CALDECOTT FOURTH BORE TOUR Article by Bob Fracolli Photos by Mark Huston

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1 CALDECOTT FOURTH BORE TOUR Article by Bob Fracolli Photos by Mark Huston On Friday, February 22 nd, fifteen members and guests of the Northern California Region met in Lafayette for a presentation and site visit on the Caldecott Tunnel 4 th Bore project. We first met off-site and combined everyone into four cars (we ended up in two Lincolns, a Cadillac and a GMC-all non-classics). Parking was very limited where we were headed, and the destinations were not a good fit for Full Classics, even though it was a nice sunny day. At 10:00 am, we met with Senior Project Manager Ivy Morrison at the Fourth Bore Construction Office in Lafayette. In a large conference room, she gave a PowerPoint presentation on the history, funding and construction of the Oakland to Orinda Fourth Bore tunnel. With all of Our Tour Organizer Bob Fracolli our questions and subsequent discussions, the normally one- hour presentation stretched to two and a half hours! Before leaving, we were given hardhats, construction vests, safety glasses and boots to wear at the construction site. Next, we were off carpooling to the East Portal for the site visit. We parked in a heavy gravel lot with a significant incline, and then walked up a way to the construction office where we signed in. Single file, we walked back through the gravel lot and down a trail through large construction equipment. We continued down two long flights of temporary wooden stairs, finally reaching the East Portal. There, we had a close-up view of the East Portal and inside the tunnel. The site was quite busy with construction vehicles and workers going in and out of the tunnel. In the tradition of mining, each worker entering the tunnel had to have two numbered brass tags; one was left on a board outside the tunnel and the other one was carried inside by the worker. In an emergency, one could tell exactly how many workers were inside the tunnel and account for each as they came out. Although we had a spectacular view, we were not allowed to actually enter the tunnel for safety reasons. The East entrance to the Fourthbore of the Caldecutt Tunnel After hiking back to the cars, we carpooled through the Third Bore to the West Portal. Unfortunately, there was no parking so we weren t able to view the construction from that side. Back through the First Bore, 8

2 we drove to the Europa Hofbrau in Orinda for lunch. Taking over a section of the restaurant, we ate and talked during a leisurely paced lunch. After lunch, the protective clothing was returned to the construction office and people were driven back to their cars. All who attended saw local history in the making and learned a great deal about the history and construction of the Caldecott Forth Bore Tunnel. Ivy Morrison, giving the attendees all they needed to know, background and construction of the Caldecott Forth Bore Tunnel HISTORY AND BACKGROUND The first tunnel from Oakland to Contra Costa County was the Kennedy Tunnel, built in It was also known as the Broadway or Upper Broadway Tunnel, and finally closed in The tunnel is now filled in, but a plaque can be found memorializing it near its west portal off Tunnel Road. In 1937, the Lower Broadway, or First and Second Bores of the Caldecott Tunnel, were completed. The Work Progress Administration (WPA) funded their construction during the Great Depression. In 1964, the Third Bore of the Caldecott Tunnel was completed. Right-of way for the Fourth Bore was purchased at the same time. The rock where the tunnels are is comprised of vertical strata, which is folded. The Orinda side is made up of younger rock, and was an ancient riverbed. During the Fourth Bore construction, a paleontologist was required to be on-site. Among things discovered during the excavation were a camel tooth, three-toed horse leg bone and bones from giant sloths. The Oakland side was a deep marine environment. Fish and clam fossils have been recovered from that side. There were many Fourth Bore construction challenges. Different types and densities of rocks were located next to one another, making the excavation difficult. Due to trace levels of methane, the Fourth Bore was designated as a Gassy Tunnel, requiring specialized ventilation during construction. The City of Oakland sued the project, resulting in a $9-million dollar settlement and mitigation measures to the Oakland side residents including the largest temporary sound wall in California, the installation of nine sound level monitors (monitored throughout the day), and strict restrictions on times dynamite could be used (making its use impractical). The completed Fourth Bore will have two 12-foot lanes, a 10-foot shoulder and an emergency pedestrian walkway. The tunnel interior will be covered with a water proofing membrane, a concrete reinforced steel rebar cage, and a thin outer lining. There will be 20 jet fans capable of exhausting air in multiple directions. Seven emergency crosspassages have been dug between the Fourth and Third Bores. The tunnel can survive an earthquake up to a magnitude of 7.2 and a 2200-degree fire for two hours. The final roadway will be two-feet above the excavation line to address groundswell effects. Bores Three and Four will share a radio re-broadcast system. While there were multiple fatalities in 1937 construction and one in 1964, there have been none in Fourth Bore construction. 9

3 The New Austrian tunneling method developed in 1960 s is being used in the construction. This method employs sequential excavation of first the top portion, then lower eight feet. The excavation is in a horseshoe shape. One to one and a half meters are excavated at a time, depending on stability of rock. The excavated area is immediately covered with shotcrete, a mix of concrete and fiberglass-type material. Three-quarters of work was been done from the east side. This is because the rock is more stable, it is downhill, it is away from residents living nearby, and there is room for staging equipment. On the Orinda side, a Roadheader was used. It is a machine with a huge drill head, designed and manufactured in Austria. The Roadheader drills in circular pattern. It is electrically powered and remotely operated. The machine spits out rock onto a conveyer, which is then loaded into muck trucks and removed. For the Oakland side and for most of the bottom level, a Caterpillar 330 Excavator was used. The dirt was designated as clean or dirty. Dirty dirt had traces of methane gas and was taken to landfills. Clean dirt was taken to Treasure Island. Groundbreaking of the Fourth Bore was in January of The upper lever excavation broke through November 29, By August 8, 2012, the excavation was completed. Currently, they are installing electrical and drainage systems (water treated and piped to Lake Temescal), façade work (including portals and retaining walls) and the actual roadway. The Fourth Bore is scheduled to open in late The cost of the project is $402.1 million, which includes design, administration, construction and final freeway traffic alignment modifications. Of that, $180 million came from federal stimulus funds and only $11 million from state funds. Contra Costa County funding includes $123 million from Measure J and $50.3 million from other regional measures. Alameda County contributed no money toward the project. Left: Leaving the pre Tunnel Tour presentation in Lafayet for the construction site Lower Left: Andy Campbell & Anne Steele waiting to get started Below: Ed Gunther and Bob Fracolli 10

4 Top Right & Left: Checking in at the construction office Left: Lining up to cross Fish Camp Road to the Tunnel construction site. Below: From the top of the New Tunnel Bore looking east. Duck!!!! This is an active construction site the hard hats are required with good reason as shown here. 11

5 Above, Top & Center: An active construction site. With lots of dangerous areas. Now we understand why the Contractor was so picky about the shoes we wore on site.. 12 Above: Visiting after Lunch at the Eupoa Hofbrow in Orinda

6 Thank You all who Attended! Paul Borgwardt Andy Campbell Peter Frazier Ed Gunther Ed Holloway Soo-Yin Holloway Mark Huston Gordon Johnson Dean Scott Sheila Scott Jim Serwer Anne Steele Elaine Zinzer Maike Zinzer Thank You to Bob Fracolli for arranging the visit!! 13