Over the past three years, Oregon public power utility Eugene Water and Electric Board has been upgrading Eugene's downtown underground power system by replacing six cable vaults with modernized, cost-effective infrastructure.
A cable vault is typically 8 feet by 13 feet across and 9 feet high and made of concrete, rebar, and steel I-beams. Underground electric cables deliver power to downtown Eugene businesses and homes.
The vaults allow access to the underground cable system for repairs and routine maintenance, and they’re typically beneath the road, at every intersection and mid-block in downtown’s core.
Crews replaced each of the 65-year-old corroded vaults with an innovative Voltek vault.
The patented modular, lightweight composite panels are installed through the manhole opening of the existing underground decaying vault and pieced together to create a new vault. The system dramatically simplifies the task, shortens the time required, and reduces the cost of an underground vault replacement, EWEB noted.
It was able to install the new vault while the cables are still energized, minimizing disruption to customers and traffic while cutting construction time in half.
Traditional vault replacement would require de-energizing the power supply and road excavation, but EWEB was able to avoid those constraints with the Voltek installation.
A traditional vault replacement would cost approximately $1 million, but the Voltek vault’s unique design and installation method cut overhead costs to one-third of traditional costs, allowing EWEB to save money while modernizing infrastructure.
"This new infrastructure will provide reliable, safe access to and protection for the next 50 years and beyond, while reducing the risk of outages from equipment failure," it said.
The downtown vault replacements are part of EWEB’s major infrastructure investments through its Capital Improvement Plan to rehabilitate, replace, and install new infrastructure.
