by Ross Kemp
They set out again when the storm appeared to be subsiding the following morning, but it was only a lull and Rønneberg quickly ordered them to turn back. The combination of powerful winds and deep drifts of snow made progress all but impossible. The storm howled for a week, during which the entire raiding party developed heavy fevers. Without any W/T equipment, they were unable to contact SOE. Sheltering from the same storm a few miles away, SWALLOW were gravely concerned for their comrades.
On 22 February, the storm lifted almost as quickly as it had descended. Clear skies and a dazzling sun revealed the Hardanger in all its snow-blasted glory. Leaving behind more nonessentials to be collected at a later time, they set out on what all knew was going to be a grinding march through tough terrain and extremely deep snow. Taking British uniforms and weapons for SWALLOW plus five days’ worth of rations and the demolition equipment, each rucksack weighed twenty-five kilograms. They also had two small toboggans weighing roughly forty kilograms.
As they left the hut, a man claiming to be a hunter appeared. The Commandos were under strict orders to kill anyone who might compromise the successful execution of the operation, but the Norwegians were reluctant to dispatch one of their compatriots unless they knew for sure he was a Quisling. The man gave his name as Kristian Kristiansen; uncertain whether he was a Quisling or ‘Jøssing’ (a good Norwegian), Rønneberg put him to work pulling one of the toboggans. He turned out to be an excellent guide and first-rate skier, an indispensable extra pair of hands during a gruelling march.
Later that morning, drooping with fatigue, they caught sight of two men skiing hard across the horizon. While the rest of them took cover, clutching their Tommy guns, Haukelid waited to greet them. The two men looked completely wild. Their clothes were caked in filth and reindeer blood, their beards were thick and unkempt, their faces drawn and unhealthy. It took Haukelid some time to register that it was Helberg and Kjelstrup! It was a joyful moment for the two parties. Finally, they had made contact – and all ten men were still alive. After four months of effort and delays, Operation GUNNERSIDE was on. ‘We greeted each other with as much emotion as Norwegian men can,’ Helberg recorded drily.
After the back-slapping and hand-shaking, they had to decide what to do with the reindeer hunter. Did they kill him or set him free and risk him jeopardising the operation? Rønneberg’s instinct told him that Kristiansen could be trusted but, as a precaution, he made him sign a statement that he owned and used a rifle, warning him that it would be handed to the Gestapo if he failed to hold his tongue. (The Germans threatened the death sentence for anyone found carrying a weapon.) They also gave him several days’ worth of rations in the hope he would stay up on the Hardanger until the raid was over.
By the time they reached SWALLOW’s hut, GUNNERSIDE had covered forty-five kilometres of heavy terrain in sixteen hours. It was an impressive achievement. They were shattered, but their spirits were soon lifted by a feast of reindeer dishes and the chance to exchange news with their comrades. There were just forty-eight hours to go before the ten Commandos launched one of the boldest and most important raids in the history of warfare.
On 25 February, leaving Haugland the W/T operator behind, the raiders set off in driving snow for the hut from which they would launch the raid. Fjosbudalen, as it was known, was the perfect launching point for the attack: close to the plant but difficult to access. Situated 800 metres above the valley, looking to their left was the town of Rjukan, strung out for 2 miles along the main road and the banks of the River Måna. About two miles to the right, hidden from view by a kink in the valley, lay the giant Vemork plant. The slope leading down to the Vestfjorddalen valley was extremely steep. Descending it would be hard enough; coming back up would be punishing.
Following Operation FRESHMAN, a raft of measures had been taken to beef up security at Vemork and in the surrounding area. A detachment of 30 first-rate German soldiers had arrived to take over the defence of the plant itself, the garrison at Rjukan increased to 200, and at the Møsvatn Dam, troop numbers were quadrupled to 40. Batteries of anti-aircraft guns and searchlights had been installed.
From intelligence from inside the plant and Helberg’s recce trips, they knew that every night two guards patrolled the suspension bridge across the gorge connecting the plant to the main road; the guards changed over on the stroke of midnight and floodlights would illuminate the entire plant and immediate area in the event of an emergency.
