Alaskan Way Viaduct Replacement Tunnel

[Bruce]

If this keeps up, it should be named the Stop-And-Go Tunnel.

We already have a Stop-And-Go Tunnel. It's the one the buses and trains use downtown.

Well, now you have another.

And we're building another train tunnel that will also be stop-and-go, though with only 3 stations in downtown. Pending a vote in November.

[707]

If this keeps up, it should be named the Stop-And-Go Tunnel.

We already have a Stop-And-Go Tunnel. It's the one the buses and trains use downtown.

Well, now you have another.

And we're building another train tunnel that will also be stop-and-go, though with only 3 stations in downtown. Pending a vote in November.

Like the saying goes, three's a crowd. How many more tunnels before Seattle's renamed "Tunnel City"?

[Bruce]

If this keeps up, it should be named the Stop-And-Go Tunnel.

We already have a Stop-And-Go Tunnel. It's the one the buses and trains use downtown.

Well, now you have another.

And we're building another train tunnel that will also be stop-and-go, though with only 3 stations in downtown. Pending a vote in November.

Like the saying goes, three's a crowd. How many more tunnels before Seattle's renamed "Tunnel City"?

Well, we're nowhere near the level of a city like New York, but we're pretty well ahead of our peers in Vancouver and Portland. More small tunnels for light rail, please!

[707]

If this keeps up, it should be named the Stop-And-Go Tunnel.

We already have a Stop-And-Go Tunnel. It's the one the buses and trains use downtown.

Well, now you have another.

And we're building another train tunnel that will also be stop-and-go, though with only 3 stations in downtown. Pending a vote in November.

Like the saying goes, three's a crowd. How many more tunnels before Seattle's renamed "Tunnel City"?

Well, we're nowhere near the level of a city like New York, but we're pretty well ahead of our peers in Vancouver and Portland. More small tunnels for light rail, please!

In that case, why not a whole light rail subway?

[Bruce]

If this keeps up, it should be named the Stop-And-Go Tunnel.

We already have a Stop-And-Go Tunnel. It's the one the buses and trains use downtown.

Well, now you have another.

And we're building another train tunnel that will also be stop-and-go, though with only 3 stations in downtown. Pending a vote in November.

Like the saying goes, three's a crowd. How many more tunnels before Seattle's renamed "Tunnel City"?

Well, we're nowhere near the level of a city like New York, but we're pretty well ahead of our peers in Vancouver and Portland. More small tunnels for light rail, please!

In that case, why not a whole light rail subway?

We're basically building that. Grade-separated light rail from Lynnwood to Downtown/Bellevue by 2023. No grade crossings until you hit the Rainier Valley or the Bel-Red area on the Eastside.

[jakeroot]

No grade crossings until you hit the Rainier Valley or the Bel-Red area on the Eastside.

Which is something they should have avoided from the start. I'd like to think the trains could operate without a driver at some point. That'll be hard to achieve with at-grade crossings. Not to mention, you're at the mercy of cars and pedestrians when you're at-grade, which could be bad for overall system efficiency.

[Sub-Urbanite]

As a sometimes-MAX-riding Portlander, I am quite jealous

[Bruce]

No grade crossings until you hit the Rainier Valley or the Bel-Red area on the Eastside.

Which is something they should have avoided from the start. I'd like to think the trains could operate without a driver at some point. That'll be hard to achieve with at-grade crossings. Not to mention, you're at the mercy of cars and pedestrians when you're at-grade, which could be bad for overall system efficiency.

Well, it was the price we paid for getting the project built in the first place. A Rainier Valley tunnel would've been expensive and a bit riskier than other tunnels (especially for a new agency). An elevated guideway would've been hugely controversial with both residents and social justice groups (who are already mad that Rainier Valley got stuck with street-running while North Seattle has tunnels, ignoring the general topography and such).

If ST3 is fully built out, the operating plan is to isolate the surface-running segments of the system (Ballard's moveable bridge and Rainier Valley) from the grade-separated system (with the exception of a mile of East Link east of 130th Station). It would be very much possible with today's technology to automate the Red Line (West Seattle-Everett).

[Rothman]

I'm still snickering over the South Lake Union Trolley.

[Jardine]

Too late now I realize, but I am curious, is anyone keeping track of the cost and cost overruns on the replacement tunnel as compared to what a cut and cover alternative to the TBM tunnel would have cost ??

[kkt]

I'm still snickering over the South Lake Union Trolley.

Do you have the T-shirt?

