Bridge deck delivery grazes span
June 12, 2008 · Updated 1:05 PM
The ship delivering the first load of deck sections for the new Tacoma Narrows Bridge had to turn around this week after its cargo hit the underside of the old bridge, according to the Tacoma Narrows Constructors(TNC).
Spokeswoman Erin Hunter said 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.
No damage was done to any structure, Hunter said, explaining that the ship was moving so slowly that crews were able to stop and turn around once they realized some of the scaffolding struck the bridges catwalk and rolled over.
Hunter said the ship then headed back to Commencement Bay, where TNC managers will be looking again at all the measurements and evaluating everything to ensure its not repeated.
She said the actual off-loading of the bridge sections, scheduled to begin the second week of July, should not be delayed by the mishap, and that the SWAN will return to moor at the bridge in time.
The boat left Commencement Bay Friday afternoon and headed to the Tacoma Narrows bridge, where it was expected to remain until all of its deck sections were lifted into place.
Since June 19 and continuing until Nov. 15, the U.S. Coast Guard has been enforcing several safety zones for the duration of the deck installation phase, and violations can incur a $32,000 fine.
The zones include a 500-foot, moving perimeter around the construction barge Marmack 12 at all times, another 500-foot zone around the waters directly below the lifting beams that will be installing each large section of the bridge, along with a complete closure of the waters underneath the West, or Gig Harbor, span of both bridges.
Hunter said that particular area will be off-limits because the ship carrying the sections will be docked there as crews carefully unload and set each 420-ton piece into place.
To make sure the weight is evenly distributed at all times along the new bridge, she said crews have a detailed map outlining where each section of the bridge should be added. While this is happening, the ship will stay under the west side of the bridge and barges will carry each section to its destination on the span.
The deck 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.
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