Brenda, you’ve looked better (Image: Sound Transit)

After only seven months of digging, Sound Transit contractors already have bored more than 60% of the twin tunnels running between Husky Stadium and downtown via Capitol Hill. An update on the project from Sound Transit and a few notes from CHS are below.

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The monthly newsletter update — you can sign up here — also makes some positive notes about the Montlake Murmur issue with our neighbors down the Hill. Notes from last month’s community meeting posted in the most recent edition of the Montlake Flyer (PDF) are less sanguine and the group notes it has asked Sound Transit to return for its March meeting to offer further updates on the noise and vibration problems some residents are facing.

CHS has reported that similar vibration issues felt around Volunteer Park have mostly faded away. We still receive an occasional burst of one and sometimes two or three reports from an area as tunnel boring machines pass nearby but nothing on the scale of the Montlake complaints.

Boring began last May with a dignitary and champagne-fueled ceremony at Husky Stadium. The Broadway to downtown component got underway in June. With the tunnel boring progress, we’ve asked Sound Transit if their contractors are ahead of schedule but haven’t yet heard back. UPDATE: A Sound Transit rep says they’re happy with the progress but even after the tunnel routes have been bored there will still be more work digging out the cross passages required to connect the twin tunnels.

Meanwhile, Sound Transit says that TBM Brenda is back on the move again climbing her way on a second journey from Broadway to the Paramount. Here she is in early December after having broken through on her first journey downtown. From the picture above provided by Sound Transit as she began her second trip, you can see the underground work has been tough on her skin.

 

(Image: STArt)

Sound Transit also announced the addition of a new work on the big red construction wall. “Otters Holding Hands”  by artist Vida Rose now appears at Broadway and Denny. The paintings were inspired by a popular YouTube video.

Here’s the latest update sent out by Sound Transit:

The tunnel boring machines are continuing their underground journeys. All three have made tremendous progress. Brenda has started her second trip towards downtown Seattle (see below). Togo and Balto are both due at the Capitol Hill station this spring.  

Brenda is Off on Her Second Run  Brenda is digging her second tunnel from Capitol Hill to downtown Seattle. She made her first run in a little less than six months, digging 3,795 feet. Her estimated arrival in downtown Seattle is in early summer. Once Brenda has reached her final destination below Pine Street she will be disassembled, and parts of her will remain underground. Too bad she can’t be part of the official Seattle Underground Tour.

View Brenda’s trailing gear and lots of great construction activity at the Capitol Hill construction site.

Construction Vibration As Togo and Balto dig their way south to Capitol Hill, their passing has not gone unnoticed. In recent months, some residents above the path of the tunnel have reported hearing a low rumbling from the machines as they dig. However, the disturbance only lasts a day or two. Digging at 50+ feet per day, the TBMs quickly move on.

A number of people have also reported experiencing noise and vibration from the construction supply trains used to carry heavy tunnel segments up to the TBMs, mainly in the Boyer and Shelby-Hamlin neighborhoods. Sound Transit has reduced the impact from the supply trains by grinding the joints between sections of temporary rail, and installing thick rubber pads underneath the temporary rail support. The mitigation appears to work well, as many residents report the noise and vibration is now unnoticeable or substantially less of a nuisance.

It is possible that construction vibration may be noticeable above the alignment on Capitol Hill as the TBMs work their way towards the station at Broadway and John. If you have concerns about the tunnel construction or questions about noise, please contact Sound Transit’s 24-hour construction hotline at 1-888-298-2395.