I just saw another public service announcement where adorable kids are talking about fire safety tips. One of them syas “never use an elevator in a fire, because it will go straight to the floor where the fire is”.
Of course I’ve heard this one a million times, and it always stikes me as highly improbable. Whether old fashioned mechanical controls, electrical relays or modern computer controls, I still can’t come up with a scenario that would cause this to happen.
Are there any documented cases of this actually occurring, or is it yet another urban legend? (I checked snopes) If it really does happen, what causes it?
I am fully aware that using an elevator in a fire is a dumb thing to do, whether the UL is true or not. Please, let’s try to keep the WAG’s somewhere to this side of RRWAG’s (Really, Really Wild Ass Guesses).
TT
“It is better to know some of the questions than all of the answers.”
–James Thurber
Well, there’s a damn good chance it’ll stop on the fire floor, provided the fire was below you. You’d have an entire floor of people trying to escape, and there’s a good chance one or more of them will hit the down button.
I imagine there might be a risk of the building or elevator losing power (due to the fire itself, sprinklers, or firemen). All in all, I think avoiding the elevator is good advice.
As a “Deputy Fire Warden” for my floor in a high-rise office building, I’ve heard the official spiel given by Fire Marshalls during countless fire drills regarding proper procedure during a fire. My understanding is all elevators automatically return to the lobby when an alarm is pulled. There, the firemen can use the fireman control in the elevator to get to the fire floor quickly. There is no other access to the elevator control while the alarm is in effect.
So, anyone actually on an elevator when an alarm is sounded would find themselves in the lobby, and anyone waiting for an elevator at another floor would not get an elevator until the alarm was cancelled.
I’ve never heard that an elevator will automatically go to the fire floor. The call buttons are not supposed to work during an alarm, and it serves no purpose for the elevator to be at the fire floor before the firemen get there.
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man.
I have never heard that either. I had always heard that it was because the fire could knock the power out and there you would be stuck between floors in a burning building with nowhere to go. Quixotic’s explanation I like best though. makes sence that they would have some sort of safty device like that.
An older elevator, without a recall function, can be called to a fire floor. The fire can melt and thus short out the floor call buttons, calling the elevator to that floor.
However, thats not very likely today. All phases of elevator recall bring an elevator to the “designated egress floor” (ground floor) when an alarm is recieved, unless thats the floor the alarm came from. These alarms can be the building’s fire alarm system, or it can be a seperate set of smoke detectors in each elevator lobby (look for a detector head about 2’ from the elevator door).
There are 4 reasons why elevators are bad in a fire:
People seeking to escape from a fire by using an elevator may have to wait at the elevator door for some time; during that time they may be exposed to fire or smoke and become panicky.
Automatic elevators travel to floor by responding to pressed buttons, both in the elevator car and in elevator lobbies. Because this operation cannot be cancelled once a button is pressed, it is possible for an elevator descending from floors above a fire to stop automatically at the floor of the fire. The doors will then open automatically, thus exposing occupants to smoke and/or fire. A further consideration is that an elevator shaft will act as a chimney in a high-rise building. Unless positively pressurized with respect to the fire floor, the shaft will carry heat and smoke from a fire and expose passengers to toxic levels of both, even if the elevator does not stop at the floor of the fire and contines to function. An elevator moving within its shaft enclosure might act as a piston within a cylinder and push the smoke and gasses of a fire to floors not initially involved.
Modern elevators will not operate until the doors are fully closed. In an emergency, large numbers of people may try to crowd into the elevator, preventing the doors from closing and preventing the elevator from operating. Also, smoke may also obscure “magic eye” type door openers, not allowing the door to close in a smoke condition.
Any power failure, such as the burnout of electric supply cables during a fire, might render the elevators inoperative or may cause people to become trapped in elevators stopped between floors. Under fire conditions, there might not be enough time to rescue the trapped occupants through emergency escape hatches or doors.
But, after all of this, there may be emergency elevators in hospitals, high-rises, and underground buildings designed for use in fires. That doesn’t mean go looking for one, if you know its there and know how to use it, than use it. You could be losing valuable time waiting for an elevator thats not coming that could be much better used in traditional evacuation.
Yes, stairwells can make great chimneys. That is why they are built with heavy doors that are supposed to be left closed except when actually entering or leaving the stairwell. (That is also why stairwells are pretty much barren of ornamentation. They are not the victims of cheap interior designers; they are specifically built to have little flammable material so that they cannot ignite and create their own self-sustaining chimney fire.)
I recall a trend in the 60’s and 70’s of using heat sensitive elevator buttons. At least that’s what we called 'em.
You bearly seemed to touch the button and it would light up.
Could this have spawned the “It will stop on the fire floor” legend?
The heat-senstive buttons did create problems, and there were cases of firefighters trying to use the elevator to get around the fire and ending up on the burning floor. I don’t know if there were any deaths.
With the various systems and electronics, the problem was no one could know exactly what the elevator would do in the case of a fire.
“What we have here is failure to communicate.” – Strother Martin, anticipating the Internet.
As tomndebb said, they make great chimneys. Any vertical opening (stairwells, elevator hoistways, utility shafts, dumbwaiters, etc) must be protected from fire with a rated enclosure. If it connects four or more stories, the enclosure must have a 2 hour rating (2 hour wall, 1.5 hour door). Less than 4 stories, the enclosure must have a 1 hour rating. Also, the shaftway must have a Class A interior finish, meaning it has a Flame Spread of 0 to 25. In layman’s terms, the stuff on the walls and ceiling hardly burns (if at all). The Code has more than 25 pages of stuff about the protection of vertical openings. Don’t even get me started on protection of atriums…
As a sidebar, just because the wall is a 2 hour wall, it doesn’t mean that at 1 hour 57 minutes its time to leave. The wall is tested against a “standard” fire, developed from live fire testing in the 1930’s. Today’s fires are much hotter and faster than a fire of the 30’s, and 3 hour walls have been known to fail in 15 minutes.
Moving on…
I’m 95% positive that there were some line of duty deaths because of these buttons. For some reason, I’m thinking Los Angeles; but I could be talking with rectal-cranial inversion. I’ll check up on this one this week.
Jeremy…
Nobody ever calls me after they’ve done something smart.
Let me clarify that…I’ll check on where the deaths were, not on my rectal-cranial inversion. I know about that one right now.
I also forgot to give the cite for the list in my 1st post in this thread. The list came from the Life Safety Code (NFPA 101) Handbook, Section 7-4. Gotta give NFPA their due, after all.
Jeremy…
Nobody ever calls me after they’ve done something smart.
