Inside the Never Sweat Tunnel

Deep beneath the desert floor in Superior, Arizona lies a tunnel with a name as bold as its history: the Never Sweat Tunnel.

A Tunnel That Changed the Game

Completed in 1973 by the Magma Copper Company, the Never Sweat Tunnel stretches 8,600 feet (1.6 miles) long and sits at a depth of 1,100 feet. At the time, it came with a hefty price tag of $74 million, but what it delivered was priceless. It created a direct underground connection between the East and West Plant sites.

This wasn’t just any tunnel. It was one of the first in Arizona to be built using a tunnel boring machine, marking a major leap in mining technology and efficiency. Tunnel boring is a method used to dig deep, long tunnels through rock, soil, or mixed ground. Instead of blasting or drilling manually, engineers use a Tunnel Boring Machine (TBM) a massive, rotating cylinder that chews through the earth like a mechanical earthworm. The Never Sweat Tunnel was ahead of its time, using this method in the early 1970s, making it one of Arizona’s first tunnel-boring machine projects. That’s part of what makes it such a standout in mining history.

The name “Never Sweat” is rooted in purpose. Designed to streamline underground operations, the tunnel helped reduce the physical strain and time it took to move between sites. In short: less sweat, more progress.

More than 50 years later, the Never Sweat Tunnel is far from retired. It plays a critical role in daily mine operations:

• Ventilation: Acts as a primary exhaust system for the mine

• Dewatering: Helps remove groundwater from shafts

• Muck Hauling: Transports blasted rock from underground to surface

It’s a testament to smart engineering and long-term thinking. Still delivering value decades after its creation.

A Legacy of Innovation

The Never Sweat Tunnel isn’t just a piece of infrastructure. It’s a symbol of Arizona’s mining legacy and the innovation that drives it forward. From its pioneering construction to its ongoing utility, it stands as a reminder that great engineering doesn’t just solve problems. It endures.