Sonnenberg bunker draws renewed interest after 50 years

A Swiss civil-defence shelter built inside the Sonnenberg motorway tunnel was designed to protect 20,000 people from a nuclear explosion and its fallout. The facility is attracting renewed interest, including from the Federal Council, SRF reports.

The tunnel’s two tubes were meant to be converted into the country’s largest civil-defence shelter within days. Heavy concrete doors would seal both ends, while the shelter was divided into sections for 64 people, with three-tier beds. Air filters, an emergency generator and a small hospital with an operating theatre were intended to help some of Lucerne’s residents survive for two weeks.

Built in 1976, the facility was put to the test for the first time in 1987 during an exercise called Ameise. Both tubes were closed for several days, forcing road traffic to take other routes. Civil defence personnel set up the infrastructure and tested procedures, but the exercise exposed construction defects and other problems. They also failed to assemble the required beds quickly enough.

The shelter’s usefulness had been questioned from the outset, with critics describing it as excessive civil-defence planning. Its role came under increasing pressure after the Cold War ended. The facility now hosts 300 to 320 tour groups a year, according to Andrea Huwyler-Bachmann, president of the unterirdisch leben association.