WEST SEATTLE BRIDGE CLOSURE: 3 chances to talk with ‘immersed tube tunnel’ proponent

Several local groups have heard lately from the retired civil engineer who suggests an “immersed-tube tunnel” could be a better way of crossing the Duwamish River if the West Seattle Bridge needs to be replaced. Now Bob Ortblad invites you to his own presentations of the idea. He asked us today to share this announcement:

All who are interested in the West Seattle Bridge

Duwamish Crossing – Bridge or Tunnel
Wednesday 7:30 PM
June 10, 17, or 24

Join Recurring Zoom Meeting
us02web.zoom.us/j/81632786315
Meeting ID: 816 3278 6315

Bob Ortblad will answer questions and update the presentation.

In our most recent conversation with SDOT’s bridge-project leader Heather Marx, she said no potential alternatives have been ruled out.

49 Replies to "WEST SEATTLE BRIDGE CLOSURE: 3 chances to talk with 'immersed tube tunnel' proponent"

  • Also John June 7, 2020 (4:49 pm)

    This is fantastic.  I don’t know which day I’ll join in, but I definately want to learn more about this alternative.

  • AR June 7, 2020 (5:14 pm)

    Ditto.  How can we get the city to go down this road?

  • LP June 7, 2020 (5:29 pm)

    Does the Duwamish Tribe get a seat at the table? Are they represented during all these meetings? Who else is being left out?

    • WSB June 7, 2020 (6:38 pm)

      The meetings in this announcement are organized by a private citizen, but he’s extending the invitation to anyone who wants to show up; this is NOT part of the official process – he’s just having informational sessions. As for the official process, the membership announced for the city’s Community Task Force includes Jolene Haas of the Duwamish Tribe. – TR

  • sna June 7, 2020 (7:25 pm)
    1. I know a lot of people are drawn to this tunnel idea but there are many issues with it in reality.  

    1) Pull up a map.  The tunnel is just one part.  You need 1300 feet of roadway on each side of the tunnel to get to grade.  2) Then it has to connect to existing roadways like the Spokane viaduct and fontleroy expressway.  You’ll need to rebuilt several on ramps and off ramps as well.  Lots of construction. 3) You’d need to demolish almost a mile of the existing bridge structure. 4) The construction of the tunnel would interrupt one of the main detours we have today and the ports roadway and rail. 5) It’s unclear how the light rail path would make its way to Delridge and what grade constraints would be required.6) It would likely trigger far more EIS studies.An immersed tunnel would be a truly massive project and cost far more and take much longer than replacing the bridge. 

    • TrappedinAlki June 8, 2020 (9:20 am)

      Why don’t you join the meeting and ask your questions instead of making so many assumptions.  I think it’s worth looking into.  Yes, there will be ramps but the graphics do a great job in explaining the length and grade required.   Light rail is still a decade+ away…they will have to deal with whatever is decided.   And who says it will take longer?  We don’t even know how long it will take to fix the  bridge if even it CAN be fixed.  MY armchair assumption is that it is unfixable, close to collapsing at any time and we’re starting from square one.

      • sna June 8, 2020 (10:10 am)

        Take a look at his proposed connections to existing roadways.  Imaging all the existing roads that need to be removed and rebuilt to make these connections.  There’s no way you’re not completely blowing up all the roadways and rail lines near the Chelan Cafe on the west side and similarly on Harbor Island.  Just about everything East of Nucor would need to go.  This would be a massive project that would cut off one of the few remaining routes out of WS.  I don’t need to join the call to see how incredibly disruptive and expensive this would be compared to just replacing the high span.  

        • Nick June 8, 2020 (1:28 pm)

          You know that 10 yr time frame that nobody likes, double that for this tunnel. It’ll take 5 years of legal battles with the Duwamish. Another 5 in studying fish impacts. 5 years in design. 5 years to build. Replace in kind with a joint use bridge between ST and SDOT and you remove the first two. You can probably get it down to 7 if funding sources are identified early enough.  

  • Joe Z June 7, 2020 (7:47 pm)

    How will this tunnel be protected against rising sea levels? 

  • Kram June 7, 2020 (8:09 pm)

    I feel like I’m living a crazy dream and it’s getting crazier before I wake up. Nothing would be cheaper than rebuilding the bridge and those costs are astronomical. Please please please stay on track people!!! I realize this will go nowhere but man could you imagine the design time and cost for something like this?!? 

