Spiral (bobsleigh, luge, and skeleton)

The Spiral is a bobsleigh, luge, and skeleton track located in Iizuna village, located north of Nagano, Japan. Used for the bobsleigh and luge competitions for the 1998 Winter Olympics, it is the only permanent bobsleigh, luge, and skeleton track in Asia and the only one of its type in the world with two uphill sections. It is officially referred to as the Nagano Bobsleigh-Luge Park in Japan.

The track was among part of the venues used for the 1998 Winter Olympics that was started in 1990. Construction on the track started in November 1993 and was completed in March 1996 with homologation from the International Bobsleigh and Tobogganing Federation (FIBT) on 28 March 1996 and from the International Luge Federation on 24 June 1997. This track was referred to as the "Spiral" because of the winding track and dynamic movement of the sleds.

Overall track construction cost ¥ 10.1 billion. The course was constructed in conformance of the natural topography of Mt. Iizuna. Three indirect ammonia refrigeration systems are located along the track, limiting the amount of ammonia to be under 800 kg (1,800 lb). During construction, rocks and trees that were dug up were used as materials to build settling ponds and a retaining wall to prevent landslides. Topsoil that had been removed during construction was returned to the site once groundwork was completed. About 40,000 saplings, mainly beech and oak, were planted two per square meter, as part of the environmental stewardship committed during the Winter Games.

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