California conveyors

In the Insight section of the June T&TI, Desiree Willis, Robbins’ technical writer, has put together a feature discussing the use of continuous conveyors.

It’s an interesting article, not least because Willis references the Lower and Upper Northwest Interceptor projects in Sacramento, California. When I visited San Francisco’s Bay Tunnel project in March contractor Michels/Jay Dee/Coluccio was quite excited to discuss their decision to use a continuous conveyor belt, and cited the Sacramento project as a success story.

The 5-mile (8km), soft ground Bay Tunnel with a 15ft (4.6m) diameter will not have any intermediate access shafts and the conveyors offer a time-saving solution to avoid the extending haul times and passing switches a train would require.

While it’s a bit early to see the Bay Tunnel set-up (the Hitachi EPBM has been lowered into the launch shaft, but is still being assembled for its launch later this summer) be sure check out the Sacramento project, and others:

Online subscribers can read Willis’ article here: http://www.tunnelsonline.info/story.asp?sectioncode=2&storycode=67083&c=2

In the printed issue ‘Complexities of conveyance’ can be found on page 25.