Editing Roof and tunnel hacking (section)

==Tunnel hacking==

Some universities have [[utility tunnels]] to carry [[steam]] heat and other utilities. Utility tunnels are usually designed for infrequent access for maintenance and the installation of new utilities, so they tend to be small and often cramped. Sometimes, utilities are routed through much larger pedestrian access tunnels (MIT has a number of such tunnels, reducing the need for large networks of steam tunnels; for this reason, there is only one traditional steam tunnel at MIT, built before many buildings were connected).

Tunnels range from cold, damp, and muddy to unbearably hot (especially during cold weather). Some are large enough to allow a person to walk freely; others are low-ceilinged, forcing explorers to stoop, bend their knees, or even crawl. Even large tunnels may have points where crisscrossing pipes force an explorer to crawl under or climb over a pipe—a highly dangerous activity, especially when the pipe contains scalding high-pressure steam (and may not be particularly well insulated, or may have weakened over the years since installation).

Tunnels also tend to be loud. Background noise may prevent an explorer from hearing another person in the tunnel—who might be a fellow explorer, a police officer, or a homeless person sheltering there. Tunnels may be well lit or pitch-dark, and the same tunnel may have sections of both.

Tunnel access points tend to be in locked mechanical rooms where steam pipes and other utilities enter a building, and through [[manholes]]. As with roofs, explorers bypass locks to enter mechanical rooms and the connected tunnels. Some adventurers may open manholes from above with crowbars or specialized manhole-opening hooks.

[[Tunnel Bob]] is a prominent example of an individual who has gained notoriety for tunnel hacking within the [[University of Wisconsin–Madison|University of Wisconsin-Madison]] steam tunnels.