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[Max Rockatansky]

I used the Spokane Viaduct while returning southbound towards Seatac this morning.  Afforded some decent pictures of the West Seattle Bridge from below:

https://flic.kr/s/aHsmkcLNEc

Ended up with some decent distance shots near Hamilton Viewpoint:

https://flic.kr/s/aHskAMhidq

[Max Rockatansky]

Updated my album with a blog post.  I think that I documented all the historical Spokane Street crossings:

http://surewhynotnow.blogspot.com/2018/05/spokane-street-bridge-and-west-seattle.html

[Bruce]

I figure we should be using this thread for West Seattle Bridge news.

Seattle recently issued a bid for design a new West Seattle Bridge, with a potential 10-year contract. There is also a 31-member task force that will explore options, including a shallow tunnel, gondola, and anything other than rebuilding the same flawed design.

https://www.seattletimes.com/seattle-news/transportation/sdot-solicits-engineers-to-design-a-replacement-for-the-cracked-west-seattle-bridge/

[Bickendan]

My vote's for the vehicle trebuchet.


Oh wait. I'm told that would very impractical...

[Chris]

What is actually flawed in the design? This bridge type is commonly used across the world in any type of terrain and environment. Or was there a construction deficiency? There's also speculation about the possibility of earthquake damage.

[jakeroot]

What is actually flawed in the design? This bridge type is commonly used across the world in any type of terrain and environment. Or was there a construction deficiency? There's also speculation about the possibility of earthquake damage.

I don't think the actual design flaw is quite clear yet. The earthquake likely had a role given the bridge's close proximity to the east-west Seattle Fault, which was only discovered as seismically hazardous in 1992, eight years after the West Seattle Bridge opened.

If that's the case, this would almost certainly make the West Seattle Bridge, and possibly the low level bridge, the last bridges constructed in the Seattle area where the structures were not built to designed to withstand significant earthquakes. But that is a total guess, and the I-90 bridge and the rest of the I-90 ramps in Seattle were also constructed in the early 90s, around the time of the fault discovery, so they could also be in trouble. Maybe.

[Alps]

What is actually flawed in the design? This bridge type is commonly used across the world in any type of terrain and environment. Or was there a construction deficiency? There's also speculation about the possibility of earthquake damage.

Something about the steel bars rusting through tells me there was an issue with materials or methods during construction.

[kkt]

My vote's for the vehicle trebuchet.


Oh wait. I'm told that would very impractical...

 

[kkt]

I would think it would be wiser to find out why the current bridge failed prematurely before putting out bids for a new one, so they can tell what they need to specify in the replacement.

[jakeroot]

I would think it would be wiser to find out why the current bridge failed prematurely before putting out bids for a new one, so they can tell what they need to specify in the replacement.

I would be incredibly surprised if any replacement was considered, voted on, designed, built, and opened without some extensive research done on why the prior bridge failed. People are already begging for answers.

[roadfro]

I would think it would be wiser to find out why the current bridge failed prematurely before putting out bids for a new one, so they can tell what they need to specify in the replacement.

I would be incredibly surprised if any replacement was considered, voted on, designed, built, and opened without some extensive research done on why the prior bridge failed. People are already begging for answers.

Just a terminology note: When referring to a "bridge failure", that typically means that some portion of the bridge collapsed. That hasn't happened here, to my knowledge. But potentially some subsystem of the bridge's overall structure may have failed, causing the damage to the bridge that prompted the closure.

But yes, it would seem very prudent to figure out the cause of the structural issue prior to taking next steps on repair/replacement.

[jakeroot]

I would think it would be wiser to find out why the current bridge failed prematurely before putting out bids for a new one, so they can tell what they need to specify in the replacement.

I would be incredibly surprised if any replacement was considered, voted on, designed, built, and opened without some extensive research done on why the prior bridge failed. People are already begging for answers.

Just a terminology note: When referring to a "bridge failure", that typically means that some portion of the bridge collapsed. That hasn't happened here, to my knowledge. But potentially some subsystem of the bridge's overall structure may have failed, causing the damage to the bridge that prompted the closure.

But yes, it would seem very prudent to figure out the cause of the structural issue prior to taking next steps on repair/replacement.

Totally understood. I was just being casual with my terminology. But thank you, because I'm still learning all the terms.

[kkt]

Oh, that was me... I did not know that "failed" only meant it fell down, not that it became unusable.

[jakeroot]

Oh, that was me... I did not know that "failed" only meant it fell down, not that it became unusable.

I mean, it is rather interesting that the bridge, even if it doesn't fall over, cannot be considered as having "failed".

What's the term for a bridge that will fail but is taken down before it does? Because that seems to be the case with the West Seattle Bridge.

[Alps]

Oh, that was me... I did not know that "failed" only meant it fell down, not that it became unusable.

I mean, it is rather interesting that the bridge, even if it doesn't fall over, cannot be considered as having "failed".

What's the term for a bridge that will fail but is taken down before it does? Because that seems to be the case with the West Seattle Bridge.

Imminent failure, perhaps? Unstable?

[TEG24601]

Condemned?

[jakeroot]

Condemned?

Once it gets to that point, I like this the best so far.

Oh, that was me... I did not know that "failed" only meant it fell down, not that it became unusable.

I mean, it is rather interesting that the bridge, even if it doesn't fall over, cannot be considered as having "failed".

What's the term for a bridge that will fail but is taken down before it does? Because that seems to be the case with the West Seattle Bridge.

Imminent failure, perhaps? Unstable?

