A Road Header Rendezvous

9:46 AM June 12, 2012

Inside of a 13-foot diameter hole carved into the Alameda foothills, crews waited yesterday morning staring at an imposing rock wall.  A moment later, as if it came from within the mountain, a spinning titanium studded knuckle broke through. It moved back and forth and up and down until the wall disappeared.  What happened next was a long time coming: two crews, dressed in identical hard hats, headlamps and goggles stepped through the new hole, shook hands and then shared a laugh.

Video Captured with Permissible Camera

After 13 months of digging the New Irvington Tunnel from four separate tunnel headings, miners from two of the headings met up with each other underground today. Called a ‘hole-through’ in tunneling terminology, the road header teams from the Irvington Portal in Fremont and the Vargas Shaft 4,500 feet away shook hands somewhere under the mountainside and formally completed this section of tunnel excavation.

The road header holes-through the rock face

Miners at the Irvington Portal watch the road header hole-through from the Vargas Heading 

Miners celebrate their achievement

Photographs by R. Scheswohl ©2012 SFPUC, All Rights Reserved

The tunnel is excavated using conventional mining methods including a road header (a tracked tunneling machine) and, in sections of hard rock, controlled detonations.  In May 2011, a 55-ton road header was lowered down the 115-foot Vargas Shaft and began to grind its way west.  A month later, miners at the Irvington Portal in Fremont began tunneling east and set the two crews on a collision course.  

Following today’s hole-through, miners will prepare the tunnel for the installation of 102-inch diameter steel pipe.  The pipe, manufactured in California, is installed in 50-foot sections and welded together inside of the tunnel.   The much longer 14,400-foot Alameda West-Vargas tunnel segment is currently being excavated and is expected to hole through in fall 2013.  Construction of the entire project is scheduled for completion in fall 2014.

Final Road Header Rendezvous Challenge Entries

All entries are in for the Road Header Rendezvous Challenge.  Thank you to all that participated! As of today, miners are within 120 feet of holing through!

Project neighbors, tunnel enthusiasts and the general public all tried figure out when the Irvington-Vargas hole-through would take place.   Entries ranged from June 1 through July 20.  Here’s a look at the final entries:

The winner will be the person that correctly guessed the day and timeframe when tunnel crews meet underground.  If no one selects the square with the date and time of the hole-through then the “Price is Right” rule goes into effect.  The person with the closest selection without going over is the winner. 

For example:

Jane from Fremont selects June 22 6:01PM – 12:00 AM

John from Sunol selects June 23 12:01 PM – 6:00 PM

The actual hole-through takes place on June 23 between 6:01 AM – 12:00 PM.  Jane is the winner because she guessed closest to the actual hole-through without overshooting her estimate.

The winner of the challenge will be contacted by the SFPUC and receive a prize pack featuring local gift certificates and SFPUC gear.

If you didn’t get a chance to participate in this hole-through challenge you’ll have another chance.  The main hole-through of the 3.5 mile tunnel will take place sometime in 2013.  Only 9,533 feet to go!

Calaveras Dam Replacement Project Air Monitoring Results

The replacement of Calaveras Dam will require the movement of more than 7 million cubic yards of rock and earth, a portion of which may contain Naturally Occurring Asbestos (NOA). Construction activities could cause asbestos fibers to become airborne, which could present a health concern. We have put into place an extensive dust control and air monitoring program to ensure that we are not exposing any members of the public to increased levels of Naturally Occurring Asbestos. We have monitored background air quality levels in the area prior to construction for more than two years. We will continue to monitor air quality at perimeter and ambient air quality monitoring stations and will make the data available on this website. Protecting the health of our workers and the public is our utmost priority.

To view the latest air quality monitoring results, click on our website here. Results are updated weekly and data is archived on a quarterly basis for the duration of the project. See map for monitoring locations and Q&A about how to read the graphs and data.

