Fascinating. Is there really any other way to describe Bertha, the world’s largest diameter tunnel boring machinethat arrived to Seattle this week after a 5,000-mile ocean journey from Osaka, Japan?
The next big step for Bertha is getting her 41 pieces—the largest weights about 900 tons—transferred from Seattle’s Elliott bay ports to the 80-ft-deep pit to the west of Seattle’s two stadiums. After that she’ll be rebuilt again and prepped for digging this summer.
For those already near downtown Seattle, there were various points along the sailing route to witness the arrival and you may still catch a glimpse of crews moving pieces of Bertha on and off the ship. For those not venturing to the site, a live webcam will go online in the coming days at the Port of Seattle’s Terminal 46 to show off exactly how Bertha—in all her pieces—is getting along.
The $80 million machine will eventually rip through the earth below Seattle, digging a tunnel 1.7 miles long and over 57 ft in diameter.
Bertha was built in Osaka by Japanese firm Hitachi Zosen Corporation and then taken apart and loaded on the Jumbo Fairprtner in March. The trip started on March 19, with Bertha entering Elliott Bay on April 2.
The pieces are arranged strategically on the Fairpartner so that crews unloading the ship can move them to predetermined storage locations within the work zone. Offloading crews must work around regular port activities, so there could be periods of inactivity or times when the Fairpartner has to leave her spot at the terminal to make room for an incoming cargo ship.
The stored pieces of the machine will eventually be lowered into the pit for reassembly and testing, a process that could take three months.
Work has also started near the north end of the Battery Street Tunnel to prepare the area where Bertha will emerge at the end of tunneling.
Fascinating, I say, fascinating.
Tim Newcomb is Engineering News-Record’s Pacific Northwest contributor. He has also written for TIME, Popular Mechanics, Popular Science and more. You can follow him on Twitter at @tdnewcomb or visit his website here.