West Seattle, Washington
Back on Monday, we reported that WSDOT was launching (and advertising) an info campaign about the Alaskan Way Viaduct demolition that’ll start after the Highway 99 tunnel opens, expected in early 2019. As part of it, an “online open house” was set to go live today. While it wasn’t ready when we looked this morning, it is now. Go here to check it out, including some of the side topics that have been discussed here, including the transitional tunnel-to-Viaduct plan, and what happens to the Battery Street Tunnel. The last page of the “open house” site includes a chance to comment – and remember there’s also an in-person open house downtown a week from tonight (drop in 5-8 pm Thursday, August 10th, 1400 Western Ave.).
Though the Highway 99 tunnel is still about a year and a half from opening, WSDOT is ready to talk about what happens once it’s open – the demolition of the Alaskan Way Viaduct. Published on the AWV website today:
With tunnel boring complete, we’re deep in the planning stages for demolition of Seattle’s Alaskan Way Viaduct. On Thursday, we’ll launch an online open house to show what’s ahead and give the public a chance to comment on the work to come.
Removing the seismically vulnerable viaduct will be the most visible change to Seattle’s waterfront in decades. The demolition work begins after the new State Route 99 tunnel opens, which is estimated for early 2019.
WSDOT has successfully completed this type of work before. In 2011, we demolished the viaduct’s southern mile and built a new road in its place. However, the remaining section of the viaduct is more challenging, as it is much closer to buildings, businesses, homes and the busy Colman Dock ferry terminal.
Demolition is expected to take up to nine months, with the viaduct being demolished in sections to minimize localized disruptions. This contract will also involve other project elements, like filling in the Battery Street Tunnel and reconnecting several surface streets across Aurora Avenue North, which will take additional time.
Several weeks before the new tunnel opens, WSDOT will shift Alaskan Way to the west of the viaduct, which will allow traffic to move along the waterfront before and during viaduct demolition. This new video below explains some of the planning for the demolition.
Online open house
The online open house will be live from August 3 – 14.
In-person open house
WSDOT is also hosting an in-person open house on August 10 for anyone interested in the work or who wants to speak with project staff. Representatives from Waterfront Seattle, Center City Connector Streetcar, Colman Dock, King County Metro and One Center City will also be available to answer questions.
Date: Thursday, August 10
Time: 5 to 8 p.m. (walk-in style, no formal presentation)
Where: Waterfront Seattle, 1400 Western Avenue
We’ll publish a reminder Thursday when the “online open house” is ready to go.
(Note: WSDOT is advertising the open houses on WSB right now to help get the word out.)
The northbound Highway 99 closure for the Seafair Torchlight Run is over, and 99 is open again both ways. But if you are headed downtown, remember that the parade is now under way, which means surface-street closures continuing for the next few hours, primarily 4th Avenue – the parade heads southbound on 4th from Seattle Center to the International District.
(SDOT screengrab from 3:45 pm)
6:37 PM: If you’re heading back this way from points north of downtown, note that SB Highway 99 is closed from Denny, just before the Battery Street Tunnel, to Columbia. This is in the aftermath of a fire under the Alaskan Way Viaduct that closed NB 99 for a short time as well (but that’s since reopened). Seattle Police report an arrest related to the fire:
Both the Seattle Police and Seattle Fire Department responded to a report of a brush fire in the 1900 block of Alaskan Way just before 4 p.m. Sunday. The firefighters quickly extinguished the blaze that engulfed a nearby homeless encampment. Officers arrested a man who witnesses claimed set the fire. Officers will book the man into King County Jail for investigation of arson.
The Seattle Department of Transportation will be inspecting the underside of the viaduct in the area to see if there was any structural damage caused by the heat.
7:48 PM: SDOT says Highway 99 has reopened southbound, too.
Tonight (Wednesday), after the peak of evening commute, you might want to avoid The Viaduct. WSDOT explains why:
Drivers who use State Route 99/Alaskan Way Viaduct to get through downtown Seattle should expect up to thirty-minute delays on Wednesday evening, July 12.
