not whipping out your wallet to pay. It's not having a wallet at all. Jack's been an Apple Card user since 2019. That's the same year he tossed his wallet in the trash. Because Apple Card holders earn 2% daily cash back on purchases made using Apple Pay. It's the only credit card designed for the iPhone. I tap to pay with Apple Card at the grocery store, at the gas station, at restaurants. And yes, I use it at my second home, the farmer's market. Jack tapping to pay with his Apple Card with Apple Pay is his favorite thing to do. And the pleasant vibration and chime sound means I just got 2% daily cash back on my latest purchase. Apply in the Wallet app on your iPhone today. Subject to credit approval.

• 52:02Speaker 02

  Apple Card, issued by Goldman Sachs Bank USA, Salt Lake City branch. Terms and more at applecard.com.

• 52:11Dan Snow?

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