text: Bertha Finally Breaking Through | Kansas Public Radio
  Bertha Finally Breaking Through
  It was the world's biggest tunneling machine, when it first chewed into the loose dirt and gravel on Seattle's waterfront in 2013. With a cutting head nearly 60 feet wide, it had been built in Japan and shipped across the Pacific to dig a two-mile-long double-decker highway tunnel under downtown.
  In Bertha's case, that meant digging an 11-story-deep pit to perform Herculean engineering efforts which insiders say were more challenging than the tunnel project itself.
  That's all behind Bertha, now.
  After the two-year-pit stop, it went on to complete its journey toward the Space Needle so smoothly that most Seattleites forgot about it. Many assumed it was still being fixed.
  But in fact, it's now at the finish line: At some point today, the 57.5-foot wide cutting head will gnash through the massive retaining wall on the north end of the tunnel, where a live video feed awaits to capture the moment --and perhaps the off-screen sound of engineers sighing with relief.