When they were halfway down, the ravine twisted slightly, providing them with their first glimpse of the moonlit Norsk Hydro perched atop its stack of rock. To Haukelid’s eyes, it looked like ‘an eagle’s eyrie, high up on the mountainside’, sinister and remote. ‘It was blowing fairly hard,’ he said, ‘but nevertheless the hum of the machinery came up to us through the ravine.’19
They finally reached the bottom, checked that everyone was unharmed and then crossed the ice bridge unseen by the sentries on the suspension bridge. One by one they ran through the deep shadow towards the sheer rock face that marked the other side of the gorge.
The ascent was far tougher than the descent. They hauled themselves up, clutching at the dangling branches and finding precarious footing on icy ledges of rock. The packs weighed heavy on their backs and they were soon drenched in sweat. Even Haukelid, who was at the peak of his form, confessed that it was ‘a wearisome climb’.20 But the black horizontal line in the rock face above soon sharpened into focus. The men were nearing the ledge that held the single-track railway.
As they climbed on to the ledge, the moon was shrouded in cloud, making their position less exposed. The temperature was on the rise and the thaw that had begun that afternoon was sending down chutes of melting snow from the treetops. They prayed that the ice bridge, upon which their escape depended, would not collapse.
At 11.30 p.m., they reached a snow-covered building some 500 yards from Norsk Hydro. Rønneberg motioned to the men to rest up in the shadows and eat chocolate while they waited for the change of guards on the suspension bridge. As they sat there in the darkness, Rønneberg suddenly appreciated the quality of their training – not just at Brickendonbury but also in the Scottish Highlands. ‘When we were sitting there waiting, it was like a short rest on a training exercise in Scotland,’ he thought. ‘It was the same atmosphere, the same telling of stories and so on, the noise of the factory was so strong we could talk more openly and even laugh.’
Rønneberg felt supremely confident of success, partly ‘because everyone seemed tremendously calm’.21 Indeed they were all so concentrated on the job ahead that they had no thoughts of the danger.
Haukelid looked at his comrades and was struck by how well they were armed: ‘five tommy guns, two sniper rifles among nine men, and everyone had a pistol, a knife and hand grenades’.22
* * *
At precisely 0030 hours, Rønneberg ordered the advance towards the store shed that lay less than a hundred metres from the giant mesh gates. Here, they split into their two prearranged groups. Haukelid made a silent dash towards the gates, clutching his giant bolt-cutters. These snapped easily through the thick chain. As the gate inched open, Haukelid motioned to his covering party to advance inside the plant and on to the upper platform. From here, they could see inside the guard post, lit by a warm glow. The German sentries inside were clearly oblivious to anything untoward taking place. They were equally oblivious to the fact that they would be sprayed with machine-gun fire if they stepped outside.
Rønneberg and his three saboteurs had meanwhile forced a second gate that led down to the lower platform. This provided access to the basement where the plant machinery was housed, along with the high-concentration heavy water cells. ‘Everything was still quiet,’ he said. ‘The black-out of the factory was poor and there was good light from the moon.’23
He gave a pre-agreed signal to Haukelid and the covering party now shifted their positions, moving even closer to the hut housing the German guards. Rønneberg’s own group split into two pairs, each armed with a complete set of explosives. If one group failed to get inside, it was hoped that the other could complete the task.
As Rønneberg peered through a small window into the dimly lit transformer room, he glimpsed a scientist working on the floor below, ‘reading instruments and writing in a log book’.24 He made his way over to the cellar door that was supposed to have been left unlocked by one of Einar Skinnarland’s contacts. It failed to open, for, unbeknown to Rønneberg, the man had fallen ill and been unable to go to work.
He didn’t panic. He knew from his Brickendonbury training that there was another means to enter the heavy water plant. A narrow cable shaft led through the bedrock directly into the plant room. He and Fredrik Kayser now clambered up a short ladder and crawled into this shaft, pulling themselves along on hands and knees and trying to avoid snagging their sacks of explosives on ‘the mass of pipes and leads’.
