by John Nichol
On 1 March 1945 Goebbels wrote in his diary that ‘the air war has now turned into a crazy orgy. We are totally defenceless against it. The Reich will be gradually turned into a complete desert.’11 However, the Luftwaffe was not completely diminished, as its new jet-powered fighters had already begun to appear in the skies over Europe. They were a potent enemy. In one forty-eight-hour period between 20 and 22 February, Bomber Command suffered the loss of 62 aircraft, most to fighters. And on 4 March, German night-fighters followed the Main Force stream back to England, attacking 27 airfields and shooting down some 20 aircraft.12 Although the war may have been in its final stages, the dangers were still ever-present.
A series of mass daylight raids on Berlin during February carried out by USAAF bombers, and augmented by night-time raids by Bomber Command, reduced much of the city to rubble. On 7 March US ground troops crossed the Rhine for the first time, at Remagen. The question was no longer if, but when, the Nazis would be forced to surrender.
After a long period of raids on naval targets, during February and March 617 Squadron’s attacks were chiefly on more traditional targets, including no fewer than five attempts to destroy the Bielefeld railway viaduct in north-west Germany. Four hundred metres long and twenty high, its twenty-eight graceful arches spanned the Johannisbach river at the head of the Obersee Lake. The railway line that ran over the viaduct connected Berlin, Hamburg and north-eastern Germany with the main industrial zones of the Ruhr and was the busiest freight line in Germany, with over 300 trains a day using it.
On 13 March 1945 twenty Lancasters and one Mosquito took off from Woodhall Spa for yet another attempt to flatten it. The scale of the devastation around the viaduct showed how often Allied bombers had previously tried and failed to topple the structure. It had been the target of no fewer than fifty-four previous attacks, but even when the track was struck seventeen times in one raid, the damage was repaired within twenty-four hours, and none of the attacks had had any significant impact on the viaduct itself. Chipped and scarred, it still stood upright, defying everything the Allies could throw at it, though the landscape around it was pockmarked by hundreds of craters, punctuating a sea of torn earth, ruined buildings, uprooted trees and barren, bottomless mud.
In the previous November alone the Americans had dropped over 2,000 high-explosive bombs and 33,000 incendiaries on the viaduct, damaging two spans and a pier, but the Germans had simply placed steel girders over the damaged sections and relaid the track. ‘Winter rains turned the crater landscape in[to] a nightmare sea of water-filled holes and deep mud … The area was alive with unexploded bombs and the bomb disposal workers – the “Suicide Squads” – had a difficult time even reaching the UXBs.’13
A Lancaster over Bielefeld viaduct
By mid-March, ‘over seven million pounds of high explosive had been dropped on the structure but still it stood, chipped and pock-marked by numerous hits and near misses.’14 Allied air superiority meant 617 should have a relatively trouble-free flight to the target, and they had attacked the viaduct so often that the navigators could find it without reference to their maps. However, the next attack would have one crucial difference: two of the Lancasters were carrying another brand-new bomb devised by Barnes Wallis.
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On the morning of 13 March 1945 Wallis took his normal bracing constitutional swim in the frigid waters of the Channel near the Ashley Walk bombing range in Hampshire. Having towelled himself dry and dressed, he took up station behind a blast-wall to witness a live test of his new super-weapon: the monstrous 10-ton bomb that he had christened ‘Grand Slam’. It was the largest ‘iron bomb’ ever built.
Wallis had first proposed the weapon as far back as 1941 in a paper titled ‘A Note on a Method of Attacking Axis Powers’. He had suggested that sufficiently large bombs exploding deep underground could destroy targets with the seismic shockwaves transmitted through the earth, rather than the blast effect of high-explosive bombs detonating on impact with the ground. He also designed a huge aircraft, ‘The Victory’, capable of carrying such bombs, but the Air Ministry rejected that proposal on cost grounds, and since the RAF then had no aircraft capable of carrying such a monstrous weight, his idea of a huge ‘earthquake bomb’ was also spurned.
