SAN FRANCISCO (CBS / AP / BCN) – A state transportation official said it could take weeks or even months to find a solution for bolts that snapped on the new eastern span of the Bay Bridge.
California Transportation Commission Chief Engineer Stephen Maller made the comments at a Toll Bridge Program Oversight Committee meeting Wednesday, raising concerns that the span will not be ready in time to open on Labor Day as planned.
The bolts that snapped last month connect steel earthquake safety devices called shear keys to the deck of the span and a large concrete cap.
Another official, Metropolitan Transportation Commission Executive Director Steve Heminger, added that there were “no definitive answers yet” to important questions such as why the bolts failed, what the best solution is, and how much it will cost to fix the problem.
He told the committee, “Based on what we know today… we can’t give you a guarantee” that the new span will open on time in early September.
San Francisco Supervisor John Campos called it “scary” that there was not a certain date for the bridge’s opening, and Oakland Mayor Jean Quan expressed concern that her city needed timely notification of any possible delay to help avoid impacts to local businesses, particularly hotels.
Both Campos and Quan are members of the committee.
Transportation officials learned about a month ago that roughly one-third of the 96 bolts that were installed on a pier just east of Yerba Buena Island had popped out several inches after they were tightened recently.
Those bolts, which were manufactured in Ohio in 2008, are located near where the new span’s self-anchored suspension span meets its skyway.
Both Maller and Heminger said several options for addressing the issue were being explored.
There are a total of 288 anchoring bolts on the new span. Officials were still trying to determine whether the other 192 bolts, which were manufactured in 2010, would be OK or if they would also have to be replaced.
Maller said there was a clear hydrogen embrittlement problem with the first group of bolts but that “it’s not clear where it came from” and whether the same problem could affect the second group of bolts.
Heminger added that the process of determining the best solution was taking time because engineering experts were still investigating the problem and an independent peer review panel was checking the engineers’ work so that there would be “a fresh set of eyes” to make sure everything is done properly.
(Copyright 2013 by CBS San Francisco, the Associated Press and Bay City News Service. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)