March 3 project update: Bertha tunneling toward South Washington Street

Posted on Mar 3 2016 3:21 PM
Bertha, the SR 99 tunneling machine, has traveled approximately 110 feet since Seattle Tunnel Partners resumed mining on Feb. 23. The machine has tunneled a total of 1,391 feet and is approaching South Washington Street.
STP is now 17 concrete rings into the 25-ring demonstration period that was put in place when WSDOT conditionally lifted the Jan. 14 suspension for cause. Crews are mining north to a planned maintenance stop just south of Yesler Way. Once there, they could spend several weeks performing final maintenance before the machine tunnels beneath the Alaskan Way Viaduct. 
Update on barging
While mining is ongoing, barging activities are still restricted pending submittal of additional documentation. STP is removing excavated soil by truck as they continue addressing the barging issue. Repairs to the pier that was damaged during the Jan. 12 barging incident were completed last month.
Recent updates 
For earlier program updates, please visit our archive page.


Order: 1.1