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Bertha repairs will take months: WSDOT

The contractor building the Highway 99 tunnel will decide by the week's end whether to access a damaged bearing seal through the back of the machine, or by digging a hole.
Bertha's cutter head is lifted into place, during the machine's assembly in 2012.

Bertha's cutter head is lifted into place, during the machine's assembly in 2012. WSDOT

Fixing Bertha’s main bearing seal will take months, Washington State Department of Transportation said Monday night.

To repair the seal, Seattle Tunnel Partners, the contractor digging the Highway 99 tunnel, will have two options. One is to dig a shaft in front of the idled boring machine, which sits 60-feet beneath the ground in Pioneer Square, amid groundwater-inundated earth and muck. The other is to access the bearing through the back of the tunneling rig. The company, WSDOT said, will make a choice about the best way to undertake the repairs by the end of this week.

“[Seattle Tunnel Partners] has not yet fully determined the cause of the seal problems,” WSDOT said late Monday night in a press release.

The nearly $90 million machine has moved a little more than four feet since Dec. 7, after it encountered unusual resistance while digging. The damaged seal protects Bertha’s main bearing, which allows the machine’s 57.5-foot “cutter-head” to spin. After moving the machine a short distance during the last week of January, sensors showed unusually high operating temperatures. The hotter than normal readings led workers to find the busted seal. WSDOT has not indicated whether any other part of the machine’s $5.1 million main bearing assembly is damaged.

As for who will pay to fix the machine, Seattle Tunnel Partners, WSDOT said, has “not shown any evidence that suggests the state or taxpayers will be responsible for cost overruns associated with these repairs.” The contractor was not available for comment when WSDOT announced the extent of the delays.

For now, WSDOT said, the stalled machine will not cause delays with the Elliott Bay Seawall replacement project, which is underway nearby. The Seattle Department of Transportation is heading up that project. Old age and wood-boring sea creatures called "gribbles" have left the seawall vulnerable to severe damage or failure in the event of a strong earthquake.

Mayor Ed Murray announced on Monday that he’d formed a new Office of the Waterfront, responsible for planning and managing city projects and partnerships in the area. He addressed the seawall’s relationship to the tunnel in an emailed statement.

“The Seawall needs to be replaced because it isn’t safe,” Murray said. “This public safety issue doesn’t disappear while the Seattle Tunnel Partners and WSDOT work to get Bertha moving again.”

The bearing seal wasn’t the only problem Seattle Tunnel Partners found in recent weeks. Investigations that followed the early December shutdown revealed that the spokes on the machine’s cutter head were jammed with soil. WSDOT Program Administrator Todd Trepanier said last week that a variety of factors, including soil type, additives injected into the mined soil and the machine’s speed, could’ve caused the clog. 

The deep bore tunnel is the centerpiece of the estimated $3.1 billion Alaskan Way Viaduct replacement project. Bertha is scheduled to finish digging the 1.7-mile underground roadway, which runs from Sodo to South Lake Union, in late 2014. A four-lane highway inside the tunnel is slated to open by the end of 2015. So far the machine has completed about 1,000 feet of mining and is stopped near South Main Street. WSDOT said it is waiting for Seattle Tunnel Partners to provide a plan that details how they can "recover lost time." A January Crosscut analysis raised questions about whether the drilling can be done in time.

Based on the contract terms, Hitachi Zosen, the company that manufactured the machine, owns it for the first 1,300 feet of digging. After that point, Seattle Tunnel Partners, a partnership between Dragados-USA and Tutor Perini, will take over ownership of the tunneling rig. Hitachi Zosen representatives are here, working with Seattle Tunnel Partners to diagnose and fix Bertha’s mechanical problems.

Bill Lucia writes about Seattle City Hall and politics for Crosscut. He can be reached at bill.lucia@crosscut.com and you can follow him on Twitter @bill_lucia.


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Comments:

Posted Tue, Feb 11, 7:25 a.m. Inappropriate

Nothing to see here folks. Machines break, and are repaired, all the time.

What is interesting is that there is a spare already manufactured, and in europe. Seems someone may have had a clue this part may fail.

