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Saabs secret rooms

Saab’s secret room: The underground workshop

3 min read

One of the most secret rooms in Sweden was built deep down in the primary rock of Linköping: Saab’s underground factory. The underground workshop had room for a thousand employees and came into existence in order to safeguard the operation of the Swedish aviation industry during the Second World War.

Saabs secret rooms
Deep in the mountain was one of Sweden's most secret rooms: Saab's underground factory with space for a thousand employees. The facility was established to ensure the operation of the Swedish aviation industry during World War II. Photo: Åke Lärkert.

In the middle of World War II Saab and the Royal Swedish Air Force Administration (KFF) worked together on a secret plan: an entire factory just over 30 metres down in the ground below Saab’s conventional industrial zone at Tannefors in Linköping.

There was fear of enemy air raids and that Sweden could be drawn into the war. Its neighbouring countries, Norway and Denmark, had already been occupied by Nazi Germany in 1940. The underground workshop would safeguard Saab’s ability to continue manufacturing even in a troubled situation. The ventilation would even be capable of resisting a gas attack.

Built during the war

Construction got underway in March 1943, and in December 1945 the huge premises were finished. By then the war was already over, but the workshop would also continue to play an important role in the post-war period and during the Cold War. Saab had been responsible for the construction, while KFF owned and paid for the workshop until 1968, when Saab took over ownership.

There is still an escalator to the workshop, which was the longest one in Sweden when it was opened in 1945. In order to reach it you would have to pass through three air raid doors. The underground workshop was long a well hidden secret and even today there are few outside the company who have seen it.

Saabs secret rooms
The underground workshop was a well-kept secret for a long time, and at the ground level, the size of the plant was unaware. Here the personnel entrance to the underground workshop. Photo: Åke Lärkert.

The size of four football pitches

A few figures give an indication of the dimensions of the project. The floor area covered more than 20,000 square metres, which is equivalent to four football pitches. A total of approximately 146,000 cubic metres of granite were blasted away – rock masses which generated their own hill alongside the aerodrome. In the mountain there was room for a sheet metal workshop, engineering workshop, drop hammer workshop, refectories, kitchens, changing rooms and offices. Some 1,000 people could work down there on each shift.

A concern about the air conditioning resulted in fresh air being pumped into the mountain, and one objective was to create one of the country’s most healthy workplaces. But it was certainly a special world, being down there in the underground factory, far from daylight and world events. Work colleagues sometimes played tricks on one another and reset the special clocks which showed the temperature and weather outside: anything from rain and low temperature to sun and plus 20 degrees, for example! There was also a hierarchy within the company, which was reflected in the attitude towards those who worked down there – many thought that it was much nicer to work in workshops above ground.

Saabs secret rooms
The so-called "cave" in the mountain factory. The floor area of ​​the entire facility amounts to more than 20,000 square meters, equivalent to four football plans. Photo: Å. Andersson.

Conversion to storeroom

Over time the frosty relations between the world powers thawed. In the early 1990s Germany was reunited and the Soviet Union was dissolved. The Cold War came to an end and there was less of a need for an underground workshop. At the turn of the millennium the underground area was converted to a storage area.