How to access the plant was an issue that provoked a great deal of debate among the raiders. If they tried to fight their way in over the bridge, the German reinforcements from Rjukan and Møsvatn would quickly be on the scene. If they were to become involved in a prolonged gun battle against a vastly superior, more heavily armed force, there was a risk that they might not be able to lay the explosives. It was unlikely any of them would escape either. If they survived the fight and were captured, they would be summarily executed as Commandos. Still, a minority of the party, including Rønneberg, argued that this approach gave them the best chance of success.
There was one possible alternative. At first light on the day of the attack, Helberg made a final recce to see if it was possible to climb the gorge. The Germans thought it impossible and never patrolled that end of the plant that Helberg had pinpointed. If it was possible to scale the virtually sheer icy wall of rock, it would give the saboteurs a number of advantages. There was a much greater chance they could enter the plant unnoticed, avoid any contact with the enemy and prevent the alarm being raised until the charges were detonated. It also meant they could leave the equipment and provisions for their escape at the hut, allowing them to carry only their weapons and demolition kit, and therefore escape more quickly.
Either way, with giant searchlights lighting up the plant and hundreds of troops scouring the area, the chances of all nine men escaping were very slim. This was partly because the Germans would work out that there was only one exit route open to the saboteurs – up the steep slope opposite the plant. Behind the plant was a towering cliff almost one kilometre high, and taking the only road through the valley was not an option. To get out of Vemork, they must either cross the bridge or climb back down the gorge, negotiate the river, cross the main road and then make the energy-sapping climb up the same, near-sheer valley wall they had descended earlier. The party was as good as resigned to not making it to safety. ‘Our chances of being trapped in the valley were very great indeed,’ recorded Rønneberg. ‘We knew that we might not come through it.’
When Helberg returned from his mission, he revealed that though the ice on the river was starting to thaw, there was a narrow point where they might be able to cross. On the other side, he pointed out, there was a band of small trees linking the bottom of the gorge to the plant. If trees could climb the gorge, so could they, Helberg argued. A vote was taken and the climbing option carried the day. The group were split into two: a covering party led by Haukelid and consisting of the SWALLOW members Helberg, Kjelstrup and Poulsson, and the demolition party led by Rønneberg and including Strømsheim, Kayser, Idland and Storhaug. Their operational orders covered every possible eventuality. ‘If fighting starts before the High Concentration (heavy water) plant is reached the covering men shall, if necessary, take over the placing of the explosives. If anything should happen to the leader, or anything to upset the plans, all are to act on their own initiative in order to carry out the operation. If any man is about to be taken to prisoner, he undertakes to end his own life.’ The raiders weren’t aware of the stakes that rested on the raid. Were they to fail, the Allies had just two courses of action left open to them: a saturation bombing raid that would most likely claim the lives of scores of their compatriots, or blowing the dam and flooding the valley, killing hundreds of innocent Norwegians, including dozens of their own family members.
The conditions were perfect when the nine saboteurs, dressed as British soldiers and carrying British papers, left the hut at 2000 hours and began the long descent. It was c
loudy and windy. What they didn’t want was a still night with a bright moon. They were travelling light, which was just as well, given the intense physical exertions ahead of them. Between them they carried five Tommy guns, three Colt .32 pistols, seven Colt .45s, ten Mills bomb hand grenades, two sets of explosive charges and fuses and a small quantity of food. The wet snow was three feet deep in places and made it impossible to proceed on skis. Advancing on foot, with their skis and poles slung over their shoulders, the men regularly sank up to their chests in the drifts. On reaching the powerline, they buried their skis, dashed across the main road and disappeared into the darkness at the bottom of the gorge as fast as the snow and rock allowed them.
