The Erection Co. is meeting its production predictions of about two floors per week for the 58-story Rainier Square Tower (ENR 12/25/17-1/1/18 p. 18). As of March 18, the 850-ft-tall skyscraper’s novel “sandwich” core—made from modules of cross-tied steel plates filled with rebar-less concrete—was at levels 23-24, with surrounding steel close behind at levels 21-22. Steel work started last October and the topping out is set for August. If all goes as planned, construction of the frame—the brainchild of ENR’s 2018 Award of Excellence winner Ron Klemencic of Magnusson Klemencic Associates—should take nine months less than a steel structure with a concrete core.