As predicted, the Erection Co. topped out Seattle’s 850-ft-tall Rainier Square Tower, with its radical composite steel frame dubbed “speed core,” in only 10 months.

With floors 10 and 11 of Seattle’s 58-story Rainier Square Tower under construction concurrently, crews from the Erection Co. are meeting or exceeding speed predictions for the radical composite steel frame’s steel erection, core welding and core concrete casting.

The team setting the stage in seismic Seattle for a 58-story composite steel frame calls the project “a game-changer”