Hardangerfolk shows how mountain skills and perseverance helped crew stop Hitler developing atomic bomb

The original crew were forced to brace treacherous weather conditions, scale icy plateaus and eat moss for survival.

Scottish director Gregor D Sinclair joined former SAS and US commandos to retrace the team who carried out Operation Gunnerside (Scotia Film)

Crossing almost 400 miles across Europe’s wildest plateau in February 1943, a team of saboteurs accomplished a top secret mission to destroy Hitler’s hopes of getting his hands on an atomic weapon.

In winter conditions said to be the worst crew members had ever seen, Operation Gunnerside saw British-trained Norwegian resistance fighters destroy a Nazi-held power plant in Vemork, 100 miles west of Oslo, Norway. The site was developing deuterium oxide — also known as ‘heavy water’ — a key ingredient in the production of plutonium.

The team had to forage for survival, with only moss as an option for food up on the Hardangervidda plateau, which lies in the country’s southern Telemark region.

The team said they didn't see a tree or running water for over a week during their expedition retracing the steps of the original crew (Scotia Film)

Each member also carried a suicide capsule knowing capture by the Nazis would see them tortured to death.

It was not the first time the mission had been tried. Just months earlier, a squad of British counterparts had attempted the same quest across the plateau but failed, with the crew being captured and executed by the Germans.

This year, 80 years after the operation was accomplished, Scottish film director Gregor D Sinclair joined a group of former SAS and US commandos in retracing the steps of the saboteurs who he believed showed “one of the most incredible acts of strength of man in the 20th century.”

Marching some 20 miles a day in conditions reaching minus 30C across the plateau, Sinclair captures reworked scenes of the mission in his new film Hardangerfolk, which premiered at Cumbria’s Kendal Mountain Festival last month.

Scottish film director Gregor D Sinclair said the saboteurs' mission was one of the most incredible acts of human strength and perseverance of the 20th century (Scotia Film)

Despite being hut-bound for three days due to extreme weather conditions and not seeing a tree or running water for over a week, the filmmaker said the group “had it easy” in comparison to the original crew.

"It was still really tough on us, and we took longer to do it, so that’s a testament to how hard these guys had it,” Mr Sinclair said.

"We had to take cover in a hut for three days which we only left for going to the toilet or getting phone signal to let people know we were okay. But the original team would have had to keep moving whatever the weather as they were being chased by the Germans.

"I think what they did is one of the most incredible acts of mountain and survival skills, perseverance and endurance that any humans in the 20th century went through.”

The international team of military veterans and Norwegian wilderness experts who took part in the honorary expedition followed the original 373-mile route through the barren, blizzard-ravaged wilderness of the Hardangervidda – Europe’s highest plateau – in Norway’s southern Telemark region (Scotia Film)

North Ayrshire-born former Special Forces member Matt Smith, who organised the mission, described the tribute expedition eight decades later as “hardcore.”

"It was a tough time; there were some really testing conditions,” he said.

"There were six other teams trying to do the same expedition for the anniversary and four had to get pulled.”

Mr Smith described the original crew, who were in their early 20s at the time of the operation, as “true Olympians” after completing the honorary adventure.

North Ayrshire-born former Special Forces member Matt Smith

"They took 19 days to cover 600kms,” said Mr Smith, who founded SOE Expeditions, which delivers WW2 endurance and survival expeditions across Europe, North Africa and Asia.

"They were carrying what they had on them while breaking into huts, sleeping under trees, building survival shelters and relying on people to give them food.

"They covered about 30 miles a day when it was about minus 30C while being chased by about 1,000 German mountain troops.”

The film features never-before-seen details of the mission, as well as original footage of and taken by the resistance fighters who took part who returned to the route several years later.

Mr Sinclair, whose work is often focused on people’s connection with the land, also examines the role of the skills and experience these saboteurs gained growing up in the mountains in Norway and what physically one must go through to navigate this type of landscape.

“What was so interesting to me was ultimately the story is about eleven guys in the mountains of Norway using nothing but their mountain and survival skills, bravery and perseverance to overcome a military, industrial machine,” he said.

"And they succeeded and won.

"Their ability to read the landscape like the back of their hand, to hunt and forage on their mission helped them navigate the landscape in a way that the Germans simply couldn’t do; and that is how they survived.”

The mission came about after the Nazis conquered Norway in 1940.

They seized control of Europe’s only plant capable of developing deuterium oxide in Vemork, 100 miles west of Oslo.

Plans to decommission the facility were made after Norwegian resistance fighters tipped off the British that the Germans had ordered production of heavy water at the plant to be ramped up which indicated they had plans to create an atomic bomb.

Bombing the site was out of the question given the risk to civilian life nearby. Instead, several operations were launched and overseen by Special Operations Executive (SOE) – Britain’s wartime intelligence gathering and sabotage unit – of which Gunnerside succeeded.

In preparation for their mission, the Gunnerside team were trained at Glenmore Lodge in Aviemore in the Scottish Highlands under the British Forces.

The landscape of the Cairngorms is more similar to Norway than any other part of Britain with its rugged mountains and snow and its sweeping upland plateau similar to Norway’s Hardangervidda national park.

Here the secret agents lived off hunting deer in the hills and salmon in the river.

They were parachuted in to start their mission on February 16 and made their way to Vemork 11 days later.

The Glenmore Lodge features in the film as there’s a monument erected by the people of Badenoch, a district to the east of the Cairngorms, in honour of the company of the Norwegian patriots who lived among them in the mountains between 1941-1945.

In a return tribute to the people of the Highlands, a message reading “you opened your homes and your hearts to us and gave us hope” is written on the monument from the Norwegians.

Historical records today tell us the Nazis were never close to developing a nuclear bomb, but that fears this was the case were very much felt at the time.