Men's singles luge start house (left) and bobsleigh start in 2007.
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.
Overall track construction cost ¥ 10.1 billion. The course was constructed in conformance of the natural topography of Mt. Iizuna. Three indirect ammoniarefrigeration systems are located along the track, limiting the amount of ammonia to be under 800 kg (1764 lbs). 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.
To help with ice making techniques, Nagano Organizing Committee officials recruited Ralf Mende, who works for the bobsleigh, luge, and skeleton track in Altenberg, Germany to train staff to make proper ice. Mende and his crew worked 18 hours a day during the 1998 Games to ensure track thickness was 2–3 cm (0.7-1.25 in) of ice. Sun shades are used in an effort to maintain the operating temperatures of -10 to -15 deg C (5 to 14 deg F). Track competitions were also moved to the afternoon during the games to avoid the sunniest hours. There are a total of 56 sensors located throughout the track to maintain constant ice temperature and thickness.
There are no listed turn names for the track. The track's two uphill sections are right after turn 8 with an average uphill inclincation close to 4% and between turns 10 and 11 with an average uphill inclination of nearly 10%.
FIBT track profile - Image is from a skeleton racer perspective shown at night. Men's single luge intersect prior to turn one while the luge - women's singles and men's doubles intersect prior to turn two.