I stand slightly corrected - it wasn’t a journalist, it was a nearby resident and eyewitness.
http://www.washingtonpost.com/wp-dyn/articles/A38120-2001Sep15.html
One of the big dangers of parachuting out of a building like that is that there is no safe landing spot. From the top of the WTC, the ground below is a mass of other buildings, spires, antennas, wires, roads with traffic, etc.
If you know what you are doing and have a square, steerable parachute, you can find a spot to land and steer into it. Even then, there’s a lot of danger because the winds around high-rise buildings are very unpredictable.
But if you’re a novice under a round parachute, you are going to land wherever you hit. That means hanging off of power lines, caught up on the sides of neighboring buildings, impaled on antenna structures, you name it. For every person that lands safely on the ground there will probably be ten people in some kind of distress. It’s just a stupid idea.
That doesn’t mean that there isn’t a possible way to build ‘lifeboats’ out of skyscrapers. There is. The best plan mentioned so far would be some kind of weighted cable, and a belt with a friction lock on it. The egress point could actually be inside the building, kind of like a laundry chute. Have people on each floor who have to be trained in how to fit people into their belts and latch them properly to the apparatus, then they slide through a door and down into an enclosed shaft for maybe 50 ft before exiting outside the building on the cable.
I already mentioned another device that has been tested on buildings - it’s a cloth tube made out of a kevlar-wound cloth that has a lot of internal friction. You jump in one end, and naturally slide down inside it at a nice slow speed. There’s nothing you can do to stop yourself or speed up - the descent rate is controlled by the friction of the tube and the weight of the person. The tests of it that I’ve seen looked flawless, but I really don’t think we have the capability to make one that long.
Again, I think you guys are looking at the wrong risks. First of all, there are a limited number of buildings tall enough to skydive from in the first place. The vast majority of skyscrapers are 15-40 floors high. And on the tallest ones, it would only be the people on the top floors that this would do any good for in the first place.
Another thing to remember - BASE jumpers and other skydivers tend to ignore jumping in storms and in poor visibility, but high-rise fires don’t care. So there’s a good chance that the day you need your parachute it will be in a thunderstorm with rain pounding down and 50 mph winds. Good luck.
And yet, Sam, were you in that situation and had a parachute, I would hope you would jump rather than face certain death. I certainly would. Better a 25% chance of survival than zero. (As a general policy, however, it is a non-starter.)
BTW, I’ve talked to a group of “radical BASE jumpers” (as opposed to ordinary BASE jumpers) and one of them said the minimum safe height when jumping with a special type of chute is about 100 feet. Yes, 100 feet. The chute opens explosively. She also said that, at that height, the parachute would not be fully pressurized, but would slow you down enough to prevent serious injury or death. She said her friends had jumped from bridges that were less than 150 feet–and then landed in 2-3 feet of water which, yes, cushions the landing some. The use of such a chute, however, takes considerable expertise.
I’ve done a jump from a 20 story building (about 195 ft) over hard earth. There is a new development using vents on the bottom skin of the parachute that permits pressurization much quicker–like from 100 feet it’d be fine.
Use of a non steerable round would still be the best way because with a square they are going to get hurt possibly killed. You also won’t have to contend with off heading of a square parachute that would result in a fatal building strike. Off headings by first timers are much more likely. Rounds one doesn’t have to worry about off headings.
I’m picturing external ramps with an overhead rail. Inside, there would be rows of 'chutes along the corridor. When someone puts one on, there is a static-line already attached that tracks along overhead. All there is to do is open a safety-door, not a window, leading out to the platform/ramp (which would be ranged/spaced to prevent falling directly on to others below). Jumping automatically pulls the static-line and that is that.
Round 'chutes forgo the need for training. Broken ankles are far better than the alternative.
Floors below the 10[sup]th[/sup] would have the slides described before, but you would also assume that they would be close enough to make a standard, stair-well escape.
$0.02.
Something I had seen back in 1987 was an esophagus type rigging that would literally swallow a person who escaped into it.
These were ribbed tubes made of heat and tear resistant material. The report I saw said a completely unconscious person could be dropped into it and they would be safely “swallowed” to the ground.
The interesting part of these is that they would fit into a window. The pack could be “blown” by hitting a fire alarm type button on it’s front side. Whether or not this kind of thing would work in a building as tall as the WTC 1 or 2 were I doubt.
Anyone else ever heard of this type of thing?
-Waneman
How about a belt harness that fits into an external rail on the building? The rail runs vertically the entire height of the building. The belt harness could clip to the rail in such a way that it could use a ratchet or friction system to slow the user’s rate of descent to say… I dunno… 10 or 20 MPH. At about the second storey, the rail disengages, and the user is directed onto a curving ramp, avoiding any impact at all, and moving them out of the way of people following. Such rails could be thin, and placed all around the building in such a way that they appear to be part of the design.
