Crews building the new Tacoma Narrows bridge hauled the transport vessel the Teal out of the Narrows on Thursday, having finished unloading the 15 massive deck sections the ship brought from South Korea.
The Teal steamed out from under the bridge at 2:30 p.m., hung a big U-turn south of the bridge and then headed for Commencement Bay, where crews will remove and store custom-designed mooring equipment.
Wednesday afternoon and evening, Tacoma Narrows Constructors crews aboard the Teal used cutting torches to cut away the custom-made packing material attached to the ship’s deck and used cranes to transfer the heavy steel pieces onto work barges.
Meanwhile, more than 5,000 miles away in South Korea, crews finished loading the Teal’s sister ship, the Swan, with the third and final shipment of 15 deck sections and readied the ship for its return trip.
Unless it encounters bad weather as it crosses the Pacific, the Swan will arrive in Tacoma around Thanksgiving, said Claudia Cornish, an information manager with the state Department of Transportation.
Thirty-one of the 46 sections that will support the new bridge’s mile-long roadway hang from the new bridge’s main cables, though six are not in their final positions and need to be moved sideways into place.
While waiting for the Swan to return, bridge workers will “trapeze” sections on the Tacoma end of the bridge into position and begin permanently bolting and welding the sections together, Cornish said.
So far, the deck sections have been temporarily pinned together, allowing the new bridge’s main suspension cables to gradually form the proper curve with each deck lift.
Now that two-thirds of the deck sections are in place, the cables are close enough to their final positions to allow permanent bolting to begin.
The bridge builder hopes to have all 46 sections in place on the main cables by the end of December, but state project manager Linea Laird cautioned that the schedule depends on the weather.
High winds and freezing temperatures could complicate and slow the lifting operation, Laird said.
So far, TNC has been assembling the deck sections at the anchorages and in the center of the span.
The deck sections aboard the Swan will be placed next to and within the legs of the bridge towers – positions that require difficult and time-consuming trapezing maneuvers, according to engineers.
On average, the deck sections weigh 450 tons and measure 120 feet long. All are 78 feet wide and 30 feet deep.
Rob Carson: 253-597-8693