Story Summary

Bertha and Seattle’s waterfront tunnel

The Alaskan Way Viaduct Replacement Tunnel is a bored road tunnel that is under construction in Seattle. It is scheduled to open in late 2015. The 2-mile tunnel will carry State Route 99 under downtown from the Sodo neighborhood to South Lake Union in the north.

Since 2001, the proposed replacement of the Alaskan Way Viaduct has been the source of much political consternation.  Options for the structure, which carries 110,000 vehicles per day, included either replacing it with a cut-and-cover tunnel, replacing it with another elevated highway, or eliminating it while improving other surface streets and public transportation. The current plan emerged in 2009 when government officials agreed to a deep-bore tunnel.

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The Alaskan Way Viaduct winds past downtown Seattle. The viaduct, which was constructed in the 1950s and carries 110,00 cars a day, is slated to be replaced by a deep bore tunnel. (Photo credit: Stephen Brashear/Getty Images/2009)

SEATTLE — New and widening cracks were found along some of the Alaskan Way Viaducts girder supports Saturday, leading the Washington State Department of Transportation to schedule a viaduct closure so the cracks and what’s causing them could be better studied.

Transportation department officials said they planned to close the viaduct for an “in-depth” inspection on March 22. As part of the inspection, crews will install monitoring devices to track the movement and growth of the cracks over time.

WSDOT inspects the viaduct four times each year, including two inspections that require full closures. During the most recent inspection, transportation officials observed new cracks as well as widening cracks along the supports near Spring and Seneca streets. Officials said the new cracks were about 1/16″ wide.

The section of the viaduct where cracks was found is located more than a half mile north of the SR 99 tunneling machine. The cracks were not related to tunneling activity, officials said.

“These small cracks are evidence that the 60-year-old bridge continues to deteriorate, and will continue to need constant attention to remain open,” Tom Baker of the WSDOT said Monday.

This story will be updated as more information becomes available.

SEATTLE — The Alaskan Way Viaduct will be closed in both directions for inspections this weekend.


Bertha in the launch pit (Courtesy: WSDOT)

That will happen as we learn the tunnel that will replace it faces more delays. The boring machine won’t be chewing up dirt again for at least six months.

This tunnel project has seen setback after setback. The machine, nicknamed Bertha, hasn’t been running normally since December.

And at 10 p.m. Friday, the Alaskan Way Viaduct closed down so engineers can take a closer look at how the fragile structure is reacting to the work underground.

Bertha is stuck and the timeline for completing the Highway 99 tunnel keeps pushing further and further past the 2015 deadline.

“We would be obviously pleased to start tunneling earlier than that, but this isn’t the time to try to accelerate things or take shortcuts,” said Chris Dixon, who is with the contractor for the project, Seattle Tunnel Partners.

A series of broken seals means the biggest tunnel-boring machine in the world can’t push on.

Now Seattle Tunnel Partners, and Bertha’s Japanese manufacturers, are coming up with a plan to repair the damage.

“These things do happen on tunnel projects,” said Dixon. “We’re really testing the limits of the state-of-the-art for tunnel-boring machines.”

Contractors plan to dig a giant shaft between 11 and 20 meters wide and more than 100 feet deep so they can either fix the seals underground or bring the cutting head to the surface.

“We know that the seals need to be replaced. They’re still investigating the condition of the main bearing to see what needs to be done there,” Dixon added.

Sitting above Bertha is the Alaskan Way Viaduct, which will eventually be demolished.

The structure survived the magnitude 6.8 Nisqually earthquake 13 years ago, but officials worry another one could cause serious damage.

The viaduct has settled nearly a half-inch since tunneling began – and starting this weekend, engineers will be taking careful measurements to see if it’s sinking any further.

The survey work is part of ongoing, scheduled inspections.

“They want to make sure there’s no additional cracking or stress or widening of existing distress, or signs of any new distress in the bridge,” said Matt Preedy with the Washington State Department of Transportation.

Business owners on South Washington Street say the benefit of a new waterfront trumps what they call minor setbacks with Bertha.

“Years after it’s constructed and finished, nobody’s going to remember that,” said David Bovard, owner of Pioneer Pet Feed and Supply.

For decades, the Alaskan Way Viaduct has stood in the way of a clear view of the Puget Sound.

“We gotta take care of it, we gotta get the viaduct down before it falls down,” said Sake Nomi’s owner, Johnnie Stroud.

Bertha’s manufacturer is supposed to come back to the table in 10 days with detailed plans on exactly how they plan to repair the boring machine

Local News

WSDOT to drivers: Alaskan Way Viaduct is safe

SEATTLE — The Washington State Department of Transportation is reassuring drivers that the Alaskan Way Viaduct is safe.

On Monday, City Councilman Mike O’Brien raised concerns after news that the viaduct has settled 4/10 of an inch since tunneling began last year.


A view of the Alaskan Way Viaduct from ground level. (Photo: KCPQ-TV)

The contractor building the tunnel under the viaduct — Seattle Tunnel Partners — had agreed in its contract that the viaduct would not sink more than an inch total.

