Weekend Viaduct Closure and What is the What in the Pit?

A flock of cranes at the southern end of northbound SR 99
A flock of cranes at the southern end of northbound SR 99

Driver alert: SR 99 will be closed all weekend, to allow crews to reinforce the shorn end of the Viaduct, so it doesn't fall down when they eventually tunnel directly under it. Look for snarly traffic around downtown and Pioneer Square this weekend; the closure will affect the highway between the north end of the Battery Street Tunnel and the West Seattle Bridge, from 11 p.m. Friday through 5 a.m. Monday.

Meantime, the SoDo "pit" of the Viaduct—in the shadow of its shorn end—is bristling with cranes these days; I counted eight, although I'm not sure all of those mammoth things are actually called "cranes." According to WSDOT, the machines are being used to build the underground walls of the pit from which the gigantic tunnel boring machine will be launched in about a year.

If 520's your bridge, take a look at the many, many cool new renderings of the finished project (look! viewing platforms!) on WSDOT's Flickr stream here. Now there's lots of talk about how best to span Portage Bay (a cable-stay bridge?); you can look at design concepts at a public meeting tomorrow, Saturday, from 9-12 at Seattle Preparatory School.