They usually have them at airports or at the entrance to large buildings. They are big enough to comfortably fit maybe ten people in each section.
I see them on TV and I wonder, what would happen if someone got their arm caught in one? Would that be an instant breakage, or even dis-arm of the arm?!
When I’ve had occasion to actually use one I’ve felt a little unsafe shuffling myself along with everyone else as the thing revolves.
How safe are they? (I’d feel much safer pushing open a conventional spring-shut glass door)
I have never thought about this before; interesting question! I’ve done some Googling, and it appears that there have been accidents, even deaths, involving motor-driven revolving doors. Here is a story about an accident involving revolving doors in Tokyo.
I found this website which describes the doors from a particular manufacturer, and explains the safety features they have.
I also came across this Google Book reference that indicates that these doors shouldn’t be used in high traffic situations, but rather in constant traffic situations. I don’t think they are intended to have so many people between sections, but I don’t really know. This is an interesting read about these doors and people with disabilities.
Sorry to give a Google-search post, I hope you can get a more precise response!
While it is no guarantee of completely eliminating accidents, the ones here have optical and physical feedback sensors to prevent pedestrians being `shoved along’ or crushed by the slowly revolving doors, that stop automatically when no one is using them and start when someone approaches.
During times of high volume traffic they fold away (and stop revolving, of course).
What were your search terms? I just googled [ “revolving door” fatalities ] and got only items involving metaphorical revolving doors (ie: the kind installed in certain state prisons).
They’re pretty easy to stop, I don’t think they could take off an arm. Unless someone inside it decided their haste was more important than your arm, and kept pushing.
The door in mnemosyne’s cite that killed the kid apparently was designed to keep pushing. Instead of stopping, it was set to advance 10 inches. Whose bright idea was that?
It was a big wooden one, but it wasn’t motorized. I was a kid at the time, on a field trip to the Capitol building in Madison. Everyone else was still pushing, but I was caught in between the door and the outside wall. It was pretty scary.
The big ones that are motorized are difficult to mess up, especially the ones that only advance when you enter the door.
I did have an accident just last month with one. I was in Florida on business, and the shuttle from the airport was air conditioned. I got off at the hotel/convention center and instantly my glasses fogged up, bad. This door revolved constantly, and had an L shape rather than a star shape. I ran directly into the bottom of the L.
As a safety feature, they stop when you touch any part of them.
Which in itself is unsafe, as various dingbats/aggressive chavs at airports try to push them to make them go faster, thus making them stop suddenly, leading to nose-to-glass contact from the unwary (happened to me last week).
Hereyou go, Red Barchetta from Wikipedia. They’re the doors used a lot in office towers, hotels and airports, in part because they help manage heating and cooling when there are regular entries and exits from a building. They are also useful when the entrants are likely to have full hands, thus the popularity for hotels and airports.
The one I have used will stop dead, with almost no resistance. I touched it a couple times on accident and it stopped. This is how they are supposed to work.
About 18 years ago (or so), I got my ear stuck in one. My dad was holding my hand and took me into a segment of the door. These kind weren’t automatic- you had to push. I leaned against the wall and he pushed. The wall behind me swung right around and caught my ear. Luckily it wasn’t high traffic and dad just pushed the door backwards and got me out. Painful but no injury.
A coworker of mine broke his arm in one. This was in Brisbane, just south of San Francisco where the winds were fierce enough that sometimes you just couldn’t even open the doors to go outside. A gust of powerful wind evidently quickly spun the revolving door around quickly and his arm got caught, breaking it.
The ones the OP is asking about are much larger. I saw one at an airport once, though I can’t remember where: The radius was about 10 or 15 feet.
If anything, it seems to me that the large ones would be even safer than the one-person-per-compartment size: With arms that long, the door would have terrible leverage out at the end.
The ends of the wings where they touch the outside wall are made up of about a 4"-6" (10-15cm) rubber flap. So it would be pretty hard to break an arm in that – you can easily push or pull the rubber flap with your hand.
This one moves pretty slow – enough to push loaded grocery carts through it. And it stops if it encounters resistance. Not much resistance is needed – I once saw a 10 pound bag of sugar drop off a cart onto the floor – the door stopped when it hit that bag.
I’ve never felt at any danger inside this – just impatience, it seems really slow to me.