Monday, May 18, 2009

Second truss set, final pontoon section placed

WSDOT reached two huge milestones today on SR 104 Hood Canal Bridge Project, floating in the draw span pontoons and setting the east truss. The construction completes placement of major bridge components for the project.

The 596-foot-long draw span assembly is scheduled to be joined with pontoon RST on Tuesday, May 19, completing the placement of the three new east-half pontoon sections.

Three derrick barges lifted the 280-foot-long, 70-foot-wide, 40-foot-tall truss off a nearby barge and moved it into place. Setting the massive truss, which tips the scales at 1.6 million pounds, took about three hours to complete.

One question we're getting now is, "With all the main pieces in place, will the bridge open early?"

It's tough to say one way or the other, because while it is true most of the major components are now at the bridge site, some very unique technical and engineering challenges still must be overcome before we reopen.

Crews still have complex pontoon joint operations ahead, which include work that is dependent on having winds less than 15 miles per hour. WSDOT also must set drop-in spans and connect them to the pontoons, and post-tension the pontoons – pulling them together – to stabilize and strengthen the east half as a whole.

In a nutshell, there's a lot to be done inside the pontoons.

It's kind of like driving a car without tightening the lug nuts on the wheels... everything is there, but try to drive and you're not going to get very far. Pretty much everything is at the construction site, but it all still needs to be fastened into place so we can assure that the bridge will function properly.

See the latest project photos including the east truss set at Flickr.

2 comments:

The Geezer said...

So, how close to on time are we right now?

Will the June 15 date endure? I want to ride the Edmonds-PT ferry, and would hate to wait, and have you finish the bridge early, and have the thing stop running.

The Geezer

irwinj@wsdot.wa.gov said...

We're still assessing the six-week schedule, which starting from May 1 has us opening June 12.

I'd reccommend taking a ride on the PT-Edmonds run when time permits just to make sure you don't miss out.