Construction this week on the new Tacoma Narrows bridge:
It's going to be a busy week for tower construction.
Tuesday, concrete crews will pour the third 17.5-foot lift on the north leg of the Gig Harbor tower, and Wednesday they'll pour the third lift on the south leg. Saturday they'll pour the fourth lift on the north leg of the tower, raising it to 80 feet above the top of the caisson.
On the Tacoma tower, both construction platforms - known as "bird cages" - are in place, and Friday crews will pour the first lift on the south tower leg.
Roadways: Road crews are putting the finishing touches on the subgrade of what will be the eastbound lanes leaving the new bridge. They'll spread a layer of crushed rock on the new roadbed late in the week. Then they'll be ready to pave.
On the Gig Harbor side, look for more paving in what will be the eastbound lanes in the vicinity of the 24th Street overpass.
Drainage work is finished in the median strip, and crews will spread a layer of crushed rock this week. The plan is to have the area paved and eastbound traffic moved onto it by the end of September.
Anchorages: No concrete pours this week on either anchorage. Crews will spend the week moving forms, placing rebar and preparing for pours next week.
Watch for more night lane closures this week. Crews will continue landscaping work adjacent to the westbound lanes of Highway 18 on the Gig Harbor side and will close the right lane between 24th Street and the weigh station.
Work hours are 9 p.m. to 7 a.m. Monday through Thursday.
Q. In watching the Tacoma Narrows bridge construction, I'm having trouble with the scale involved. What are the dimensions of the "bird cages"? - John Baxter, Port Ludlow
A. The bird cages - the moveable concrete forms being used to build the tower legs - are 26 feet deep, 39 feet wide and 46 feet high. They weigh 105,000 pounds.