Norway became the first country with a commercial plant for producing heavy water when Norsk Hydro went into operation in 1934. In 1940, Norway was invaded by Nazi Germany, and control of the plant fell into German hands. It now controlled most of the world’s heavy water production, which was an essential process in the race for developing nuclear weapons. With the start of World War II, German control of this process was very concerning to the British, and later to the American Allies, since this meant that Germany might win the race to weaponizing nuclear power before the Allies. They decided to remove the heavy water supply and destroy the plant by aiming raids targeting the power station supplying power to the commercial plant.1 However, prior to the German invasion of Norway, French military intelligence decided it would be necessary to remove a fraction of the heavy water and transport it to France during the war.2
Germany started to procure heavy water in late January 1940. In response, British Special Operations Executive (SOE) started planning several operations aimed at limiting or completely stopping German production of heavy water. The first operation, code-named Operation Grouse, launched on October 18, 1942.3 During this operation, four Norwegians parachuted onto a plateau above and near the Hydro plant. Their mission required them to gather as much information as they could regarding the plant and the heavy water operations. All the information that the team gathered was sent to SOE to plan for the next phase, code-named Operation Freshman. In this operation, a group of combat engineers were sent by gliders to join the Grouse team. Together, both teams were to set and detonate demolitions in key parts of the Hydro plant, and escape to Sweden.4
On November 19, 1942, Team Freshman left England to carry out their mission. However, the night of the operation, the weather conditions in the designated drop zones were extremely harsh, causing the first glider to crash into a mountain killing the entire crew. The second glider also crash landed, killing most of the people in the glider.5 Even after the gliders crashed, some of the crew members survived, but eventually they were captured by German soldiers, tortured, and eventually killed.
Due to the failed mission, Germans became aware of the Allied interest in the heavy water plant. This caused the Germans to increase the defenses in the perimeter, including establishing a mine field, floodlights, and deploying more guards on the site. However, this did not impede SOE. Planners continued to search for ways to send in commandos to link up with Team Grouse, which by now was renamed Team Swallow. All four members of Team Swallow lay low for several months in the mountains on top of the Hydro plant keeping contact with SOE by radio.6
After a while, SOE was able to finalize the plans for the next phase, Operation Gunnerside. In this operation, six more commandos parachuted in Norway on February 16-17, 1943. After several days, Team Swallow joined Team Gunnerside, and they started planning their assault, deciding to attack on February 27, 1943.
Several months had gone by since Operation Freshman, and the German defenses were still up, but security had become somewhat slacker. Only the bridge across the Maan River was still fully guarded, limiting their ways to get through the guards. The commandos realized that the only option they had to get inside was to climb down the 656 ft. ravine, cross the freezing river, and climb back up the other side of the ravine.7 Using information obtained, the teams then followed a rail line into the plant area without being detected by guards.
Once inside, they met with a Norwegian caretaker who assisted them in getting where they needed to be.8 The teams moved quickly into where the heavy water chambers were and placed the explosives, attaching a long time-delay fuse to the explosives. The saboteurs also made sure to leave a British sub-machine gun hoping to lead the Germans into thinking the sabotage was the British’s doing. They then lit the fuse the same way they came into the plant, and once they were clear of the plant, the explosives detonated destroying the heavy water chambers as well as 120 gallons of heavy water stored in the Hydro plant.
After the explosion, the Germans launched an all-out search for the commandos, but were unable to find them. All the commandos were able to escape the site, some into Sweden, others to Oslo, Norway, and some staying in the general area. After the successful execution, Germany started rebuilding the destroyed parts of the Hydro plant and produced more heavy water in the following months. SOE considered launching another operation but saw it as too difficult. So in November 1943 the US Army Air Forces were given orders to conduct bombing raids on the plant. Finally, after the bombing raids, the plant received extensive damage causing the Germans to halt production.
