• United States



The World’s Largest Tunnels

Jul 01, 20061 min
Critical InfrastructureCSO and CISO

But Measurable Nonetheless.

Worlds longest road tunnel: The 24.5 kilometer Laerdal in Norway opened on Nov. 27, 2000, as part of the E16 Bergen-Oslo highway. ­Began in 1995.

Longest rail tunnel: The 53.9 kilometer marine railway tunnel, Seikan, joins the Japanese islands of Hokkaido and Honshu.

Largest underground construction project (depending on how you count): The Chunnel was opened for traffic in March 1994 and cost $14 billion for 50 kilometers of tunnel and two terminals with all rolling stock. Employed 11 TBMs on two large-­section running tunnels and smaller service tunnel driving from shafts at Sangatte in France and Shakespeare Cliff in England. Two major crossover chambers under the Channel.

Largest unsupported span: Gjovik Ice Cavern,

Norway. Dimensions of hall are 62 meters wide, 91 meters long and 25 meters high. Excavated in eight months during 1991 for the 1994 Lillehammer Winter Olympics.

Largest underground treatment plant: Viiki sewage plant in Helsinki was constructed from 1988 to 1991 to serve a population of 650,000 together with associated industry. Involved excavation of 997,000 cubic meters of rock.