Sections slide under successfully this time
June 12, 2008 · Updated 1:06 PM
Trying again during a low tide, Tacoma Narrows Constructors (TNC) succeeded in mooring a shipload of new bridge deck sections underneath the old Tacoma Narrows Bridge that couldnt quite fit last weekend.
Washington State Department of Transportation spokeswoman Claudia Cornish said the SWAN left Commencement Bay early Thursday morning and arrived at the bridge site around 3:30 a.m., where it will remain for most of the summer.
Cornish said TNC will begin offloading the first of the 16 deck sections sometime in the first two weeks of July, waiting for another slack tide period before starting the lengthy and complicated process.
During its first attempt to moor the ship, TNC spokeswoman Erin Hunter said that some of the temporary scaffolding on the deck sections made contact with the bridge as the crews were attempting to moor the SWAN underneath it.
Hunter said no damage was done to any structure, and that the ship returned to Commencement Bay while TNC managers went over their calculations to ensure the mishap did not happen again.
She said the failed mooring attempt should not delay the overall schedule of the bridges completion.
Once the section offloading begins, crews will be placing them on the new span in a carefully plotted order designed to maintain equal stresses on the bridges two towers, which will pull the towers back to a plumb vertical position.
Cornish said the deck-lifting process, which includes two more deliveries of deck sections, will take about four months to complete.
The sections are expected to be completely assembled early next year, and once the deck has been bolted and welded together, the surface will be coated with a membrane and then topped by two inches of asphalt.
The west side span is currently closed to all marine traffic, and the areas surrounding the barge MARMAC, the gantry cranes lifting the sections and other equipment.
Boaters concerned about safety zones and the progress of deck section work can get updates from the U.S.C.G.s Vessel Traffic Service(VTS) via Marine VHF-FM Channel 14, or by calling 206-217-6151.
Updates on all areas of bridge construction can be obtained online at www.tacomanarrowsbridge.com