Ship Canal Water Quality project update 2/14/22

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Ship Canal logoMudHoney control room

MudHoney control room

How do you stay on track when you can’t “see” where you’re going?

It’s true that there’s a team of people “driving” MudHoney, but how in the world do our TBM operators know where to go when all that’s in front of them is soil (and a mix of glacial tills, sand gravels and boulders)?

MudHoney operators keep track of where they are and where they need to go using a high precision laser guidance system and state of the art surveying equipment. The accuracy that the team can achieve is amazing – we measure to 40 thousandths of an inch (1mm) and when we get to the end of the tunnel nearly 3 miles from Ballard, we expect to be within 2 inches of the planned position. MudHoney steers using thrust arms, which push off the tunnel segment rings that MudHoney has constructed behind the cutterhead. Think about how a mole propels itself underground, using its hind legs to push off tunnel walls and propel itself forward. MudHoney is also one of the first TBMs to use a boulder detection system, but that’s a topic for another email.

Take a look at our Flickr albums to stay updated on the most recent construction, including images of our new tunnels.

Ballard & MudHoney

After a planned pause, MudHoney, our 18-ft diameter tunnel boring machine (TBM), resumed tunneling on February 7. Before starting MudHoney, we sent our engineers and workers inside the excavation chamber under compressed air to check on the condition of the cutting tools. Pressurized air allows workers to safely enter the cutterhead chamber without groundwater entering the TBM. The pressure here is equivalent to recreational scuba diving at an 80-ft water depth.

Since MudHoney has already advanced nearly 1000 feet, which includes cutting through the very strong concrete of the shaft slurry wall, we expected to see a lot of tool wear. We saw much less wear than we anticipated, which is very encouraging for the rest of the drive.

During tunneling activities, you should anticipate:

  • Truck deliveries of concrete segments and MudHoney equipment
  • Tunneling activities
  • Nighttime segment deliveries and tunnel spoils being hauled off
  • Noise and vibrations typical of a construction site

Crews are working 24 hours a day, 6 days a week and will continue until MudHoney reaches Wallingford in late 2022. Sunday work may also occur.

Ground monitoring is ongoing along the tunnel alignment and is done from both inside MudHoney and on the surface.

East Ballard

Excavation work for underground mechanical and electrical vaults on NW 45th St is currently suspended due to the concrete strike. CDF (Controlled Density Fill) is required to support the ground during excavation. During this time, you can expect:

  • NW 45th St closed to traffic; vehicles must detour onto NW 46th St
  • Burke-Gilman Trail users remain detoured to the north side of NW 45th St through 2022. Please follow all detour guidance on site. For safety, bicyclists should either dismount or cross train tracks at a 90-degree angle. Please use extra caution in wet weather as ramps may be slippery.

Regular work hours would be Monday through Friday, from 7 am to 5 pm. Night and weekend work may occur.


Crews continue jet grouting. This work includes lane reductions on Leary Way NW, between 1st Ave NW and NW 39th St, with an optional detour through early March.

During this time, you should anticipate:

  • Lane reductions on Leary Way NW through approximately early March 2022 (see map with optional detour). We will continue to look for opportunities to open up the lanes whenever possible.
  • Excavators working on-site for utility installation work
  • Truck traffic on Leary Way NW as trucks bring and remove materials to and from the site
  • NW 36th St between Leary Way NW and 3rd Ave NW closed (through remainder of the project)
  • Pedestrian detours on Leary Way NW, please follow all detour guidance on site
  • Generators running during work hours to power equipment
  • 2nd Ave NW, between Leary Way NW and NW Canal St, closed to vehicle and pedestrian traffic for sewer and diversion structure work at least through the end of 2022
  • NW Canal St is open to two-way traffic to allow access during this closure. Please do not park at the west end of NW Canal St to allow two-way traffic to turn around at the closure.
  • Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5 pm. Night and weekend work may occur.


Crews continue working on the shaft liner walls and preparing for MudHoney’s arrival later this year. For the next couple of weeks, steel reinforcement and timber formwork are being installed for the lower part of the shaft lining wall. Work may be suspended before the end of February if the concrete strike has not been resolved.

During this work, you should anticipate:

  • Trucks coming in and out of the site to deliver reinforcing steel and formwork materials
  • Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5 pm.

Queen Anne

Crews have nearly completed the installation of temporary shoring. Work is now suspended until the concrete strike is resolved.

During this time, you should anticipate:

  • Trucks coming in and out of the site
  • Noise and vibrations typical of a construction site
  • The West Ewing Mini Park parking lot to remain closed through mid-2023
  • A localized Ship Canal Trail detour through summer 2022 (see map)

Regular work hours will be Monday through Friday, from 7 am to 5 pm. Night and weekend work may occur.

Contact us

Please email with questions or comments or call our hotline at (206) 701-0233. You can also find information online at support the community during active tunneling, we have changed our hotline hours to 24 hours a day, Monday through Friday.

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