OAKLAND -- Months of tortured back-and-forth over when to open the new Bay Bridge could come to an end this week as signs point toward a likely restoration of the original Labor Day weekend schedule.
With multiple outside experts now agreeing that temporary shims will make the new $6.4 billion span perfectly safe for motorists until seismic repairs are completed in December, the bridge oversight committee will unveil the opening date at a public meeting Thursday in Oakland.
The most obvious and favorable date would be the original Labor Day weekend, due to the three-day holiday that would allow bridge officials to close the span for five days with less impact to commuters.
Spokesmen for the bridge team insist the date has not been finalized. But their decision has been made easier now that the question of the new span's seismic safety has been answered.
"Safety has always been the driving factor for any decision related to this lifeline bridge, and these reports confirm that the temporary fix could allow us to safely move traffic while work continues on a permanent retrofit," said Steve Heminger, oversight committee chairman and executive director of the Metropolitan Transportation Commission.
The three-member oversight committee a month ago asked the Federal Highway Administration, the Toll Bridge Program Seismic Safety Peer Review Panel, and internationally known bridge designers Peter Taylor of Canada and John Kulicki of Pennsylvania to evaluate the interim fix.
The experts' views are purely advisory but the bridge committee considers them "very meaningful," said Metropolitan Transportation Commission spokesman Randy Rentschler. "The question we had, and the question we asked the experts to answer, was whether or not the shims would make the bridge safe to open while the repairs were being done."
The highway administration's opinion was good enough for Mark DeSaulnier, state Senate Transportation Committee chairman.
"If there is a consensus among the experts, then they should go ahead and move people onto the new bridge," said DeSaulnier, D-Concord. "No one wants to leave anyone on the (old) bridge a day longer than necessary."
The question now is how quickly can the public agencies and contractors mobilize staff, materials and equipment for the massive five-day undertaking and prepare the public for the loss of a very busy crossing. Aside from notifying the public, the contractors had really never stopped moving toward a Labor Day weekend opening.
That weekend was chosen because commute traffic is traditionally lower during a holiday week. The plan was to shut down the current bridge at 8 p.m. Aug. 28 to allow the contractors to align Interstate 80 with the new span and reopen before 5 a.m. on Sept. 3.
There were clues in recent days that bridge officials expected to restore the Labor Day weekend opening. The California Highway Patrol last week began signing up personnel to staff the long weekend bridge closure in the event the original schedule was restored, Sgt. Diana McDermott said Monday. The agency provides traffic control and security during state highway closures.
Back in July, the oversight committee -- comprising the executive directors of Caltrans, MTC and the California Transportation Commission -- canceled the opening indefinitely when the retrofit of defective bolts embedded in seismic stabilizers in the large pier east of the main tower proved more time-consuming and complex than expected.
The contractor estimated the $15 million repair job would take until at least Dec. 10 to complete, and the oversight committee wanted to wait until the work was finished.
But the seismic safety peer review panel -- three outside experts and engineers -- called the delay a potential disaster in the event of a big temblor, citing the existing span's known earthquake vulnerability.
The panel repeatedly called for the state to open the new bridge as scheduled and install temporary shims in the large rocker bearings adjacent to the broken stabilizers, which would allow the bearings to absorb the motions generated during an earthquake while the stabilizers are repaired.
In its three-page letter to the oversight committee on Aug. 9, the Federal Highway Administration agreed with the peer review panel.
"We see no reason to delay opening the bridge to traffic prior to the shear key retrofit being completed," wrote Division Administrator Vincent Mammano.
The "interim solution will restore the capacity lost prior to and during the retrofit ... and provide a comparable level of seismic performance," Mammano wrote.
The federal agency also blessed the bridge team's retrofit strategy, an exterior steel saddle and cable assembly that will take the loads intended for very large steel anchor rods that failed earlier this year.
In March, 32 out of 96 rods embedded in seismic stabilizers east of the new tower snapped. The stabilizers -- also known as shear keys -- help keep the bridge deck and columns aligned during an earthquake.
The Toll Bridge Program Oversight Committee will announce when the new Bay Bridge will open during a public meeting at 10 a.m. Thursday at MetroCenter Auditorium, 101 Eighth St., Oakland.