When they reached the end of the shaft, Rønneberg slid down into the outer plant room, swiftly followed by Kayser. The two men then approached the high-concentration room in absolute silence and tentatively pushed the door. It was unlocked. Rønneberg knew that his moment had come. He and Kayser burst inside and took the Norwegian guard ‘completely by surprise’. Rønneberg later said that the man was ‘somewhat frightened, but otherwise quiet and obedient’,25 probably because Kayser was holding a gun to his head.
Rønneberg now unpacked the explosives and began attaching them to the metal cylinder shafts. He was struck by the accuracy of the models that had been built back in England. The actual machinery was identical and ‘the charges that had been made at Station Seventeen’ – Brickendonbury Manor – ‘fitted like a glove. It was amazing.’26
He had already placed half the charges when there was the sound of shattering glass as one of the windows was pushed in. He spun round in alarm, only to see Strømsheim and Kasper Idland climbing down into the room. ‘Having failed to find the cable tunnel, they had decided to act on their own initiative.’ Their arrival meant that both groups of saboteurs had made it into the factory unseen, a remarkable achievement.
When all the fuses were attached to the charges, Strømsheim checked them twice while Rønneberg coupled them in preparation for detonation. The original plan had been to set the time-delays to two minutes, ‘but as everything had gone so well up to now, we did not wish to run the risk of anyone coming in and spoiling our work.’27 Rønneberg therefore changed the fuses to thirty seconds.
He was just about to light them when the guard, still held at gunpoint, asked if he could fetch his glasses before they were blown up in the explosion. ‘They are impossible to get in Norway these days,’ he explained.28 The tension was broken for an instant. They allowed the man to get his glasses and then told him to take cover on the floor above.
* * *
Crouched in the snow outside, the covering party was growing increasingly jumpy. Each man was guarding a crucial access point to the factory, with Jens Poulsson and Knut Haukelid hiding behind casks just twenty yards from the German guard hut. ‘The factory buildings had seemed large from a distance. Now that we were among them, they seemed gigantic.’ The tension was high. ‘We waited and waited. We knew that the blowing up party was inside, but we did not know how things were going.’
Jens Poulsson kept his tommy gun trained on the hut. He told Haukelid that ‘if the Germans gave the alarm, or showed any signs of realizing what was going on, he would start pumping lead into the hut.’
Haukelid himself had six hand grenades, which he was intending to throw through the windows and door of the hut. ‘You must remember to call out Heil Hitler when you open the door and throw the bombs,’ whispered Poulsson.
Despite the nerves, Haukelid felt supremely in control. ‘We knew that the Germans’ lives were now completely in our hands,’ he said. ‘The thin wall of the wooden hut was no protection against our automatic weapons.’
Three years earlier, while fighting against the German invasion, he had attacked a very similar wooden house occupied by soldiers. ‘There were dead Germans hanging out of the window and dead Germans lying inside before we had finished shooting the house to pieces.’29
* * *
Inside the basement, Rønneberg lit the fuses and then gave a signal to the other three men. Time to get out. All of them rushed outside, using the steel cellar door. They were no further than twenty yards from the building when they heard the muffled thud of an
explosion. Knut Haukelid was still crouched behind casks when the detonation occurred. He had been expecting a terrific bang and an erupting ball of fire. Instead, it was ‘astonishingly small’ and insignificant. It was deeply disappointing.
‘Was this what we had come over a thousand miles to do?’ he asked himself. ‘Certainly the windows were broken and a glimmer of light spread out into the night, but it was not particularly impressive.’30
But this is exactly what George Rheam had intended. The explosive charges had been specially designed to wreak maximum damage with minimum risk to the saboteurs. The sausage-shaped charge was a work of genius, for it imploded into the machinery, rather than exploding outwards.
To Poulsson’s ears, ‘it sounded like two or three cars crashing in Piccadilly Circus.’31 It was certainly loud enough to attract the attentions of the German guards in the sentry hut. One of them opened the door of the hut, but ‘showed no sign of alarm, flashed a torch in the direction of the Norwegian guardhouse and disappeared back into the hut’.
