Video: Changing cutting tools on Bertha TBM

The massive 13-mile wastewater tunnel project known as Brightwater is approaching the final stretch of tunneling, but perhaps the most difficult. This portion of the project has already claimed one contractor’s slurry TBM and put […]

From WSDOT’s video description: After nearly a week of tunneling under the Alaskan Way Viaduct, crews are steadily continuing Bertha’s underground drive towards downtown Seattle. This video gives you a behind-the-scenes glimpse into how the […]

The world’s largest Tunnel Boring Machine or TBM just arrived in Seattle last week from Japan. Hitachi Zosen Corp built the 57 foot diameter TBM and tested it before disassembling it for the journey by […]