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The Dambuster Raid…Part One

Wing Commander Guy Gibson
Wing Commander Guy Gibson (United Kingdom Public Domain)

On 21 March 1943, well over 100 officers and NCOs from 21 bomber crews jammed the briefing room at Scampton, Lincolnshire, a Royal Air Force base 150 miles north of London to find out what the heck all the excitement was about. So far, they were known simply as Squadron X. They hailed from every corner of the Commonwealth, except for one Brooklyn-born American officer. They were all veterans, hardened by aerial battle--pilots, navigators, bomb-aimers, wireless-operators, gunners and flight-engineers. Nearly all were in their mid-20s or younger. They were handpicked, the cream of the crop, the best of RAF Bomber Command. Almost like a World War II version of Special Ops. Most crews had already completed a full combat tour of 30 operations over German-held territory. Some had even defied the odds by finishing 2 tours. They all had one thing in common--none of them volunteered to be there that morning. Glancing around, one of the Canadian gunners in the group commented, “This looks like an NHL {National Hockey League} All-Star team.”

At 0930, a hush fell over the crowd as the commanding officer, Wing Commander Guy Gibson, a handsome, muscular Englishman entered the room . He was already a decorated legend in the RAF with 3 tours in bombers and one in fighters, a man who had beaten the odds and then some. To be exact, he had seen 73 bombing operations; and 99 night-fighter ones, where he had 4 enemy kills to his credit. He had already been awarded a DFC (Distinguished Flying Cross) and a DSO (Distinguished Service Order) and a Bar.

“You’re here to do a special job,” Gibson began. “You’re a crack squadron. You’re here to carry out a raid on Germany which, I am told, will have startling results. What the target is I can’t tell you. Nor can I tell you where it is. All I can tell you is you will have to practice low flying all day and all night until you can do it with your eyes shut.” Gibson went on to say that security was vital and under no circumstances were they to talk to anybody off the base about what they were doing. Then he dismissed them.

One of these brave young men was a relative of mine…Sergeant Steve Oancia, Canadian born and raised near Stonehenge, Saskatchewan. His father and my grandfather were first cousins, farming only three miles from each other—a sheer stone throw on the prairies. Steve’s birth-name was Stefan. His parents were Romanian descent. At 18, Steve enlisted with the RCAF two years before and was now a bomb-aimer with the crew of Flight Sergeant Ken Brown, a fellow prairie boy from Moose Jaw, only 70 miles from Stonehenge.

The targets would be 3 main hydro-electrical dams feeding the industrialized Ruhr Valley--the Mohne, the Eder and the Sorpe. The Eder was the largest of the three, with a water capacity of 200 million tons. In all, 300 million tons for the 3 combined. The operation was based on an invention by British aeronautical engineer Barnes Wallis codenamed Upkeep, named after his powerful skipping bomb so gigantic in size that each aircraft could carry only one. Resembling a depth charge or a huge oil drum and weighing 9,500 pounds, each bomb held 6,500 pounds of RDX high explosive. It would be fitted under the fuselage of an Avro Lancaster 4-engined bomber, and carried by two V-shaped legs with a mechanism that spun the bomb backwards at 500 RPM by way of a belt drive connected to a motor inside the fuselage. Once Upkeep was released towards a dam from upriver, the backspin was expected to allow the bomb to skip forward and over the torpedo nets, then to hold the bomb against the wall of the dam as it sank. A depth-activated fuse would set off the explosion near the base of the dam, causing the wall to be breached. All this would have to be done at night under a full moon and at an altitude of 150 feet (later changed to 60 feet upon more testing), 425 yards from the dam, in the airspeed range of 230-240 MPH. The best time for the strike would be the middle of May, a full-moon period, when the water levels were at its highest as a result of winter runoff and spring rains.