    • ITT Fan June 8, 2020 (8:32 am)

      Actually, Immersed Tube Tunnels (ITT)  have proven to be the more economical and a better value than bridge options when you look at the approximately 100 ITT’s currently in use around the world. For example ITT’s are designed for 150 year life span compared to 75 years for bridges.

      • Ron Swanson June 8, 2020 (10:46 am)

        In a greenfield situation where you’re starting from scratch, maybe.  In a situation where you’re connecting to miles of already existing elevated roadway in a crowded urban environment and would be disturbing the sediment of a Superfund site to install the tube? $$$$

        • ITT Fan June 8, 2020 (1:14 pm)

          Take another look at the 110 years of ITT’s. In most cases, they were the most economical answer to complex problems. The Port of Seattle is planning a dredging of the waterway so the sediment will be disturbed with or without the ITT.

  • Steve June 7, 2020 (8:44 pm)

    City leaders need to focus on one thing – reopening the West Seattle Bridge as soon as possible.  The residents of West Seattle need to make it clear that the current situation is unacceptable and they need to move quickly to reopen the bridge.  The tunnel may be an interesting alternative, but it will take our fair city at least 1-2 years just to make a decision.  Add in the permitting, environmental reviews, negotiations with US Army Corps, Port of Seattle, Duwamish and other affected parties and it becomes pretty clear that a tunnel is many years out.  We really cannot afford to toss our city leaders a distraction like this.  I am for a West Seattle Bridge NOW!  

  • GT June 7, 2020 (9:26 pm)

    It looks like a job for Musk’s Boring Company. Too much for Big Bertha revival but Sound Transit has tunnels under the ship canal.  i was thinking maybe some high tension wire with basically a gondola ski lift thing  that could carry cars across.  The problem with the tunnels is that’s a huge elevation change from all the existing viaducts and WS freeway.  The original style drawbridge is affordable and would be huge improvement.

    • ITT Fan June 8, 2020 (12:06 pm)

      Deep bore tunnels and Immersed Tube Tunnels are different.

  • OMG June 7, 2020 (9:59 pm)

    A tunnel?? Anyone over 50 will be dead by the time its done! Haha. This is not complicated people, while all the people who love to talk about things meet, those of us with jobs and an interest in working and normal life as fast as possible will fix the bridge. Good? Good! Meanwhile, enjoy the Seattle pastoral hobby of forming meetings to discuss beefs about who is “not represented” and who will bring coffee and end up accomplishing nothing. However, when the bridge is fixed you are welcome to stop meeting and use it. 

  • Peter June 7, 2020 (10:21 pm)

    Would the Duwamish still be navigable with a sunken tunnel?

    • GT June 8, 2020 (1:12 am)

      The river can be dredged to sufficient depth, that’s doable….but you have to incline a tunnel/ tunnels on the East side, and on the West side get under the railroad and existing lower bridge West Marginal intersection mess, then get back up to the existing freeway.  Keep in mind, it’s not an Interstate or State Highway, just a street in Seattle, so who is going to pay for any of it?  Do you think the rest of the people in Seattle want more gas tax, property tax, car license tax just for West Seattle folks?  Rebuilding a modern drawbridge more or less like the original that clears the existing lower bridge swing would be fine.

      • Chemist June 8, 2020 (1:54 am)

        No drawbridges unless there’s some restricted schedule for openings like the ship canal has.   I think the high bridge project was originally conceived from the trouble that was being experienced with 8 lanes of drawbridge in the late 70s.  It’s not like the past 40 years have decreased the number of folks who rely on the bridge.

      • Seaviewer June 8, 2020 (2:10 pm)

        Let’s secede from the city, join with White Center, Top Hat, South Park and Burien to form a new municipality and boom, now we have ourselves a Washington State problem. I’m only half kidding.

  • Jon Wright June 7, 2020 (11:07 pm)

    Here’s a crazy idea: instead of posting rhetorical questions here, tune in to one of Bob’s sessions and ask him yourself.

    • Kram June 8, 2020 (7:18 am)

      Bob’s session is also rhetoric.

  • Joe June 7, 2020 (11:07 pm)

    I’m in if it includes a glass top for marine viewing.

  • Mellow Kitty June 8, 2020 (7:28 am)

    Did everyone develop amnesia about the last tunnel debacles – yes, plural – there were several?! Way over budget, way behind schedule, and a solid 2 years of the city paying for the most advanced, expensive tunnel machine to sit motionless and broken because of a metal pipe no one remembered was burried in the path?! What’s the plan if/when this happens under the river? Are they going to drain the river so the can dig down to the broken machine to fix it? What. The. Heck! I don’t know what Seattle has against pragmatism, but can we, for once, find a cost effective solution and not jump right to the most expensive, complicated one? Those who do not remember the past are condemned to repeat it. 