Geezer

Posted Tue, Feb 11, 9:55 a.m. Inappropriate

^^^^^the screen name above^^^^^^

. . . is used by somebody employed by the Tim Ceis PR firm.

crossrip

Posted Tue, Feb 11, 9:55 a.m. Inappropriate

The bearing is toast. The seals are damaged, which allowed sand to get into the bearing. It was the bearing that overheated -- seals don't overheat. When a bearing gets sand in it and overheats, it is damaged. That is why the bearing overheated -- because it is damaged.

How can anyone say with a straight face that a 6-month delay in drilling will not prevent the tunnel from being completed on time? lol Of course this will prevent the tunnel from being completed on time, if it is ever completed at all.

They should immediately stop all work at both ends of the tunnel until it is determined that the boring machine can be re-designed and rebuilt while it is 60 feet underground. There is going to be at least a 6-month delay in drilling, so they should delay all other parts of the project until the drilling resumes, if it ever does.

Lincoln

Posted Wed, Feb 12, 11:08 a.m. Inappropriate

The Bore Tunnel is NOT the best alternative. It was only chosen to supposedly avoid disruption of traffic on the AWV. If completed, it displaces the most vehicles from SR99 through Queen Anne and South Lake Union to I-5 and along Alaskan Way and other city streets. In other words, to avoid disrupting highway traffic, already terrible street traffic worsens with consequent number of traffic accidents increasing. Wsdot directors, department heads and cohorts at Sdot are evil bastards. Their final insult, if Bertha is allowed to finish, will leave historic Seattle in piles of rubble and crushed bodies. The Bore Tunnel makes buildings above vulnerable to collapse in earthquakes. Uppity Seattle liberals will be taught to fear the boss's running the show.

Wells

Posted Tue, Feb 11, 10:13 a.m. Inappropriate

If this can only be fixed from the front, that is by digging a hole, and we do fix the problem but then we have the seal/bearing problem again after the machine has gone some distance, will it be feasible to dig another hole from all locations where the machine could be located? If not, then what do we do?

I hope our regional leaders can have a realistic conversation about what the real cost of this tunnel is going to be. While it would cause a lot of people to lose face, if we can't pull this project off without massive cost overruns, then it is going to set us way back on getting anything else done.

sjenner

Posted Thu, Feb 13, 12:57 p.m. Inappropriate

It's like your car breaking down on the freeway in the worst spot. You don't want it to happen. But it's not likely to happen. Neither was it like for this to happen where it did. The odds of it happening again are high..but that doesn't mean it is impossible. This is one of those things where you know it probably won't happen...and maybe you, we, everyone should hope to hell it won't happen.

Keep in mind that two of them just built tunnels from downtown to the University District going under Portage bay without a problem and months ahead of schedule. Not every construction project has problem after problem

acbytesla

Posted Tue, Feb 11, 8:14 p.m. Inappropriate

Before they replace the bearings and send Bertha on her way, you'd think they'd want to clear identify WHY the bearing failed, so that it doesn't do happen again (underneath the Federal Building seems to be the accepted worst case scenario).

Posted Tue, Feb 11, 10:59 p.m. Inappropriate

Boston had the "Big Dig" Seattle has the "Slow Dig".

Djinn

Posted Wed, Feb 12, 4:55 p.m. Inappropriate

Well, now Seattle has the "No Dig" ... what are the odds it will ever start up again?

Posted Wed, Feb 12, 5:52 a.m. Inappropriate

Is there a spare bearing? It's not a an off the shelf items I would bet. How long to manufacture and transport it to Seattle?

Cameron

Posted Thu, Feb 13, 12:51 p.m. Inappropriate

You're right it isn't an off the shelf item. But WSDOT insisted that a spare be manufactured as part of the project. It is built and only needs to be shipped. It will be here long before they are in position to replace it.

acbytesla

Posted Wed, Feb 12, 1:41 p.m. Inappropriate

R.I.P. Bertha

salmonjim

Posted Wed, Feb 12, 2:37 p.m. Inappropriate

Complicated - yes. Delay - yes. Greater cost - yes. R.I.P? That is just silly. It's amazing how many mechanical engineers/geophysical scientists/wannbes come out of the woodwork every time a tunnel story gets posted.

It's like flies to honey, or S*** I suppose.

Lily32

Posted Wed, Feb 12, 4:48 p.m. Inappropriate

Lily32 prefers the 'don't question authority' syndrome.

Posted Fri, Feb 14, 2:28 p.m. Inappropriate

Whats silly is this entire tunnel fiasco, the best is yet to come cha-ching

salmonjim

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