Over the next several weeks, the intense day-night training began, closely supervised by Gibson, one of the few on the base who knew the true targets ahead of time. In order to simulate nighttime flying in daylight hours, light-blue screens were placed over the aircraft windows, and the crews donned yellow glasses. Low-level flying was no longer a no-no. It was a must. Like giddy school boys, the airmen were given the green light to perfect normally-forbidden low-flying practices. In Britain, no area between Cornwall and Hebrides was safe from Squadron X. The crews flew under bridges, skimmed wheat fields, brushed treetops, blew soot from chimneys, and scattered herds of cattle and sheep, all in the name of practice makes perfect. Any complaints from outraged civilian--and there were many--were totally ignored.

Then major problems presented themselves. After plenty of practice, the height of 150 feet over the water was too difficult to judge with the Lancaster instruments. So, a technician suggested to Gibson placing 2 spotlights on the bomber. One in the nose, pointing straight down, the other just forward from the tail, pointing at an angle towards the first light and converging with it to form a figure-eight on the water at the proper 150 feet. Also, during Upkeep bomb tests over England’s south shore, with Wallis looking on, the casings were breaking apart once they hit the water. With 2 weeks to go before the attack, his suggestion now was for the pilots to head towards the targets at 60 feet! Gibson’s first reaction was, “If 150 feet was too low, 60 feet was very low. At that height you would only have to hiccough and you’d be in the drink.”

The crews then made their tests at these scary heights and found they could actually do it. Other changes were roller maps for the navigators instead of cumbersome flip charts, and a hand-held bombsight--a small, wooden, triangle-shaped board with 2 nails on each end and a peephole in one corner. From aerial photos, RAF intelligence determined that the flak towers on the hydro dams were 600 feet apart. Technicians constructed the board so that when the bomb-aimer looked through the hole, he would line up the towers with the nails. At this point, the bomber was then at the required 425 feet from the wall in which to drop the bomb.

Into the first week of May, Gibson could see that his squadron was a little uptight, so he issued 3-day passes for his overtaxed aircrews, with orders to keep their mouths shut. Two days before take-off, Gibson briefed the pilots, navigators, bomb-aimers and flight-engineers of Squadron X (now named 617 Squadron) on their targets. The raid had a codename too, “Operation Chastise.” The shocked men were shown detailed scale models of the Sorpe, the Mohne, and the Eder down to exact flak positions and surrounding terrain. They all realized it would be one tough job. The next evening, Gibson briefed the gunners and wireless-operators. The next afternoon, Allied reconnaissance aircraft reported that the water in the dams was 4 feet from the top of the 3 targeted dams. The raid was on. At 9 PM, 16 May, the 7-man crews boarded 19 Lancaster bombers, each with an all-up weight of 63,000 pounds.

Formation Two took off first because they had the greatest distance to cover. These were 5 aircraft belonging to Flight Lieutenant Joe McCarthy (the American from Brooklyn), Sergeant Vernon Byers, Flight Lieutenant Norman Barlow, Pilot Officer Geoff Rice and Flight Lieutenant Les Munro. Their job was to fly east across the North Sea, then head south to attack the Sorpe Dam from the west. But the formation got off to a late start when Joe McCarthy discovered an oil leak in his bomber while it was on the tarmac. The rest left without him, while he switched to a spare aircraft, leaving him 20 minutes behind the group he was supposed to be leading.

Gibson’s Formation One consisted of 9 aircraft in 3 waves taking a more direct route to the Mohne. They were to breach it, then head to the Eder. In the cockpits were Pilot Officer Les Knight, Squadron Leader Melvin “Dinghy” Young, Squadron Leader Henry Maudslay, and Flight Lieutenants John Hopgood, Harold “Mickey” Martin, David Shannon, Bill Astell, and David Maltby. Taking off 2 hours after Formation Two was the reserve group of Formation Three, these 5 aircraft commanded by Pilot Officers Warner Ottley and Lewis Burpee, and Flight Sergeants Bill Townsend, Cyril Anderson and Ken Brown, with my relative aboard.

