Safeco's roof is divided into three independent panels made of a thin gypsum and glass fiber board. A waterproof skin covers the panels. The three panels are staggered so that the roof can slide completely away from the field of play. The panels roll on motorized steel wheels that move over steel rails. The wheels are powered by 96 10-horsepower, DC motors.
Power is provided by long cables that are reeled in and out as the roof slides open and shut.
The newest of the retractable-roof stadiums, it consists of three panels with staggered heights that slide completely off of the top of the playing field. Even the glass walls on one side of the stadium retract to allow baseballs to be hit competently out of the stadium. Opening and closing takes between 12 and 20 minutes. The panels are made out of a translucent Teflon-coated fiberglass. Five trichord trusses will support each panel and span between supertrusses.