Now, three years later, its time had come. He designed the 26-foot-long Grand Slam with an aerodynamic shape and a casing forged from a single piece of perfectly formed chrome molybdenum steel. It took almost a week to cast and machine each casing, and although the exterior was perfectly smooth, the inner surfaces of the casing were often quite rough when cast. When two 617 crews were sent to the English Steel Corporation in Sheffield to boost the morale – and the production rate – of the men manufacturing them, they were shown one casing that was being finished off from inside by ‘two little men, smaller than jockeys, with pneumatic hammers’. They shone torches into the casing and whenever they spotted an imperfection, one of them climbed inside and hammered it out. ‘He could only stand about twenty or thirty seconds of this and then they hauled him out, his legs shaking.’ The insides of the casings were further smoothed with angle-grinders and then varnished inside to remove any risk of premature detonation by friction between the casing and the explosive charge at the moment of impact with the ground.
When a steelworker asked John Langston, one of the visiting aircrew, what he did, he was told, ‘I drop the bombs.’
‘What do they pay you?’
‘Thirteen shillings and sixpence [67½ pence] a day.’
‘You’re a fool,’ the man said. ‘I get ten quid a week for doing this!’15
The finished casing was strong enough to survive the 10-ton bomb’s brutal impact with the ground and allow it to bury itself deep below the surface. A time-delay fuse would then detonate the 9,500 pounds of Torpex explosive (a mixture of TNT, RDX and aluminium powder) it contained, and in theory the shockwaves radiating outwards would create a localised ‘earthquake’ that would shake any nearby structures so violently that they would inevitably collapse.
Residents in the villages surrounding the Ashley Walk range had not, of course, been told what was being tested that morning, but they had all been advised to keep their windows open to avoid having them shattered by the blast. As the bomb, fitted with an eleven-second delay-fuse, impacted with the ground, Barnes Wallis began silently counting to himself. He had reached nine when the ground erupted. Detonating well below the surface, the visible effects of the blast were perhaps less dramatic than most of the dignitaries assembled to watch the test might have expected, but the inhabitants of the surrounding villages all felt the ground shake from Wallis’s ‘Earthquake Bomb’.
Unlike the area bombing of the industrial Ruhr, this superbomb offered the possibility of disrupting or destroying key elements of Germany’s industrial infrastructure without causing civilian harm – a particularly important consideration when used against targets in the occupied territories of France, Belgium, the Netherlands, Poland and Scandinavia – and it was hastily pressed into service.
Astonishingly – a new weapon would only be passed for operational use today after being tested for years under every conceivable condition – a handful of hours after Wallis had watched that trial drop on the ranges at Ashley Walk, two aircraft of 617 Squadron were carrying Grand Slams across the Channel, making for the Bielefeld viaduct. The new weapon was so expensive to produce that it was only to be used on the most crucial targets, and those that were not susceptible to attack by more conventional bombs. The viaduct met both of those conditions.
None of 617’s existing Lancasters had been powerful enough to lift the massive 10-ton bomb-loads off the runway – the all-up weight of the aircraft when loaded with fuel and the Grand Slam was well over 30 tons – and newer, more powerful B-1 Lancasters, with strengthened undercarriages and more powerful Merlin engines, had been rushed through production to carry them. The bomb-bay doors were removed, the bomb-bay itself faired into the fuselage, and, to save additional weight, e
ach Lancaster carrying a Grand Slam dispensed with its wireless operator and his equipment, the nose turret and mid-upper gun turret and the gunners who operated them, as well as two of the guns and most of the ammunition from the rear turret. As one navigator remarked, they were flying ‘virtually naked’.
Even though he was no longer needed as a wireless operator, Colin Cole still flew on some ops ‘so I could be with my crew. Just along for the ride really, I didn’t want to be left out, though I didn’t put those trips in my logbook as we really weren’t meant to be doing it.’16
Even with all the excess weight removed, as pilot Benny Goodman remarked, ‘it was still a major achievement to get a 22,000-pound bomb airborne.’ Such was its weight that, after it was loaded aboard the Lancaster, the aircraft’s wingtips were ‘bent upwards by six to eight inches on either side’, said navigator John Langston.17 It took every inch of runway and every ounce of power that could be coaxed from each Lancaster’s four bellowing Merlin engines for the two aircraft carrying Grand Slams, flown by the squadron CO, Group Captain Johnny Fauquier, and Squadron Leader Charles ‘Jock’ Calder, to get airborne. Eighteen Lancasters carrying Tallboys accompanied them.
However, yet again their flight across Germany was in vain, for the viaduct was completely obscured by cloud and they had to return home still carrying their Grand Slams. The huge weight of the laden Lancaster would have made it impossible to bring it to a halt before the end of the relatively short runway at Woodhall Spa, and they were diverted to the RAF’s emergency landing strip at RAF Carnaby near Bridlington on the Yorkshire coast, where the runway was five times the width of a normal one and 9,000 feet long.
