Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Bertha undergoing a $125 million underground repair

Bertha undergoing a $125 million underground repair

Bertha undergoing a $125 million underground repair

Figured this one would interest the general engineering audience:

Fixing a 7,000-Ton Drill

A 7000 ton tunnel boring machine nicknamed "Bertha" has been stuck under downtown Seattle since last December after it struck a pipe and a seal failed. Work is under way to enact a fix: a vertical shaft is being excavated to reach the stricken TBM, supported with massive concrete pilings. As I understand it, once the shaft reaches the depth of the TBM, the TBM will be inched forward, cutting through those pilings, until the front of it reaches the centre of the shaft. The damaged cutting head will then be detached, lifted up to the surface, and a new, more powerful cutting head will be lowered in place.

Not only is the engineering involved in planning and performing the fix quite extraordinary, the background debate about who is responsible for the colossal repair bill will be an interesting fight to watch.

RE: Bertha undergoing a $125 million underground repair

regarding the repair bill , there is no doubt whatsoever that the Seattle taxpayer will be saddled with it. Every Seattle project , whether executed or even just simply proposed, ends up soaking the Seattle/ King county taxpayer way in excess of the original projections. The contract T+C's seem to be produced by a kindergarten class.

"Whom the gods would destroy, they first make mad "

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close