“God,” said Flight-Lieutenant H.B. ‘Mick’ Martin, DSO, looking up at the overflying plane, “is that a Lanc or isn’t it? What a monstrosity!”
It was, indeed, a horribly ungainly adaptation of a Lancaster. Like all the great aircraft of WWII, the Avro Lancaster conformed to the saying “if it looks right, it is right”, and few aircraft have ever looked better. The Lancaster was a superb heavy bomber, born from a terrible heavy bomber called the Manchester. The Manchester was underpowered, with a pair of straining Rolls-Royce Vulture engines (each Vulture being, in turn, a pair of Peregrine engines bolted to each other, the bottom one being upside down) trying to drag a 50,000lb aeroplane to a useful altitude and speed and, more often than not, failing at both. The Lancaster was even bigger and heavier, but it had long, graceful wings mounting four Rolls-Royce Merlin engines. The Merlins were already known and beloved as the powerplants to the Spitfire, Hurricane, Mosquito and later the Mustang, and the Lancaster flew brilliantly.
It was also, as Martin had seen to his horror, adaptible. The Avro Lancaster B.III Special (Type 464 Provisional) was one of the most ungainly designs ever to emerge from a workshop. It was an extraordinary engineering achievement. Avro, led by chief designer Roy Chadwick, took the standard Lancasters in and, in just a few weeks, comprehensively mauled them. The upper turrets were taken off, to save weight – and, with the loss of two machineguns, incidentally removing a quarter of the aircraft’s defensive capabilities. That wouldn’t have been so bad if, to save further weight, most of the armour plating hadn’t also been taken away. Then there was the bomb bay, where the most startling and comprehensive destruction had been wrought. The bomb bay doors were gone and a chunk carved out of the fuselage. Beneath were two sturdy legs, each shaped like an open set of calipers. (One aircrew, seeing the ungainly arrangement, was heard to remark that the aircraft didn’t need wheels anymore – it could waddle to and fro about the airfield. The squadron leader described it as looking “like a pregnant duck”). On the aircraft’s starboard side a monstrous chain-and-sprocket drive, like the gearing off God’s own bicycle, attached to a lightweight electric motor taken off an obsolete submarine. The sprocket was for the bomb.
Ah yes. The bomb. Imagine a beer barrel, seven feet long, lying on its side. Imagine it filled with high explosive and weighing five tons. And now imagine, as you fly in your hastily-modified, lightly-defended aircraft just sixty feet – less than a wingspan – above enemy territory, that you have to spin that bomb at 500rpm and hope that it doesn’t shake your airframe to pieces.
This was Barnes Wallis’s revolutionary ‘bouncing bomb’, ‘Upkeep’, and these Lancasters had been modified to take it on one mission only. On the night of 16th – 17th May 1943 19 B.III Specials of 617 Squadron attacked the Moehne, Eder and Sorpe dams. The squadron had trained intensively for weeks, because the date of the raid was fixed: in mid-May the water levels in the reservoirs behind the dams were at their highest.
The man who trained the squadron and led the raid was Wing Commander Guy Gibson. He had two DFCs, two DSOs, and 173 missions – more than 600 hours of combat time – to his name. He was 24 years old. He and his aircraft, ‘G for George’, would be first to attack.
The flight to the Ruhr was not without incident. Although obsessive care had been taken to thread the bombers’ route past known flak concentrations and night-fighter bases, low flying in a heavy bomber carried its own risks. One aircraft, ‘H for Harry’, had a malfunction in its searchlights (two lights, shining from the bottom of the fuselage, that when their beams coincided told the crew that they were at the correct 60′ altitude required for a successful drop) and hit the North Sea. Its pilot, Rice, slammed open the throttles and hauled back on the control yoke, and ‘H Harry’ climbed soggily away. They turned for home once they realised the bottom had been torn out of the plane and the bomb had gone, much to the relief of the rear gunner, who had nearly drowned in his turret when the Lanc scooped up a couple of tons of seawater.
