(Water Taxi’s West Seattle vessel Doc Maynard at downtown dock, expecting lots of riders during the closure)

11:49 AM: Just wrapped up on the King County Water Taxi dock downtown: One last media megabriefing before the Alaskan Way Viaduct’s two-weeks-or-so closure, now a little over 10 hours away (onramp closures start at 10 pm, so don’t count on using The Viaduct after that). Those on hand for brief statements followed by Q&A included Dave Sowers from WSDOT, Jon Layzer from SDOT, Paul Brodeur from the King County Marine Division (Water Taxi), Victor Obeso from Metro, Bruce Gray from Sound Transit, and Peter McGraw from the Port of Seattle.

We have it all on video and will upload as soon as we’re back at HQ (1:45 pm update – here it is):

Nothing dramatic but a few points of interest we hadn’t heard much about before:

*SDOT mentioned that the “maritime community” has indeed been asked to try to minimize bridge openings during the closure, but as Layzer acknowledged on our followup question, all they can do is ask – maritime use has priority, particularly for the West Seattle “low bridge” (formally the S. Spokane St. Swing Bridge) – UPDATE: Here’s what SDOT is asking the Coast Guard about, for bridges including ours:

The Seattle Department of Transportation would like to request that the US Coast Guard send out a notice to mariners requesting voluntary compliance at each of the following bridges for the period of 12:01 am on April 29, 2016 to 11:59 pm on May 12, 2016:

Ballard Bridge: Weekday voluntary compliance one hour before and one hour after the existing restrictions (i.e. In addition to the existing restrictions, 7-9 am and 4-6 pm weekdays, we are asking for mariners to try and limit the number of bridge openings between 6-7 am, 9-10 am, 3-4 pm & 6-7 pm, whenever possible).

Fremont Bridge: Weekday voluntary compliance one hour before and one hour after the existing restrictions (i.e. In addition to the existing restrictions, 7-9 am and 4-6pm weekdays, we are asking for mariners to try and limit the number of bridge openings between 6-7 am, 9-10 am, 3-4 pm & 6-7 pm, whenever possible).

University Bridge: Weekday voluntary compliance one hour before and one hour after the existing restrictions (i.e. In addition to the existing restrictions, 7-9 am and 4-6pm weekdays, we are asking for mariners to try and limit the number of bridge openings between 6-7 am, 9-10 am, 3-4 pm & 6-7 pm, whenever possible).

Lower Spokane Street Swing Bridge: Weekday voluntary compliance between 6-10 am and 3-7 pm (there are no existing restrictions on this bridge).

*A temporary stop is being added so that WS bus riders can connect to light rail in SODO – it’s marked on the reroute maps (second page of this PDF shows the West Seattle routes)

*If you want to connect to light rail, the Water Taxi is also an option, it was pointed out to us in conversation with the Marine Division reps after the briefing, since you can walk a few blocks east and get to the transit tunnel (King Street Station, also served by Sounder rail, isn’t far either)

*We asked what happens when they get word that the tunneling machine has made it the full 385-foot distance beneath The Viaduct, to the other side. Sowers says WSDOT would then do one more inspection of The Viaduct, along the lines of what they do twice a year, to check it thoroughly for cracks, settling, etc., before deeming it safe to reopen for traffic.

More to come when we’re back at HQ.

1:45 PM UPDATE: We’ve added the briefing video above. Also, since the briefing, WSDOT has added an online update with yet another reminder plus some news that wasn’t part of the briefing. See the full update here; below, the sections that followed the general reminder:

Seattle Tunnel Partners tunneling operations

Seattle Tunnel Partners is making final preparations for their tunnel drive beneath the viaduct. They have told us that the overnight crew will spend the early hours of Friday restarting and testing Bertha, the SR 99 tunneling machine. Tunneling is expected to begin sometime during the day shift on Friday.

STP expects to start slowly as Bertha digs out of her planned maintenance stop, which is essentially a block of concrete buried in the ground near Yesler Way. The machine must dig through approximately 10 feet of concrete to exit the maintenance stop and enter the soil near the intersection of Yesler and Alaskan Way. Initially, trucks will carry away the excavated material. Crews intend to proceed deliberately throughout the weekend, carefully monitoring the machine’s performance and the surrounding ground as Bertha inches forward.

STP expects to pick up speed early next week. The tunneling operation – tunneling forward, building rings and doing maintenance on the machine – will continue around the clock throughout the closure.

You can track Bertha’s tunneling progress here. We’ll be updating the progress graphic twice each day.

Barging operations to resume

The suspension for cause that has restricted barging operations since January was lifted this week. That means that STP will be allowed to remove excavated soil from the work site via barge using new procedures they developed over the past two months. Having the barging operation back online allows STP to remove excavated material more quickly than trucking the material offsite.

Check out our construction cameras page to get a closer look at the barging operation when tunneling begins on Friday.

Again, we’ll have an update when the closure begins late tonight, as well as expanded coverage of morning and afternoon/evening traffic/transit starting Friday.