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Updated: Nov 5, 2019

Few stories from the Second World War are as fascinating as the story around the heavy water production at Vemork, located in Tinn Municipality in the Wild Telemark. Even now, over 75 years after, there are many questions still unanswered.

Enjoy the story below – with the Ian Brodie photos from the award-winning 2015 NRK production ‘The Saboteurs’, the latest classic story about a timeless tale.


Operation Gunnerside is the February 1943 WWII operation that has been called the most successful act of sabotage in all of World War II. Penetrating a virtually inaccessible location in the frozen mountains of Telemark, Norway, Norwegian commandos successfully destroyed the heavy water production facility may have brought Adolf Hitler the atomic bomb.

After invading Norway in the spring of 1940, the Nazis took immediate notice of the Hydrogen Production Factory, the only facility in the world that produced heavy water in large volumes. This heavy water would be the key ingredient in the German atomic research program – and the Allied forces feared that should Germany get the bomb, London would be well within range with population of over 8 million – one of Hitler’s military fixations.

The Race for the Bomb

As World War II moved into 1943, heavy water production at Vemork was producing 100 kilograms per month - more than enough to fuel German research. By then, the tide of the war had begun to shift in favor of the Allies, but at the same time a dangerous wartime intrigue was developing.

Who would be the first to get ‘the bomb’?

The year before, in 1942, the United States had decided to go full-steam ahead at producing an atomic bomb, but the simple fact was that no one really knew for certain who had the lead in developing “The Bomb”.

Impossibly Inaccessible

Allied hopes of disrupting the Nazi atomic program naturally focused on sabotaging the Vemork Hydrogen Production Factory, fortified and heavily guarded in a nearly impossibly inaccessible part of Norway.

For centuries, the only way into Rjukan and Vemork was to brave travels over the high mountain plateau of Hardangervidda, Europe’s largest high mountain plain, an endless chain of lakes and rocky outcrops, over half a mile above sea level.

Even with the modern technology and military expertise at the Allies disposal, any penetration of Vemork seemed doomed. The first attempt to disable the factory ended in utter failure with Operation Freshmanin November 1942 when two gliders dispatched from the UK crashed in southern Norway.

All 41 English commandos on board the two gliders were either killed in the crash or executed afterwards. This marked a low point of the war.

The story of the Norwegian saboteurs and Vemork will live for an long as stories are told

The Heroes

After the Operation Freshman failure a small special operations force was created consisting of Norwegians, a team that knew the local area around Rjukan and Vemork. The Operation Gunnerside sabotage that took place just after midnight on February 28th1943 is described as one of the most heroic that took place during the Second World War.

The darkest of nights in February

Under the cover of night, 12 saboteurs were dropped by parachute onto the barren and frigid Hardangervidda. Then, just before midnight on 27 February, nine of the twelve Norwegian saboteurs descended the steep canyon wall from the frozen plateau into the deep valley, down the cliff to cross the frozen Måna river basin and then up the hill to the railroad line.

Making their way towards the Vemork installation, unnoticed and never challenged, the saboteurs made their way along the railroad track, unchallenged through the entrance gates, and into the cellar of the Vemork Hydrogen Production Factory.

There, they detonated the explosive that would temporarily sidetrack Adolf Hitler’s heavy water production – key in his quest to create a bomb that may have fulfilled his dream of eradicating London with its 8 million inhabitants.

The Story Continues

The latest research from NIA indicates that not only did Hitler manage to resurrect heavy water production after the heroic sabotage on that winter’s night in February 1943 – that even the sinking of the Hydro one year later did not stop the heavy water entirely.

There is much to be learned, and NIA is deep into the search for the answers. It was in September 2017 the Norwegian Industrial Workers Museum (NIA) began the excavation of the Heavy Water Cellar using an industrial-archeological excavation method. The first discovery followed in October that same year.

Then, in the summer of 2019, guided tours of the original site of the Heavy Water Cellar began, with major preparations now under way to open the much-anticipated museum in 2021.

In the meantime, the story continues to unfold. There is much to be learned, and NIA is deep into the search for the answers. Visit the Wild Telemark and the Heavy Water Cellar at Vemork.

There are still so many stories yet to be told!

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