Officers from the Seattle Police Department will perform intermittent rolling slowdowns on both directions of SR 99/Alaskan Way Viaduct between 7:30 and 9:30 p.m. The rolling slowdowns will allow crews to safely film a commercial.
Northbound SR 99 traffic will gradually slow to 10 mph starting near South Royal Brougham Way. Southbound SR 99 traffic will slow down near Western Avenue. Pilot cars will lead the slowed traffic across the viaduct until the roadway is clear, then allow traffic to accelerate back to highway speeds.
In case you missed the alert in our daily traffic coverage – here’s another reminder, just in from WSDOT, about this Sunday’s NB Highway 99/Alaskan Way Viaduct closure:
The 2017 Seattle Rock ‘n’ Roll Marathon will close northbound SR 99 through downtown Seattle on Sunday, June 18. Northbound SR 99 will be closed from South Hudson Street to Halladay Street between approximately 7 a.m. and 3 p.m.
Although the marathon is scheduled to last until 3 p.m., the Seattle Department of Transportation is planning to reopen SR 99 and the Alaskan Way Viaduct as early as possible once the runners have passed this part of the course. Please refer to the event website for more specific information on other road closures and parking restrictions related to the event.
Here’s a map showing the closure zone, from south of West Seattle to north of downtown.
By Tracy Record
West Seattle Blog editor
If all goes well, the Highway 99 tunnel will open in January 2019 – after three weeks with no Alaskan Way Viaduct, and no tunnel.
That’s what Joe Hedges, the West Seattle resident who currently runs the Alaskan Way Viaduct Replacement Program for WSDOT, told the West Seattle Chamber of Commerce at its monthly lunch meeting today.
His presentation was introduced by Pete Spalding, the Chamber’s government-affairs committee chair, who also has long served as a member of the Viaduct/Tunnel project working group advisory committee.
Hedges called it a “wonderful treat” to be able to “come home” for the presentation. He’s been running the project for more than a year.
The “most important lesson learned” – “This Viaduct Replacement Program is a couple decades old, and the contribution to it involves a couple thousand people … what’s important is that (all that) is going to transform Seattle for the next couple centuries.”
He didn’t bring a slide deck, saying he just wanted to “catch you up, tell you where we’re at, where we’re going.” Right now: “Out of 32 projects that comprise the program, and $3.4 billion, we’re about 85 percent complete …” Read More
It’s been a month and a half since the Highway 99 tunneling machine finished digging. Besides roadbuilding and other work underground, the task of breaking the machine into pieces continues. Here’s the latest from WSDOT.
In the disassembly pit near Seattle Center, work is continuing around the clock – cutting, lifting and removing heavy pieces of the SR 99 tunneling machine. As of yesterday, eight small spokes and the bulk of five larger spokes have been taken out of the disassembly pit. More than 50 percent of the iconic cutterhead has now been removed.
Crews are also working inside the tunnel to remove the tunneling machine and other pieces of the tunneling operation no longer needed now that the tunneling portion is complete. Seattle Tunnel Partners is removing conveyor system components which had been used to carry the dirt underneath Seattle out to waiting barges. Temporary utilities, hydraulic lines and hoses are also coming out. And STP has started disassembling the back end of the trailing cars that carried all the equipment for tunnel-building. In all, eight thousand tons of equipment will eventually be removed from Seattle’s new tunnel to clear the path for building the rest of the double-deck road inside.
See five more photos accompanying this update on the WSDOT website. The most-recent schedule projects that the tunnel should open to traffic in early 2019, with demolition of what remains of the Alaskan Way Viaduct to follow.
Not far from the most recognizable above-ground Seattle icon, the Highway 99 tunneling machine finished its 9,270-foot journey under watchful eyes this morning, as shown in our as-it-happened report earlier.
Photojournalist Christopher Boffoli was there for WSB and put together these video highlights:
If you noticed the drone – that was operated by WSDOT, which has since published this minute-long highlight reel:
So – now what? First: The tunneling machine, which arrived in pieces four years ago, will be taken away in pieces. After the cutterhead’s appearance this morning, removal of the braces began.