Haukelid and Poulsson breathed a sigh of relief, but they soon discovered it was premature. A second German, unarmed but holding a torch, came out of the hut and walked over to the casks where they were hiding ‘and threw the light along the ground’.32 Poulsson raised his gun and moved his finger on to the trigger. ‘Shall I fire?’ he whispered.
‘No,’ said Haukelid. ‘He doesn’t know what has happened. Leave him as long as possible.’
As the sentry raised the beam of his torch towards the casks, ‘once more Jens raised his tommy gun.’ But the German suddenly turned and went back into the hut, unaware that he had three tommy guns and four pistols trained on him.
Haukelid knew that Rønneberg and the three other saboteurs must by now be somewhere close to the perimeter fence. His covering party therefore left their positions and made their way over to the fence. As they approached, they saw a figure crouched in the snow. It was Arne Kjelstrup, who called out the agreed password: Piccadilly. Haukelid was anxious not to make any noise and declined to answer. Kjelstrup persisted, whispering Piccadilly for a second time. Haukelid and Poulsson both replied: ‘Shut up, for God’s sake!’ Kjelstrup was indignant. ‘What’s the good of having passwords if we don’t use them?’33 he said as he rushed over to join the men in their flight.
The ten of them regrouped on the railway track, not quite believing that they had got in and out of the plant without being spotted. Still unnoticed by anyone, they began clambering back down the ravine until they reached the bottom. They managed to cross the ice bridge without mishap and were about to start scaling the other side of the gorge when the first air-raid sirens sounded. ‘This was the Germans’ signal for general mobilisation in the Rjukan area,’ said Haukelid. ‘They had at last collected their wits and found out what had happened.’
The men quickened their pace up the snow-clad sides of the ravine, pulling heavily on the branches, until they reached the road. They hid in the snow as several military cars sped past en route to the plant. They then ran across the road, narrowly avoiding being spotted by another car ‘that came so close that we had to throw ourselves into the ditch’. They then plunged back into the relative safety of the forest.
It was clear that the hunt was now on. ‘On the other side of the valley, away on the railway line, we could see the lights of electric torches moving about. The German guards had discovered the line of our retreat.’34
The ten of them collected the skis they had hidden some hours earlier and began climbing rapidly upwards through the forest and on to the mountainside. Within three hours they had reached the bleak expanse of the Hardanger plateau, which afforded some degree of safety. After covering a further seven miles, they took their first break. For Rønneberg, it was a moment to savour.
‘It was sunrise, it was a lovely morning, excellent, and we were sitting there knowing that the job was done, nobody had been hurt on either side.’ They hadn’t even fired their guns. ‘And when we were sitting there, we were eating chocolate and raisins and biscuits and nobody said anything at all, they were occupied by their own thoughts.’35
They did not rest for long. The sky suddenly darkened, the breeze became a squall and snow began tipping down in earnest. Within a few minutes, they were caught in a ferocious snowstorm and it was a punishing march through the blizzard towards their first goal, the refuge hut on the shores of the frozen Lake Langesjaa. The Arctic tempest drained every last drop of stamina, but it was nevertheless extremely welcome. For they all knew that the Germans would be unable to hunt them down for as long as the snowstorm swept across the wild expanse of the Hardanger. And they also knew that their tracks would soon be obliterated.
* * *
Colin Gubbins received news of the successful sabotage within hours. Rønneberg managed to get a wireless message transmitted to London. ‘Attacked 0045 on 28.2.43. High concentration plant totally destroyed. All present. No fighting.’36
Gubbins was ecstatic. ‘Magnificent,’ he said to his secretary, Margaret, as she typed up a memo. ‘Well planned and beautifully executed.’37
News of the success spread rapidly through Baker Street. For months, Gubbins had been facing criticism from Bomber Command, who objected to his constant request for planes. Now, his persistence had been triumphantly vindicated, as Bickham Sweet-Escott was quick to point out. The Norsk Hydro operation ‘was the classic proof of our contention that one aircraft which drops an intelligent and well-trained party can do more damage than a whole fleet of bombers’.
