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Maglev Elevators by 2008?
An anonymous reader writes "CNN is reporting that the first magnetic levitation elevators could hit the market as soon as 2008. The Toshiba Elevator and Building Systems Corporation has stated that the same technology used to develop high speed trains will soon be available in their elevators. From the article: 'The maglev elevators will be quieter and more comfortable and will travel 300 meters (984 feet) per minute -- not as fast as the company's conventional lifts that can move up to 1,010 meters (3,314 feet) a minute, Toshiba said.'"
Asia? Well, sure, if you exclude everything but Japan and South Korea. And regarding the former, this Economist article once again seems relevant: "Better than people: Why the Japanese want their robots to act more like humans." It's one (intelligent) journalist's take on why Japan seems so open to new technology while Western culture is more ready to view it with suspicion.
I believe the Mythbusters disproved this; their findings showed that a magstripe card would have to be subjected to extremely strong magnetic fields to be damaged.
The elevator might be a different story though.
Why would a maglev elevator be prohibited from having the standard safety braking systems that cable elevators have? Despite what Hollywood might have you believe, breaking the cable supporting an elevator will not bring you crashing to Earth. Worst case, you might fall a few feet before being safely stopped.
What?
Dangerous failure mode
Probably not. It is probably based on a toned down version of the ride you see at some amusement parks (e.g. the Pit Fall at Kennywood in Pittsburgh). In the Pit Fall, most breaking is done by large permanent magnets that surround metal fins. As the car falls, the magnets induce a current in the fins that oppose the motion.
With the magnets already needed for propulsion, it wouldn't be difficult to add something similar to the elevators.
(Also, there's not enough detail in the article, but there's no reason that you couldn't use almost all the safety features used in traditional elevators in a maglev one.)
This has been used routinely with great success at amusement parks in those drop-towers where you are lifted several stories in the air, then dropped freely most of the way down only to be stopped in the last few meters. There is no active breaking system to stop you: if you look closely you can see metal plates sticking out of the tower that pass behind the car, where magnets are positioned to pass very close to the plates (I'm talking specifically about the one in Six Flags Great America).
You can play with this yourself by dropping a strong magnet down a vertical copper pipe. It will move very slowly, even if it is only barely touching the sides.
I'm not saying that the elevator is a good idea, just that it is probably safe.
Don't Bogart the fish sticks
No. Wallets erasing credit cards is a myth. It takes an insanely intense magnetic field to erase credit cards. When you go on a modern roller coaster that uses magnetic brakes are you asked to leave your credit cards behind?
-1 overrated isn't the same thing as "I disagree".
Reasons I think your wrong
This will lead to a new generation, elevator shafts that do not require their own floor on the building, elevators that are capable to travel as many floors as we can build from a single shaft. Improvements such turning the elevator shaft into a vacuum would allow the elevators to travel at insanely fast speeds. Sure the first one will be expensive, but in 20 years, every new elevator will be a maglev one.
# Simple, instead of pullies and leavers and motors, your left with a system with no moving parts. Nothing will ever wear out, except the permanent magnets in a long long time
# Failure can be handled like todays elevators, clamp to the walls and put the breaks on
You're being inconsistent. The reason that brakes (Ha! I'll not make the same mistake I did in my last post!) in today's elevators work remotely well is that there's a counterweight. Lose that and probably your safety systems become crap.
So you either need something new in the maglev elevator, or a counterweight. But if you have a counterweight, you've got at least a pulley.
Now, it's possible that the induction-based brakes I and another poster described would substitute for a counterweight, in which case you could get away with no moving parts, but I'd have to see some experiments and calculations before I would trust it as a replacement.
The reason that brakes (Ha! I'll not make the same mistake I did in my last post!) in today's elevators work remotely well is that there's a counterweight. Lose that and probably your safety systems become crap.
I've thought about this a little more (I should do that before posting, but we all know the desire to get something up before someone beats you) and it might not be true. Safety systems currently are probably designed to withstand a cable break, in which case there goes the counterwight's braking power. (Yay for homophones.)
(I STILL think though the benefits of a counterweight outweigh (no pun intended) the additional cost and complexity.)
I agree.
And considering in most countries there are standards that companies have to adhere to when installing elevators, i find it highly unlikely that when the power fails, we will all plummet to our bloody doom.
In Australia a lift is required to have a certain amount of brakes in case of emergency as standard.
I suspect that if these are to be commissioned in other countries, the install will have to adhere to each countries individual building code standards.
Here's the technical reference: "Electromagnetic Non-contact Guide System for Elevator Cars", Morishita, M., Akashi, M., Toshiba Corporation, Japan.