WSDOT elaborates on what’s ahead:
STP will disassemble the machine by cutting it into pieces. The pieces will be removed from the pit by crane and placed on trucks. Due to roadway restrictions, each truckload will weigh no more than 20 tons.
Some pieces of the machine may be reused on other tunneling projects, while others will be recycled. Because the machine is so large, removing it will likely take several months.
And then there’s a lot of work to be done inside the tunnel – digging it, and “building rings” along the way, was just the groundwork. This WSDOT post goes into details of what happens inside, from road-building to systems installation to testing and commissioning.
Once the tunnel is tied into the surface network, as recapped in the Viaduct/Tunnel FAQ (and discussed in WSB comments), here’s how Highway 99 is planned to connect to the south end of downtown:
Outside the tunnel, other matters remain unsettled. A big one: How much will the toll be? $1-vicinity recommendations were made three years ago. The Washington State Transportation Commission is charged with determining the final toll but there’s no date set for a vote yet. And of course you’ve heard a lot about court fights over cost overruns, mentioned again today in Seattle Times transportation reporter Mike Lindblom‘s look at what’s ahead. (Asked today about the cost overruns, Gov. Inslee said, ““There will be other days to talk about paying for this. We know that our State is going to be insistent that the contractor be financially responsible for the project. We have to get that resolved. I know that will be resolved. And I think there is reason for confidence that the State is going to be held harmless here.” Mayor Murray, asked about a legislator’s proposal to require the city to cover those costs, said today, ” I know we have our annual ‘Let’s bash Seattle’ down in Olympia every legislative session. But again it is a State project and the State will make sure it gets paid. And we will pay for the brand new park that will knit Seattle back to its waterfront.”)
Once the tunnel is open – that clears the way for the remainder of the Alaskan Way Viaduct, which opened 64 years ago today, to be torn down. It’s been more than five years since the south mile was demolished.
11:06 AM: Now that WSDOT says Bertha the tunneling machine is in the final foot before breakthrough, we are going to do what everybody else is doing and put up the live stream. What we’re hearing from those on scene: It’s dusty. Very dusty. More to come. (And if you just want to check back later to see how it all came out, so to speak, Christopher Boffoli is there for WSB and we’ll have pics from him.) If you use Twitter, watching tweets with the hashtag #BerthaBreakthrough is a mix of commentary, observations, humor, and memories (WSDOT notes that today is the Alaskan Way Viaduct’s 64th birthday).
11:28 AM: Christopher sends this view of what it looks like where he and other media are right now.
The site was opened to media about two hours ago. And now as we type this – it just happened:
The cutterhead is visible #BerthaBreakthrough
— Bertha (@BerthaDigsSR99) April 4, 2017
11:35 AM: Pic from Christopher at the pit:
WSDOT has said it’ll take “weeks” before the machine is in its final position in the pit, to be broken down and hauled away in pieces … which is how it arrived, four years ago, via ship from Japan.
12:07 PM: Just in from Christopher, a new, clear view as the cutterhead continues its slow breakthrough:
And here’s the official news release just sent by WSDOT:
A year ago, SR 99 tunnel crews were about to face their biggest challenge: a trip beneath the Alaskan Way Viaduct they were working to replace. Today, with the viaduct and more than 9,270 feet of new tunnel safely behind them, there was nothing left to face but daylight as the SR 99 tunneling machine chewed its way into a pit near Seattle Center.
Bertha’s 1.7-mile drive beneath Seattle came to a successful end Tuesday afternoon, 64 years to the day since the viaduct first opened to traffic. Led by the Washington State Department of Transportation, and designed and built by contractor Seattle Tunnel Partners, the tunnel project will move a two-mile section of SR 99 underground when it wraps up in early 2019. Crews will then demolish the viaduct, clearing the way for the city’s new waterfront.
“This is a historic moment in our state’s transportation history,” Gov. Jay Inslee said. “Innovation and perseverance are the engines that keep Washington in the forefront. There is still more work ahead but this moment is one worth celebrating.”
