SR99 TBM starts digging

13/08/2013

On 30.07.2013 TBM Bertha, involved in the Alaskan Way Viaduct Replacement, broke through the north wall of her 24.38 m-deep launch pit. She’s expected to emerge in about 14 months near the intersection of Sixth Avenue North and Harrison Street. The initial advance will be set at 1.83 m/day, later reaching 10.67 m/day. For tunnelbuilder archive click here and us/69. Visit www.AlaskanWayViaduct.org and www.wsdot.wa.gov. 33/13.