At lunchtime on the following day, 14 March, sixteen Lancasters from 617 Squadron tried again. This time, as Fauquier was testing his aircraft prior to take-off, one of his engines failed. With his crew, he at once scrambled from the aircraft and sprinted across the tarmac to commandeer Calder’s Lancaster. However, seeing Fauquier’s aircraft still at dispersal with one engine stopped, and the CO running towards him shouting and waving his arms, Calder realised that he was about to lose his own chance of Grand Slam glory, and opened his throttles and taxied away, leaving his furious CO struggling to stand up in the wash from his propellers. As the laden aircraft slowly gained altitude another fourteen Lancasters, which had taken off from Woodhall Spa, joined Calder’s aircraft and set course for Bielefeld. There were no other Grand Slams available, and, as before, the remainder of the squadron were carrying Wallis’s earlier invention, Tallboy. Regarded as an almost unimaginably devastating weapon just a few months before, it must now have seemed almost puny in comparison with the massive and fearsome Grand Slam.
Flying alongside Calder’s aircraft, Sydney Grimes had a ringside view: ‘It was the strangest sight I’d ever seen. I could see the wingtips flexing upwards in a bow shape under the strain – the wing was no longer flat. The bomb looked brutal hanging there, a lethal weapon. I thought, If we don’t destroy the viaduct with this, then we never will!’18 ‘It looked like a huge, mean bomb,’ a member of Calder’s crew, Murray Vagnolini, added. ‘I did think about the death or destruction it would cause. I’d suffered it all myself during the Blitz so had a good idea what it might be like for the Germans. It must have been pretty awful, but it was war, and what we were doing was a necessary part of that war to defeat the Germans.’19
The Germans were well aware of the Bielefeld viaduct’s strategic importance, and it was heavily defended. A 20mm flak battery was sited on the hillside above the viaduct and a Wehrmacht Nebel Kompanie – Smoke Company – had stationed its smoke generators along the valley sides. They fired them up when the alarm was given, and by the time the Lancasters had reached the target, the northern end of the viaduct was obscured by smoke, but the southern end was clearly visible as the raiders began their bomb-runs.
The other aircraft dropped eleven Tallboys, but despite a number of near-misses that damaged the viaduct and blocked the train line to the south of it, none of them had demolished the structure. Then Calder began his run. At precisely 4.28 that afternoon, his bomb-aimer, Flight Lieutenant Clifford Crafer, released the very first Grand Slam. The effect on the aircraft, relieved of its 10-ton bomb-load, was immediate and dramatic.
Freed of the massive burden, the aircraft hurtled upwards and Crafer, lying on his stomach in the bomb-aimer’s position, was pinned to the floor. When the headlong rise stopped, he ‘shot up from the floor and came down with a bang which knocked me breathless’.20 Sydney Grimes saw the aircraft ‘leap upwards’, and Murray Vagnolini, who was poised to wind in the retractable arms that had held the bomb when it was dropped, found himself plastered to the floor of the aircraft as it shot up like a cork from a bottle. ‘When an aircraft dropped a bomb that size it leapt about two to three hundred feet into the air, but this was something they didn’t tell us,’ he recalled with a rueful smile.21
Dropped from just under 12,000 feet, the Grand Slam cut a graceful curve on its thirty-five-second fall through the air, as the spin imparted by its vanes – like the Tallboy’s, offset at an angle of 5 degrees – kept it tracking unerringly towards the target, the central span of the viaduct.
Keen eyes in the circling Lancasters saw the ‘squirt of mud as it speared into the marsh’ about 20 feet from the stone piers. Impacting at near-supersonic speed, it drilled down deep into the muddy earth alongside it. Eleven seconds later, the time-delay fuse triggered a massive explosion, creating a crater 60 feet deep and 200 feet wide, blasting debris hundreds of feet into the air and sending up a towering column of dust and smoke.
‘It exploded with a fantastic flash which was at once smothered by a high column of smoke,’ said Clifford Crafer, whose aircraft was battered by the force of the explosion, which he described as ‘worse than from the severest flak’.
