“This is one of those fun projects that you only get to do once in a lifetime,” says Hogni Setberg, Bridge Construction Engineer for Caltrans in Sacramento. “We have a good team on this project.”
The job began as a response to an emergency in August 2018 when the bridge was stuck in the up position, due to damaged gear assemblies, forcing cars wanting to cross to take a 75-mile detour.
“The focus of this project is the emergency,” says Soka Soka, Project Manager for Caltrans. “It’s an electrical and mechanical upgrade.”
About 23,000 vehicles per day travel on the two-lane bridge. It is 2,890 feet long, and a 300-foot span lifts. The bridge was constructed in 1960 and is registered by the state as a historic structure, which would make replacing it more difficult.
Recognizing the critical situation, Caltrans officials called the restoration bridge experts at Golden State Bridge in Benicia to provide emergency repairs and increase the reliability of the bridge’s electrical and mechanical systems.
“In August of 2018, the bridge was lowered within hours of getting stuck, but due to the broken gear box, it took Caltrans and Golden State Bridge two days to rig a temporary lifting system with winches and cables,” Setberg says.
This lift system was used twice a week for six weeks until the broken gearbox was rebuilt.
“I’m proud we could get out there so quickly and get the gear boxes out and back in service in record time,” says Will Reames, Vice President of Golden State Bridge, established in 2005. “We modified a truck to put a hoist on the vehicle, so we could lift the gear boxes at the top of the tower out and down onto the deck to work on them. The Coast Guard was saying ‘you have to open the bridge, there is cargo that needs to get to Sacramento.’”
The team took a major inspection of the aging bridge and documented mechanical problems, an old electrical system and an out-of-order elevator. However, it found the bridge steel structure in great shape, Reames reports.
“One of the more interesting facts is because it’s a historical bridge, you have to operate on that foundation,” says Dennis Keaton, Spokesman for Caltrans. “We are trying to keep it in its historical reference and add 21st Century technology.”
The bridge will appear the same because the upgrades are within the cabinets in the bridge. The Rio Vista bridge is manned 24/7 with a bridge tender.
“It’s probably been needed for a long time,” Reames says. “It’s not a quick fix. There is a lot to it, with a complex design.”
The State Highway Account funded the $24 million project as a Major Damage Restoration. With this repair, Caltrans expects to get a few more decades of use from the bridge.
“The project entails a complete mechanical rebuild at the top and a back-up system,” Reames says. “We’re in the process of testing and acquiring the parts to do that.”
However, many parts have been delayed, due to the current economy.
In addition to the new mechanical, electrical, and back-up systems, the bridge will receive a new mast elevator and monitoring equipment, including closed-circuit television cameras, so the tender can watch the barriers rising, gates lowering and the traffic stopping before lifting the bridge. The system will be upgraded during the project.
“If something goes wrong, the engineers will be able to diagnose on the spot where the issue is,” Setberg says.
Crews are installing a temporary and smaller system, which will eventually become the back-up system.
“It will be a little slower, but will still be able to lift the span,” Setberg says.
Another challenge was keeping the bridge open to vehicular and marine traffic while repairs were made, Setberg reports. Golden State has had flaggers and intermittent, 10-minute traffic holds while some of the work takes place.
“A lot of what we do can be done in one lane,” Reames says. “If we are hoisting something, we will hold traffic. Once the load is secure, we can let the traffic go.”
Most work is taking part during the day, since the work is in the tower or control room, Setberg says.
“We can’t let the bridge go out of service, but at the same time we have to change over the system,” Reames says. “Everything has to work in concert for a while until we can abandon the old stuff.”
Crews ran electrical submarine control cables under the water in the riverbed. The work was completed from a barge, and crews worked around the shipping schedule and had contingency plans in place to move out of the way if needed.
“There is a lot of balancing that goes into replacing the deck,” Setberg says. The thinking was “the weight changes as concrete dries. It was good to do it while we were making adjustments.”
The team coordinates with the Coast Guard for the best times for a short closure. They have also coordinated with the cities, counties, and other entities.
“Coordination has been a lot, and all agencies are on board with the project,” Soka says.
Caltrans and Golden State aim to complete the project in 2023.
“It’s a really neat bridge and worth saving,” Reames says. “It’s great we are doing it and a win-win for everybody.”