In Switzerland, the Sonnenberg Tunnel, considered to be the largest civilian shelter in the world, is to be converted into a motorway tunnel.
The 1.5km long tunnel was built at a cost of US$32.5M to satisfy Swiss statutory requirements for the provision of shelters for the population in the event of war or natural disaster and was designed to accommodate 20,000 people, 10,000 in each tube of the system.
A seven storey cavern between the two tunnels housed a command post, emergency hospital with operating theatre, radio studio and other facilities. The main shelters were divided into sections that would hold 64 people with each allocated a bed.
The shelter construction was subsidised by a motorway that was built at the same time. It seems that now the city authorities in Lucerne have decided the diminished threat of conventional, nuclear or chemical attacks mean the facility is best repackaged as a motorway tunnel. To this end the tunnels and cavern will be re-worked to provide a more suitable use. A reduced shelter with a capacity for 2,000 people will remain at the site of the seven storey cavern.
During its operational life as a shelter, the Swiss authorities encountered operational and logistical problems maintaining a shelter with Sonnenberg’s capacity. Indeed, shelters are generally now built to hold only 2,000-3,000 people due to the practically of housing people in a confined space.
