What is Tokyo Dome?
The most well-known in Tokyo Dome City and the first-ever all-weather, multi-purpose stadium in Japan.
Since the opening in 1988, all kinds of events have been held such as concerts, exhibitions, and not to mention baseball games.
It is an all-weather stadium, so you can utilize it, not worrying about weather.
|Floor area ／ 46,755m²
(This is what is usually stated when people say "the area of Tokyo Dome")
|About 1.24 million m³
|2 floors under ground ・6 floors above ground
|Highest point ／ 56.190m from the ground
Height above baseball ground ／ 61.690m
Baseball field surface ／ 5.500m under ground
|55,000 people（for baseball games, about 46,000 people）
Left and right fields ／ 100m
To center outfield／ 122m
Fence height／ 4m
The membrane roof is made up of glass fiber membrane materials coated with fluoropolymers, which was created specifically for Tokyo Dome. It is supported by 28 cables and the total weight amounts to 400 tons. The membranes are two-layered, and the thickness of the inside layer is 0.35 mm and that of the outside 0.8 mm, which are so thin that about 5 percent of the sunlight goes through them.
Tokyo Dome is an air-supported structure, which supports the membrane roof with air pressure. Pressurized ventilation fans constantly send air inside the stadium so that the air pressure inside is 0.3 percent higher than that of outside, which supports the membrane roof. This difference in air pressure equals the one between a first floor and ninth floor. A body does not detect this difference. In addition, revolving doors are installed as entrances and exits in order for the air not to go out of the stadium.
Pressurized Ventilation Fan
A total of 36 fans are situated in the highest area of stands, surrounding Tokyo Dome.
For events, 10 to 18 fans are operated, but when it is closed, two fans are operating.
Revolving Door・Blanced Door
To maintain the air pressure inside Tokyo Dome, revolving doors are installed at entrances and exits (a total of 54 locations). Also, after baseball games or in case of emergencies, balanced doors (a total of 54 locations), functioning as supplementary to revolving doors, are used so that many people can enter or leave the stadium at the same time.
On June 28th, 1987, the roof was lifted up (putting air inside Tokyo Dome and inflating the roof).
Mild wind blowing in early morning. Air sent, decreasing Internal pressure.
Membrane inflating from the peripheries to central.
The roof successfully reaches the targeted height, and the process is done.
It took about 2 and a half hours.