    • wscommuter June 8, 2020 (10:01 am)

      You should get your facts straight.  The SR 99 tunnel was a state project – not city.  A jury rejected the “pipe broke Bertha” theory that Seattle Tunnel Partners tried to sell, rejecting its claim for $350M and instead awarded the state around $70M in damages (check my numbers – I don’t remember the precise amounts).  The jury found that Bertha broke because of STP’s mismanagement of the machine.  The SR 99 tunnel was the most pragmatic solution to the problem we had; if you don’t know this, then please explain what solution was better.  I am agnostic/skeptical of this current idea but mostly because I don’t know anything about it.  I will listen to facts; if there is a persuasive argument that it can be built at a reasonable cost relative to other options, accounting for the infrastructure at either end to connect to, so be it.  But I will reserve judgment until there are actual facts and not just ranting on a comment page.  

      • Mellow Kitty June 8, 2020 (2:25 pm)

        First, whomever was held accountable for the breakdown by the courts, the fact remains that the machine was broken by a pipe. It ran into a pipe and broke, and sat there broken for two years. Second, a blvd would have been way more cost effective and, in my opinion, be a much more pleasant drive along the waterfront. Third, the tunnel was rejected at least once by the voters. The voters didn’t want a tunnel due to cost. Fourth, I misspoke when I said Seattle is solely responsible, I was wrong, that’s on me. Finally, the project was nearly four years, YEARS, late in finishing and went millions of dollars over budget. It was supposed to be finished and in use by the end of 2015 for a cost near 3.1 billion dollars. It ended up costing close to 3.3 billion, and didn’t open until February of 2019. I don’t claim to be an engineer or accountant, but, I do look at past mistakes and say, “well, that didn’t work. Let’s look into other options for the future.”  And again, what will they do if/when a new machine breaksdown under the river? The tunnel will take years longer to complete than a bridge. That’s my reasoning for my comment. 

        • Matt P June 8, 2020 (3:13 pm)

          They are making a massive boulevard to go along the redesigned waterfront.  There’s no way that could handle the traffic after it was finished and would have left no way to get through Seattle while it was being built. 

    • Jon Wright June 8, 2020 (8:31 pm)

      Mellow Kitty, apparently you developed amnesia about recent tunnel successes.

    • Also John June 9, 2020 (9:23 am)

      Please read the article.  This is not a bored tunnel.   These are precast concrete sections that are sunk (or is it sank?) into place.

  • tk June 8, 2020 (7:56 am)

    Looks like 2 lanes + 1 “bus only” lane in each direction (plus, eventually trains).  Unfortunately, it would take care of only some of the current traffic in/out of WS. Even the 2 draw bridges built in the 1930’s had 4 lanes in each direction = 8 lanes total.

  • Another neighbor June 8, 2020 (8:16 am)

    I encourage everyone with concerns in these comments to attend, or at least read up on the articles Mr. Ortblad has published already. This type of design could be started sooner, finished sooner, cost less, and last longer than a bridge replacement. All of the concerns you’re bringing up are valid, and they all support this approach. 

  • Thomas M June 8, 2020 (8:56 am)

    Is there a reason why the tunnel MUST follow the same footprint as the existing bridges?    Once underground, who cares where it goes?  The Chunnel between UK and France is very long; the Turks’ tunnel; at the entrance to the Bosporus and Dardanelles is 5.4 miles.  Chesapeake Bay has a series of tunnels.  We replaced the Alaska Way viaduct with a tunnel, and tunnel to UW from SLU.  I think we can get this done.  The key to speed is tamping down the lawsuits and  NIMBY nonsense.  

  • Aerial Observer June 8, 2020 (10:07 am)

    For reasons others have given, the tunnel idea for surface vehicles is a non-starter. If you don’t believe it, then please review the vast amount of work WSDOT had to do to align SR-99 to switch from bridge to a tunnel at the south end of downtown. That was one connection’s worth of re-grading. Multiply that by all of the connections to the current West Seattle Bridge, and watch the cost and time required multiply rapidly as well.Meanwhile, for all we know, replacing the locked bearing atop Pier 18 will return the bridge’s crack propagation rate to a level acceptable for restoring vehicle use. Then we would have more time to plan a replacement.If we want to build a tunnel under the Duwamish to West Seattle, then let’s obtain the money to put Link Light Rail into such a tunnel.