Everything didn’t go as planned, with Formation Two getting the worst of it. Upon reaching the coast at low level, Munro’s aircraft was hit by German flak badly enough to sever the intercom and radio lines. He had to turn back to base. The crews of Barlow and Byers were shot down near the same spot. Over the Zuider Zee on the Dutch coast, Rice slipped his bomber too low and struck water, tearing a hole in the fuselage. He too had to turn back. This left only McCarthy from the original 5 to head for the Sorpe.

Over the Dutch countryside, Gibson, Martin, and Hopgood flew tightly together, dodging trees, houses, and telephone wires. In the second group of Formation Two, Bill Astell’s crew missed their turning point and were never heard from again. Now 5 planes were gone and they still hadn’t reached any target yet. The remaining 8 in the Gibson formation reached the Mohne just as the moon was at its brightest, illuminating a set of hills ahead and the mirror-like Mohne Lake leading up to the huge dam. The crews looked on in awe at the size of the target they had been trained to destroy. Suddenly, German flak (which RAF airmen called ack-ack) from as many as 10 guns opened up on the Lancasters. Gibson began to circle the target with Hopgood and Martin, as he contacted the other aircraft in his formation. Except for Astell, the others answered and flew into view. Over the radio, Gibson let the other 7 aircraft know that he was going in first.

“Well, boys, I suppose we had better start the ball rolling,” he said calmly to his crew over the intercom. 

The Mohne Dam
The Mohne Dam breached, 1943 (United Kingdom Public Domain)

Gibson turned his aircraft, G-George, around the eastern part of the massive lake, while his bomb-aimer Fred “Spam” Spafford hit the switch to start the motor spinning the bomb at 500 RPM. Edging towards the surface at 240 miles per hour, Gibson eased the Lancaster down, then carefully began to level off over the smooth black sheet of mirroring water. The navigator flicked the 2 spotlights on and watched for the figure-eight to appear on the water surface below. Gibson held the bomber steady, aiming for the center point of the towers to the west, seemingly oblivious to the fiery balls of ack-ack closing in on him from the other side of the lake. His front gunner fired back, while Spafford peered through the peephole of the makeshift, hand-held aiming device, waiting for the towers to line up on the nails. When they did, he dropped the bombed. Gibson roared the bomber over the wall of the dam and down the valley, then banked to take a look along with his crew. The bomb exploded and a massive spire of water hung in the air at the base of the wall. But when the spray subsided, the dam still held.

John Hopgood made the second run on the Mohne. But by now the German flak gunners had found the range and made several hits. Hopgood’s wing began to burn before he reached the wall. His bomb-aimer, presumed injured, dropped the bomb on the powerhouse on the other side of the wall. The other aircraft could see Hopgood climbing for the sky, probably to give his crew time to bail out. Moments later, a bright flash lit up the night. A wing separated and the Lancaster disintegrated into many flaming pieces 3 miles from the dam. Then the powerhouse blew up, making another fiery explosion in the darkness. Gibson waited for the billowing smoke to ease, then called on Mickey Martin, followed by Dinghy Young to drop their bombs. Both runs were perfect, but the wall still stood after the bombs were dropped. Then David Maltby was called upon by Gibson, and his bomb-aimer let the bomb go on target. At first, nothing. Then several radios from the other bombers came to life. Pilots hooted and hollered. Below a great flow of foaming water emerged from an enormous, 100-yard-long hole in the wall.

Gibson’s excited wireless-operator sent a signal back to their English base at Scampton that their first objective had been destroyed. Gibson later recounted in his excellent autobiography, Enemy Coast Ahead, “The whole valley was beginning to fill with fog from the steam of the gushing water, and down in the valley we saw cars speeding along the roads in front of this great wave of water, which was chasing them and going faster than they could hope to go…The floods raced on, carrying everything with them as they went--viaducts, railways, bridges and everything that stood in their path. Three miles beyond the dam the remains of Hoppy’s aircraft were still burning gently, a dull red glow on the ground. Hoppy had been avenged.”

Gibson then ordered Martin and Maltby to set course for Scampton, while he with the remainder of Formation One flew east to the Eder. The night was far from over…

Part Two--next week


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