[Bruce]

The viaduct closure so far has been a mixed bag.

Traffic doesn't seem to have increased too much in most corridors, transit ridership is up and causing delays, water taxi rides have spiked to record highs as have bikes crossing the Duwamish River.

[The Ghostbuster]

I hope the remainder of the tunnel can be completed without too much additional trouble. Given the project's history, that's being extremely optimistic.

[jakeroot]

I hope the remainder of the tunnel can be completed without too much additional trouble. Given the project's history, that's being extremely optimistic.

I think it's a little far-fetched to assume, that in 2016, we can't dig a tunnel. Certainly there's been some issues, but how many megaprojects go completed without a few issues here and there?

[Gnutella]

Bertha, seen before she was put together:

Hey, when you're done with that thing, send it to Pittsburgh. The Fort Pitt Tunnel needs to be enlarged.

[Rothman]

I hope the remainder of the tunnel can be completed without too much additional trouble. Given the project's history, that's being extremely optimistic.

I think it's a little far-fetched to assume, that in 2016, we can't dig a tunnel. Certainly there's been some issues, but how many megaprojects go completed without a few issues here and there?

I don't know about this; the issues they've had with the TBM do seem to be extraordinary to me. 

Although there was the absolute travesty with the Big Dig tunnel's roof panels that started falling due to crooked contractors, my recollection about the Big Dig is that a lot of the difficulties encountered were before they actually started tunneling.  For instance, they planned out the tunnel under the Fort Point Channel and discovered that they really didn't have a means of getting pre-cast tunnel sections to the location.  So, they had to go through the enormous endeavor of creating a casting basin on site, which boosted the costs incredibly. 

Having have one of the largest TBMs ever come to a standstill?  That's not an issue "here or there"; that's disastrous.

[Henry]

So how much longer before Bertha can dig again?

[Kacie Jane]

So how much longer before Bertha can dig again?

Bertha is currently digging.  The viaduct closure that Bruce reported is because she is currently under the viaduct itself, and she's currently on pace to make enough progress to reopen the viaduct on time.

[kkt]

I hope the remainder of the tunnel can be completed without too much additional trouble. Given the project's history, that's being extremely optimistic.

I think it's a little far-fetched to assume, that in 2016, we can't dig a tunnel. Certainly there's been some issues, but how many megaprojects go completed without a few issues here and there?

I just hope it gets finished in less time than the Second Avenue Subway.

[noelbotevera]

I hope the remainder of the tunnel can be completed without too much additional trouble. Given the project's history, that's being extremely optimistic.

I think it's a little far-fetched to assume, that in 2016, we can't dig a tunnel. Certainly there's been some issues, but how many megaprojects go completed without a few issues here and there?

I just hope it gets finished in less time than the Second Avenue Subway.

I'll admit that you're gonna be correct by the time we're all dead. They haven't even finished the stations and it's gonna be 2078 or something like that before it's even past 96th Street.

[jakeroot]

WSDOT has uploaded several new images to their Flickr page:

April 2016 view of progress on the future northbound SR 99 lanes (L) and northbound off-ramp (R) at the SR 99 tunnel's north portal in Seattle:


This March 2016 photo shows the future northbound entrance for drivers entering the SR 99 tunnel from the South Royal Brougham Way on-ramp in Seattle:


This is the view looking south from the future northbound off-ramp at the north portal of the SR 99 tunnel in April 2016. When the SR 99 tunnel opens to traffic, northbound drivers will use the off-ramp to get to the South Lake Union and Queen Anne neighborhoods:


A specially designed truck carries the next 10 tunnel liner segments — one ring's worth — into the SR 99 tunnel. That's a 360,000-pound load:

[Bruce]

Bertha has dug 182 feet so far, or about 47 percent of the way:

http://www.seattletimes.com/seattle-news/transportation/bertha-halfway-done-with-dig-under-alaskan-way-viaduct/

[Rothman]

Makes me wonder how the tunnel is being lined, mechanically.  I know of other TBMs that somehow lined the tunnel as they went; not sure how they were reloaded with the lining panels, though. 

Makes me wonder if they just have crews following Bertha, lining the tunnel in a totally separate process from the drilling?

[english si]

not sure how they were reloaded with the lining panels, though.

It's not hard to create a supply line (conveyor, trucks, whatever) in the already-built tunnel behind the TBM.

[Bruce]

Our long national nightmare is over.

The viaduct re-opens tomorrow morning.

http://www.wsdot.wa.gov/News/2016/05/8_viaductreopensformondayamcommute.htm