Alaskan Way Viaduct Replacement Tunnel

[Rothman]

And it looks like they should get back to work now! I find it quite a coincidence that they're scheduled to continue digging on the same date that will go down in history as an event that never occurred three years ago, like the Mayans once said it would.

what the fuck

I got it.

[jakeroot]

And it looks like they should get back to work now! I find it quite a coincidence that they're scheduled to continue digging on the same date that will go down in history as an event that never occurred three years ago, like the Mayans once said it would.

what the fuck

I got it.

I think I got it as well, but a follow-up would be nice.

[Bruce]

18 whole inches in 2 years. What progress!

I moved that much in my sleep last night. Probably more.

[noelbotevera]

18 whole inches in 2 years. What progress!

I moved that much in my sleep last night. Probably more.

Now let's see if they get 20 inches in ten years!

[Bruce]

Also, when the machine is planned to cross under the viaduct in March, the latter will have to close for two weeks. It's going to be a great time to get pictures of the empty viaduct! And the resulting traffic at each end!

[Alps]

18 whole inches in 2 years. What progress!

I moved that much in my sleep last night. Probably more.

Now let's see if they get 20 inches in ten years!

These are what she said.

[Alps]

Also, when the machine is planned to cross under the viaduct in March, the latter will have to close for two weeks. It's going to be a great time to get pictures of the empty viaduct! And the resulting traffic at each end!

Given the tone of this thread - how many months do you think the viaduct will actually have to be closed?

[Bruce]

Also, when the machine is planned to cross under the viaduct in March, the latter will have to close for two weeks. It's going to be a great time to get pictures of the empty viaduct! And the resulting traffic at each end!

Given the tone of this thread - how many months do you think the viaduct will actually have to be closed?

4 months beginning in August or something. Or Bertha gets stuck under the viaduct and shuts the thing down permanently, since recovery (even if not via pit and from the back of the machine) could send the thing tumbling down with thousands of commuters.

[jakeroot]

Something tells me that Bertha won't have any more problems. STP has had two whole years to re-scan the proposed path. If there's something else they didn't see, and this thing gets stuck again, the people of Seattle will probably set fire to the construction site, because mob justice.

[noelbotevera]

You know, my opinion is that this project is long overdue. How does Bertha get stuck in a tunnel bore? How long has it been going on? Why have only a foot and half been completed over two years?

[jakeroot]

You know, my opinion is that this project is long overdue. How does Bertha get stuck in a tunnel bore? How long has it been going on? Why have only a foot and half been completed over two years?

Bertha got stuck, apparently, because of a pipe. The machine's cutters weren't able to cut through the metal pipe. The machine has been inoperable for about two years. Only this Monday was the machine finally able to bore again. It only moved a foot and a half because STP only wanted to move it that far, so they could lay another concrete ring around the exterior of the tunnel. The workers are on holiday break now. Normal boring is expected soon (you don't want to go full-boat right out of the gate and break something else).

[NE2]

Bertha is boring.

[The Ghostbuster]

Here's a question for my fellow AARoads posters: Are there any other existing freeways (elevated, double-decked, or otherwise) that you believe should be replaced with a tunnel? We can dispense with the details of making it happen (costs, likelihood, etc.)

[mgk920]

I haven't been able to check a detailed map of this tunnel's routing, but does it have to pass over or under BNSF's ex GN mainline tunnel, too?



Mike

[mgk920]

Here's a question for my fellow AARoads posters: Are there any other existing freeways (elevated, double-decked, or otherwise) that you believe should be replaced with a tunnel? We can dispense with the details of making it happen (costs, likelihood, etc.)

Money being no object, IMHO I-278 through/around downtown Brooklyn, NYC would be a prime candidate for replacement with a tunnel (Gowanus to BQE 'straight shot').

Mike

[Bruce]

I haven't been able to check a detailed map of this tunnel's routing, but does it have to pass over or under BNSF's ex GN mainline tunnel, too?



Mike

It passes where under the Great Northern Tunnel near Pike Place Market, which is at the northern end of that 100-year-old tunnel.

Speaking of, it really needs to be replaced sometime soon. The current plan in the event of an oil train fire is to seal it off and let it burn, which is not acceptable when it's also used by passenger services. It's unlit, has no escapes, no safe havens, and no firefighting equipment.

[jakeroot]

Speaking of, it really needs to be replaced sometime soon. The current plan in the event of an oil train fire is to seal it off and let it burn, which is not acceptable when it's also used by passenger services. It's unlit, has no escapes, no safe havens, and no firefighting equipment.

I wonder how we could go about replacing that tunnel? A secondary bore would be necessary just as a detour, but I think they could rebuild the GNT as well, and have two bores under the city. I'm not sure if four rail lines is overkill this day in age, but I get the feeling this new HSR line that WSDOT is building might boost train ridership.

[Bruce]

Speaking of, it really needs to be replaced sometime soon. The current plan in the event of an oil train fire is to seal it off and let it burn, which is not acceptable when it's also used by passenger services. It's unlit, has no escapes, no safe havens, and no firefighting equipment.