Crews will spend the next several days removing steel support braces that stand between Bertha and the interior of the 90-foot-deep disassembly pit. When the braces are gone, crews will drive the machine into its final position and begin cutting it into pieces for removal. As owner of the machine, the contractor will determine which pieces could be salvaged for use on other projects or recycled.
“We were always confident that we would successfully complete the tunnel drive,” Seattle Tunnel Partners Project Manager Chris Dixon said. “The dedication and commitment of everyone on the Seattle Tunnel Partners team has been exceptional, and we wouldn’t be at this milestone without the hard work of our crews. We look forward to continuing this outstanding progress through project completion.”
STP still has significant work to complete before the tunnel opens. Crews must finish building the double-deck highway within the circular walls that were built by crews inside the tunneling machine. Mechanical and electrical systems, plumbing and safety features also must be installed.
Even as crews are installing these systems, crews will begin the extensive task of testing and commissioning the tunnel to ensure it’s ready for traffic. Inspectors will individually test more than 8,500 separate components before testing each of the tunnel’s various systems as a whole.
“This truly is a remarkable feat of engineering,” Transportation Secretary Roger Millar said. “There’s still work to be done, but the individuals working on this job should be proud of this accomplishment.”
Over the next several years, the City of Seattle’s Waterfront Seattle project will build new public space and a surface boulevard in the place of the double-deck viaduct, which is scheduled for demolition in 2019.
“Today is a major construction milestone in our plan to reclaim Seattle’s waterfront,” Seattle Mayor Ed Murray said. “We are one step closer to taking down the viaduct to make way for a reimagined waterfront and surrounding downtown neighborhood. We will build a waterfront for pedestrians, transit and sensible car trips without a freeway wall casting a shadow over our vision of a well-connected 21st century city.”
King County Metro will continue to rely on SR 99 to route buses to Seattle after the tunnel opens, said King County Executive Dow Constantine.
“The new tunnel will provide fast, reliable travel for transit and freight past downtown traffic, and reunite the city with its waterfront,” said Constantine. “The breakthrough highlights what we can accomplish when we think big, act boldly, and embrace the ‘can-do’ tradition of our region.”
Port of Seattle Commission Commissioner Courtney Gregoire said the tunnel will work with the new waterfront surface street to accommodate freight traffic.
“This Alaskan Way route is essential to a strong port and linking our industrial lands between SODO and Ballard,” Gregoire said. “Strong, vibrant transportation connections are essential to keep our economy growing and creating middle-class jobs.”
Background on tunneling machine repairs
Manufactured in Japan by Hitachi Zosen Corp., Bertha arrived in Seattle in April 2013. The machine was launched from a pit near the stadiums in July of that year. In December 2013, STP stopped mining after measuring increased temperatures in the machine.
After an investigation, STP discovered damage to the machine’s main bearing. Crews completed repairs and resumed mining in December 2015. The cause of damage to the tunneling machine is in dispute and is currently in litigation. Neither WSDOT nor STP is able to comment further on ongoing legal issues.
1:37 PM: Just in case you were wondering, the machine’s movement is done for the day, by the way, Christopher and other media at the scene were told.
4:08 PM: Pending our “what’s next” second wrapup later today, here’s Christopher’s video of highlights from the breakthrough and the comments afterward, including the governor, mayor, county executive, and others:
More later. WSDOT, meantime, says the livestream camera will be up until 9 tomorrow morning.
Four years and two days after the Highway 99 tunneling machine arrived in Seattle, in pieces, after a trans-Pacific trip from Japan, it’s scheduled to finish its part of the tunnel-building job tomorrow. WSDOT announced this afternoon that the machine is on the brink of “breakthrough”:
Crews will spend this evening making final preparations. Then, early tomorrow, the massive machine will begin mining through the wall and into the pit where it will be disassembled. Machine operators will proceed slowly through the wall, so it may take several hours for the cutterhead to emerge.
