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lago1
location:
the 'Go
 |  |  | Alarms on fire escapes
< on 4/7/2004 11:42 AM >
|  | | | Today I was trying to get to the roof of a live semi-skyscraper via a fire escape much like the one in this link: http://www.striguil.co.uk/images/chicago/escape.jpg . The escape stops at about ten feet below ground level and then there is a fall-down set of stairs that stays up with a counterbalance. Since the struts that provide the support of the escape were within reach from the sidewalk, we just reached up and climbed up to the platform. For a moment we lay quietly to see if anybody heard us and then began moving towards the main staircase. About halfway to it, an alarm went off in the building. As the neighborhood is heavily patrolled, we jumped off like monkeys and ran off without getting a chance to look for what triggered the alarm. From any of your experience, is it more likely to be a pressure sensitive or motion sensor based alarm? Additionally, in big cities like Chicago, do most such fire escapes tend to be alarmed on large buildings? Or is it only when the platform is within jumping reach of street level?
Thanks in advance for any insight... I am a lover of rooftops.
Peace
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MacGyver
location:
St Paul, Minnesota
Gender: Male
"Someone go find me a paperclip, a D-cell battery, and a cheese grater"
| | Re: Alarms on fire escapes
<Reply # 1 on 4/7/2004 12:06 PM >
|  | | | I can't say I've ever heard of or encountered an alarmed fire escape. I also haven't worked with fire escapes in cities much bigger than Fargo, ND, so I don't have a well rounded view, either.
My guess (and that's all it is) would be that the alarm was triggered by a pressure sensor on the platform you were standing on, a mercury switch on the hinged part, or even a PIR inside a window or doorway that didn't like seeing you.
If you get a chance to stop by again, look for any wiring or little boxes and stuff anywhere in the area you went past. Pictures would be helpful as well.
Like a fiend with his dope / a drunkard his wine / a man will have lust for the lure of the mine
"If you are not part of the solution, you are not dissolved in the solvent." |
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Plytheman
 
location:
Lawrence, Massachusetts
Obey The Deer
| | | Re: Alarms on fire escapes
<Reply # 2 on 4/7/2004 8:31 PM >
| | | | Alarming Fire Escapes? Sounds wierd... guess I'll have to be that much more carful now... Any chance that the alarm was triggered by something completely different coincidentaly at teh same time? (I know its a stretch but alarming a fire escape seems really paranoid...)
I would gues infared since it went off after you ahd been up there for a bit and had moved around...
I'm achin, I'm shakin, I'm breakin, Like Humans Do!!
-Byrne |
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lago1
location:
the 'Go
| | | Re: Alarms on fire escapes
<Reply # 3 on 4/8/2004 2:59 AM >
| | | | Yeah, it sounds weird to me, too. I'm fairly sure there were no large, obvious wiring setups and junction boxes of any sort as I'd checked out this particular point of entry several times before... though if it was small I could have overlooked it. I'm also leaning toward infrared since we'd been on the landing for a while and did not disturb the push down staircase.
What I'm really wondering is if they only alarmed a fire escape like this one because it's support struts are low enough to the ground to be climbed up... on most similar structures in Chicago you'd have to be twelve feet tall to reach the bottom of a fire escape. Anybody with experience in big city security trends? This building is on the border of a very economically depressed area and crime rates are fairly high, especially in terms of burglary... the tower is residential.
Hopefully this won't be a trend as I'd like to be able to just sling ropes up onto the higher fire escapes, pull the stairs down, and climb up without setting off alarms. That would suck if it turns out to be impossible.
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HAMMERTIME
location:
Reading Pennsylvania
Gender: Male
mmm, a box . . . just a box
| | Re: Alarms on fire escapes
<Reply # 4 on 4/8/2004 3:37 AM >
| | | | PIR is unlikely since it doesn't go through glass, and a motion sensor would be set off by crows, raccoons, pigeons, wind blowing trash?. Snow fall on the escape ladders should rule out a pressure sensitive mat, unless it is turned on only in the spring and summer. If I had to guess, I would think that it was an unrelated alarm or someone inside, saw you and hit the alarm button. One good thing is that it is an audible alarm that you can hear and respond to. This lets you know it's time to ski dattle out of there before the men in blue come to visit. I would try it again, (quieter on the stairs) and see what happens.
HAMMER
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lago1
location:
the 'Go
| | | Re: Alarms on fire escapes
<Reply # 5 on 4/8/2004 3:39 AM >
| | | | Hammertime, you make good points. And my partner was not especially quiet on the stairs, so somebody could have heard us. I'm also beginning to think that there was a camera somewhere that we couldn't see and the security guard just set off an alarm to scare us. We'll find out next time...
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ursusarctos
| | Re: Alarms on fire escapes
<Reply # 6 on 4/12/2004 4:26 AM >
| | | | Living in Chicago myself, I've had a chance to scope out a lot of fire escapes....sadly all too few chances to climb up any of them. But many of the fire escapes I've seen do have some sort of alarm at their lowest level. This will either be a "drop alarm"--a mercury switch that is activated when the last set of stairs drops to street level, or a pressure sensitive switch. I've seen other types of alarms as well, like IR beam tripwires, but these generally are obvious.
Fortunately, fire escapes are open and easy to look over--there's none of the "is this door really alarmed" phenomenon, where you can't see the other side. And the alarm wires are almost always in conduit. But there's lots of other conduit there too, for emergency lighting and the like, so one has to take a little time to figure out what does what.
Once you know what you're dealing with, it can be pretty easy. If it's only a drop alarm, then you just have to figure out how to get up without dropping the last staircase. Pressure alarms, or pressure and drop alarms together are more difficult--perhaps you can bypass the lowest level of fire escape entirely? (No, that extension ladder won't look suspicious at all...) Perhaps get onto the fire escape from some unalarmed access in the building? I've seen escapes that are heavily alarmed at the lowest level, but with people standing outside and chatting higher up.
Edit: By "pressure sensitive switch," I meant a device that senses vibration. This is generally mounted on a support point beneath one of the level stretches of grating. It's probably calibrated so that birds and varmints aren't too likely to set it off, and remember that fire escapes are pretty good at shedding snow.
[last edit 4/12/2004 4:30 AM by ursusarctos - edited 1 times]
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New York Urban Explorer
This member has been banned
Gender: Male
H.I.M.
| |  |  | | Re: Alarms on fire escapes
<Reply # 7 on 4/16/2004 8:39 PM >
| | | | Well I have heard of fire escapes where the latter when pulled down hits a momentary switch wired into a regular sucurity system. Sometimes people who cant afford then make a crude version of it. All needed is a existing sucurity system, one momentray switch, and about 20 feet of 16awg wire.
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