Rescue in sight for massive tunneling drill stuck underneath Seattle

SEATTLE (Reuters) - The world's largest tunnel-boring machine, stuck for over a year deep underneath downtown Seattle, was within feet of rescue on Friday, a state official said, raising hopes that a stalled $3.1 billion roadway overhaul could get back on track. The machine, known as Bertha, stopped working in December 2013 after digging just 10 percent of a planned tunnel to replace an aging waterfront highway, leaving crews scrambling to determine how to rescue and repair the 2,000-ton drill. Using its own power, Bertha was able bore through nearly 20 feet of concrete on Thursday to break through a wall leading to the rescue pit's opening, the Washington State Department of Transportation said. There had been concern that Bertha, buried 120 feet underground, might not be able to move itself to the pit opening. The machine had experienced various mechanical issues, including increased temperatures, before it stalled out. The machine's breakdown and other construction issues have left the project two years behind schedule and sparked concern about cost overruns and other unforeseen obstacles. Supporters, including Seattle Mayor Ed Murray, have said it was important to make sure the corridor project is completed. The original highway overhaul was expected to cost $2 billion and be completed by 2015. The new timeline for replacing the busy Alaskan Way Viaduct, damaged in a 2001 earthquake, is 2017. State transportation officials, contractor Seattle Tunnel Partners (STP), and manufacturer Hitachi Zosen were readying next steps in Bertha's removal and repair, a project spokeswoman said on Friday. "STP has told us that taking the machine apart and lifting it to the surface will take significant time and effort," a statement said. The machine will have to be lifted by a massive crane specifically designed to hold its girth. (Reporting by Victoria Cavaliere; Editing by Cynthia Johnston and Eric Beech)