Nipro Hachiko Dome

The Nipro Hachiko Dome (ニプロハチ公ドーム, Nipuro Hachikou Dōmu) is a large wooden stadium in Ōdate, Akita, in northern Japan. The stadium covers an area of 12,915 m². It was completed in June 1997 and is made from 25,000 Akita cypress trees which are covered with a special double Teflon-coated membrane. This allows enough sunlight into the stadium so that during the day no artificial lights are needed. The stadium is principally used for baseball games, but thanks in part to its removable grandstands, the stadium can also be used for other sports and events. Nipro, a Japanese medical equipment manufacturing company, purchased the naming rights to the dome in 2017.

Structure

The roof was made from 25,000 Akita cypress trees which were aged over the course of 60 years. This wooden framework is covered with a special double Teflon-coated membrane made from translucent fluorethylene resin-coated fibreglass. This membrane is very strong and light. The stadium is located in a region of Japan that it subjected to heavy snowfall of 2 to 3 m (6.6 to 9.8 ft). Because of this, the dome itself also has an aerodynamic design to resist strong winds and heavy snowfall. Buildup of snow on the roof is prevented by circulating warm air between the two Teflon-coated membranes; this shakes off the snow and allows the stadium to be used in all weather.