There have been some "ropeless elevator" proposals, including ones where linear induction motors drive the elevator cars. The most elaborate proposals involve multiple cars per shaft and switches, like a vertical railroad. This would cut down the amount of building space devoted to elevator shafts considerably. Mitsubishi did some R&D in this area back in the 1990s, but there's no working hardware yet. There's been some military R&D in this area for shipboard weapons lifts, but that's more like a conveyor system. Eventually somebody will probably build such a system, but not yet.
Incidentally, the limit on elevator speed is human tolerance for changes in air pressure. 8 meters per second (downward) appears to be the comfort limit. The Sears Tower elevators were originally set for 9 m/s, and a broken eardrum was reported.
Too bad Faraday cages block electric fields, not magnetic fields.
Magnetic shielding is done using highly permeable metals - "mumetal", an alloy of copper, chromium, nickel, and iron, is the standard material used.
It'd be nice if magnetic fields were blocked by a simple Faraday cage. Mumetal's expensive.
http://release.nikkei.co.jp/detail.cfm?relID=12048 4&lindID=4 is the original press release from Toshiba Elevator, written in Japanese. They replaced only guide rails with maglev magnets for smoother feeling. You still need conventional rotating motor and cable.
It is trivial - really - to design an elevator system capable of withstanding a cable break. Imagine a system in which the tension on the cable is keeping a pair of arms from slotting into teeth on the sides of the elevator shaft walls. That's probably the simplest method.
If passenger elevators really would fall to the passengers' deaths if the cables broke, do you think that there would be any distinction between passenger and freight elevators? Mr. Otis was able in the late 1800s to demonstrate that his design was capable of withstanding a complete cable transection.
Not that the parent addressed this, BTW, but elevator transit speed is limited by how quickly our ears can equilibrate, not by how quickly the boxes can move. If you don't mind painfully popped ears, you can easily double the rate of travel of conventional elevators.
you'll find that most new lifts being installed these days have their motors sitting on top of the actual lift As components become smaller and more powerful, lift motor rooms are fast becoming redundant. This excludes taller office towers as they obviously need massive winches etc for the amount of cable that needs to be recoiled.
The reason that brakes (Ha! I'll not make the same mistake I did in my last post!) in today's elevators work remotely well is that there's a counterweight.
What's your next guess?
To pass safety certification, an elevator's gravity brakes have to work if the main hoist cable fails. IE, no connection to the counterweight.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
Compared to the South African mining elevator incident(Vaal Reef?) where the elevator got stuck in the shaft and cable piled up on top of the elevator until it was too heavy to hold, at which point it fell down the shaft because of all the slack cable that had piled up. The momentum of the falling elevator sheared it off the cable, where it kept going until it hit the bottom of the shaft, reducing its remains to a wreck only 2 feet high.
Two Roommates and a Boyfriend, updates Monday, Wednesday, and Friday
I've been in that elevator last year, around the september period. The speed is amazing. You do have to buy a (relatively) pricy ticket to use it and go up to the observation lounge though. It's worth the view and the ride. I think going up was quicker than going down. The elevators also have a nice display, specifying speed, number of floors and seconds travelled.
France does not have Maglev trains. Germany developed a protoype of one and sold it to China (which uses it on the cummuter line between Shangai airport and the city center). The German parliament is perenially discussing building a Hamburg-Berlin link but it is pretty expensive and there is now a new high-speed rail link which makes it less viable. Maglev is not THAT fast.
:)
The French TGVs are high-speed trains but they use normal rail technology. The French Train system is powered from the normal grid which is largely nuclear. The Germans also have a high-speed train, the ICE (InterCity Express). The trains are 20 km/h slower than TGV at the fastest points but the trains are waaaay more comfortable. They still do 280km/h though. Travelling by ICE rocks.
Both systems can travel on normal tracks but both system also have special ultra-high-speed sections dedicated to them. In the case of ICE the main one lies between Frankfurt Airport and the Ruhr, which bypasses the Rhine Valley and cuts the journey time Franfkurt Airport -> Bonn from 2 hours to 45 minutes. Sadly you skip the nice scenic Rhine Gorge at the Lorelei, so its not ALL better
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- Aslong as the cable is intact, the cable can be braked by a drum-brake at the top.
- If that drum-brake goes, there's a second, independent cable-brake that basically clamps around the cable.
- If both those go, the cars still don't accelerate very much, because there's a counterweigth so only the imbalance of passengers would cause acceleration.
- If that's still bad, or the cable itself is broken, then the wagons instantly clamp to the rails they travel along. This is so because the tension on the cable is working against a spring that tries to push brake-shoes up against the rails. If the tension goes away, the spring wins.
- Yeah, if *all* of that fails, you migth have a problem.
Needless to say, this never happened. Inspite of the thing being in operation for like literally a hundred years and transporting thousande of passengers daily. I imagine newer designs can be even more secure, but I don't really think it's worth the effort -- it's good enough. People plummeting to their death in elevator-accidents is not a major cause of death outside of Hollywood.