People who need to escape from a tall building are usually faced with either a “Don’t use the lifts” notice or to scramble down multiple flights of stairs.
An alternative, today’s invention, is a hybrid of abseiling technique and the traditional fireman’s pole. It requires almost no technique, avoids panic-related bottlenecking and doesn’t depend on physical strength.
Buildings would be equipped with an array of fireproof, (opaque) cylindrical shafts. Down the centre of each, a pole would run from the top of the building to the ground. There would be multiple discs centred on each pole and free to slide down it. The annular gaps between disc and pole and between disc and cylinder would be sufficiently narrow that they would provide viscous air resistance to the downwards motion of each disc.
In the event of eg a fire, people could enter a cylinder, stand on a disc and descend the pole at a rate which would quickly settle down to a fixed velocity (this would be designed to be slow enough to allow people to jump on a disc, as in a paternoster system, but fast enough to allow effective mass egress).
Nearing the bottom, an electronic stop would ensure that each disc would only be free to cover the last 2m or so, once the person beneath had stepped out of the tube.