Waneman: That’s the same thing I was talking about. It did look like you are ‘swallowed’.
While I don’t discount the idea and it’s merits, the fact of the matter is, you canNOT prepare for the unexpected.
When towers are built, architects and engineers think out a number of emergency scenarios like
- Enough escape routes in case of fire
- Sealed levels in case of fire
- Sprinkler system in case of fire
- Reinforced internal structure in case of earthquake
- Reinforced structure to combat high winds
- Drainage system for rainstorms
- Grounded electrical systems for lightning storms
- Emergency brake systems for elevator failures
- Escape hatches for trapped elevators
10)Lights to ward off aircraft from straying into them
11)Radio antennae connected to fire and security alarms that send out signal to local emergency services
12)First aid kits on each floor for medical emergencies
13)First aid stations in the middle or graound floor to attend to medical emergencies
14)Air vents large enough for people to crawl though that connect to every part of the building (Okay, maybe that last one was just cooked up by Hollywood writers)
But up until Tuesday morning, wouldn’t you have found it extremely odd to see a hammer, a red box with a windowed door and a sign stating “Break in case of airplane crashing smack-dab into center of building”?
Let’s be honest, you probably would’ve chuckled and said, “WTF?”
I believe the point is that if for any reason a tall building catches fire in the middle to lower floors, there needs to be a good way out. The WTC is just an extreme case but people die in high-rise fires every year.
You can die just as easily from smoke and fire as the building collapsing.
I seem to remember something about the implementation of fabric escape chutes (as described above) in the Mediterranean region somewhere, in holiday apartment blocks; they consisted of a room in the (same) corner of each floor of the building, in this room was a hole in the floor, hanging downwards from this hole was a tube of some sort of fabric, but it was just long enough that the end of the tube was inserted into the mouth of the next tube on the floor directly below.
The idea was that you would sit with your legs in the tube, look up and wait for a moment when nobody was descending from above, then you would launch yourself into the tube.
IIRC it was implemented because it took up far less space than any other type of fire escape, but I think it was quickly abandoned due to practical problems; very large people would get stuck in the tubes and if you misjudged the timing, you could end up getting into your segment at the same time as someone descending from above was passing through it, again, you’d get stuck, but the people entering the system from above would not know this and it would quickly turn into a nasty human bottleneck situation.
Can’t find any documentation for this, but I remember seeing it on TV.
Er, no. Real estate is expensive because there’s a limited amount of it. Especially on things like islands. Like, say, Manhattan.
As I think has been alluded to, engineers don’t design buildings to be jumped out of, they design buildings so you don’t have to jump out of them (fire protection, emergency exits, etc.). Obviously, this was an extreme case that the designers did not account for.
Not to divert/hijack this thread, but something I meant to include before was this:
Could they use Halon rather than sprinkler systems? Obviously, water isn’t going to work against fuel fires, but Halon doesn’t care what is burning, it just takes all the oxygen…not good for humans, but neither is smoke.
I know next to nothing about parachutes, but I do seem to remember that they aren’t particularly cheap. Apologies if someone else has mentioned this already (I haven’t seen it, though) but how much would, say, 5,000 skyscraper-escape parachutes cost? What maintenance would they require?
I ask because I suspect that there might be wiser ways of spending the money, on a lives-saved-per-dollar-spent basis. Like more and bigger fire escapes, better fire-supression systems, better communications, better escape drilling and co-ordination, or even some kind of building monitoring and modelling system (to predict imminent collapse, spread of fire, etc). Parachutes would only be useful to relatively small numbers of people in a fairly limited set of circumstances, whereas a lot of that other stuff would be useful for all the building’s inhabitants in many kinds of disasters.
A base rig (one parachute system) with no parachute would cost between $500 and $600. The parachute assuming rounds are used would be between $450 and $900. This is assuming they go with new. You can find lots of old round canopies for as little as $150.
So rough total for one = $1100 * 5000 units = $5,500,000
Since most skyscrapers that would be involved in a situation like this are ususally surrounded by other skyscrapers of similar heights, couldn’t some kind of escape network be hooked up between buildings. Basically Taller buildings would have high tension cables connecting to the roofs of lower buildings nearby. Any people trapped on the roof would use a harness of some sort that would clip to the wire and slowly lower them to the nearby roof.
The harnesses would be stored in containers on the roof in bunkers similar to those holding life jackets on boats.
Obviously this would only be feasible in certain situations where there was appropriately sized buildings and no air traffic, but it would provide a more controlled escape than groups of people all jumping at the same time.
-fornit
Snopes agrees:
http://www.snopes.com/inboxer/hoaxes/survivor.htm