Sabotørstien, Vemork & Mæl stasjon
Thinking about the history of Norway, very often we see bunch of tall, beared warriors with helmets on their heads and swords or axes in hands, jumping out from wooden ships and starting one of many plundering attacks. But history of this country is not only medieval vikings.
The most famous sabotage action of the Second World War took place in Norway, at the Norsk Hydro factory, near Rjukan, where heavy water was produced. In the winter of 1943, Norwegian commando slipped into the factory, guarded by German soldiers and destroyed the installation that could lead the Nazis to create an atomic bomb. And the one in Hitler’s hands was able to change the history.
Today, part of the route that these commandos descend from Hardangervidda, can be done on your own feet. The path is called Sabotørstien (Saboteur trail) and it starts a few kilometers west of Vemork factory. The most reasonable way to get there is to park the car on parking lot at Vemork factory and catch the bus which once a day goes in that direction and stops at Rjukan Fjellsue, where the trail starts. Sabotørstien has 8,5 km and ends close to the parking lot at the factory, so it is not necessary to make this route again in opposite direction.
The trail is quite easy and mostly goes downhill (except the first section). There are information boards along the route, telling the story about the sabotage action. At the end , a short distance of the route leads along a road 37 and that can be not comfortable because of the traffic.
From the parking lot under the Vemork factory, you can go along the narrow suspension bridge to the other side of the gorge and visit the museum at Norsk Hydro factory. Ticket cost in 95 NOK (for adult) and you can learn more not only about production of heavy water and attempts to destroy it by Allies during the war, but also get into history of establishment of the Norsk Hydro and Rjukan itself.
When you visit Rjukan, you can see the monument of Sam Eyde at the market square in front of the town hall. He saw the potential in Norwegian waterfalls and at the beginning of 20th century he acquired control over Rjukan Falls in Telemark. Soon, he used the water energy in industry. In 1911 he founded Norsk Hydro and completed hydro electric plant in Vemork, where production of chemical fertilizers were produced (hydrogen, nitrae, ammonia and nitric acid). Nearby Rjukan from small village soon turned into a worker’s town.
In 1932, Professor Harold Urey discovered that ordinary water contains 0,015% of so-called heavy water (D2O), in which part of the hydrogen atoms is the 2H isotope: deuterium. Heavy water behaves differently than ordinary water. It is 10% heavier, has a boiling point 1,4 degrees higher and freezes at +4 degrees Celsius. Plants also germinate and grow more slowly when watered with heavy water.
Two things were necessary for heavy water production: large amounts of water and energy. The Vemork factory had both of these components in excess and in 1934, as part of experiment (as no one knew how to use D2O at the time), they began to produce heavy water by slow electrolisis method.
In these days they believed that this newly discovered substance could be used in medicine as cure for cancer, but soon completely different use of heavy water was discovered.
At the end of 19th and the first half of 20th century, many scientists were fascinated by the discovery of the smallest components of matter: the atoms. Physicists have learned to study the internal structure of atoms, proving that they are divisible. Further discoveries in this area began to appear like mushrooms after rain. In 1938, the first nuclear atom was split. It has been discovered that a single neutron can split a uranium core by releasing two consecutive neutrons that have split another two cores. From these two, four new neutrons were formed, and thus the number of neutrons increased exponentially, splitting more and more uranium atoms and producing more and more energy. The possibilities of using the energy of the atom were discussed more and more often. From here, there was a short way to the idea of building an atomic bomb.
It turned out that heavy water can be used as a moderator in atomic reactors to slow down neutrons, which was the key to controlling the chain reaction of atom breakdown. After capturing Norway in 1940, the Germans immediately took under their wing the Vemork factory, which was the only one in the world to produce heavy water and demanded to increase its production by 100%
The Allies, aware of the importance of heavy water and the fact that the German nuclear research program was ongoing, decided to stop production at Vemork. One of the commanders of the operation was Leif Tronstad, professor of chemistry at the Polytechnic in Tromheim, co-founder of the heavy water production plant in Vemork and a member of the resistance during the Norwegian campaign. After the capitulation of Norway, he managed to get to Great Britain, contacted the local command and joined the SOE (Special Operations Executive). It was a British secret government agency, whose task was, among others conducting sabotage and supporting the resistance movement in occupied countries.
Operation Grouse (Grouse) plan was developed, and four Norwegian commandos trained in England were moved to the Hardangervidda Plateau (October 19, 1942). They had to prepare the area for a larger group of British specialists. The Allies had their man in Vemork , Einar Skinnerland, who sent by radio information about enemy forces, the layout of rooms in the factory and the current level of heavy water production.
