WSDOT Bertha's shield, pictured during assembly in Seattle in the summer of 2013. WSDOT Bertha's cutter head, pictured here prior to assembly in summer 2013, will be augmented by an improved main bearing and more robust seals, which repair crews will install this summer, according to the contractor. Related Links: Seattle Tunneling Behemoth Bertha Awaits Repairs to Bearing Seals Divers Searching for Way To Get TBM 'Bertha' Moving Again There will be no tunneling in 2014 of the new state Route 99 under downtown Seattle. The latest repair schedule, released on April 21, for North America’s largest tunnel-boring machine, dubbed
The market is generally healthy and steadily growing, and margins are up for large specialty contractors. Further, advances in design tools and owner demand for collaboration are giving subcontractors a seat at the table early on in projects.