- Funk & Wagnalls New World Encyclopedia, 2016, s.v. “World War II.” ↵
- Funk & Wagnalls New World Encyclopedia, 2016, s.v. “World War II.” ↵
- Neal Bascomb, The Winter Fortress (Boston: Houghton Mifflin Harcourt, 2016), 30-35. ↵
- Neal Bascomb, The Winter Fortress (Boston: Houghton Mifflin Harcourt, 2016), 45. ↵
- Neal Bascomb, The Winter Fortress (Boston: Houghton Mifflin Harcourt, 2016), 109-111. ↵
- Janet Voke, “Hero of Telemark: Janet Voke meets Joachim Ronneberg, survivor of one of the most daring actions of the second World War: the sabotage of a German heavy water plant deep in occupied Norway,” History Today 60, no.10 (2010): 57-58. ↵
- Neal Bascomb, The Winter Fortress (Boston: Houghton Mifflin Harcourt, 2016), 189-192. ↵
- Janet Voke, “Hero of Telemark: Janet Voke meets Joachim Ronneberg, survivor of one of the most daring actions of the second World War: the sabotage of a German heavy water plant deep in occupied Norway,” History Today 60, no.10 (2010): 50-59. ↵
41 comments
Teresa Valdez
The narrative of this article was amazing. I love reading about this subject. Operations like this one are not meant to make the headlines, but they are still crucial to ending wars and saving lives. It is awesome that the article went about commemorating it. No one would think that the prevention of a German atomic bomb during the war was thanks to the Norwegians.
Ryann Cervantes
Wow all this time and I never knew the Germans even had a small amount of progress in creating their own nuclear arsenal. Up till now I thought it was just the Americans. I really like the tone of the story and how dedicated the soldiers were to make sure Germany did not obtain nuclear weapons. And how after the first successful attack we decided to instead just destroy most of the plant since the Germans would still be determined to make it work.
Justin Garcia
This was a very well thought out article. The focus on the advantage Germany had over the allies for a time was very interesting. In history we tend to overlook times when our enemies held massive advantages. So to find out that Germany could have made nuclear weapons before us was probably frighting for many U.S. Officials. Overall this was a very well written article.
Sam Vandenbrink
Interesting article. Before reading this article I had no clue that any of this transpired; this is a lesser known fact of World War II. Shocking to hear that Hitler had potentially had a nuclear bomb. It was noble of the Norwegians to sacrifice their lives on such a perilous mission. I’m glad that all the commandos were able to survive the operation.
Deanna Lummus
I liked this article mostly because of how relevant it is due to the current events over the past six years or so. With nuclear power as an even hotter commodity than ever, I think this article gives important insight to just how dire all this information about nuclear ability actually is. Today we face actual danger because of North Korea and our own Presidential leader who is claiming how powerful we are as well when it comes to nuclear power.
Aaiyanna Johnson
This is such a harrowing and gripping recount of the efforts to get rid of the heavy water. I did not ever hear of this story, but I am really glad that I know of it now. Their bravery was so immense. To carry out such a dangerous plan, and relying on the information given is truly respectable. Again, I really like this article.
Rafael Azuaje
It’s amazing to me that scientists were able to create the atomic bomb without the aid of modern computers. We use computers in almost everything we do nowadays. If soldiers were to go on a mission like Operation Grouse today, they would probably be able to gather the necessary intelligence without getting anywhere near as close as their 1940’s counterparts. Right now there are probably military operations taking place to limit possible damage from a North Korean missile strike. I cannot believe our commander in chief referred to Kim Jong-un as “Rocket Man” at the U.N. General Assembly.
Ezequiel De La Fuente
I really enjoyed reading this article. It was very straight to the point and informative, which I like. I had no idea that this event took place in history. The Nazi’s acts and what they did to thousands of people were truly despicable so I’m glad that the mission was a success. Who knows what would’ve happened if they were to successfully create nuclear weapons.
Christine Sackey
This was defiantly a cool event to write about. I did not know that the heavy water was such an instrumental ingredient for making the bombs. It is sad to think that both gliders crashed and killed the crew inside. At least their lives did not go into vain because the Germans eventually were stopped. War is an evil thing and truly is destructive.
Matthew Rios
It was a shame Norwegian lives were sacrificed for such a dangerous mission, only for it to be overshadows by air raids after. I’m not sure why they didn’t just make air raids the primary strategy to begin with. It should’ve been a primary focus from the get go, but at least it worked out for the better in the end.