The man, the myth, the mystery.

Few campus legends permeate as deep into University of Wisconsin’s student consciousness as the myth of Tunnel Bob. The shadowy figure has earned his spot among the city’s most notorious urban legends by allegedly living in the subterranean labyrinth of steam tunnels running for approximately 20 miles under campus.

Students are naturally captivated by the idea of an elusive tunnel traveler patrolling the catacombs beneath their feet as they walk to class.

Entering the steam tunnels without explicit permission is illegal. John Harrod, the University’s physical plant manager reported that Tunnel Bob repeatedly asks for permission to access the tunnels, and is repeatedly denied.

An Isthmus article titled “Secrets of the UW” referred to the sprawling network of tunnels running beneath campus as “UW-Madison’s worst-kept secret. No one is supposed to know about them, but many people do…” A UW news release from 1999 referred to Tunnel Bob as a “lurking itinerant.”

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The legend is Tunnel Bob used to hold “tunnel games” under the city, inviting students to come play hide and seek or flashlight tag with him. Others claim that his fear of women drove him underground.

According to one past UW employee who was familiar with Tunnel Bob, “[Tunnel maintenance workers] leave a box of bulbs and he changes them as he finds them because they couldn’t find a way to keep him out.”

A theory from the same employee about tunnel Bob’s history is that “he’s a Vietnam vet and was a tunnel rat there.”

Rumors question Tunnel Bob’s harmlessness. One Madison resident claimed, “I’ve seen him lose his temper and damage things.” Another questions if he’s dangerous saying, “I was at UW from 1993 to 1998, and he would follow me around a lot. I do think he has the intent to harass women and he is definitely mentally disturbed.”

Jacob Ahrens-Balwit/The Badger Herald

Some believe the rumors have been exaggerated and distorted over decades of oral retelling. “He is a really nice guy if you get the chance to have a conversation with him. Contrary to popular belief, he does not live in the tunnels, but rather visits them on the weekends,” claims a blogger who believes that common perceptions about Tunnel Bob may be inaccurate due to the man’s slight social awkwardness.

The man, the tunnels

Only one person knows which of these rumors are real. The Badger Herald delved below to discover the man behind the mystery.

Standing at six feet, six inches tall, Tunnel Bob, or Robert Gruenenwald, crouches on his tunnel explorations, scattering tunnel roaches as he passes.

Nyal Mueenuddin/The Badger Herald

The tunnels are 120 degrees Fahrenheit from the heating pipes they are pathways for. The pipes carry 430 degree Fahrenheit steam across campus. The pipes are insulated with asbestos, and spray scalding water in all directions when they burst, as they did in 1979. It smelled like rats, musty and humid–like the occasional gust of wind that comes out of a New York City Subway grate.

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In an “AskAbe” forum, the Wisconsin Alumni Association said “even the legendary Tunnel Bob has suffered steam burns, and he knows the tunnels like the back of his hand.” Although no burns were apparent on Tunnel Bob’s hands or face to support this statement, a malfunctioning pipe was shooting a geyser of hot steam, which appeared to have the capacity to injure anyone who got too close.

Tunnel Bob said he hadn’t taken anyone into the tunnels for 10 years before this trip.

“I used to take people down here and play hide and seek,” he said.

Nyal Mueenuddin/The Badger Herald

As the shadowy figure strolled coolly along, deflecting questions and speaking in fragmented sentences a picture began to emerge of a man who trusted very little and was obsessed with steam tunnels. He had visited the steam tunnels of other schools around the nation but had returned to Madison’s, where his subterranean exploration began years ago.

Tunnel Bob had been exploring, but not living in, UW’s century-and-a-half old steam tunnels for more than 30 years.

“Wouldn’t spend a night sleeping in these tunnels … You would end up dead,” he said.

Tunnel Bob has been in legal trouble for trespassing in tunnels before, but continues his underground lifestyle. When asked about the reasons for his interest in the tunnels he redirected the question with raised eyebrows.

“Look at them, aren’t you interested by them?” he asked.

Later he said he enjoyed being in the tunnels in winter simply because “they are the best place to be.”

Tunnel Bob doesn’t like to get personal. He flinches when women accidentally brush against him and will not shake a woman’s hand. Not out of disrespect or aggression, but out of discomfort.

Tunnel Bob has been exploring Madison’s catacombs since the ’70s, but he will not allude to how he first discovered them. He didn’t give a clear answer when asked if he assisted with UW’s maintenance of the tunnels.

Tunnel Bob quietly acknowledged his legend-status on campus. He said he didn’t mind it. After the hour-long tour, Tunnel Bob showing off his favorite vents to view the bustle of campus from underground, he politely extended an invitation for “tunnel games” sometime.

Once again he avoided the minimum $151 trespassing fine from UWPD.

Correction: The article said the steam moved 9,000 feet per second. This has been removed due to inaccuracy. We regret the error.