Workers float a pontoon into place in Hood Canal.
The first pontoons for Washington state¹s Hood Canal Bridge were towed to Seattle this week where the structures will be fitted with electronics and have roadways installed marking an important milestone for the beleaguered project.
In late 2004, discovery of an Native American remains caused the Washington Dept. of Transportation to abandon a dry dock in Port Angles. This set the project back three years and added $195 million to the price tag. The project is two months ahead of its new construction schedule, which calls for completion of the bridge in 2010.
"This accomplishment is another step toward providing drivers with a bridge that is wider, safer and more affordable to maintain," says project director Eric Soderquist. "Completing these pontoons is an important project milestone leading up to the May-June 2009 bridge closure and replacement." It's crucial to keep the project on track in order to meet the bridge's scheduled closure, which will last for six weeks. A foot ferry will shuttle people across Hood Canal during the closure. In addition, the state is widening and improving portions of U.S. Highway 101 in Jefferson County to accommodate additional vehicles. Traffic volumes on the highway from Hood Canal to Olympia are expected to increase by 50 percent during the bridge closure.
The Washington state Dept. of Transportation and general contractor Kiewit-General will construct remaining 11 pontoons at the Tacoma graving dock in four cycles. Three pontoons were built in this first cycle. Five pontoons will be constructed in the second cycle, four pontoons in the third cycle and two pontoons in the fourth cycle.
The one-and-a-half-mile-long Hood Canal Bridge is the longest floating bridge over saltwater in the world. The structure, which opened in 1961, connects the Kitsap and Olympia peninsulas on State Route 104. Twenty-seven years ago, the western half of the bridge sank in a windstorm but later reopened in 1982.
Earlier this month, 15 ft of water filled the graving dock at Tacoma Concrete Technology lifting up the first three pontoons. Tugs towed the structures, which weigh more than 6,000 tons each, and moored in them Blair Waterway. Crews there spent two weeks preparing them for the 35-mile journey to Seattle. Moving at two miles per hour, the pontoons were towed to Todd Pacific Shipyards in Seattle this week.
When the project is completed the eastern floating portion of the bridge, east and west approach spans and east and west transition truss spans will be replaced. The improvements will widen the bridge to include eight-foot continuous shoulders across the entire length of the 7,869-foot structure. The western portion of the bridge will be retrofitted and its electrical system updated.
Originally, the pontoons to replace the older eastern span were scheduled to be constructed in Port Angeles at a new drydock. But the discovery of human remains from an ancient Native American village halted construction of the graving dock and operations were shifted to Tacoma and Seattle. The initial construction schedule called for the project to be completed this year for an estimated cost of $292 million. Neither the tribe nor the state's archaeology consultant raised warnings about potential problems when the 22-acre site was chosen. After the artifacts where found during excavation, the state followed the procedures of the National Historic Preservation Act.
The site was investigated and all of the parties, including the tribe, agreed in mid-March of 2004 to resume work. But the parties still didn't have a full picture about the site and the graving dock was later shut down permanently. In an 224-page internal report released in May, state Transportation Secretary Doug MacDonald said treated the experience as a cautionary tale about considering areas with known Native American sites when planning projects.
"The graving dock story would have had a much different outcome if the second assessment had brought more materials to light" or if the experts or anyone else had "raised a more forceful alert," MacDonald wrote in the report.
Kiewit-General and the state WSDOT are working diligently on putting the project's expensive mishap in the past. The Hood Canal Bridge Design Team has worked with Kiewit-General crews to create electrical and mechanical layout drawings and to integrate the electrical and mechanical drawings into three-dimensional drawings. The process included taking the electrical and mechanical layouts for the first three draw span pontoons, Q, PA and PB, and placing both sets of layouts onto one drawing. Conflicts were identified with electrical, mechanical, and structural elements such as post tensioning ducts, rebar and piping. Revisions to the drawings were made to resolve these issues.
"The extensive integrated drawing process was intended to find conflicts between mechanical, electrical and structural elements prior to work being started on those elements," says Becky Hixon, state department of transportation spokeswoman. "By solving issues up front, WSDOT and Kiewit-General save time and money during the construction, and ensure pontoons are built right the first time."