The operation of sending 34 soldiers to occupied Norway was unfortunately called Operation Freshman. It was decided to do it with the help of two gliders towed by Halifax bombers. It was the first operation of this type of allied forces, and despite the solid training of crews, it ended up disaster (November 19, 1942). Poor visibility prevented Halifax pilots from tracking the drop site. The deteriorating weather conditions and decreasing fuel levels in the tanks led to a decision to return to Scotland. The planes fell into a strong wind area and violent turbulence tore the tow ropes in both gliders. Machines crashed in the mountains. Those who managed to survive the catastrophe fell into the hands of the Gestapo and soon shared the fate of their dead companions. Only one of the Halifaxes managed to return home. The second crashed into the mountainside around Egersund, Norway. None of the crew survived.
After this catastrophe, the British were aware that Germany had further strengthened the factory’s protection and the attack with a larger group of commandos would be doomed to failure. It was decided to bet on a smaller group consisting only of Norwegians. On the night of February 16, 1943, as part of Operation Gunnerside (this was the name of the hunting lodge belonging to the head of the SOE), six commandos were dropped on parachutes in the Norwegian mountains. After a few days, they were able to connect with the Grouse group (in the meantime renamed to Swallow), hiding in the Norwegian wilderness and feeding on mosses and lichens.
The factory was attacked on the night of February 27, 1943. Because the only road to the Norsk Hydro plant, running across the 75-meter bridge over the gorge, was guarded by the Germans, the Norwegians under the command of just 23-year-old Joachim Roenneberg (they were dressed in British uniforms, so in case the mission failed, there would be no repression on locals inhabitants), they went down the steep slope of the gorge to the frozen Måna River and climbed the opposite slope. They reached a completely unsecured railway line at the back gate of the plant. The unit split up. Part of the group remained at the entrance, ready at any time to open fire to German soldiers in the case of an alarm. Others slipped inside and reached the heavy water distillation room in cellar. There they put on explosives. The explosion was suppressed by a thick layer of concrete. There was no sound of explosion outside. The siren did not started. The commandos joined their hiding colleagues and went back to the gorge. They reached the plateau from where six of them moved further for a long, 400-kilometer skiing route to Sweden. The other four joined the local partisans. During the whole operation, not a single shot was fired and there were no casualties.
Despite the complete destruction of the distillation installations and heavy water reserves, the Germans quickly resumed production. The Allies learned about this by Skinnerland who was working at the factory. This time there was no way that an armed group could get to the factory because of the reinforced guards. A bombing was ordered.
On the morning of November 16, 1943, 199 of bombers B-17 Flying Fortresses flew over Vemork and dropped more than 1,000 bombs, the vast majority of which did not got in the target. The destruction included a suspension bridge leading to the factory, two upper floors in the corner of the hydrogen plant and a generator room. Several homes in Vemork and Vær have been demolished. During the raid, 21 people, residents of Rjukan were killed.
And although the heavy water production installation did not damaged as a result of the raid, the Germans, concerned about the American bombers appearing more and more often in the sky, decided to send all production including D2O supplies to the Reich. A railway line was connected to the Norsk Hydro plant, which ran through Rjukan to the quay of Lake Tinnsjå (the third deepest lake in Norway). There, in the small town of Mæl, the wagons were taken over by a ferry heading south, where the railway continued.
The Allies made one last desperate attempt to destroy the heavy water supply. This time, explosives were placed on the bottom of the ferry SF Hydro, which was to carry a dangerous cargo. Casualties were expected, as local people usually traveled by ferry. No one could be warned of danger to not to make the Germans suspicious. At 10.45 in the morning, on Sunday, February 20, 1944, SF Hydro blew out and sink together with heavy water cargo and 26 people on board (27 survived). The shipwreck rested at a depth of 460 meters. The sinking of the ferry with the entire D2O supply (16 tons) was the final stage of the „battle for heavy water”. The German research program irretrievably lost the substance necessary to control the chain reaction in the reactor (the Americans successfully used graphite rods in their reactors instead of heavy water) and in the face of the impending defeat of the Third Reich, it was never resumed.
Currently, the Mæl train and ferry station on the quay is a museum and tourist facility. The station building has a small cafe and you can also see how the railway in Rjukan once operated. For a fee, it is possible to visit the DF Amonia and MF Storegut, which were out of service, but in past they also ran to Tinnsjå. Ferry traffic on the lake ended in 1986-1987 and both units standing at the waterfront, restored are part of the museum.
The story of daring action in Rjukan was presented in the Hollywood movie ‘The Heroes of Telemark’ from 1965. The whole story was more realistically presented by the Norwegians in the 2015 miniseries ‘Kampen om tungvannet’ (Battle for Heavy Water) from 2015. However, the most on this subject can be found in the book ‘Winter Fortress’ by Neal Bascomb, which I would recommend.
Sabotørstien (Saboteur trail)
This post was originally published 2019-08-18 on https://kraina-trolli.pl.
