seattle\'s massive tunneling machine on move again

by:Gewinn     2019-09-13
SEATTLE —
Bertha has reached her goal.
Seattle\'s troublesome tunnel drill has broken through 20-foot-
The thick wall of the rescue pit around 11: 15. m.
Pacific Thursday
A video of a TV helicopter shows a huge dust coming out of the pit when the machine appears.
After starting driving in the city center
2013, the machine was forced to stop after creating a tunnel of 1,000 feet.
It is believed that the seals designed to prevent sand and water from reaching the bearing failed.
The elevator shaft collapsed last week and four workers were injured in another part of the project.
One of the four is still in the hospital.
Seattle tunnel partner, the contractor who built the new highway 99 tunnel under downtown Seattle, is trying to repair Bertha-
The largest tunnel machine in the world
Therefore, it can complete the excavation of its way forward.
In preparation for the short excavation, the Seattle tunnel was drilled around the pit wall.
The work was completed on Tuesday.
State Transport officials said Bertha had advanced about 6 feet kilometers on Wednesday night;
It stopped before it resumed on Thursday morning so that the staff could build two concrete tunnel rings.
Chris Dixon of the Seattle tunnel partner said that Bertha still has 40 feet people to go to the rescue pit where the domestic demand is going.
Once there, the staff plan to remove the front of the machine and pull it out of the pit with a crane so that the staff can replace the bearings and seals.
\"These subsequent shifts will be faster because we are not digging and we are just pushing the machine forward,\" Dixon said . \".
The tunnel, which will travel about 2 miles below the city, aims to replace the Alaska Highway viaduct damaged by the 2001-magnitude earthquake.
The project was two years later than planned and transportation officials did not have a clear date for when Bertha would resume construction of the SR 99 tunnel.
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