For four years, Bertha, once the world’s largest tunnel-boring machine, came packed not only with 57.5-ft worth of diameter and over 8,000 tons of girth, but never-ending drama.
As we move closer to the 2019 milestone of opening the new State Route 99 tunnel under downtown Seattle, officials can start making plans for removal of the aging Alaskan Way Viaduct, the entire reason the new 1.7-mile tunnel was conceived originally.
It took years for Bertha, a tunnel-boring machine, to mine 1.7 miles underneath downtown Seattle, but crews will spend just five months removing the 57.5-ft-dia machine from the receiving pit near Seattle’s Space Needle.
The holiday season provided some rest for Bertha, the tunnel-boring machine roughly three-quarters of the way through its route to bore a new State Route 99 tunnel under downtown Seattle, but that doesn’t mean crews have had it so easy.
The vast majority of 2016 Bertha news has fallen into the positive category, a welcome respite for the $3.1 billion project to replace Seattle’s aging Alaskan Way Viaduct with a 1.7-mile-long bored tunnel.
