SAPPORO >>

The Hokkaido Nippon Ham Fighters baseball team plans to move from Sapporo Dome, but the facility will remain one of Hokkaido’s largest event venues, due in large part to its innovative movable turf field.

The dome boasts what is said to be the world’s only “hovering soccer stage system,” in which a gigantic natural-turf soccer pitch rolls from outside the stadium into the enclosed arena and then back out again after an event.

The stage, with a surface that spans 394 by 279 feet and just over 4 feet high, is a natural-turf soccer pitch. The turf needs water and sunlight, so the stage is usually placed in the open area outside the dome and then moved into the dome just before matches.

It weighs more than 8,300 tons, but air is blown underneath lifting it like a hovercraft, effectively reducing its weight by 90 percent. The stage is moved by directing its 24 sensor-guided wheels that roll at a speed of 13 feet per minute. It moves through a huge stadium entrance — 295 feet wide and 46 feet tall. Every time a soccer game is held, workers spend four to five hours on this process.

Recently, the wheels roared loudly as the 30 workers positioned the field.

“Don’t you think it sounds like an elephant’s call?” Nao Fujita asked with a smile. Fujita, 31, is in charge of public relations for Sapporo Dome Co.

Volunteers play an important role in maintaining the stage. During the offseason, the stage is placed outside and becomes covered by snow. In March, just before the stadium begins hosting games, about 200 fans clear away the snow in what has become a seasonal tradition.

“We have the utmost respect for such enthusiastic fans,” said Satoshi Wakai, 53, who works in public relations at the dome.

The natural turf of the stage will be completely replaced later this year for the first time. Sand is sprinkled on it to maintain the turf, but this increases the weight of the stage year by year. If this continued, the stage would become immovable.

At a nearby training ground, lawn grass has been grown since last autumn to replace the stage’s turf. Naoto Kohiyama, 56, an official in charge of facility maintenance for the dome, touched the steadily growing grass with a look of satisfaction. Kohiyama used to be engaged in the maintenance of turf for golf courses in Niigata Prefecture. However, when he heard that Sapporo Dome would open, he applied, believing he would be able to make use of his experience. He joined the company when the dome was opened.

Turf is vulnerable to high temperatures and humidity. In contrast to conditions on Honshu, turf for the dome in Hokkaido is green throughout the year. Usually, the turf is cut to a height of 1 inch but when important matches for Hokkaido Consadole Sapporo are scheduled, the turf is cut at a height specified by the team so that it can fit the team’s tactics.

In the 2019 Rugby World Cup, two matches — Australia versus Fiji and England versus Tonga — are scheduled to be held at the dome. It is said to be extremely unusual around the world for a rugby match to be held indoors.

“Overseas fans will be surprised by the matches held under the roof,” Kohiyama said. “We would like to prepare the best turf for those matches.”