Jock Calder described how their 18-ton Lancaster was tossed around by the blast as if it were a paper bag in a gale, later saying that ‘it felt as though someone had hit me severely in the back. I didn’t expect the kick quite so soon.’ The shockwave from the explosion swept his aircraft ‘well over 500 feet’ higher in the sky.22
When the smoke and dust settled, they could see at once that their mission had been completely successful. The ‘Earthquake Effect’ that Barnes Wallis had theorised had shaken the viaduct to its core, and seven arches, incorporating a 200-foot stretch of the northern span and 260 feet of the southern one, had been completely obliterated.23 One watcher said that the entire viaduct seemed to be lifted into the air before crumpling in a heap. A single 10-ton bomb had achieved what a total of 3,500 tons on previous raids had failed to do.
Anneliese Möller, a member of the first-aid unit in a nearby bomb shelter, recalled that ‘the ground vibrated like an earthquake’ when the bomb detonated, ‘and people realised at once the viaduct was hit. As we [arrived at the site] we found thirteen [dead] anti-aircraft auxiliaries on the ground. A horrifying image.’ Erna Bitter, a schoolchild at the time, saw the explosion from the windows of her school and watched as ‘the dead were brought to the funeral chapel on handcarts. There were many carts.’
Twelve-year-old Helmut Brockmann, watching from his garden only 2 miles away, remembered clearly seeing the 10-ton bomb fall towards the viaduct. ‘She plummeted from the sky like a telephone pole,’ he says. ‘I had never seen anything like it before. Then I felt the blast, my trousers were fluttering in the wind, and the earth vibrated. Women in the shelter began to scream. When I looked again, the viaduct had gone.’24
A Grand Slam is released over the Arnsberg viaduct
No doubt to the continued fury of his Commanding Officer, Calder’s reward for being the first man to drop a ‘Ten-Ton Tess’ was a Bar to his DSO (he also had a DFC).25 However, Johnny Fauquier’s chance to drop his own Grand Slam came in a similar attack on the Arnsberg viaduct the next day. Poor weather disrupted that raid, and the viaduct was undamaged, but four days later 617 Squadron returned to finish the job. Fauquier’s bomb was rele
ased early and undershot, but Phil Martin’s bomb-aimer, Don Day, made no mistake. A squadron leader from a Main Force bomber squadron, along for the ride as an observer, was peering over Day’s shoulder as he released the bomb from 12,000 feet and scored a bullseye on the western end of the viaduct. A few seconds after it detonated, ‘we were thrown upwards and almost went upside-down from the concussion because of our bomb hit. About four Tallboys also hit and exploded within, I would say, about two seconds, and we just ended up a tangled heap over the bomb sight!’26 When the smoke cleared, two arches of the viaduct had collapsed.
There was also a terrible human cost from the raid. According to Benny Goodman, who paid a visit to Arnsberg after the war, the Germans had put ‘a whole school and its teachers’ under the arches of the bridge, and when it was bombed they were all suffocated.27
The Bielefeld op proved to be Sydney Grimes’s last. As more of the 617 Squadron Lancasters were converted to carry Grand Slams, the mid-upper gunners and wireless operators found themselves redundant. Grimes was:
very resentful that I’d only got seventeen ops in my second tour, when we should have done twenty. My crew would complete the full tour and I was being left out. I wasn’t happy about that at all. I really wanted to finish with them, there was a sense of letting them down, not doing ‘your bit’, perhaps of taking the easy option out of the war. I certainly didn’t want to be accused of that! I asked my Flight Commander if I could go on ops anyway, and just stand in the astrodome and look out for flak and fighters, anything to get the last three in! I tried my best to persuade him but he showed me a signal from 5 Group telling the squadron that no spare bods would be taken on any ops. That was that.28
* * *
On 21 March 1945, Vera Gill began a letter to her beloved husband Ken, the navigator on Grimes’s crew. ‘My darling hubby,’ she wrote. ‘Isn’t it a lovely day for the 1st of Spring, I wish we could be together to enjoy it. I wonder if you have been [flying] this morning; it’s just been on the 1 o’clock news. Of course I know there are plenty more Lancasters besides yours but I just wondered.’ She gives him news of their baby son Derek and goes on to thank him for the oranges he had sent and the photograph which had arrived a few days before. It seemed Ken had not been happy with the results of the photo of the pair, as Vera wrote, ‘I think you must have stood nearer the camera! Even if you were as fat as that I would still love you the same.’ The letter ends abruptly there. Presumably there was a knock at the front door.