And even once it does, it won’t be done, as WSDOT’s update explains – “it will be weeks until the machine is in its final position in the disassembly pit.” Then, it will be broken apart to be removed from the pit. Live-stream and time-lapse cameras are already embedded on the “Follow Bertha” page, since the public isn’t allowed at the construction site to watch in person. The latest advisory from WSDOT suggests this will happen no sooner than midmorning, but timing is subject to change – the project Twitter account is a good place to watch for updates (and we’ll be tracking it here on WSB too).
Breakthrough will come on the north side of downtown, at the end of a 9,270-foot tunnel route along which there’s still road-building and other work to be done before the tunnel’s projected opening in early 2019 (here’s the newest progress report).
(April 2, 2013, WSB photo by Nick Adams)
SUNDAY NIGHT: If you’re on Highway 99 tunnel watch – the tunneling machine is now down to a double-digit distance, 89 feet as of this morning. WSDOT still is not officially predicting what day will bring the “Bertha breakthrough,” but at this rate (it’s gone 38 feet since Friday), it’s likely to be this week. They’ve said that it will happen in two phases – the machine will reach the wall of the disassembly pit and stop, while WSDOT and Seattle Tunnel Partners explain what happens next. Then, likely on the following day, the machine will be set into motion for a several-hours-long breakthrough process. They continue to promise a live camera will be available, since the pit is in a construction zone and a public viewing area isn’t feasible.
P.S. Checking the archives, we note that today is the 4th anniversary of the tunneling machine’s arrival via ship from Japan.
MONDAY AFTERNOON: So much news today that we haven’t had time to publish an update yet, but WSDOT is expecting breakthrough sometime Tuesday – here’s the latest; full update a bit later.
If the Highway 99 tunneling machine keeps digging at the same pace of the past few days – 61 feet between yesterday’s update and today’s update, and 127 feet to go – next week could bring the breakthrough. Just a reminder that WSDOT and Seattle Tunnel Partners are NOT opening the site for the public to watch it happen, but they’re working on some kind of a live feed. Once the machine gets to the end of the line, it will be broken into pieces, which is why they’re calling what you see above “the disassembly pit.”
We’ve been watching the Highway 99 tunneling-machine update page, now that “Bertha” is getting close to breakthrough, and just noticed that today’s update says 219 feet to go – same as yesterday. WSDOT explains via Twitter that “(Seattle Tunnel Partners) is wrapping up routine maintenance and plans to resume mining tomorrow.” So for those who speculated breakthrough might happen this week – highly unlikely.
The Highway 99 tunneling team has now moved from twice-weekly progress reports to daily progress reports. Not that the tunneling machine is on an “any day now” basis yet, but here’s what WSDOT reports this afternoon:
Seattle Tunnel Partners is making final preparations for the SR 99 tunneling machine’s arrival at the disassembly pit near Seattle Center. Because mining rates will continue to vary as crews approach the pit, we can’t predict when Bertha’s breakthrough will occur. We will continue to provide regular progress updates along the way.
We recognize that there is great interest surrounding this stage of the project, and we are working on ways to share this historic moment with the public. We will be activating a new time-lapse camera as well as streaming video of the disassembly pit prior to breakthrough. These cameras will offer the best view of Bertha’s arrival in the pit. We will also continue to share photos and provide frequent updates via social media, including daily progress updates. For safety reasons, the public will not be allowed in the construction zone during the breakthrough.
Look for more updates soon about the breakthrough sequence, the process for disassembling Bertha and the work that remains before the tunnel opens in 2019.
As of today, WSDOT tweeted, “Today Bertha has 320 feet to go – less than the Mariners 326′ right-field foul line in Safeco Field.” They’ve said that they won’t be setting up an in-person breakthrough-watching event because the pit is in the middle of a construction zone.
(UPDATED 4:35 PM SUNDAY with new information from SPD)
10:30 PM: Seattle Police say they’re investigating a deadly motorcycle crash on the NB Alaskan Way Viaduct. Exactly where, we don’t know yet, but the eastbound bridge exit to NB 99 is reported to be closed. More information when we get it.
