Transportation officials are investigating why nearly three dozen threaded steel bolts on the new eastern span of the Bay Bridge snapped when workers tightened the fittings.
The bolts, or rods, are up to 17 feet long and are 2 1/2 inches in diameter. The metal connects the bridge deck to the concrete cap that sits on top of the massive pier just east of the bridge tower. They tie the road decks down to a supporting pier below.
Caltrans may have to replace all 288 of the bolts.
MTC spokesman John Goodwin told Bay City News the bolts have too much hydrogen in the steel, which causes them to become brittle.
Toll Bridge Program Manager Tony Anziano told the Chronicle that construction crews started tightening the nuts on both ends of the bolts earlier this month - only to return days later to find that one-third had popped out a couple of inches making them loose and damaging the bolts.
It may cost an extra $1 million to $5 million to fix the bolts, which will need to be remanufactured specifically for the project, according to Goodwin.
"We won't be able to swing by Orchard Hardware," he told BCN.
Caltrans officials are expected to brief the Metropolitan Transportation Commission on the problem Wednesday.
The commission is overseeing the new $6.4 billion span construction with the state.
Commission spokesman Randy Rentschler told the Contra Costa Times the broken rods are not considered a structural problem and they are not expected to delay the scheduled Labor Day weekend opening.
The bolts have been in place since 2008. They are part of the roadway's deck, which will make access difficult.
The product in question was made in the USA. They were manufactured in Ohio.