The City of Seattle’s waterfront has undergone an extensive transformation over the past decade. It has involved reconstructing the 1930s Seattle seawall and boring a new 2.2 mile tunnel to create a subterranean waterfront corridor. An aging Alaskan Way viaduct has been demolished and a world-class waterfront district is in the process of being created.
At each of these stages, Barnhart has played a vital role. Most recently they were part of the final phase, joining forces with Granite Construction and Gary Merlino Construction to develop a concept to construct the new Elliot Ave. Bridge. It would be placed over some of the busiest live Burlington North Santa Fe (BNSF) railroad tracks in the Seattle area and surrounding region.
The topography of the area and close proximity to existing structures required months of planning and coordination among team members. This included the waterfront project team, the City of Seattle and BNSF. The challenge was to create a plan that would limit the impact to freight while maintaining an efficient and safe work environment.
Over the course of three days and two weekends, Barnhart placed 18 girders over the BNSF railroad tracks near Pike Place. They used their AC1300 (500 ton) and GMK6350 (350 ton) all-terrain cranes to set the concrete girders, which ranged from 63 to 150 feet long and weighed in excess of 79 tons. They were installed during six-hour windows at night when fewer trains were passing below.
This project was one of the first major structural milestones toward building the new Elliot Way. The girders will support a four-lane bridge over the tracks, which will be a key connection between the waterfront and Belltown for vehicles, pedestrians and bicyclists.
The work is part of a $728 million Waterfront Seattle program that is a complete redesign of the waterfront district. It is scheduled to be completed in 2024.