Bertha, the world’s largest tunneling machine, has been stuck under downtown Seattle since it broke in December 2013. Engineers have had to concoct a massive and expensive rescue plan—essentially a whole construction project in itself. And yesterday, the Bertha’s broken cutter head was finally hoisted out of the Earth.
In coffee shops and bookstores across Seattle this summer, advertisements for concerts and gallery shows shared space with a less common urban invitation: to a party for a really big drill.
The 2001 earthquake that brought down a length of State Route 99 running through downtown Seattle was a measly 6.8 on the Richter scale. But rather than rebuild the Alaska Viaduct, as the double-decker section was known, city officials instead decided to take the freeway underground in their very own Big Dig. To do…