The Bertha TBM just received a shipment of spare parts to repair the giant tunneling machine. The manufacturer decided to redesign the seal system to make it easier to access from the inside, if necessary. That’s probably a good idea considering the prospect of a repair like this one once the machine is moving beneath downtown Seattle. Other improvements and repairs to the TBM include:
- A new main bearing
- Enhanced monitoring systems
- Added steel to strengthen the machine and accommodate the new seal system
- Widened openings at the center of the cutterhead
- Extended arms to mix excavated soil in the chamber behind the cutterhead
[Source: WSDOT Alaskan Way Viaduct Project Page. Image: WSDOT Flickr Page]