  • Neal Chism June 8, 2020 (10:10 am)

     After a Nisqually sized earthquake, when this tunnel structure becomes a floating bridge, we can always add more lanes on top.

    • ARPigeonPoint June 8, 2020 (11:29 am)

      Take a look at the presentation and note that tunnels such as BART are mentioned. That tunnel has survived some pretty significant earthquakes.

      • ITT Fan June 8, 2020 (12:56 pm)

        You are correct! The Trans-Bay Tube for BART in San Francisco survived the 1989,  6.9 Loma-Prieta earthquake with no damage.

        • ARPigeonPoint June 8, 2020 (4:39 pm)

          And I happened to be underground in a cellar stockroom for that quake.  It was no joke! I’ve looked at the slides and am really excited about this option.  A lot of commenters here don’t seem to realize a significant portion of the tunnel is pre-fab.  This would be SO much faster than other options.

          • KM June 8, 2020 (5:18 pm)

            I love the TransBay Tunnel, and have been in it during much smaller quakes. I think it’s an awesome structure and I miss it (I know, weird). I also think it’s a very hard sell to build a tunnel connecting a mostly single-family neighborhood to downtown/I5/I90. Our neighborhood population doesn’t come close to Oakland, Berkeley, Fremont and outer East Bay suburbs, and the proposal is for a much bigger tunnel than BART. I would also love a tunnel, but it’s a wild proposal to serve a small population. 

  • Mj June 8, 2020 (10:34 am)

    AO – amen!

  • skeeter June 8, 2020 (11:25 am)

    I can’t attend the meeting but can someone ask if it would be feasible for a bike/pedestrian lane to be part of the tunnel?  Yes, I know there is an existing bike/ped route on the lower swing bridge, but my concern is the swing bridge would be retired or not replaced if there is a fast new tunnel.  So the tunnel will need to accommodate bicycles and pedestrians.  

    • My two cents ... June 9, 2020 (10:25 am)

      @skeeter – this exercise here is not associated with any official City of Seattle efforts. 

  • VE Dan June 8, 2020 (2:23 pm)

    How about suspending a saddle from four towers (two on either end outside the road right of way and placed to avoid conflicts below) to upgrade support capacity of the failing section and allow reuse of existing serviceable roadway  infrastructure elements to west and east?  Towers would be as tall as necessary (similar in height to Tacoma Narrows) to facilitate repair necessary to mitigate continued creeping of the existing post-tensioned concrete span as quickly as possible to prevent collapse, increase load capability and be designed as landmarks.

  • GT June 10, 2020 (2:19 am)

    I was the one a month back suggested 4 space needles, a pair on each side of the river, then basically do Golden Gate style cable suspension for the road deck, seems so simple.  What everyone keeps forgetting that the highrise bridge used Federal money because they were responsible for the damage to the drawbridge. That money does not exist today. It’s neither an interstate nor state highway nor county road.  It’s just a street in Seattle.  When proposals put on city ballot, who believes anyone not living in WS will agree to new taxes?  And probably will have high toll. I bet y’all the city is thinking to start a toll on the low bridge starting NOW. But it’s fun to dream. Sure glad I am not currently financialy committed to new high density residential projects here, who would move in?  One thing I find amusing, when you look at aerial photos, the river is mostly obstructed but for a very narrow pass through at multiple locations, yet the high bridge spans what, 10, 20 times that? Just dig up the original drawbridge drawings and adapt to clear low bridge, build that. Is the viaduct or ws freeway wider today?

  • Fiona June 17, 2020 (7:50 pm)

    This meeting was just zoom bombed. Please let us know if it’s rescheduled in a different format. Thanks! 

  • Bruce June 17, 2020 (8:01 pm)

    The 06/17 Zoom meeting was disastrously hacked.  We hope that the call will be rescheduled with a no-troll, educational opportunity.

  • Julie A. Baker June 17, 2020 (9:14 pm)

    How do we find out if this is re-scheduled with a better security measure intact? Very disturbing!!! Maybe we need to sign up and get a security code?

    • WSB June 17, 2020 (10:06 pm)

      I trust they’ll let us know, but please note they already have a third one scheduled. Sorry to hear about the problem. First such incident locally that I’ve heard about.

      • Jim collins June 19, 2020 (11:45 pm)

        Zoom has a number of suggestions to prevent bombing. Basically set it up so only one or two hosts can interact online. Questions could still be routed to the host separately. 

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