Naturally Occurring Asbestos found in Natural Rock Formation

For more project info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Look How Far the Water System Improvement Program Has Come

The Water System Improvement Program (WSIP) is $4.6-billion of infrastructure upgrades, including more than 80 projects located in six Bay Area counties to ensure the highest quality drinking water and a reliable water supply to customers following an earthquake. These seismic improvements include dams, tunnels, pipelines, treatment plants and many more facilities that serve 2.6 million Bay Area customers. 2011 marked the start of the WSIP’s most active construction year to date. As of March 31, 2012, 55 out of 81 local and regional projects have been completed. All WSIP projects are forecasted to be complete in 2016. To view our progress and learn more about our water system, check out our video of water system improvements in your area here: http://www.youtube.com/watch?v=5qwqUcPIOyM&feature=youtu.be 

 

Last Chance to Enter the Road Header Rendezvous Challenge!

May 31^st is the final day to make your selection in the NIT Road Header Rendezvous Challenge!  As of May 29, mining crews are now within 265 feet of connecting the Irvington and Vargas West tunnel headings.

Your challenge is to figure out the day and time you think the tunneling workers will meet. Guess correctly and you could win a prize pack featuring gift certificates to local business and other goodies! The chart has squares corresponding to a date and timeframe in June or July, when the rendezvous could happen. Selections submitted by contestants are indicated by a star.

Update: If no one selects the square with the date and time of the hole-through then the “Price is Right” rule goes into effect.  The person with the closest selection without going over is the winner. 

 For example:

Jane from Fremont selects June 22 6:01PM – 12:00 AM

John from Sunol selects June 23 12:01 PM – 6:00 PM

The actual hole-through takes place on June 23 between 6:01 AM – 12:00 PM.  Jane is the winner because she guessed closest to the actual hole-through without overshooting her estimate.

How to Enter

1) Choose your top three squares and e-mail your choices to: fzamora@sfwater.org

2) Include the date and time you think the hole-through will take place. Squares will be assigned first come, first serve. Only one square is allowed per person

3) If the first choice is available then the square is assigned to that person. If the square is unavailable then the next available choice is assigned.

4) Submissions will be accepted until May 31. Please include your name, address, phone number and e-mail so we can contact you if you're successful!

Good luck!

NIT Road Header Rendezvous Challenge Update

With just over a week to make your selection in the NIT Road Header Rendezvous Challenge, mining crews traveling in opposite directions are getting closer to a hole-through.  Don’t miss out and make your selection by May 31.

As of this week the Irvington and Vargas West headings are just 370 feet apart! 

If you haven’t submitted a selection your challenge is to figure out the day and time you think the tunneling workers will meet. Guess correctly and you could win a prize pack featuring gift certificates to local business and other goodies! The chart has squares corresponding to a date and timeframe in June or July, when the rendezvous could happen. Selections submitted by contestants are indicated by a star.

How to Enter

1) Choose your top three squares and e-mail your choices to: fzamora@sfwater.org

2) Include the date and time you think the hole-through will take place. Squares will be assigned first come, first serve. Only one square is allowed per person

3) If the first choice is available then the square is assigned to that person. If the square is unavailable then the next available choice is assigned.

4) Submissions will be accepted until May 31. Please include your name, address, phone number and e-mail so we can contact you if you're successful!

Good luck!

Scraper, scraper, scraper.

The Calaveras Dam Replacement Team has been working hard since April, scraping away at existing earthen materials to excavate for the dam foundation. We have now reached the highest point of the dam foundation for the future replacement dam. This point is located in the right abutment, an area located to the right when looking downstream from the dam. By July 2012, we anticipate to move close to 1 million cubic yards of materials. Our scrapers are excavating approximately 20,000 cubic yards per day. The scrapers operate with hydraulics using a blade which then scrapes materials into a drop can, carrying up to 30 cubic yards per trip. These materials are then moved to a disposal area within the project site. The scrapers are about 11 feet tall and the project is operating 12 scrapers for the excavation work.

For more project info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

View of Right Abutment Area

Scraper working in Right Abutment Photo courtesy of Robin Scheswohl