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UER Mobile > World > Active Utility Tunnels - a Primer (Viewed 10808 times)

post by VAD   |  | 
Active Utility Tunnels - a Primer
< on 6/28/2015 7:06 AM >

Many schools, hospitals, and other multi-building complexes have miles of utility tunnels (often called "steam tunnels") beneath their surfaces; tunnels which provide heating to buildings, and therefore access to many of them as well.

The industry term for this is "district energy" - heating is delivered in the form of steam or hot water, and cooling as a mixture of water and ethylene glycol (C2H6O2 / , "glycol" for short). In systems with both heating and cooling, glycol is generally distributed in the same tunnels as steam and hot water is.

Many tunnels are very old - the first modern district energy system was built in 1877, however the concept stretches back to the Roman baths. Many were built near the turn of the 20th century, and are therefore not always the safest.

There is a reason that their official title is "utility tunnels". Take a trip to a site which uses them, and you'll likely notice that there are no power lines visible. That is because power is delivered underground. Other utilities are too, such as communications.

Any district energy system has its epicentre in a large heating or cooling plant. Heating plants are relatively easy to find, as they will have a large stack that must be taller than nearby buildings by regulation (in most of North America). Cooling plants (called "chillers" in the industry) are much more elusive - in more suburban locations, they will be in medium-sized, featureless buildings; in dense cities, they will often be in basements. The chillers themselves operate on the same principle of your refrigerator:

But this tutorial is about the distribution tunnels - let's take a look at them!

Finding Tunnels
There are a number of tricks you can use to locate these elusive subterranean wonders:

Case Study
An example of how one can deduce its existence and location.

First, take a look at the map (these are often posted on the walls near the fire panel):

That certainly looks like a tunnel leaving from 14A. To confirm, I entered mechanical room 9, and followed the steam pipe to the wall at the very corner of the room (top-left on the map):

When I took a look at the other side of the wall, it headed under the ramp of the building's sloped basement hallway (below the fire hose):

Turning around led to stairs down to the door to 14A:

This door alone should have tipped me off: it had hissing sounds emanating from it! Classic steam tunnel.
Furthermore, looking outside revealed a tunnel emergency exit a few feet from the door:

The only things left I could do before actually venturing in is to wait for it to snow to see where it melts first, or scourge other buildings for the other end(s).
This entrance was particularly noteworthy as it exemplifies so many tricks to find tunnel entrances; now try some of them yourself on buildings near you!

Accessing Them
Once you have found where one likely is, accessing it is usually done through its exits into buildings. First you must enter the necessary mechanical room; from there, a number of things are possible:

These are in order of best-to-worst. Locked grates can be overcome by standard lock-bypass methods; they are convenient as they often have plenty of holes in them, allowing us to stick tools through and to see what we're doing! Locked boxes are similar - except that we need to bypass a solid door instead.
If it's an alarmed gate, you're out-of-luck - you usually can't open it without calling security or the police. In these cases, you can sometimes come back later in case a maintenance worker has left it open. In rare cases, it is possible to squeeze around it or to unbolt part of it and squeeze through that - if you do this, ALWAYS have someone with you, in case you get stuck.
It's also (rarely) possible to enter a tunnel via an escape hatch - usually they're difficult to bypass the lock, but sometimes maintenance workers will leave them unlocked, or the latch will be defective. Note, though, that entering via these is very visible to all around you!

Recommended Preparation and Equipment
The biggest thing that catches people off guard when first exploring active tunnels is that they're very, very hot. Water is a must for any extended explore down there; a flashlight is also a very good idea. Consider the following picture:

this part of the tunnel drops off 12' suddenly. If you're bumbling down there in the dark, it is all too easy to fall over something like this and crack your head on the concrete below.

It is also a good idea to get a map of the area, especially if it is a large network of tunnels. You'll need to exit somewhere, and it's much more interesting to do so somewhere different than where you came in! You also may need to exit unexpectedly - if one of your group starts to feel lightheaded, if someone starts pursuing you, if you can't find your way back to where you started... etc. Wherever you need to exit, you should know the degree of security in the building you exit into - or how public the exit is.