I prefer TEG's term primarily because it can fit within the context of the original sentence, which is about a bridge that will fail. Both "imminent" and "unstable" imply, to me, something that could be saved. Something that is "condemned" or "failed" is a lost cause.

To the best of my knowledge, the West Seattle Bridge is a lost cause. That's the impression I get from city leaders.

[MikieTimT]

Oh, that was me... I did not know that "failed" only meant it fell down, not that it became unusable.

I mean, it is rather interesting that the bridge, even if it doesn't fall over, cannot be considered as having "failed".

What's the term for a bridge that will fail but is taken down before it does? Because that seems to be the case with the West Seattle Bridge.

Imminent failure, perhaps? Unstable?

The term most likely used for this bridge might be summarized as "stupid engineer."

[kkt]

Oh, that was me... I did not know that "failed" only meant it fell down, not that it became unusable.

I mean, it is rather interesting that the bridge, even if it doesn't fall over, cannot be considered as having "failed".

What's the term for a bridge that will fail but is taken down before it does? Because that seems to be the case with the West Seattle Bridge.

Imminent failure, perhaps? Unstable?

The term most likely used for this bridge might be summarized as "stupid engineer."

We could wait for the investigation to be done before we decide it was the engineer's fault...

[Alps]

Condemned?

Once it gets to that point, I like this the best so far.

Oh, that was me... I did not know that "failed" only meant it fell down, not that it became unusable.

I mean, it is rather interesting that the bridge, even if it doesn't fall over, cannot be considered as having "failed".

What's the term for a bridge that will fail but is taken down before it does? Because that seems to be the case with the West Seattle Bridge.

Imminent failure, perhaps? Unstable?

I prefer TEG's term primarily because it can fit within the context of the original sentence, which is about a bridge that will fail. Both "imminent" and "unstable" imply, to me, something that could be saved. Something that is "condemned" or "failed" is a lost cause.

To the best of my knowledge, the West Seattle Bridge is a lost cause. That's the impression I get from city leaders.

From a structural point of view, failure means the structure has partially or fully collapsed. Condemned is a decision that may or may not be related to structural issues. "Imminent failure" descibes an unsafe condition that warrants closing the structure and condemning it if repairs cannot be made.

[Bruce]

New from The Seattle Times: SDOT plans new cables and carbon wraps to keep West Seattle Bridge standing

Armed with carbon strips and steel cables, construction workers will soon begin emergency shoring of the West Seattle Bridge in an effort that could last until late October.

The Seattle Department of Transportation (SDOT), in a blog post describing the methods, said Monday that the job will begin this week.

The first step is to reopen more than 100 holes on the edges of the deck that were filled following construction in the early 1980s. These holes were once used to mount a crane-like gantry, called the form traveler, that moved the molds where builders poured concrete 16.5 feet at a time.

[Bruce]

The lower bridge now has signs of cracking on the sides of the girder walls, possibly because of stress from higher traffic.

https://www.seattletimes.com/seattle-news/transportation/west-seattles-low-swing-bridge-is-cracked-too-and-needs-repairs/

The bridge isn't being closed yet, but will need to have repairs. This will force all traffic to go around the long detour via the 1st Avenue Bridge. If that one goes down, then a lot of people are totally screwed.

[TEG24601]

The lower bridge now has signs of cracking on the sides of the girder walls, possibly because of stress from higher traffic.

https://www.seattletimes.com/seattle-news/transportation/west-seattles-low-swing-bridge-is-cracked-too-and-needs-repairs/

The bridge isn't being closed yet, but will need to have repairs. This will force all traffic to go around the long detour via the 1st Avenue Bridge. If that one goes down, then a lot of people are totally screwed.

Figures.  It seems like the Puget Sound Region isn't conducive to bridges.  See: Tacoma Narrows, Hood Canal, US 10/I-90 Floating Bridge, and now the West Seattle Freeway/Bridge and Spokane Street Bridge, that doesn't include that bridge in Seattle, that they weren't going to fix, just close until everyone complained about the long bypass... or the bridge in Tacoma that was just closed, rather than repaired.

[jakeroot]

or the bridge in Tacoma that was just closed, rather than repaired.

11th St Viaduct? I mean, it had to be closed ASAP. It's now 109 years old, and was completely destroyed by constant vehicular traffic prior to the opening of the 509 bypass around the port. At that point, the city took over. By city, I mean Tacoma. And I don't usually speak highly of Tacoma when it comes to maintaining infrastructure, since the city is not made of money. Up until about ten years ago, every road in the port was asphalt; the surface of most roads was so bad, you often had to drive into oncoming traffic. Traffic did not follow lane lines at all. Reconstructing roads as concrete has been Tacoma's focus. Once Taylor Way (from 509 to the north) is rebuilt, I think the city could possibly consider rebuilding the bridge and viaduct. Although other roads still need work too.

Hell, the bridge is so old, you can still see the old trolley tracks. The trolley system closed in the 1930s!!

I mean, just look at how many cars used to flood along 11th Street back in the day. This is 11th & A in downtown in 1948, 40 years after the viaduct was built, and about 50 before it was closed. The bridge in the background is the Murray Morgan Bridge, but it connected to the viaduct, and approximately 98% of the traffic would have also crossed that viaduct:

[TEG24601]

Sorry, it was a little bit of sarcasm mixed with hyperbole.


But you do have to raise questions about WSDOT and other agencies in the state, when they do have a mixed record with bridges (and ferries).  I hope we don't have to replace both, but if we do, I hope there can be some more comprehensive discussions of what the crossing should look like, and allow outside engineering firms and construction companies to be involved.