The first wave of nine aircraft, led by Gibson, had as their primary target the Moehne Dam. Holding back something like 135 million cubic metres of water – 134 million tons – it was an enormous concrete structure a hundred feet thick that the Germans already knew to be impervious to any known form of bomb. Even a torpedo attack had been thought of and defended against: anti-torpedo nets had been slung in front of it. (It was partly because of the presence of those nets that Barnes Wallis had decided his bomb should bounce: that way, it would skip clear over the top of them to the target.) That said, at least one man was not blind to the target the dam represented. His name was Oberburgermeister Dillgardt, and over the course of the three years prior to the raid he requested searchlights, barrage balloons, light flak, heavy flak and smoke screens. By the time May 1943 came around he had managed to get some 20mm guns posted, but nothing else aside from some ornamental pine trees to decorate the top of the dam. (Those trees, incidentally, had worried the hell out of the raid planners. It was not at all clear from the pre-mission reconnaissance pictures what they were, and they assumed that there had been a security leak somewhere and the Germans had posted more guns. They didn’t find out the truth until long afterwards).
Gibson’s nine were already eight. ‘B for Baker’, flown by Astell, hit high voltage electrical cables near the German village of Marbeck and crashed into a field, cremating everyone on board. The rest found the dam and Gibson went in first. He made one low pass over the target and then circled back for his attack run. Taerum, the navigator, flicked the searchlights on and Gibson lowered ‘G George’ down to 60 feet. The gunners on the dam were awake now, and they had the lit-up bomber to target. Red-coloured flak started curling in at the Lancaster, each red shot a tracer bullet to enable the flak gunners to track their fire, and each red shot representing only a quarter of what each cannon pumped out. Pulford, the flight engineer, juggled the throttles to keep their speed constant at 240mph. Spafford, hunkered down in the nose, called out course corrections as he took aim. He switched on the motor in the carved-up bomb-bay and Wallis’s portly mostrosity began to spin until ‘G George’ was thrumming like a live thing. From the nose came a deafening spattering crackle as Deering, the nose gunner, lashed out at the flak on the towers with his twin Vickers machineguns. Spafford called out “Bomb gone!” and ‘G George’ tore between the towers, Upkeep skipping along behind them, and they dived and vanished from the flak in the river valleys beyond the dam as Trevor-Roper, in the tail, took his turn to fire on the flak that had come at them. They circled back in time to see the explosion: a gout of white water erupted a thousand feet into the air and hung glistening in the moonlight. For a moment they thought the dam breached, but the water calmed again and the dam still stood.
Gibson ordered in Hopgood in ‘M for Mother’. Like Gibson he came in at sixty feet, 240mph, straight down the reservoir. The flak was ready for him. Shells hammered into the port wing, and the Lanc was already burning when she reached the dam. Her bomb-aimer was hit and he released Upkeep too late. The bomb bounced clear over the top of the dam and exploded on the power station below. Silhouetted by the explosion ‘M Mother’ was nose up, straining for altitude so the crew could bail out, but then the wing folded and she blazed into the ground like a meteor.
Martin, in ‘P for Peter’ (“P for Popsie” he always insisted), came next. This time Gibson flew across the dam as Martin thundered in at it, trying to draw fire from the vulnerable attacker. Deering and Trevor-Roper opened up, six lines of tracer hammering into the dam, mixing bullets with chips of concrete as they tried to put the flak out of action. Martin was for several seconds unnoticed, until the flak found him. He bulled straight though, Foxlee in ‘P Popsie’s nose firing back, and then the big bomber lunged between the towers and her bomb split the water but not the dam. He banked away, a little dicily: several shells had exploded in his starboard wing.
‘A for Apple’, Young’s aircraft, was up next. This time Martin joined Gibson as flak bait, and Young got through okay. Again the Upkeep went off beautifully, but the dam remained standing. Maltby, in ‘J for Johnny’, followed. It was the same as before. The bomb bounced into position with its customary accuracy and exploded, and again the great plume of water rose into the sky. Gibson called in Shannon to make his run, but Martin interrupted. “Hell, it’s gone! It’s gone! Look at it!” ‘P Popsie’, circling back, had been next to the dam when the concrete face spit and crumbled and a ragged hole a hundred feet deep and three hundred across gaped open like a wound. The water – all 134 million tons of it – came pouring out in a vast torrent 25 feet high moving at 20 feet a second.