10:52 PM: SDOT confirms that the NB 99 closure starts at the West Seattle Bridge. A traffic camera indicates the crash happened on the rise to the elevated section of the Viaduct, in the stadium zone.
(Added: Traffic-camera image showing SPD investigator working at crash scene on NB Viaduct)
11:16 PM: This is at least the fifth deadly motorbike crash in that area of 99 in five years. From our archives, a crash killed a 34-year-old man in 2014, also on the northbound side, where 30-year-old Nathaniel Hammer died in 2013; less than 24 hours after that crash, a 52-year-old motor-scooter rider was killed in a crash. On the southbound curve at that end, 48-year-old West Seattle musician/therapist Lisa Mills was killed in 2012.
1:50 AM The highway has reopened.
ADDED 4:35 PM SUNDAY: From SPD Blotter:
Police were called to investigate a fatality collision on the Alaskan Way Viaduct around 9:40 p.m. last night. Preliminary indications are that speed played a factor in the collision.
According to witnesses, a 22-year-old man was traveling in the northbound lanes of the viaduct when he lost control of his motorcycle, struck a concrete barrier, and fell to the surface streets below.
Seattle Fire Department medics provided emergency care at the scene, but were unable to revive the man.
Traffic Collision Investigation detectives responded to the scene, processed the collision site and collected evidence.
This is an active and ongoing investigation. Information is subject to change as the investigation proceeds.
ADDED: The rider has been identified as 21-year-old Isaac Barajas.
We didn’t get a chance to write about this back on Thursday when WSDOT made it public, but here on a quiet Saturday night, we’re mentioning it in case you missed it: A 360-degree video tour of the Highway 99 tunneling machine and the in-progress tunnel. The 5-minute tour is narrated/hosted by Joe Hedges, current Alaskan Way Viaduct Program Administrator. Here’s the update that accompanied the video (including a reminder of how to watch/interact with 360-degree videos, if you haven’t tried it before).
The machine now has less than two blocks left to dig; here’s the page with the latest stats and map. When digging’s done, of course, there will still be a lot left to do – as the machine is broken into what WSDOT describes as “small pieces” over the course of several months, construction will continue in the tunnel, including road-deck-building (part of that, and some preparation, is shown in the video above).
Also yet to be settled before the tunnel opens – currently projected as early 2019 – is what the tunnel toll will be. That remains in the hands of the Washington State Transportation Commission, whose tolling plans for the year ahead are in this report. No date yet for them to make a decision; they meet monthly – next meeting March 21-22, though the agenda’s not up yet.
P.S. The summary of last weekend’s Alaskan Way Viaduct inspection isn’t out yet but should appear soon on this page, where other results are listed.
The Highway 99 tunneling machine is back on the move, and re-aligned after veering a half-foot off course, according to this update late today from WSDOT:
Seattle Tunnel Partners resumed mining today after conducting additional survey work to verify Bertha’s position and to make necessary adjustments to complete the tunnel drive. Crews performed routine inspections and maintenance while mining was stopped, including the replacement of cutterhead tools.
As of this afternoon, Bertha was tunneling north toward the intersection of Denny Way and Sixth Avenue North, less than 1,000 feet from the disassembly pit.
STP stopped mining on February 28 after survey data indicated the tunneling machine may be several inches off the tunnel alignment. Three independent surveys confirmed the 57.5-foot machine was approximately six inches off alignment.
STP designers made a slight change to the tunnel alignment between the machine’s current location and the end of the tunnel drive. Adjustments are common during tunneling, including on this project. STP made a similar adjustment to correct Bertha’s course after the machine mined out of the access pit following repairs.
Crews steer Bertha based on information they receive from its on-board guidance system. The system is now set to the new tunnel alignment. According to STP’s most recent schedule, Bertha will arrive at the disassembly pit in May.
This weekend’s Alaskan Way Viaduct inspection has ended early and Highway 99 has reopened. No inspection closure tomorrow but, WSDOT says, the Hot Chocolate 15K closure just north of the Battery Street Tunnel is still planned for Sunday morning. (added) Specifics on that:
Hot Chocolate 15k/5k details
6 a.m. to noon, Sunday, March 5
SR 99/Aurora Avenue North will close in both directions.