Churchill agreed and had but one question for Gubbins: ‘What rewards are to be given these heroic men?’38
They were all awarded either the Distinguished Service Order, the Military Cross or the Military Medal. Gubbins made sure that the planners were also rewarded, for he knew that without George Rheam’s exemplary training ‘it is doubtful whether the operation could have taken place at all’.39
Over the days that followed, Gubbins received further news about the destruction of Norsk Hydro, including a report from a Norwegian agent working inside the plant. He had arrived less than ten minutes after the explosion and had been witness to the devastating extent of the destruction.
‘It was at once evident that the object of the action had been achieved. Each one of the eighteen cells had been blown to pieces and their contents of lye and heavy water had long since run off into the drains.’40
It was not just the high-concentration cells that had been knocked out, but also the water tubes feeding the plant. ‘The whole room was full of spray,’ reported Alf Larsen, the chief engineer, ‘which was obviously caused by shrapnel from the explosions having penetrated the water tubes to the plant.’41
On 10 March, ten days after the attack, Gubbins received the sweetest news of all. He received a message from another agent at the plant, describing the visit to Norsk Hydro of General von Falkenhorst, the commander of the occupying German forces in Norway.
‘At the sight of the ruined plant, he smiled and said: “This is the most splendid coup I have seen in this war.”’42 A consummate professional, he admired the saboteurs’ work and conceded that they had pulled off a dazzling act of destruction. Once he had inspected the damage, he ordered the release of all the Norwegian civilians who had been rounded up. He then issued a second order: that all the German sentries on duty that night were to be arrested. Their eventual fate remains unknown, although the senior guard was later said to have been sent to the Eastern Front as punishment.
The saboteurs themselves were to have many extreme adventures as they made their getaway. Rønneberg and most of the men undertook a 400-kilometre endurance trek across the Hardanger plateau towards the border of neutral Sweden. It was ‘an awful labour’,43 conceded Rønneberg, and would have been even more stressful if they had known that 2,000 German soldiers were on their trail. All his party eventually made it back to England, where they were handed their various military decorations.
Claus Helberg, one of the Grous
e team, stayed behind to help organize resistance to the Nazis. It almost cost him his life. He was surprised by German soldiers while hiding out on the Hardanger and ended up in a marathon ski-chase across the frozen wasteland. He got away after a close-range gunfight, although he broke his arm in the process. He was eventually arrested by the Germans and transported to Oslo, but he jumped off the bus and, after many more scrapes, made it to Sweden.
Knut Haukelid was to provide the Norsk Hydro mission with its triumphant postscript. He had opted to remain in Norway in order to train new recruits to the resistance, but soon found himself with a more urgent role to play. The attack on Norsk Hydro had crippled the heavy water machinery, but the Nazis still had a stockpile of 3,600 gallons. Hitler now ordered that this be transported to Germany, in order that it could be kept secure in specially constructed bunkers in Bavaria until required by the atomic scientists.
Einar Skinnarland was still working at Norsk Hydro and managed to lay his hands on vital intelligence: the heavy water was to be transported to Mel, a little ferry port on nearby Lake Tinnsjo, using the single-track railway line that linked the plant with the port. It was then to be shipped to Hamburg in northern Germany.
Haukelid made it his mission to destroy this remaining heavy water. This was fraught with danger, for the entire Rjukan valley had been placed under SS guard and two aircraft were engaged in round-the-clock patrols of the surrounding mountains. The railway line that linked Norsk Hydro to Lake Tinnsjo was also under heavy guard, since this was the only means by which the Germans could transport their stock to the waiting vessel. The Hydro was a train-ferry: the train itself was to be loaded on to the vessel and would continue its journey by rail when it was offloaded at Hamburg. Skinnarland weighed up the options and told Haukelid he believed ‘the safest solution to be sinking of the ferry’ while it was crossing the lake.44