Beyond water and a flashlight, you should wear regular UE gear - clothes that can get dirty, good shoes, etc. Your clothing should also protect you should you accidently brush past an exposed hot pipe. Long pants are a good idea - ideally cotton or denim. Things like nylon or polyester could melt onto you if you touch a pipe. If perchance that does happen, do not try to pull it off yourself - pour water on it to cool it off, and seek medical attention immediately.

Anyone exploring tunnels should also watch his medical condition - they are HOT. And you will be exerting yourself. The human body only has one way to cool itself - by sweating. However, many tunnels are humid enough that sweating is ineffective - this means you'll lose a lot of water to sweat, without cooling down much. If you have fainting spells, you will almost certainly faint down there. If you have low blood pressure, it's going to get even lower. It is critical that you follow the buddy system while in active tunnels - if you faint, you'll keep sweating and losing fluids, preventing you from regaining consciousness. If you take reasonable precautions though, and take someone with you, these risks can be eliminated.

Anatomy of a Steam Tunnel
Steam tunnels generally have a similar layout, and similar things to look out for within. In the lower left is an old 1911 tunnel (still active), illuminated by camera flash. In the upper right is a newer (1948) tunnel illuminated by its own lights.

Of note are the calcite stalactites and stalagmites that line the older sections of tunnel. These form when water in the tunnels bring out the lime (CaO) in the concrete; this then precipitates on the surface, where it reacts with carbon dioxide in the air to create calcite (CaCO3). Calcite is also the primary component of coral reefs!

In addition to the above, which generally runs the entirety of a tunnel, the following will also show up every few yards:

Escape Hatches
These allow workers to get out quickly in case of a steam leak, an injury, fire, etc. They should not be used by explorers unless it is an emergency, because a) it is difficult to determine where it comes up - it could be a secluded courtyard, but it could also be the middle of a busy roadway! b) It is a safety hazard to those above you and c) it is very, very visible.

See the above case study for what these look like from above ground.

The tunnels are all equipped with lights, however the switches for them are not always obvious. While "regular" style switches are not unheard of (1), they are rare in the tunnels. You'll most commonly see the push-plug style (2) - to operate these, pull or push in the plug at the bottom. The positions may be labelled "on" or "off", but this is often reversed due to a dual-switch setup with another one at the other end of that bank of lights. Style (3) is also common, comprising a rotary switch instead. Note, as in (4), that sometimes the switches are not obvious - this one is hidden on the roof of the tunnel, above a pipe and at an odd angle! Note that there is a wire connecting it to the light, which is one way to find oddly-placed switches.

Shutoff valves

Two rules of shutoff valves:
1. You do not touch shutoff valves.
2. You do not touch shutoff valves.

Rule 1 is important because you could cause some serious trouble if you shut off steam where it is needed, or worse, turn it on where it is expected to be off.

Rule 2 is important because there are perils to literally just touching the valves: note the fact that it protrudes out of a significant thickness of insulation. These valves are often uninsulated, but still connect to very hot pipes. Don't touch them.

Pipe expansion folds
Steam pipes carry very hot substances very long distances, and are made of metal: consequently, they will expand and contract considerably with changes in heat (or turning steam on and off). You'll therefore intermittently see the pipes do a little "dip", which gives them somewhere to expand and contract into.

Sump pits
In cases where the tunnel runs below sewer level, it needs some way to remove water runoff. This generally comes in the form of a sump pit, along with accompanying pump. The main thing to know about these, is to make sure the pit cover is secure before stepping on it! Stepping into a sump pit isn't terribly dangerous, but it is incredibly dirty and inconvenient.

Power outlets
In case you want to plug in a rice-cooker down there. Everyone loves steamed rice!

Ladders to nowhere

Nowhere is a big place - don't get lost!

Occasionally a gate will block your way to control airflow - this isn't much of a concern, just be wary that they're sometimes hot.

Locked gates
Sometimes there are one-way locked gates, to frustrate free tunnel-running. In these cases, if you find yourself on the wrong side of them, use a lock-bypass method. Just make sure it isn't an alarmed gate (below) first...

