EWEB modernizes downtown vaults, shaving traditional costs by two-thirds
Have you ever wondered what’s underground in downtown Eugene? While we can’t speak about everything that’s below, we can tell you a little about EWEB’s intricate downtown electrical network, which is connected by a series of vaults beneath the city’s streets.
Over the past three years, EWEB has been upgrading the downtown underground power system by replacing six cable vaults with modernized, cost-effective infrastructure.
EWEB is working diligently to cut costs wherever possible in order to keep customer rates low, even as the price of maintaining the grid grows ever more expensive. For instance, EWEB is deferring the rebuilds of six substations by three to five years to manage rate impacts on customers. All told, EWEB is pushing $65 million worth of work originally planned for the near term.
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.
Image: Crews lower the modular vault design through the pre-existing manhole.
New design saves EWEB money, time, and avoids planned outages
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.
We’re 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.
We’re building a safe, reliable electric grid
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.
The downtown vault replacements are part of EWEB’s major infrastructure investments through our Capital Improvement Plan to rehabilitate, replace, and install new infrastructure.
Image: Example of the aging and corroded materials removed from the preexisting vault.