I wonder how we could go about replacing that tunnel? A secondary bore would be necessary just as a detour, but I think they could rebuild the GNT as well, and have two bores under the city. I'm not sure if four rail lines is overkill this day in age, but I get the feeling this new HSR line that WSDOT is building might boost train ridership.

I'd hope that a second bore is built to handle all traffic while the original is rebuilt (with cross-passages between the two). All with room for HSR and electric centenary as well so it can be installed easily and with minimal closures in the near future.

I don't see BNSF fronting the money, though, so there's not a good chance it will ever be done.

[jakeroot]

Speaking of, it really needs to be replaced sometime soon. The current plan in the event of an oil train fire is to seal it off and let it burn, which is not acceptable when it's also used by passenger services. It's unlit, has no escapes, no safe havens, and no firefighting equipment.

I wonder how we could go about replacing that tunnel? A secondary bore would be necessary just as a detour, but I think they could rebuild the GNT as well, and have two bores under the city. I'm not sure if four rail lines is overkill this day in age, but I get the feeling this new HSR line that WSDOT is building might boost train ridership.

I'd hope that a second bore is built to handle all traffic while the original is rebuilt (with cross-passages between the two). All with room for HSR and electric centenary as well so it can be installed easily and with minimal closures in the near future.

I don't see BNSF fronting the money, though, so there's not a good chance it will ever be done.

More than likely not. The tunnel has an impeccable safety record as-is. The only reason for a rebuild/replacement would be as a result of the tunnel losing its "grandfathered" status. I could see this happening in the future if a similar tunnel has an insane accident (along the lines of the Mont Blanc disaster), and the regulatory group responsible decides to end the grandfather system.

[mcarling]

Here's a question for my fellow AARoads posters: Are there any other existing freeways (elevated, double-decked, or otherwise) that you believe should be replaced with a tunnel? We can dispense with the details of making it happen (costs, likelihood, etc.)

The Interstate Bridge on I-5 between Portland, OR and Vancouver, WA needs to be replaced with something.  There is a clearance constraint below for shipping traffic and a clearance constraint above for PDX flight traffic which together don't leave much space for a bridge.  Tunnel boring might be an option.  It would certainly make the airport and the shipping companies happy.  With a need for five lanes in each direction, that would require two double-stacked bores (probably two full-height lanes below for trucks and buses and three limited-height lanes above for cars).  Bore diameter would be similar to Bertha's.

[Rothman]

Here's a question for my fellow AARoads posters: Are there any other existing freeways (elevated, double-decked, or otherwise) that you believe should be replaced with a tunnel? We can dispense with the details of making it happen (costs, likelihood, etc.)

The Interstate Bridge on I-5 between Portland, OR and Vancouver, WA needs to be replaced with something.  There is a clearance constraint below for shipping traffic and a clearance constraint above for PDX flight traffic which together don't leave much space for a bridge.  Tunnel boring might be an option.  It would certainly make the airport and the shipping companies happy.  With a need for five lanes in each direction, that would require two double-stacked bores (probably two full-height lanes below for trucks and buses and three limited-height lanes above for cars).  Bore diameter would be similar to Bertha's.

Dear heavens.  Tunnels that size would never be built in that area.  The cost would simply be too prohibitive.

[Alps]

Here's a question for my fellow AARoads posters: Are there any other existing freeways (elevated, double-decked, or otherwise) that you believe should be replaced with a tunnel? We can dispense with the details of making it happen (costs, likelihood, etc.)

Yes. But that would belong in Fictional Highways.

[mcarling]

Here's a question for my fellow AARoads posters: Are there any other existing freeways (elevated, double-decked, or otherwise) that you believe should be replaced with a tunnel? We can dispense with the details of making it happen (costs, likelihood, etc.)

Yes. But that would belong in Fictional Highways.

Really???  Speculative upgrades to "existing freeways" belong in Fictional Highways?   

[mcarling]

The Interstate Bridge on I-5 between Portland, OR and Vancouver, WA needs to be replaced with something.  There is a clearance constraint below for shipping traffic and a clearance constraint above for PDX flight traffic which together don't leave much space for a bridge.  Tunnel boring might be an option.  It would certainly make the airport and the shipping companies happy.  With a need for five lanes in each direction, that would require two double-stacked bores (probably two full-height lanes below for trucks and buses and three limited-height lanes above for cars).  Bore diameter would be similar to Bertha's.

Dear heavens.  Tunnels that size would never be built in that area.  The cost would simply be too prohibitive.

The cost of tunnel boring continues to decline.  The TBMs are becoming more efficient, more capable, more automated, etc.  So the labor costs are going down as the crews get smaller and the overhauls become less frequent.

The Interstate Bridge is either going to be replaced by a new bridge or by a tunnel, sooner or later.  The cost of a bridge that would be useable following a major Cascadia Subduction Quake might exceed the cost of tunnels.  One TBM could bore the northbound replacement tunnel (the existing northbound span is older and narrower than the southbound span) and then turn around and bore the southbound tunnel.

I cannot think of any existing roadway in the Pacific Northwest in greater need of a tunnel, though there may be several or many that I'm unaware of.

[jakeroot]

Really???  Speculative upgrades to "existing freeways" belong in Fictional Highways?

Anything speculative should go in fictional highways.