VIDEO: Why the Highway 99 tunneling machine ‘is a submarine’

| Alaskan Way Viaduct | Highway 99 tunnel | West Seattle news

WSDOT just published that new video about working hyperbarically with the Highway 99 tunneling machine as it continues a maintenance stop before moving on to dig the final 25 percent of its 9,270-foot path – explaining, among other machines, that the machine is underwater as well as underground and is therefore something of “a submarine.” During the maintenance work that’s been under way since January 5th, crews have replaced 250 cutterhead tools, like these:

See the latest tunnel update here; the machine’s current location is shown here.

Mr. B January 13, 2017 (10:07 am)

There’s lot’s of tunnel haters in this town but you have to respect all of of the engineering and technology which goes into construction.

sw January 13, 2017 (10:12 am)

Absolutely correct. Many do not fully realize that this is a world-class construction project which will influence other projects worldwide for years to come.
Heather January 13, 2017 (10:54 am)

This project has been absolutely amazing to watch and I’ve pretty much forwarded all the videos to everyone I know. Kinda geeking out.

dsa January 13, 2017 (11:21 am)

I only hate that a tunnel was selected for this project.

TheKing January 13, 2017 (12:53 pm)

I don’t hate the tunnel. The 3.2 BILLION dollar price tag is crazy. Especially as 35th ave looks like a leftover war zone
- West Seattle since 1979 January 13, 2017 (1:57 pm)
  
  Different government entities though.
- old timer January 13, 2017 (2:17 pm)
  
  If 35th was lined with $million dollar condos, it would look a lot better.
  
  You have to remember, we suburbs exist only to feed downtown.
  
  If there is something left over, well we can fight each other for the scraps.
- chemist January 13, 2017 (2:30 pm)
  
  That’s not a road defect, that’s a special feature that controls vehicle speed. :-)
Mike January 15, 2017 (9:16 am)

Why would you hate the tunnel as the option picked? It’s the best for your money and longevity and safety, it’s a win all around. Replacing the viaduct or more patch fixes to the existing viaduct was the absolute worst idea.

wscommuter January 13, 2017 (4:16 pm)

@TheKing … what do you expect to pay for a project like the SR 99 job? $3.2Billion is what it costs to replace a major highway over two + miles where most of the work is done in a 58-foot wide bored tunnel. This is the biggest TBM ever used.

And understand, the $3.2 billion isn’t just the tunnel – its also all the work (mostly completed now) south of the tunnel and as well, the work being done north of the tunnel.

Infrastructure isn’t cheap. But doing is right – building the tunnel – will prove to be one of the smartest decisions our state government leaders have ever made.

TheKing January 13, 2017 (5:18 pm)

It’s not even done yet and you are putting it in the same category as the pyramids. Let’s hope they don’t run into another pipe. We only have so many billions left to squeeze out of the taxpayers.
- Mike January 15, 2017 (9:17 am)
  
  You think politicians do math? hahaha, they only count their bank account balance.

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