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TRANSACTIONS NEWSLETTER ONLINE

November-December 2009

Diary of a Dramatic Construction Operation

Crews Race Against Time to Install Last Piece of Bay Bridge Bypass and
Repair Failed Eyebar


In this aerial view taken early Saturday morning during Labor Day weekend, the old deck piece has been rolled out of the way (to the right), and the replacement piece (to the left) — and last link to a bypass — is ready to roll in. (Photo: © 2009 Barrie Rokeach)

A series of loud metallic pops in the late afternoon of Friday, September 4, was music to the ears of the Caltrans and Bay Area Toll Authority (BATA) officials perched at a strategic location on Yerba Buena Island and monitoring the movement of a massive deck section of the old East Span of the Bay Bridge.

The noise indicated that after nearly 24 hours of preparation that had commenced with the bridge closure the night before, the 3,200-ton, 300-foot deck section was finally free of its moorings and was ready to roll. Once it started to move on skids reportedly greased with common dish soap, the double-deck piece slid out with relative ease and speed, assuming its resting position 150 feet above the ground by early Friday evening of Labor Day weekend. Much on-the-scene preparation and angst went into that climactic moment, and not everything went according to plan when it came to amputating a chunk of the 73-year-old span.

“When you open up an old bridge, you find out a few things. It has a few secrets to give up. We found a few of them today,” Caltrans Toll Bridge Deputy Program Manager Brian Maroney said that Friday, midway through the process. “We found some extra steel that was welded and needed to be cut.”

According to Maroney, the engineers were dealing with 80-year-old plans that weren’t necessarily in sync with shop drawings of a similar vintage that were inked on linen. “The old shop drawings are works of art; they’re pieces of history,” he said. Adding to the bridge’s mysteries, still more changes were made in the field during the Depression-era construction, and they weren’t always well documented.

Engineers also had to prescribe measures to ensure that the remaining portions of the old bridge wouldn’t tilt precariously into the “maw,” the cavernous hole left when the deck section was removed.

Fortunately, the engineers had a powerful ally on their side in the form of the prime contractor on the job, C.C. Myers Inc. Based in Rancho Cordova, Calif., the firm has carved out a reputation for tackling “impossible” construction projects under extreme time pressures, including the demolition and roll-in replacement of an upper-deck segment on the same bridge over Labor Day weekend in 2007.

Roll In: Hurry Up and Wait

With the most challenging phase of the procedure completed, crews on Saturday morning (September 5) turned their attention to the rolling in of the last piece of a detour structure. The temporary detour will carry traffic to and from the Yerba Buena Island tunnel over the next several years while the new East Span of the Bay Bridge is connected to the mouth of the Yerba Buena Island tunnel. The Skyway portion of the new East Span, consisting of a pair of sleek road decks stretching more than a mile westward from the Oakland shore, is already complete. Closing the gap between the Skyway and the Yerba Buena Island tunnel will be a striking self-anchored suspension span with an iconic tower rising 525 feet above the water.

All day Saturday it was hurry up and wait as crews prepped the bypass piece and then started and stopped the roll-in procedure a couple of times. By lunchtime on Saturday, the piece appeared to have slid halfway in, a position it maintained until the late afternoon, at which point it traversed the last stretch smoothly and nearly silently, with a swift pace that belied its 3,600-ton weight.

Just as onlookers were celebrating the successful completion of the tricky roll-out/roll-in procedure and the impressive closure of the gaping hole in the double-deck structure, Caltrans delivered stunning news at a Saturday evening press con-ference: Inspection crews had detected a significant fracture in an “eyebar” piece of the cantilever structure farther down the line on the old East Span. The presence of rust indicated that the break had been there for some time and was not caused by the weekend’s trauma to the bridge.

The fracture was not entirely surprising, given the span’s age; in fact, it underscored the urgent necessity for replacing the old East Span, which failed in the 1989 Loma Prieta earthquake along one section.

Fractured Eyebar Triggers Scramble

The discovery of the broken eyebar set in motion a scramble to design, commission and install a fix. Stinger Welding Inc. in Arizona was able to fabricate crucial steel repair components in a day and ship them on a charter plane that landed in Oakland by midday on Sunday. Underscoring the time pressures, the flatbed truck that hauled the 18,000 pounds of steel from the airport to the bridge was escorted by the CHP.

“An eyebar is a tension member; it is very important to the structure, which is the reason for the urgency to repair it now while the bridge is closed,” Mike Forner, Caltrans’ district division chief for the San Francisco-Oakland Bay Bridge, said at a late-afternoon press briefing on Sunday.

“It has been an incredible effort to get fabricators together and the design done and all the materials here during Labor Day weekend while most people are out enjoying barbecues,” said Caltrans spokesperson Bart Ney at the press briefing.

While the eyebar repair took center stage Sunday and Monday, other important work was going on as well, most notably a major reconfiguration of the bridge’s toll plaza (see story) that was timed to coincide with the rare bridge closure. Crews also were striping lanes, painting, hooking up the utilities that traverse the bridge, installing traffic barriers and the like.

All day on Monday, Labor Day proper, the region held its collective breath, wondering if the work would be done in time for the planned reopening of the bridge at 5 a.m. on Tuesday morning. Keeping track of the progress wasn’t hard: News outlets covered the unfolding drama nearly continuously, while Caltrans public information officers posted updates on Twitter at frequent intervals. And BATA had six stationary still cameras as well as a stationary video camera trained on the bridge construction zone, delivering fresh images to the Web 24/7.

At a 6 p.m. press conference on Monday, officials confirmed commuters’ worst fears: Contractors could need another full day to complete the eyebar repairs, pushing the opening back 24 hours to 5 a.m. Wednesday. But thanks to the perseverance of the crew of ironworkers and other craftspeople who struggled on through the night, commuters woke up Tuesday morning to a pleasant surprise: starting at 6:10 a.m., the CHP began to remove barriers on the approaches, and by 7 a.m., the bridge was fully open — just two hours beyond the original planned opening time.

It was yet another dramatic twist in a dramatic weekend. End of story? Not quite. Some seven weeks later, high winds appeared to trigger vibrations that snapped a key element in the eyebar repair assembly, causing debris to fall on the bridge deck. Officials quickly shut down the bridge once again, and kept it closed while they reengineered and reinforced the repair. While the repairs took longer than expected and the closure stretched over a work week, the region’s commuters adjusted quickly and flocked to transit, pushing BART ridership to its highest daily levels ever.

Slowing for the “S” Curve

Drivers also have been adjusting to the pronounced “S” curve that is a necessary feature of the new bridge bypass leading to and from the Yerba Buena Island tunnel. The speed limit on this nearly half-mile section has been set at 35-40 mph, down from the 50 mph in force elsewhere on the bridge. The stretch has been a navigational challenge for those motorists and truckers who fail to obey the new speed limits, and has been the scene of a number of accidents. Caltrans has been installing signage and pavement markings while also undertaking an informational campaign to alert drivers to the new configuration, which will be in place for the next four years, until the striking and seismically sturdy new East Span of the Bay Bridge completes its march toward the Yerba Buena Island tunnel.

— Brenda Kahn (with field reports by Karin Betts)

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