Bertha’s little sister set to begin new tunnel beneath Seattle
Apr 28, 2014, 5:18 PM | Updated: 5:44 pm
While Bertha remains bogged down, another tunnel machine is getting set to head under Seattle with a proven track record of success that puts the higher profile drill to shame.
Officials gathered Monday near Northgate for a dedication ceremony for “Brenda,” a smaller tunnel boring machine that will dig one of two tunnels between Northgate and the University of Washington as Sound Transit continues extending light rail in the region.
The $2.1 billion Northgate Link Extension is scheduled to open in 2021. It will run mostly underground, with underground stations serving the University District and Roosevelt and an elevated station at Northgate.
“This project will cut through some of the worst traffic in the state, creating the capacity to move up to 800 riders in each direction every few minutes with zero congestion,” said Sound Transit Board Chair and King County Executive Dow Constantine. “It will immeasurably improve the lives of its riders. It will also prove critical to the functioning of I-5 as the region’s population grows approximately 30 percent in the next two decades.”
Brenda has already proven her digging prowess, successfully completing two one-mile tunnels for the University Link light rail project between Capitol Hill and downtown Seattle between 2011 and 2012. The stretch is currently scheduled to open in the first quarter of 2016, six to nine months early, and is more than $100 million under budget, Sound Transit says.
After her dedication with officials breaking a bottle of sparkling apple cider to send her off Monday afternoon, Brenda will now be moved to a launch pit for final assembly before beginning drilling in June alongside I-5.
The machine looks like a miniature version of Bertha, for good reason. It was manufactured by Hitachi Zosen Corp. of Japan, which also built Bertha. It has a similar design, but is about one-third the size of the tunneling machine stuck beneath the Seattle waterfront since December.
A second machine, now just known as TBM 2, is scheduled to being digging the second of the twin tunnels sometime this fall, likely in October.
Sound Transit will launch the construction of East Link light rail from downtown Seattle to Mercer Island, Bellevue and Redmond’s Overlake area in 2016.
Preliminary planning and environmental work are moving forward to extend light rail from Northgate to Lynnwood and Seatac to the Kent/Des Moines area.