The river ice was thawing rapidly in the mild air and the one stretch that Helberg had singled out as passable now had three inches of water running over it. The ice cracked as, one by one, they shuffled across to the foot of the cliff. Looking up at the virtually vertical rockface, there was some doubt cast on Helberg’s optimism, but one after the other, they yanked themselves upwards, grasping roots and branches and icy outcrops for support. One slip or loose stone and they would tumble to their death. All nine men were first-rate outdoorsmen and there were no mishaps, although by the time they scrambled onto the railway tracks at the top they were sodden with sweat from the strain.
A few hundred metres along the tracks, they could just make out the dark outline of the Vemork plant’s two enormous main buildings. The faint rumbling of the machinery inside was carried along on the wind. Like clockwork, on the stroke of midnight, the two sentries pacing up and down the suspension bridge were relieved by a new pair. In planning the fine details of the advance, the raiders had decided to wait for thirty minutes, figuring the vigilance of the guards would start to fade. The nine men sat patiently in the shadows of the towering cliff at the eastern end of the plant before making their move. They crept towards the plant’s fenced perimeter and crouched. Haukelid sprinted up to a set of high wire-mesh gates and snapped the thick chainlock with a pair of shears. The covering party were the first into the compound, bursting through the gate to take up their positions. The demolition team followed and quickly broke open a second gate leading to the basement where the heavy water was stored. So far so good. The only setback was that the moon had appeared and some of the lights inside the factory had been left on.
Leaving one man on guard, the other four members of the demolition party split into pairs. A cellar door and a second entrance that were meant to have been left unlocked by a contact inside Vemork hadn’t been. (The contact, it transpired, had been taken ill and failed to come to work.) Thanks to Tronstad’s meticulous planning of the operation, one option remained: Rønneberg and Kayser climbed a ladder and crawled into a narrow cable shaft. Pushing their demolition equipment ahead of them, it took several minutes to wriggle their way to the far end of the shaft. They slid down a ladder and burst into the room housing the cells of high-concentration heavy water, overwhelming the terrified Norwegian guard. After locking the doors, Kayser held the guard while Rønneberg set about laying the sausage-shaped explosive charges on each of the eighteen cylinders. Both men were at pains to show the guard the insignia and stripes on their British uniforms. Fearing reprisals against the local population, they left further evidence, in the form of their English-made tools, that this was a British operation, and not one carried out by the Resistance.
The original plan was to lay two-minute fuses but, fearing that would give the plant engineers time to dismantle them, the raiders opted for shorter versions – a courageous decision that increased the risk of the party getting caught before they had cleared the compound. Rønneberg was poised to light the fuses when a Norwegian civilian walked into the room. Visibly taken aback by the sight of the Commandos, at the point of Kayser’s gun he was made to join the guard with their hands above their heads. Outside, the covering party were getting worried. It had been almost half an hour since they had seen the demolition team.
When Rønneberg lit the last of the fuses, Kayser ordered the two captives to sprint upstairs as they all made for the cellar door. The door had barely shut when they heard the first of eighteen muffled explosions from behind the thick stone walls. Within seconds, one and a half tons of concentrated heavy water – the essence of Germany’s atomic bomb programme – was gushing across the floor into the drains. The strong wind had helped soften the thump of the charges. Loud noises were not uncommon in the valley at this time of year in any case. Ice cracked and large quantities of snow often fell down steep slopes, especially during the thaw. But expecting some reaction from the garrison all the same, the nine raiders took cover and waited. Sure enough, the door of the barracks house swung open and the silhouette of a soldier appeared in the light from within. Swinging a torch from side to side, he moved slowly towards some tin drums. Haukelid was crouched behind them. There were three Tommy guns and five pistols pointing at the soldier’s back as he pulled up just short of the drums, a few feet from Haukelid. The beam of his hand torch brushed the Norwegian’s head; his comrades flicked off their safety catches. The guard stood for a few moments, then turned slowly and made his way back to the barracks. As the door shut, Rønneberg gave the hand signal for the team to pull out.
The next few minutes were to be critical. It was imperative they put as much distance between them and the plant as possible before the alarm was raised. Clambering to the foot of the gorge as quickly as they could without risking a fall, they found the Måna was flowing much faster than it had been just a couple of hours earlier and the ice was that much more unstable as they dashed across. Hauling themselves up the icy bank towards the main road, the party froze on the spot when the eerie wail of the plant’s alarms broke the night’s silence. Grabbing their skis and poles, the nine men melted into the darkness of the woods at the foot of the slope before them.
Walking switchback rather than straight up the steep slope, several kilometres and hours of draining marching lay ahead of them, but with every German soldier in the region pouring into Vemork, they had all the motivation they needed to press on without delay. Their route followed the open area beneath the cable car used by sun-starved locals in the winter to get onto the plateau above the town. It was the only plausible route, but there was a danger that the plant’s searchlights might reveal them, and the Commandos were surprised that the lights had not been turned on immediately. An even greater worry was that the Germans would turn on the cable car and dispatch troops to the top, but that fear was never realised either. At 0500, after three hours’ backbreaking marching, they dragged their weary bodies the final few steps onto the plateau above.
‘It was a beautiful morning as we watched the sun rise,’ recalled Rønneberg. ‘The sky was lit up in a lovely red colour and we sat there in silence eating chocolate and raisins . . . We were all very, very happy. Although we said nothing as we sat there I think we all felt great pride. But we also spared a thought for our British friends who died in the gliders disaster . . . From now on our struggle was with Norwegian nature.’
The next stage of the escape was to head for a hut owned by a Rjukan shopkeeper at a remote location called Langsja where they would rest up before heading back to the Svensbu hut. The wind howled over the Hardanger as they set off and, having not slept for the better part of two days, it was a major effort to drag their aching limbs against the force of ever-strengthening gusts. They made it to the hut with no more than an hour to spare before another violent blizzard burst over the plateau. Although they were unable to press on, the fresh snow did at least cover their tracks from the cable car and force the Germans to spread their troops over Telemark’s vast wilderness.
In the valley below, the Germans were struggling to understand how the ‘impregnable fortress’ of Vemork had been breached and its precious contents destroyed without so much as a shot being fired. General Wilhelm Rediess, the head of the Gestapo in Norway, urged reprisals against the local population after inspecting the damage, despite c
onceding that the raid had, in all probability, been a British operation. General von Falkenhorst, commander of German forces in Norway, overruled him on the grounds that it had been a military act. Von Falkenhorst, an old-fashioned Wehrmacht officer with a distaste for the practices of the Gestapo, was in open admiration of the raiders, describing the attack as ‘the most splendid coup I have seen in this war’. He was later dismissed from his post for refusing to implement the policies of the Nazi Reichskommissar Josef Terboven who, amongst other brutal acts, had ordered savage reprisals against the villagers of Televåg for sheltering two Norwegian officers.
After a good night’s rest and revitalised by some hot food and drink, the GUNNERSIDE party set out the following morning into the snowstorm for Svensbu. It was tough going and it wasn’t until 2130 that they finally arrived. At the start of what would turn out to be a heart-stopping personal adventure, Helberg peeled off to return to the Fjosbudalen hut to collect the civilian clothes and faked Norwegian identity documents he would need over the coming months. The plan was to meet the rest of the team at Svensbu, but there was no sign of him over the next two days and his comrades feared for his safety.
At this point, the eleven men of the operation (including Skinnarland, the local SOE agent) were to split into three separate groups. Five of the GUNNERSIDE party – Rønneberg, Idland, Kayser, Strømsheim and Storhaug – were to make a 400-kilometre journey to the Swedish border. Haukelid and Kjelstrup were to stay in the Hardanger, wait for the German searches to pass and then team up with the Resistance. Poulsson and Helberg were to head to Oslo before deciding on further action. Haugland and Skinnarland, the W/T operators, were to lie low until it was safe and await further orders from London. Convinced that Helberg had either been captured or killed, Rønneberg and his team strapped on their skis and pushed off for the long cross-country trek towards neutral Sweden.