O’Brien said if the viaduct continues to settle, it may become unstable. So he wants the city to start coming up with a plan to close it.

But Todd Trepanier of WSDOT says people shouldn’t focus on the one-inch measurement.

“The viaduct doesn`t have a threshold, so to speak,” he said. “The viaduct is a structure of concern, with how the settlement is occurring. But it`s monitored continually to make sure it stays within the realms that we can keep traffic on it.”

O’Brien said public safety is his primary concern.

“I don`t doubt that everyone cares about public safety. It`s just when you`re working on multibillion-dollar projects, there`s a lot of pressures on both sides to perform.”

O’Brien said he’s putting together a list of questions to WSDOT and Seattle Tunnel Partners, so he and the City Council can have more information about what’s happening with the project right now and what could happen as it moves forward.

WSDOT is shutting down the viaduct this weekend, for its biannual inspection. So they say they’ll be able to take a look then and make sure everything happening to the structure is what was expected.

Local News

Viaduct still sinking: How low can it go?

SEATTLE — City Council members know the Alaskan Way Viaduct has been sinking for years and needs to come down.  But what they didn’t know until Monday was just how much the viaduct has sunk since last year, when the tunnel project began.

“There`s been 1/10th, maybe up to 4/10th of an inch of settlement that has occurred because of some of the contractor`s activities,” Todd Trepanier, of the Washington State Department of Transportation, told the City Council Monday.


Alaskan Way Viaduct in downtown Seattle. (Photo: KCPQ-TV/Seattle)

WSDOT says that much settlement was expected.  The agency said their contractor is monitoring the situation, and they’re ready to taken action to stop it from sinking more.

But City Councilman Mike O’Brien is concerned about the thousands of drivers who use the viaduct every day. 

“Originally they said the viaduct has settled 6 inches in the last 15 years,” he said. “And we were told it could go another inch before it would be too dangerous to be on.”

So he said there could be major problems if it sinks just 6/10th of an inch more.

But WSDOT said it’s far more complicated than that. They say there`s no magic number, when it comes to sinking, that would raise a red flag.

Their engineers are constantly monitoring all parts of the viaduct, and making safety adjustments as they go along.

“There`s a lot of eyes on this, and a lot watching of it,” says Trepanier.  “There really hasn`t been any settlement except what has occurred from contractor activities.”

O’Brien doesn’t think they need to stop the entire tunneling project right now.  But he said, given the latest update, the city should start making contingency plans for a possible viaduct shutdown.

“Unfortunately now we`re in a position where some of the hypothetical risks that we were talking about a few years ago are starting to play out.”

WSDOT shuts down the viaduct twice a year, so they can do thorough inspections of it. That’s happening this weekend.

City Council members are hoping WSDOT will be able to get a little more information about the viaduct during these inspections, and then they’ll know just how concerned they need to be.

Local News

Who will pay for Bertha cost overruns?

SEATTLE –  As the world’s largest tunneling machine sits idle 60 feet underground, tension mounts between the Washington State Department of Transportation and its contractor, Seattle Tunnel Partners.

The two sides say they are working together to fix Bertha. But it was evident during Tuesday’s press conference that the two sides had some major disagreements.

berthabonvoyageWSDOT says there is no indication that taxpayers will be responsible for any cost overruns.  STP at this point is not taking full responsibility for costs. They say there may be evidence that could take them off the hook but further analysis is needed.

“We believe there is evidence, but again it is something that takes further study and further analysis. If we feel like we have a valid case under the contract that entitles us to compensation, we will present that to WSDOT and make them make their final determination,” an STP spokesman said.

WSDOT disagrees, putting the liability on STP.

“Our contract is that they supply this machine, it’s a contractor-owned machine to complete this tunnel. We have an expectation that they would fulfill that contract,” Todd Trepanier of WSDOT said.

Earlier, Gov. Jay Inslee said, “We are going to insist the tunnel either gets built on time or the contractor is going to be financially responsible to the citizens of this state for every single penny of cost overruns that the contractor could eventually be responsible for.”

The two sides are at odds over a number of other issues. The contractor says a steel pipe found underground could have possibly damaged Bertha’s cutter head.

WSDOT says their independent experts tell them the steel pipe most likely is not the reason behind the clogged cutter head, although a conclusive reason has not been determined yet.

Five seals are also contaminated with sand and other debris, and crews are trying to determine why the seals failed. The assembly of seals have to be fixed before Bertha can get moving again.

The seals work as a lubricant, allowing Bertha’s cutter head to rotate properly without friction.  STP does not have a timeline on when Bertha will be fixed, but told WSDOT it “will take months,”  perhaps into the the summer or later.

The $80 million boring machine is replacing the Alaskan Way Viaduct. The mining was supposed to be done by  October 2014, with the tunnel opening to traffic by the end of 2015.

Bertha has dug only a 1,000 feet, it has 9,000 feet more to dig.

SEATTLE — The Washington State Department of Transportation dropped a bombshell in a late Monday night press release, saying it will now “take months” to repair or replace the seals on the $80 million Bertha tunneling machine that has been stalled under the city’s streets since early December.


