After being blocked by an obstruction ("the object") which left it idle just over two years ago, repair work has continued on Bertha, Seattle's enormous tunnel-boring machine. Now, reports KOMO News and The Seattle Times, Bertha is once again ready to work. From The Times' coverage: Tuesday morning's push of one and a half feet provided Seattle Tunnel Partners (STP) enough space behind Bertha’s drive motors to fasten the next concrete ring at the 1,085-foot mark of the planned 9,270-foot tube. Chris Dixon, STP project manager, is calling this a testing phase. The team is measuring how Bertha responds while rotating through heavy loads of compacted sand. Last week, a fixed steel arm in the front end broke and needed a one-day repair. ... This week’s two-day push would leave the nose of the drill just short of the north edge of the concrete vault, dug in 2014 so STP could reach and lift the 4million-pound front end for repairs. The winning bid from STP called for the tunnel to be completed this month.