Steam tunnels are dangerous but essential to UI’s energy supply

Naked light bulbs hang every few feet along a winding, damp, seemingly never-ending passageway. Large heated pipes run the length of the tunnel, and the atmosphere is sweltering. A musty, unpleasant smell lingers. The air in the low-ceilinged channel is heavy with moisture and mystery.

A rare glimpse into the University’s steam tunnels reveals its seldom-exposed underground secrets. Over the course of several generations, few have ventured into the cramped, eerie underground tunnels that hold the University’s steam pipes. These nine miles of steam tunnels have powered a number of buildings across campus for 122 years.

“The purpose of the steam tunnels is to insulate the steam pipes,” said David Ruzic, professor of nuclear, plasma and radiological engineering. “Then you can easily tell when things are leaking, you can fix it, you can add more buildings to the network. ... So (the tunnels are for) insulation, ease of access, repair and maintenance.”

The steam pipe system within the steam tunnels is the primary source of energy for many University buildings — especially the oldest and nearest to the Quad. The 200- to 400-degree steel pipes work through a closed-loop system to transport steam across the expansive underground chambers. Because the steam is under such high temperatures and intense pressures, the pipes must be constantly taken care of.  

There are 30 steam distribution operating personnel. Their duties include fixing pipe leaks, solving equipment problems and monitoring the boiler rooms within each campus building. Their job is not easy because the conditions are stuffy, dangerous and generally difficult to work in.

Andy Blacker is the manager of external relations of the University’s Facilities and Services, which keep the steam tunnels in working order year-round.  

“All employees working in the steam tunnels receive extensive training, which includes recognizing the effects of heat, hydration strategies and rescue techniques,” Blacker said in an email about the potentially life-threatening hazards the passageways could hold. “Employees also (each have a) personal cooling apparatus to help with the heat. We can deploy large volume portable ventilation for extended work tasks.”

The air is hot and muggy near the burning pipes. While this is true for all the seasons, it is hottest in the winter because the pipes are being used so often for heating. The channels are still used in the summer, but to a lesser degree. So although the temperatures within the pipes generally stay constant, the temperature of the air around them is always fluctuating.

There are vents around campus to keep the tunnels aerated, and to make sure the workers don’t suffocate in the thick underground air. In addition, many precautions are taken to ensure the operators’ safety in the tunnels.

University steam tunnels tend to strike wonder and curiosity into students around campus — but not only locally. A number of large universities around the country operate using their own underground steam channels to house the steam pipes.

So why is this heating system so often associated with large institutions?

“(Steam tunnels are) going to be very common in a university or someplace where one entity owns a whole lot of buildings,” Ruzic said. “How many other people have power plants? If a city had a power plant, maybe it could power city hall and schools if they’re somewhere near each other.”

There would be little use for a small-scale steam tunnel system simply because it would not be worth the efforts and resources. Along with the nine miles of steam channels, the University Facilities and Services maintains eight miles of compressed air and 31 miles of natural gas pipes and 120 miles of sanitary and storm sewers, among other infrastructures.

“The fact that we have a collection of buildings all near each other (and) all owned by the same entity is when you would (use the steam channel system),” Ruzic said. “It has to be done in a really big scale; otherwise, it’s just not economical.”

Not all University buildings are powered with the steam running through the pipes. As more University buildings have been built, they have grown onto the outer rings of the existing buildings. Therefore, structures that are far away from the main Quad may run on their own furnaces. Still, it is convenient and cost-effective to connect them to the steam system when possible.

For 15 years, Ruzic has collaborated with the University Facilities and Services to offer special steam tunnel tours in his classes. On Jan. 28, students in NPRE 101, Ruzic’s introduction to energy sources class, got to explore the tunnels in a guided underground tour. Ruzic encouraged students in the class to bring their friends to experience a rare subterranean adventure, carefully monitored by the steam tunnel operators themselves.

Dana Al-Qadi, graduate student in Engineering, and Jennan Qato, junior in LAS, decided to tag along with Ruzic’s class on the tour.

“It’s like a campus legend, I think. We’ve all heard of (the steam tunnels), but no one really knows from where,” Al-Qadi said.

Both were surprised at how narrow and hot the tunnels were. It would have been difficult to navigate on their own, they said, if they didn’t have the guides leading the way.

“I’m graduating in May, so this (has been) on my bucket list for a long time,” Al-Qadi said. “So I really wanted to do it.”

These eerie, humid passageways are a vital part of the campus infrastructure and power systems. Without the operators and service workers constantly on the job, the University couldn’t keep the buildings functioning, the classes running smoothly and keep the students enjoying their college experience.

Reema can be reached at