Bertha in the launch pit (Courtesy: WSDOT)

Bertha — the world’s largest tunneling machine that was built in Japan — has been idle for the most part since early December. It was constructed to dig the State Route 99 tunnel along Seattle’s waterfront that will replace the aging Alaskan Way Viaduct.  Bertha began its work July 30, 2013, but so far the  tunnel extends just over 1,000 feet — about one-tenth of its projected 1.7 mile trip.

The tunnel was scheduled to open to drivers in late 2015. But Bertha sits idle, 80 feet below Seattle.

Inspections recently revealed that the seals on the machine’s cutter head were contaminated with sand, dirt and water.

“Replacing the seals is a complicated process and STP (the contractor, Seattle Tunnel Partners) is working closely with Hitachi Zosen, the tunneling machine’s manufacturer, to determine the best path forward.

“They are looking at two ways to access the seal area: through the back of the machine or by drilling an access shaft from the surface in front of the machine. Either way, this process will take months,” WSDOT said in its Monday night press release.

“They expect to make a decision by the end of the week, and once they do, we will share that information with the public,” the department said.

“STP has not yet fully determined the cause of the seal problems and to date, they have not shown any evidence that suggests the state or taxpayers will be responsible for cost overruns associated with these repairs. We have requested and expect detailed plans on how the repairs will be made and how STP can recover lost time on the tunneling project,” WSDOT said.

The tunneling project was estimated to cost $4.25 billion, with $2.8 billion coming from the state and federal governments.

“Since the machine is stopped and repairs need to be made, STP has also informed the city of Seattle that they can proceed with seawall replacement construction near the machine’s current location,” WSDOT said.

The problems with Bertha have led some critics to compare the project to that of Boston’s Big Dig project in the 1990s — which became the most expensive highway project in the U.S. and was plagued by escalating costs, scheduling overruns, leaks, design flaws and charges of poor execution.

Local News

New problems for stalled Bertha: Seal contaminated

SEATTLE — The State Route 99 deep-tunnel boring machine has been stalled since Dec. 6. State transportation officials said Friday that clogged cutterhead openings and high Berthatemperatures within the machine are causing the problem, and that one of Bertha’s seals has been found to be contaminated by sand, dirt and water.

The machine has been plagued by problems since it began tunneling in 2013. Bertha is already behind schedule in the digging of the SR 99 tunnel.

Officials do not yet know when work is expected to resume.

Tunnel workers performed 158 hours of hyperbaric inspections on the machine between Jan. 17 and Jan. 28. They found that many of the cutterhead openings were clogged with dirt and other material. A clogged cutterhead can affect the tunneling machine’s performance in the same way that a major obstruction would affect its performance, officials said.

Once the hyperbaric work was completed, it was determined that a major obstruction was not the cause of the mining difficulty. The more likely cause was the clogged cutterhead.

After the cutterhead was unclogged, the contractor moved the machine forward an additional 2 feet and installed one of the concrete rings that line the tunnel. On Jan. 28 and 29, higher-than-normal heat sensor readings appeared like they did on Dec. 6, 2013. In the course of investigating the temperature readings, STP discovered damage to the seal system that protects the tunneling machine’s main bearing.

STP is working with experts to determine the best fix for the issue, officials said.


Bertha in the launch pit (Courtesy: WSDOT)

SEATTLE — Bertha is stalled yet again, after the machinery overheated. This comes after crews were able to push the machinery forward about two feet on Tuesday.

WSDOT says the above-normal temperature readings Bertha is feeding back is similar to what stopped her progress in January. Outside tunneling experts are meeting with project teams and WSDOT next week to help determine what to do next.

It is still unknown what issues Bertha is facing underground. Crews say moving two feet this week created enough space to build the next concrete tunnel liner ring.

Local News

Bertha not moving, blockage cause still unknown

Bertha-stoppedSEATTLE — Bertha, the world’s largest drill, has been stopped in its tracks, 80-feet below Seattle, for a month and a half. And no one can answer why.

Crews are still working to create a new road and hammer out what will be a two story building that will house the control center for the underground tunnel. But so far, that tunnel extends just over 1,000 feet, about one-tenth of its projected 1.7 mile trip.

The enormous drill remains stalled since the warning lights went on in December. Matt Preedy, a deputy administrator with the Washington Department of Transportation, compares it to the ‘check engine’ light going off in your car.

“It doesn’t mean something is wrong,” said Preedy. “It means you should probably stop, and look, and see if there is something wrong.”

Over the last week, crews have been looking carefully, lowered down into the space just around Bertha’s cutting head. It’s called a hyperbaric inspection. They found a 3 and a half foot obstruction that is certainly causing problems for Bertha, but the chief reason the massive drill is stuck is still a mystery.

“Today we haven`t really found anything substantial, but we can`t really speculate much on how much longer it may take,” said Preedy.

The drill is apparently in good working order but WSDOT says it won’t move an inch until they know exactly what the problem is.