Contractor Earns Mega Bonus for early bridge opening

Hood Canal Bridge opens in time for summer tourist season.

By Lucy Bodilly

Crews removed the bulge in the middle of the bridge and replaced the draw span with a straight section that makes the bridge safer for drivers. Parts of the old bridge will be reused or recycled. (Photo courtesy of the Washington Department of Transportation)

Shine, Wash. - General Contractor Kiewit General, Poulsbo, Wash. earned a $600,000 bonus in June, by replacing the east half of the Hood Canal Bridge eight days ahead of schedule. The 1.5 mile span, the longest floating bridge over salt water in the world connects the Olympic and Kitsap Peninsulas about 25 miles northwest of Seattle.

The $490 million project took six years, including a delay in 2005 when contractors discovered an ancient Native American village while excavating for a graving dock in Port Angeles. Reparations to the S’Klallam Tribe and temporarily shutting down the project cost the state over $100 million.

It also gave the Washington State Department of Transportation and contractors time to plan a comeback.

The most critical part of the project, the pontoon and truss replacement, called for the bridge to be shut down for six weeks, starting May 1.

The roadway is raised and the draw span retracted when the bridge has to be opened for marine traffic or because if high winds. (Photo courtesy of the Washington State Department of Transportation)

For every day the bridge was closed after June 15, the contractor would be fined. If Kiewit opened the bridge early, it would be rewarded with a $75,000 daily bonus.

Work called for removal and replacement of the east span of the bridge including anchors, pontoons and trusses. The roadway was widened, allowing for future expansion and the draw span was replaced.

“This isn’t your typical bridge,” says Scott Ireland, WSDOT project manager. “It includes electrical, mechanical and hydraulic systems.”

All will help prevent the bridge from sinking, as it did in 1979, when 120 mph winds blew through the canal.

The bridge also had to be designed to withstand 16 foot tides,. Hydraulic anchors help keep it the proper height. Two trusses, that can bend as much as 36-inches, keep it in the correct alighment.

Bridge reconstruction was done off-site, from casting the pontoons, to paving the roadway. All the electrical and mechanical systems were installed at Todd Shipyards in Seattle. The two trusses, built under standards used by the oil industry, were fabricated in Oregon. Once all the components were floated to a nearby bay, crews removed the east half the bridge, floated the new components into place, and bolted the pieces together.

“Cutting apart the bridge went really well,” says Ireland. Putting it back together took more precision.

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The pontoons had to be ballasted, with a variance of only one-eighth of an inch every 10 ft. “We bought a laser surveying system used for marine projects, just for that purpose,” says Phil Wallace, project sponsor with Kiewit.

All the new pontoons were floated into place, except for the sections near the trusses. Those sections were lifted into place, by the D..B. General, the largest derrick barge on the West Coast, which has a 1.4 million pound capacity.

“We had to plan this entire phase several years in advance, just to make sure we would have that derrick available when we needed it,” says Wallace.

It took two additional derricks, also owned by General Construction, to make the 850 ton picks.

General Construction lifted the trusses into place using the largest derrick barge on the West Coast. (Photo courtesy of WSDOT.)

To complete the project, the WSDOT also had to make arrangements for the 20,000 vehicles that travel across the bridge every day. It spent $12 million to supply alternate buses, foot ferries and park and ride lots.

The Hood Canal is also used by the US Navy for training. “We had to coordinate with them at least four times per day to make sure the channel was open at all times,” says Ireland.

Now Goblal Diving and Salvage, Seattle, is now using remote operating vehicles to connect the anchors with the pontoons.

“We are basically threading wire through loops in the anchors and them bringing the wire back up to the bridge so it can be connected.” Says Devon

It’s planning had to be just as precise to work between the tides, marine traffic and construction activities.