North Shaft Update

At the North Shaft Site of the New Crystal Springs Bypass Tunnel project, vault work is nearing completion.

The valves and pipes within the vault have now been installed and the cast-in-place concrete foundation and walls have been poured.

Tunnel boring continues from the South Shaft, heading in the direction of the North Shaft.

The project team wishes everyone Happy Holidays and a Happy New Year.

Did You Know? Way Cool Stats about the TBM

Okay, I admit that these stats are way cool, even for non-engineers.

The tunnel boring machine (TBM) in use to create the New Crystal Springs Bypass Tunnel has 23 disc cutters in the cutterhead and they are each 17 inches in diameter.

It has a torque of 593,920 foot-lbs and an operating thrust of 1,150,000 lbs operating.

It has 5 gantry cars in its trailing gear, 2 muck conveyors and the total length of the shield and trailing gear is 155 feet.

Here is a photo showing part of its 155 foot long length during assembly in September.

TBM Making Progress in Tunnel!

The tunnel boring machine (TBM) at the South Shaft location is making progress creating the New Crystal Springs Bypass Tunnel!

As of this week, the TBM has mined 401 feet so far, and with the starter tunnel distance included, that brings us to 532 feet or 12.4% complete.

Here is a photo from the bottom of the South Shaft.

Happy Holidays from the New Crystal Springs Bypass Tunnel project staff

Happy Holidays from the New Crystal Springs Bypass Tunnel project staff. We appreciate your interest, support and patience during this important project.

We wish you and your families a wonderful holiday season.

Night Work Nov 24-25, 30 and Dec 1st

As you know, the contractor has been making necessary adjustments to the tunnel boring machine (TBM) inside the shaft during weeknights. The TBM is now launched! On Nov 24-25, 30 and Dec 1st, limited crews will work until approximately 11pm. At this time, the contractor does not plan to work on Thursday or Friday. If the contractor continues to need more time to meet the project schedule, crews could work longer evenings in December.

During this night work, the majority of activities take place inside the shaft and tunnel. The crane and site lights may be used. The project team will follow all required nighttime noise limits as specified in the project Environmental Impact Report (EIR). Some soil may be lifted from the shaft but will not be relocated to the upper terrace until the following daytime shift.

We will continue to have on-call staff monitoring the situation. You may call our 24 hour dispatch 650-872-5900.

UC Berkeley Engineering Students Tour South Shaft Site

On Friday, November 13, a group of 27 graduate students from the University of California at Berkeley toured the South Shaft site.

Members of the project team led the tour and shared information about the project.

The students are taking an engineering geology class through UC Berkeley's Department of Civil and Environmental Engineering.

Safety Reminders on Polhemus Road

We are committed to safety and recently posted new signs on Polhemus Road alerting drivers, cyclists and pedestrians about trucks entering and exiting the roadway near our South Shaft site.

Please use caution in the area as we expect more trucks entering and exiting the site when we begin boring the tunnel.

Please also watch for deer! They often graze on the side of Polhemus Road and often cross in front of traffic. Please watch speed and use caution.