Alarmed gates (grrrrrrrrrrrrrr...)
Oh grrrrrrrr indeed my friends. Oh grrrr indeed. Intermittently, many tunnels will be split by gates with a door contact alarm on them - if opened, security or the police will come looking for you. To get past these, you need to go around them - often there is room to squeeze! If not, wait some time, as sometimes the maintenance workers leave them open.

You can also buy one of your own and use that to make it think both halves are together, when one half is actually yours and the gate is open - but I don't know whether that will actually work, and it's risky besides!

Motion sensors
Even more grrrr-worthy than the gates, these are often installed in tunnels that have had too many infiltrators before. This is a very good reason why things like UER's no POE-giveaway rule is so important, especially for active buildings. If you see one, it's too late - it has seen you. Get out NOW and don't come back. Motion sensors ruin tunnel exploration completely.

Active tunnels are some of the riskiest things to explore, but some of the most rewarding as well. But be sure you are well informed of the dangers before venturing in - they're very safe places indeed if you exercise a modicum of common sense, but there isn't much that can't kill you down there if you don't. Good luck!

This tutorial is taken from a chapter of the University of Toronto Guide to Urban Exploration. This information is meant to apply to tunnels at the University of Toronto, but I'm uploading it here since tunnels are pretty similar everywhere - enjoy! I've got a bunch more chapters that I'm thinking of adding - roofing, lock bypass, elevator surfing, etc - post a reply if you have any preferences for which I do first!

[last edit 6/28/2015 7:22 AM by VAD - edited 1 times]

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post by Piecat   |  | 
Re: Active Utility Tunnels - a Primer
<Reply # 1 on 6/28/2015 4:12 PM >

Informative and entertaining. Thanks for sharing!

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post by RescueMe1060   |  | 
Re: Active Utility Tunnels - a Primer
<Reply # 2 on 6/28/2015 10:29 PM >

Nice, I think this thread should be saved to the top of this forum section. Very well put together. I'll share some of my photos from the one and only steam tunnel I went in. There really is no standing room inside this one, that ladder in the last pic is what, like 4 rungs? thats about 4 1/2 feet at most. And yes, very hot confined space






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post by VAD   |  | 
Re: Active Utility Tunnels - a Primer
<Reply # 3 on 6/29/2015 6:58 AM >

Posted by RescueMe1060
I'll share some of my photos from the one and only steam tunnel I went in.

Great pics, thanks for sharing! That's a beautiful tunnel! Where is it? Is it from a college?

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post by strangePlaces   |  | 
Re: Active Utility Tunnels - a Primer
<Reply # 4 on 7/28/2015 4:33 AM >

Great write up! I am a big fan of tunnels and sewers myself, always looking to discover new ones. Might as well throw in something from York Uni:




It is an immense system connecting every building on campus. Very easy to get lost but also plenty of ways out. Network is roughly consists of two parts divided by a pedestrian corridor. But I believe a really crazy radar sensor has been installed in a crucial connection.
The notable part is the connection to the swimming pool where you can observe people via a thick window underneath the huge pool. I imagine the maintenance guy sitting there all day enjoying the view.

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post by romainpp   |  | 
Re: Active Utility Tunnels - a Primer
<Reply # 5 on 7/28/2015 5:09 AM >

Posted by strangePlaces
Great write up! I am a big fan of tunnels and sewers myself, always looking to discover new ones. Might as well throw in something from York Uni:

369207.jpg (55 kb, 800x533)
click to view

369208.jpg (51 kb, 800x533)
click to view

369209.jpg (77 kb, 800x533)
click to view

It is an immense system connecting every building on campus. Very easy to get lost but also plenty of ways out. Network is roughly consists of two parts divided by a pedestrian corridor. But I believe a really crazy radar sensor has been installed in a crucial connection.
The notable part is the connection to the swimming pool where you can observe people via a thick window underneath the huge pool. I imagine the maintenance guy sitting there all day enjoying the view.

Oh I remember that, Ninjalicious mentions it in his book! It looks great.

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post by catdog23   |  | 
Re: Active Utility Tunnels - a Primer
<Reply # 6 on 8/8/2015 2:37 AM >

That was very informative (I like all the extra chemistry), I've never heard of the University of Toronto Guide to Urban Exploration, so more chapters would be appreciated. Unless there's a place I can get my own UoTGtUE.

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