A Kiewit joint venture was awarded a $350 million contract in June 1996 as part of the new $571 million, 47,000-seat Safeco Field – home of Major League Baseball's Seattle Mariners. Completed on-time for the inaugural game on July 15, 1999, the ballpark's most notable feature is the 11,000-ton retractable roof. The three-panel roof covers the entire nine-acre park when closed and stacks over adjacent railroad tracks when open. Powered by 96, 10-horsepower electric motors, the roof takes an average of 10 to 20 minutes to open or close and contains enough steel to build a skyscraper 55 stories tall.
During the peak construction period, the project employed more than 1,100 workers on site. Major quantities for this 37-month project included 600,000 bricks for the facade; 420,000 bolts on the roof and bowl; 106,000 square feet of turf; 600 tons of infield clay; 535 metal halide lights; 200 miles of concrete; 150 miles of electrical wiring; 40 miles of piping; and 20 to 30 miles of heating coils to heat the grass, which is made up of four kinds of blue grass and two kinds of rye grass.
The 1.1 million-square-foot ballpark also houses administrative offices for the baseball team and the Public Facilities District, the Stadium Club, restaurants, clubhouses and related retail and concession operations. The design reflects the historic Pioneer Square located just blocks away at the south end of downtown Seattle.