The permanent replacement for the collapsed Interstate 5 Skagit River Bridge span reached a major milestone this week as crews began setting eight enormous concrete girders that will support the new roadway.

Contractor crews working for the Washington State Department of Transportation expect to have all of the girders in place by the end of this week. They will then spend the following two to three weeks working on the final roadway, including the deck, barriers and other key components.

One of the eight massive girders for reparis to the I-5 bridge. Credit: Washington State DOT.

One of the eight massive girders for reparis to the I-5 bridge. Credit: Washington State DOT.

“We’re still on schedule to replace the temporary span in early September, shortly after Labor Day weekend,” said Jay Drye, WSDOT assistant regional administrator. “A full closure of I-5 is needed to complete the job, and we’re working closely with the community and the contractor to finalize those details so folks have enough time to plan ahead.”

Once the girders are on site, two cranes, one on the northern dike of the Skagit River, the other on a barge in the river, will work together to lift each girder into place. Each girder is roughly as long as the width of a football field, 162 feet,  and weighs a little more than a space shuttle when empty, 168,000 pounds.

Since construction started in early July, crews have driven piles in the river to create temporary work platforms, which will support the new bridge span during construction, while building a rail system to move the new bridge span into place. On the east side of the bridge, crews continue to drive piles that will eventually hold the temporary span after it is shifted out of the way to make room for the permanent replacement.

This project is necessary to replace the portion of the Skagit River Bridge that collapsed near Mount Vernon on May 23, after an oversized semi-truck struck critical steel supports. Three people were injured but no one was killed

The corridor carries 71,000 vehicles daily.

For more information on the project or to sign up for email updates, visit the project website.

You can also view pictures of the bridge repair effort and pictures of trucks hauling the girders in the Washington DOT's Flickr feed.