World’s largest tunnel boring machine arrives in Seattle
Written by Marine Log StaffAPRIL 4, 2013—After a 5,000-mile, two-week-long journey from Osaka, Japan, the heavy lift ship MV Fairpartner has arrived at the Port of Seattle carrying what is believed to be the world’s largest tunnel boring machine.
Bertha being assembled at Hitachi Zosen in Japan
Built by Hitachi Zosen Corporation, the five-story-tall tunnel boring machine is called “Bertha,” after Bertha Knight Landes, who served as Seattle’s first female mayor—and the first of any major American city—from 1926 to 1928. The tunnel boring machine is being transported in total 48 pieces weighing 7,777 metric tons. When assembled, the $80-million Bertha will have a 17-meter diameter and a length of close to a 100 meters.
Bertha will be used to create the SR99 tunnel beneath downtown Seattle. The tunnel will replace the Alaska Way Viaduct, which will be cleared away in 2016. The tunnel is epected to be operational in 2015. First, however, crews at the port’s Terminal 46 will spend the next several weeks offloading Bertha in pieces. 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 its spot at the terminal to make room for an incoming cargo ship.
“Construction crews preparing for this machine’s arrival have accomplished an unbelievable amount of work over the past 18 months,” said Washington State Transportation Secretary Lynn Peterson. “Thanks to their hard work, tunneling will begin on schedule.”
Once crews finish building an 80-foot-deep launch pit east of Terminal 46, the stored pieces of the machine will be lowered into the pit for reassembly and testing, which will take two to three months.
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