All right! Some history here on E2! This node was inspired by a program on NRK.
During the occupation of Norway, the Germans seized a power station and hydrogen refinement plant near Rjukan in central east Norway. The plant also produced deuterium for peaceful purposes. The Germans had possibly other plans with the deuterium, such as building atomic bombs. Today there is some argument on just how important the Rjukan production of deuterium was for the Nazi atomic bomb programme, but at the time during WWII the actions were considered justified and extremely important.
The preliminary actions
The first operation was called "The Constant Einar". Mr. Einar Skinneland parachuted down to Hardangervidda from an allied airplane on the 28th of march 1942. He had grown up nearby the factory and many of his friends and family worked in the plant. He was quickly able to determine that the production of deuterium was rising. He reported back to England, and was told to wait for the second wave of saboteurs, the "Grouse" operation.
Operation "Grouse", "Swallow" and "Freshman"
The 18th of October, the "Grouse" group made up of second lieutenant Jens Poulsson (leader), sargent Arne Kjeldstrup (XO), second lieutenant Knut Kjeldstrup (radio operator), sargent Knut Helleberg and Mr. Claus Helberg parachuted down to Hardangervidda. They were supposed to meet the "Freshman" operation, a group of 34 British elite soldiers was gliding in over Norway in Halifax planes. "Grouse" made contact with one of the planes, but the leading airplane and the gliders crashed in west Norway. The Germans arrested the survivors of the crash and they were tortured to death later by strangeling and poisoning. In total, 41 British men died.
"Grouse" now changed name to "Swallow" and were faced with the problem of surviving the harsh tundra-like winter. The only contact with the outside world was via radio, the SOE (SpecOps in London) who instructed them to stand by. The "Swallow" team now had to live on moss and reindeer. Not just the meat, but brain, liver, tongue and stomach.
In January 1943, the message arrived. The group got some new members, and a new team leader. The leader was now Mr. Joakim Rønneberg. The XO was second lieutenant Knut Haukelid. The rest of the team was Sargent Kayser, Sargent Strømsheim, second lieutenant Idland, Sargent Storhaug and the previous team.
They had been trained to reach the plant and deploy the explosives and withstand torture. Everyone in the team knew the terrain inside and out from surveillance photos and mock-ups. The 27th of February after some delay, the skied down to the valley. The crossed it at a unguarded point, there was a bridge, but the team would have to kill the German guards if they wanted to cross the bridge. If they did that, the people of Rjukan would suffer, so they searched for another crossing point.
They followed some abandoned railroad tracks until they were 500 meters from a gate. The team split up and the "Swallow" team stood guard, while Mr Rønneberg went on to deploy the explosives. They encountered only a Norwegian man, and he remained passive during the whole operation. The team left a British machine gun behind, so the Germans assumed it was allied forces who carried out the operation. Then they would not punish the Rjukan population for hiding the Home front forces.
The Germans thought initially that the explosion was a landmine that went off in the extreme cold, but soon the alarm sounded. By that time, the team had vanished into the mountains. The team split up. The explosives team went west, then north then east to the Swedish border. "Swallow" went to Hardangervidda to lie low and wait for other assignments. Thousands of German troops and a lot of airplanes searched for the sabotage team. Claus Heiberg broke his arm and ran into the German soldiers. He managed to fool the soldiers and got a German doctor to fix his broken arm. Later, he joined the others in London.
The bombing of Rjukan
Only three months later, the production was restarted. The allies then decided to bomb the plant. Using 161 "Flying Fortress" airplanes with 711 bombs weighing 500 kgs, and 200 bombs weighing 250 kgs, none of them hit the target. One bomb missed slightly and hit the power station. Thus the plant was rendered useless. The "Gunnerside" operation stopped the flow of deuterium for a while, and the loss of 400 kgs of deuterium stopped the German atom bombs plans temporarily.
The sinking of the railroad ferry
After this, the Germans decided to move to deuterium equipment to Germany. They would load the equipment on to a train for the transport. Two battalions of soldiers guarded the transport, but the allied forces found out that the soldiers would not follow the train onto the ferry crossing one of the lakes. Three members from the "Swallow" team got on to the ferry by saying they were resistance fighters running from the Germans. They could not state their real purpose of the mission, but everyone wanted to help the resistance. They planted a 9 kgs bomb on the ferry, set to explode on a timer at the deepest part of the lake.
This was successful, and the ferry blew up. Sadly, 14 civilians were killed on the ferry. For the team, this was the hardest part of all the operations, since they knew that friends and family could be on the ferry but couldn't say anything due to the grave importance of the mission.
After this, the Nazi atomic programme was crippled for the rest of the war.