When will The Viaduct’s 2-week closure start? We’re closer to finding out

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

(WSDOT photo from last week – workers walking toward the tunneling machine’s back end)

Another update this afternoon on the Highway 99 tunnel project, currently in a “maintenance stop” getting ready to tunnel beneath the Alaskan Way Viaduct, which WSDOT plans to close for about two weeks when that happens.

No date yet but WSDOT’s update says they’re getting closer:

Inspections and routine maintenance of the SR 99 tunneling machine are ongoing as Seattle Tunnel Partners continues preparing the machine for its drive beneath the Alaskan Way Viaduct.

Crews have been performing planned maintenance since the machine reached a maintenance stop earlier this month. They’ve also been preparing for a series of inspections that must occur in hyperbaric conditions. Hyperbaric conditions are those in which the air pressure is greater than the atmosphere we live and breathe in every day – similar to what scuba divers experience during the course of an underwater dive. This post explains the process for completing hyperbaric work.

So far this week, STP crews have completed a total of 10 hyperbaric shifts in the chamber behind the tunneling machine’s cutterhead. Most of that time has been devoted to cleaning muck from the cutterhead openings and building the platforms crews will stand on as they perform the inspections.

The inspections are expected to take several more days. STP will determine the expected duration of the remaining maintenance based on the results of the inspections.

The end of the maintenance period will usher in the next step in Bertha’s journey: a trip beneath the viaduct. WSDOT plans to close the viaduct for approximately two weeks to allow the machine to pass beneath the structure.

We will provide the public with advance notice of the closure, but the start date isn’t yet known. It will depend on the amount of work that must be completed while the machine is in the maintenance stop. Check 99closure.org for additional details as the closure approaches.

Local transportation and transit agencies have not yet formally announced their plans for what’ll change to help mobility during the Viaduct closure, but some tentative plans were previewed at last month’s West Seattle Transportation Coalition meeting – here’s our coverage.

P.S. WSDOT’s 99closure.org site also is adding more detailed information you might not have seen, including this, and an FAQ.

JanS March 23, 2016 (7:43 pm)

that’s one big tunnel !

K'lo March 23, 2016 (7:55 pm)

Northbound on the bottom, south on the top. Won’t look so big after the separation.

BerthaSchmertha March 23, 2016 (8:30 pm)

It’ll transport significantly less traffic than the viaduct, so I guess it isn’t big enough.

Jim Clark March 23, 2016 (8:34 pm)

I guess I am just not understanding where the lanes fit into this tunnel

WSB March 23, 2016 (8:53 pm)

This is one of the renderings that was in common use a few years ago. We have a couple versions on the site here but this one was first up via Wikimedia: https://upload.wikimedia.org/wikipedia/en/4/4e/Alaskan_Way_Viaduct_tunnel_visualization.jpg

Kay K March 23, 2016 (8:38 pm)

Cool shot.

TheKing March 23, 2016 (9:39 pm)

Does anyone know if the buildings on first ave are still sinking too.

K. Davis March 24, 2016 (1:42 am)

@berthaschmertha … Please do explain how the Battery St. Tunnel has all that extra capacity for cars compared to this tunnel. You must know something the rest of us don’t.

Or not.

dbf March 24, 2016 (6:18 am)

@ k.davis, “the viaduct” has more capacity. The battery st tunnel is for the remaining cars that don’t exit to town via Seneca or western.

watertowerjoey March 24, 2016 (6:29 am)

What DBF said. All those cars that now exit on Seneca and Western will be on surface streets.

Nice, quiet, calm waterfront compared to the current viaduct – NOT.

LC March 24, 2016 (7:29 am)

Best NOT joke used in the context of Bertha and tunneling in general – well played!

Just another chapter in the story of how Seattle can create massive bottlenecks and crushing traffic conditions to make the average working person’s life miserable.

metrognome March 24, 2016 (7:47 am)

amazing picture; really puts the mammoth size of the project into perspective.

y’all who are complaining about ‘reduced capacity’ need to look at the bigger picture; there is much more going on than simply losing the Columbia Street on-ramp and the Seneca and Western off-ramps (btw, the first two were added over a decade after the Viaduct opened.) There are several projects going on that will completely restructure the transportation approaches to the north end of downtown. In addition, all the traffic that gets off at Seneca and then turns south (i.e. sports traffic) that clogs First, incl. the Columbia on-ramp, for blocks, will now get off nearer their destination.

This is a fascinating third of four articles on the Viaduct planning and construction; use the ‘browse to …’ options at the top of the article to read the other articles. It is interesting to note the controversies surrounding what is now considered to be a major part of our transportation infrastructure.

http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=9978

JustinVP March 24, 2016 (10:20 am)

Yeah, looking at how the new roads/exits at both ends of the tunnel will work, I actually think this will be an improvement in traffic flow for most W Seattle folks driving to downtown. A lot more options and a better grid at both the N and S ends of the tunnel.

Getting to Belltown will probably be slower than right now, but the rest of downtown will be faster, and SLU/Amazon way faster.

But we still REALLY need that W Sea – downtown – Ballard subway line that is hopefully approved this fall. Geez, by the time it’s here I’ll only be 60 something… Wish they could fast-track it and get it approved/designed/built in 10 years.
- WSB March 24, 2016 (10:22 am)
  
  On that last point, check back this afternoon, as today’s the day the Sound Transit board is expected to make its “draft” plan public, and we’ll be at the meeting downtown (1:30 pm start) for a West Seattle-specific first look. – TR

K. Davis March 24, 2016 (10:35 am)

I think others above accurately describe much of the (mostly ill-informed) criticism of the tunnel – the people who are bitching about losing the “viaduct-Seneca-Western” access that we have now (and I’m one of those people who uses the Seneca exit every day). Those folks are right – other than getting to Belltown, access to downtown will likely be easier/quicker when all of the work is done – not just the SR99-tunnel portion, but also the re-vamped Alaskan Way surface street, with new connections into downtown that we don’t currently have.