As Hutchison, ‘G George’s wireless operator, sent the ‘mission successful’ signal back to Bomber Command, Gibson ordered Martin and Maltby home while he, Young, Shannon, Maudsley and Knight went on to the Eder. It took a while to find, as heavy fog was starting to come in, and Gibson circled several times before he was sure. At least there was no flak. The Germans didn’t think it was required. The reservoir nestled in a steep-sided valley surround by hills a thousand feet high. It was no place to try and fly a four-engined heavy bomber at treetop level at night.
Shannon tried first. He made six attempts, but he just couldn’t get the hang of the topography. Eventually he withdrew and continued circling, recommending that Gibson send someone else while he and his crew got their breath back and thought about the problem some more. Gibson told Maudsley in ‘Z for Zebra’ to go in. He dropped in very fast and came rocketing across the water. He dropped Upkeep alright, but too fast and the bomb bounced into the dam parapet and exploded with ‘Z Zebra’ directly above. Incredibly the badly damaged bomber got away, but Maudsley never made it home: night-fighters got him somewhere over Germany.
Shannon tried again. He made one attempt and missed; then he came back and tried again. This time it worked. He got down and got the speed and dropped Upkeep. The bomb bounced and slithered to the dam and exploded perfectly. When the plume cleared, though, the dam was still there. Gibson ordered in Knight in ‘N for Nut’. He was the only one left with a bomb. Shannon advised him over the radio, and ‘N Nut’ came sweetly across the lake and let go its bomb perfectly. It was enough. The dam burst, and fully 200 million tons of water came blasting through the breach, rolling down the steep valley at 30 feet a second. Gibson and his surviving planes turned for home.
There had been a third target, the Sorpe. Only two aircraft bombed it successfully. McCarthy, in ‘T for Tommy’, was the only surviving aircraft of the second formation. Rice had turned back after hitting the sea, while Munro had had his radio shot out over Holland and had had to turn back as well. Byers was shot down by flak and crashed into the Waddenzee while Barlow crashed into electricity pylons near Haldern. Of the third formation, the so-called ‘Mobile Reserve’, Brown in ‘F for Freddie’ joined McCarthy in successfully attacking the Sorpe, but the dam held. By the time Anderson in ‘Y for York’ reached the target the fog was too thick and he returned to Scampton with his bomb still on board. Townsend, in ‘O for Orange’ (who had had an exciting trip already: the wireless operator looked out to see treetops whipping past above eye-level, as Townsend took his bomber through forest firebreaks) attacked a dam which he claimed was the Ennepe but may have been the Bever. It was not breached. Ottley and Burpee, in ‘C Charlie’ and ‘S Sugar’ respectively, were dead without having reached their targets. Of the 133 crew who flew the raid, 53 died. At least 1,600 people were killed by the floodwaters, the vast majority of them non-combatants. It was a raid justified by the awful algebra of necessity: Germany’s industrial output for the region dropped significantly for several months, and perhaps people who would have died didn’t, as the tanks, guns, bombs and bullets that would have killed them were not made.Thousands of German soldiers were taken away from more pressing engagements elsewhere in order to rebuild the dams.
Many of the aircrew were awarded medals. They had done a difficult and dangerous job with supreme professionalism and courage, and the squadron as a whole – on the basis of a single operation, and after being in existence for only a few weeks – became one of the most famous in the airforce. Thirty-three medals were awarded, including DSOs for Martin, McCarthy, Maltby, Shannon and Knight and the Victoria Cross for Gibson.
617 went on to do other remarkable things. They sank the battleships Tirpitz and Lutzow; pretended to be a massive naval convoy sailing to Calais on D-Day and kept German defences tied up while the real landings happened in Normandy; they drained the Dortmund-Ems canal, crippling German communications; and they wrecked the V3 secret weapon, a battery of buried guns with barrels 500 feet long that would have been capable of dropping 600 tons of high explosive on London per day.
In work recently we were told to build a Dambusters model. The one we were given was the new 1:72 Airfix kit of the Type 464 Lancaster, ‘G for George’, as she appeared on the night of 16th – 17th May 1943. I built it and modified it a little – it has the full crew – and displayed it over a model of the Moehne Dam. The dam – though shortened – is also reasonably accurate. It has the 20mm flak cannon that damaged Martin and got Hopgood. It even has the ornamental pine trees. But as with any model, it improves enormously if you know the story behind it, and the story of the Dam Busters is one of the best I know.