Light rail trackway completed between Seattle and Tukwila

Sound Transit contractors on Friday hoisted the last of 2,457 concrete segments into place to finish almost five miles of elevated light rail trackway between South Seattle and Tukwila.

“We have essentially built a five-mile-long bridge connecting Seattle and Tukwila,” said Sound Transit Boardmember and King County Councilmember Julia Patterson. “Soon we’ll be carrying tens of thousands of people every day on the guideway above us.”

About 85 percent of the Tukwila trackway is elevated, supported by 190 columns rising as high as 70 feet. The contractor employed an innovative construction method never before seen in our region, using a 385-foot-long gantry truss that “walked” from column to column along the alignment. The gantry lifted each 35-ton pre-cast concrete segment into place and supported the segments while construction crews fastened them together with steel cables. Once a span between two columns was completed, the gantry moved on to the top of the next column.

“The on-schedule, on-budget completion of this landmark project is a major accomplishment,” said Patterson.

Construction of the 15.6-mile light rail line between downtown Seattle and the airport is more than 75 percent complete and moving forward on schedule toward its 2009 opening. The line between downtown and Tukwila will open for passengers in summer 2009, with free shuttles to the airport until the December 2009 opening of the 1.7-mile extension that will provide direct airport service.