Southbound lanes will be closed between the Battery Street Tunnel and N. 38th Street.
Northbound lanes will be closed between the Battery Street Tunnel and N. 47th Street.
A Project Belltown walk inside the Battery Street Tunnel may keep the northbound lanes closed as late as 1 p.m.
6:27 AM: The Alaskan Way Viaduct‘s twice-yearly inspection is here, and Highway 99 is scheduled to be closed until 6 pm between the West Seattle Bridge and the Battery Street Tunnel. As noted in WSDOT‘s announcement, the closure also is scheduled for a second day tomorrow, 6 am-6 pm, with the Hot Chocolate 15K and a community walk in the BSTunnel extending the closure north a ways until early Sunday afternoon. If you’re headed downtown, 1st Avenue So. and 4th Avenue So. exits from the eastbound bridge are options as well as I-5. We’ll be watching traffic all weekend and will publish updates if anything changes with the closure (or with the alternate routes).
P.S. Metro bus reroutes are listed here.
5:16 PM: As tends to happen, the inspection has ended early and aside from the Hot Chocolate 15K closure north of the Battery Street Tunnel on Sunday morning, the Viaduct is open for the rest of the weekend.
WSDOT says tonight that the Highway 99 tunneling machine is expected to arrive in its “disassembly pit” in May. That news comes as they also announce that Seattle Tunnel Partners has stopped digging to get the machine ready for the “final 1,000 feet of the 9,270-foot tunnel drive.” They’re checking its position because, WSDOT’s update says:
Recent surveys show that Bertha may be several inches off of the tunnel alignment. STP is conducting additional survey work and will make adjustments as needed to complete the tunnel drive.
Adjustments are common during tunneling, including on this project. STP made a similar adjustment to correct Bertha’s course after crews mined out of the pit that was used to access and repair the machine.
Crews will continue to perform routine maintenance on the machine for the next several days. They plan to resume mining next week.
According to STP’s most recent schedule, Bertha will arrive at the disassembly pit in May. The pit is located approximately 960 feet north of the cutterhead’s current location beneath Denny Way and Sixth Avenue North. Mining rates will continue to vary based on maintenance needs and soil conditions.
Crews successfully mined under the final building of the tunnel drive earlier this week. Bertha has traveled a total of 8,310 feet and built 1,270 of 1,426 concrete tunnel rings.
Because the end-of-the-line pit is part of a construction site, WSDOT has said it’s not planning to have a big event for the public to watch the machine break through.
Meantime, yet another reminder – the Alaskan Way Viaduct is scheduled to close for inspection 6 am-6 pm each day this Saturday and Sunday, with a few other events on 99 north of the Battery Street Tunnel – full details are here.
Since the last twice-weekly update, the Highway 99 tunneling machine has passed the 8,000-foot mark of its 9,270-foot route. To be specific, as of today, it’s dug 8,132 feet and has 1,138 feet to go – about two more blocks, according to today’s WSDOT update. It’s currently near 6th/Wall and set to emerge at 6th/Thomas.
P.S. If you missed it earlier today, WSDOT has announced the Alaskan Way Viaduct’s next weekend maintenance (etc.) closure will be March 4-5.
Just announced by WSDOT – the next inspection closure of the Alaskan Way Viaduct. It’s scheduled to close both ways between the West Seattle Bridge and the north end of the Battery Street Tunnel between 6 am and 6 pm Saturday, March 4th, and Sunday, March 5th. Part of 99 will close for non-inspection reasons north of the BSTunnel – that Saturday, construction crews will be working on SB 99 between the tunnel and Valley Street in South Lake Union “so construction crews can complete the work needed to reopen Harrison Street.” And on that Sunday morning, the annual Hot Chocolate 15K will extend the closure north of the BSTunnel, while a Project Belltown walk in the BSTunnel will extend the NB lane closure until about 1 pm. Full details here.