I found an article over at FerFal's place, discussing rappelling (a.k.a. abseiling) as an escape technique from a fire in a high-rise building. It's obviously prompted by the Grenfell tower fire in London earlier this month. I visit Ferfal's blog regularly, and mostly like what he has to say; but, in this case, I must respectfully disagree with his advice.
In the first place, here's what the tower looked like as it burned. Look at the flames spurting out of windows all around the building, and the burning insulation (cladding) around the concrete.
Now, imagine dropping a rappelling rope (usually of kernmantle design, made of nylon and/or other synthetic fibers that are flammable) down the side of that building. What are your chances that the rope will not catch fire? I'd say slim to none. Even if it doesn't, what are your chances of rappelling down the side of the structure, safely and uninjured, with so many flames reaching out at you? Again, I'd say slim to none. Even if you start down a side of the building that isn't visibly on fire, what guarantee is there that it won't catch fire while you're on the way down?
There's also human nature. If you're trapped in an apartment, and you suddenly see a rope dropped past your window or balcony, aren't you very likely to seize it and try to climb down it yourself? Unfortunately, if you're not fit or strong enough, or adequately trained in rope climbing techniques, to take advantage of it, you're unlikely to reach safety by using it; and, in the process, you're likely to overstress the rope's weight limit (remember, the person who dropped it will also be using it, higher up the building). Put too much weight on the rope, and it'll probably snap. Even if it doesn't, the point on the building to which it's anchored may not be able to take the added weight, and might give way. I'd say many people trapped in a burning building will behave like that, making escape problematic, to say the least.
There's also the need, not just for training, but for ongoing familiarization. Training in rappelling techniques is widely available, sure enough; but like any specialized skill, it takes ongoing practice to remain useful. If you learn how to rappel, but never practice it after that, how much good will that be in a building fire five years later? Will you remember it well enough to get to the ground in safety? More to the point, what about your kids? You may have learned to rappel as a solo climber, or with your partner; but if you now have one or two small children, have you ever practiced harnessing them to your body, so you can get them to safety as well? I'd say the odds of that are vanishingly small.
Some (particularly after the 9/11 attacks) have spoken of using a parachute to escape a high-rise building. They're available, but their use raises at least five issues. The first is that parachutes, like rappelling, require training and ongoing practice to use effectively. Next, there's the the proximity of other buildings. If yours is in a cluster of them, such as a city center, there isn't going to be a lot of empty space for your jump. The odds of colliding with another building, or getting your parachute caught on an obstruction like a protruding flagpole or fire escape, or hitting power lines or telephone wires on the way down, are pretty high. Third, the wind in such an environment can be fluky. It can vary in strength, direction, etc. as it's funneled between the buildings. That's going to affect the behavior of your parachute. So will the fourth issue; updrafts caused by the heat of the fire. They've been measured at over two thousand feet per minute - a nightmarish prospect. Winds or updrafts may carry you back against - or even inside - the burning building from which you've just jumped. Finally, parachutes, like climbing ropes, are made of synthetic materials. They're not fireproof. If you have to jump through or past flames to get off the building, and/or your parachute canopy happens to collide with a piece of burning debris, floating in the air (and there are usually a lot of them in a fire like that - just look at video clips to see them for yourself), it may catch fire. If it does, you're going to drop like a stone. On balance, I'd say that parachutes aren't a viable means of escape for anyone except trained, experienced sky-divers, and even they will have serious problems in such an environment.
On balance, I think the recommendations I gave in my first article on this tragedy still hold good. Live as low in the building as you can arrange; get out as fast as you can, as soon as the warning is received; have flashlights, fire extinguishers, and other emergency equipment to hand, so that you can use them to aid in your escape; and don't rely on emergency services to get you out. They'll doubtless do their best . . . but they can't perform miracles.
At the time of writing, the death toll in the Grenfell fire stands at 79. Many of them trusted 'official guidelines', and stayed put, waiting for a rescue that never came. Don't make that mistake.