ProGlass by Jensen Delivers Custom Trench Covers for Substation Expansion

Arizona is growing fast. And with that growth comes a rising demand for reliable power. Near Coolidge, Arizona, Salt River Project is expanding critical infrastructure to support increasing electricity demand across central Arizona.

The Coolidge Expansion Project will add 575 megawatts of new generating capacity, enough electricity to power well over 100,000 homes at once.

Of course, with expansion comes new infrastructure. Projects like this depend on miles upon miles of underground electrical routing. Beneath the surface, cables connect transformers, switchgear, and control systems that keep the grid running. Those systems require constant access for inspection and maintenance, which means something as simple as a trench cover suddenly matters a lot more.

At the Coolidge site, engineers specified fiberglass trench covers across large portions of the substation expansion. The choice was simple: fiberglass doesn’t rust or corrode, it’s nonconductive, and it won’t break down after spending years in the punishing Arizona sun. At the same time, it’s light enough for crews to easily lift during routine maintenance without the burden of heavier materials.

In total, more than 1,000 trench covers were installed across the project. That includes 484 covers measuring 30” L x 48” W, 535 covers measuring 46” L x 32” W, 30 covers measuring 46” L x 24” W, and 14 covers measuring 46” L x 36” W, along with several specialty pieces designed to match unique trench layouts.

Some projects require something standard. This one didn’t.

To meet the exact dimensions required for the Coolidge expansion, ProGlass by Jensen produced new fiberglass molds in-house. By building the molds and manufacturing the covers internally, the team delivered a solution tailored to the project’s specifications and timeline.

The result is a lightweight, corrosion-resistant system that keeps critical electrical infrastructure accessible, all while helping power Arizona’s future.

Considering fiberglass for your next project? Contact Jensen Infrastructure today.