Sound Transit thanks neighbors for patience with ‘Cross Passage 17’

Image: Sound Transit Flickr steam

Image: Sound Transit Flickr steam

Sound Transit put a ‘Thank You, Montlake’ note in its latest U-Link newsletter, acknowledging the patience neighbors showed in dealing with the Cross Passage 17 dewatering mess. Last June, 20th Ave E adjacent to Montlake Elementary was hastily closed to make way for drilling equipment to “dewater” the soil around the twin light rail tunnels below. After six months of tanker trucks, generators, pumps and pipes — peace has returned to the shire. From Sound Transit:

Thanks to the Montlake community for its patience during the construction of Cross Passage 17, which has been underway 100 feet below the surface since July, 2012.

Montlake neighbors, families and the Montlake Elementary School staff have endured the presence of large equipment, traffic and parking revisions, well drilling and other surface work for longer than anticipated.

What is Cross Passage 17?
Cross Passage 17 is one of 21 horizontal tunnels, 18-24 feet long and about 10 feet in diameter, that connect the two University Link tunnels running between downtown Seattle and Husky Stadium. Cross passages provide emergency access as well as entry and exit between tunnels for routine maintenance.

Building Cross Passage 17 became very challenging when the contractor encountered more water than originally anticipated. To stabilize the area for mining, it was necessary to remove water from the ground surrounding the tunnel to give crews a safe working environment. For more than six months, generator-powered pumps removed water from soils around the tunnels. Today, Cross Passage 17 is nearly complete and work has turned to finishing the U-Link tunnels, including installing concrete duct banks, walkways, light rail tracks, power and signaling supply lines, tunnel lighting and communications systems.

On the surface, crews recently removed equipment and restored streets. Landscaping will be completed soon in order to return the location at 20th and McGraw to its original condition.

In hindsight, neighbors — and school staff and students — were patient because they are generally supportive, excited even, about light rail coming to the ‘hood. Yet, the street closure further complicated the zoned parking restrictions around the school, causing more than a few grumbles about a bad situation made even worse. Relief may be on the way for teacher parking soon enough… and Montlakers will be able to walk to light rail come 2016.

Now that cross passage work is complete, Sound Transit contractors will start work on the track bed, including installation of those train-noise-shushing high compliance fasteners.

Previous “dewatering” posts: