ThyssenKrupp Multi – world’s first rope-free elevator [video]
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Otis considered ropeless elevators, but in 1997 it looked like it would increase the energy consumption by 7X. Without counterweights, the motors have to do a lot more work. But maybe Multi can recover some of the energy via regeneration.
There are automated parking garages that can move cars sideways.[2] Those go back to the 1960s, and tend to be high-maintenance.
The Multi system looks really complicated mechanically. All those moving parts. Worse, they're on vertical surfaces in the shafts, where maintenance will be difficult. With regular elevators, the high-maintenance items are in the machine room. This will probably go into some prestige tower, but not be replicated much.
[1] http://www.barkermohandas.com/images/Integrated%20Vertical%2...
Maybe - but movement on two axes lets you get creative with your tools. You could for instance store a "maintenance car" with special fittings that expose the shaft mechanisms. The car could be introduced into the system as needed and removed when it would just be in the way.
This would also be 1) more forgiving of "whooses", and of what I suspect are going to be some pervasive acceleration and directional issues.
Crates of goods don't get motion-sick.
Do you know the principle of a traditional elevator, and the role of a counterweight?
The elevator conserves energy by having a counterweight, and the work needed for moving the elevator (disregarding the loss of the system) is 0 if the elevator is empty and the counterweight is the same weight of the elevator.
This is true for the length of the rope.
Now if you have a 99 storey building, with side moving elevators, you cannot have counterweights, as the ropes would be in each others' way when moving sideways. Either having a rope in way for 99 storeys in worst case, or with shorter ropes you increase complexity even further and negate the energy saving. if travelling further than the length of the rope.
The only advantage of this design is the lack of ropes. The downside is increased energy use.
Regarding transient linkings: even more complexity, and possibly the cabins need to wait for the counterweight to arrive, and hand over the counterweights? Even scheduling complexity is increased. Totally useless, as to have it a bit feasable you need to sill keed the functionality of counterweightless motion.
You can understand this by drawing if still not clear.
One of 3 elevators in the office building is out of operation every two weeks. ThyssenKrupp comes and repairs it every now and then. They are simple elevators. The reliability I can imagine from my experience with TK elevators I think the floors will be a better option.
Once I was working for a TK company, and the TK elevator broke down. It was not repaired by the sibling company for a whole month because of some component shortage... That was a simple elevator in a 5 storey building.
I do agree with you that having independent counterweights would increase the complexity and the likelihood of a breakdown. Ultimately any solution would depend on the value being provided by the solution verse the increased cost or either maintenance or energy costs.
More importantly the purpose of me suggesting this solution was not to solve the elevator problem (I am sure lots of engineers have thought more deeply about this than me), but to discuss the problem.
What I thought parent meant was using counterweights in the more traditional sense.
And yes, moving down also returns the energy, after all gravitational field is conservative. The real use of the counterweight is that the power needed to lift is less (you only need to work to lift the cargo), which means cost savings in motors, wiring, electricity, etc. Those saving by a mechanical counterweight system cannot be had with this setup without insane complexity. With today's solid state power electronics it is simpler and more reliable to use an electronic solution.
https://en.wikipedia.org/wiki/Paternoster
A paternoster lift is a passenger elevator which consists of a chain of open compartments (each usually designed for two persons) that move slowly in a loop up and down inside a building without stopping. Passengers can step on or off at any floor they like. The same technique is also used for filing cabinets to store large amounts of (paper) documents or for small spare parts. The much smaller belt manlift which consists of an endless belt with steps and rungs but no compartments is also sometimes called a paternoster.
Nowadays certain safety concerns from the 1970s could be solved by incorporating modern safety features like auto-stop, automatic doors, etc in newly built ones. Express elevators could be built too, if they skip certain floors.
Say you have a 5 story building that needs a one shaft elevator. 5 floors tiles 100 sqft per floor is 500 sqft of wasted shaft space. Then say you have a 10 story building that needs two shafts. Now you are wasting 10 floors times two shafts or 2,000 sqft. And so on.
An old and terrifing solution to this was to use two shafts and run a continuous loop of open door elevators.
There's one in Leicester University (not the only one in the UK, I'm sure).
Really not that dangerous, with a cable near the top of each aperture that triggers a stop if it's touched.
I'm glad they still have it, I was nervous when I searched that I would find out it had been ripped out since I was last there.
EDIT: Unless there's some dependence between m and n, like if taller buildings always need more shafts or something.
The dependence is on keeping wait times reasonable. Taller buildings mean each shaft's elevator spends more time travelling, i.e. less time being available.
It's really rough in convention center hotels when a huge convention comes to town a lot of the time it's practically impossible to get an elevator down from the middle floors because it's already full from the floors above you.
My examples understate the real life problem though.
This missing factor is that it also costs more shaft time to serve a higher floor with a longer travel distance than it does a lower floor with a shorter travel distance. So in the simple elevator case, people from floor one hundred are going to be spending more time in the shaft than people from floor ten.
Still not exponential, but cubic-ish growth puts a hard limit on things.
Due to the passengers the rate of travel for an elevator is not constant:
* There's a maximum rate of acceleration and deceleration that people are comfortable with.
* A longer travel distance means more time to speed up / slow down.
* Thus an elevator or two which are dedicated to operate at the longer distance travel that distance at a more effective speed and provide more rapid service.
* Even more importantly, it also cuts down on the number of slow elevator shafts necessary to service floors by allowing them to be stacked.
Say you design a 50 story building and it has one bank of elevators that all run from 1 to 50. What if you wanted to make it twice as high, and have the same elevator capacity for the top half?
You can add another identically sized bank that starts at the ground floor, skips up to 51 and then covers from there to 100.
In the top half of the building you used the same fraction of space for your elevator shafts as you'd used originally. Great! Except the elevator shafts to get there had to go through floors 2-50, and they ate up as much space there as the original elevator bank did. The building has 2x the original volume, but you're spending 3x the space on elevator shafts so you didnt double the useful floor area.
As you try to design taller and taller buildings, the increasing cost of vertical circulation gets worse and worse.
There are effectively two vertical shafts, and the elevator car goes up one and down the other. If the car flipped over as it goes over the top to the other shaft, then what was the floor would become the ceiling. So, tape something to the floor to identify it as it's going up, then wait for that car to come down the other shaft and look at where your identifying paper is.
It does seem pretty obvious that it wouldn't flip over - that seems like an insanely dangerous design.
Most people are going between the ground floor and whatever floor their destination is on, so a shaft with two cars that go 0-50 and 51-100 wouldn't be very useful.
There must be more spiral escalators now. I know there's one in Nordstrom's too.
I'd be interested in why they decided to make the 'track' as complex as they did. The transition nodes are an amazing mechanism but it seems also a likely failure point.
Looks like it will be crazily expensive.
Also, they could have a completely circular horizontal segment to move people through an upper level of a round building - like a stadium...
There you go. Lost so many hours playing this game though.
Source: Myself, working in a high-rise building served by ~20 ThyssenKrupp elevators, 10 of which actually share 5 shafts (they're not the ropeless version though, AFAIK), and the scheduling sucks big time. We got them to informally acknowledge that they're being wiped every night to get around some nasty bugs, so they never learn traffic patterns, but even then it's infuriating to see how crap they are even on a Sunday with the building empty.
I'm guessing those didn't detect if no one got in the car and they still went to all their scheduled floors.
The express lifts remain for too long at the "key" floors to pick up more people. This is probably some energy vs practicality balance that can be adjusted, and that we're very likely guilty of.
The normal lifts will happily depart with nobody inside if you don't sprint to them because the consoles are 25ft away.
You book 2 adjacent floors, you get 2 lifts scheduled for only those floors. So much for saving energy, and also, now 2 lifts are busy instead of 1.
The fancy giant touchscreens are a nightmare: small touch targets, 80% of the screen devoted to static diagrams, the resistive touch film already failed in the hot spots, esp. because you are forced to touch some areas even though you have no choice!! (Choose north or south tower. Oh you chose the south tower but you're in the north one. Sorry you can't do that).
I could go on... but, in a nutshell: these people can do hardware. They fail big time at software, both the scheduling engine and the UI.
But after seeing this, now we are going back and forth on the future of the industry!
I'm sure the TK folks could manage it. The trick is that the 'tilt' of the car on the linear motor would add an additional degree of freedom to deal with. And yet it would be expensive but they seem to have already crossed that bridge :-)
I. Set the stage by showing a trend.
II. Describe two premises and derive a logical conclusion from them.
III. Show a product that not only is the objective answer to the conclusion above but also fits perfectly into the initial narrative.
Interesting technological discussion means criticizing.
Some of the comments here about increasing throughput provide clearer motivation - they do show this super briefly in the video with elevators operating in a cycle, but the benefits didn't really click.
Systems like this have been invented repeatedly throughout the decades, but they never succeeded for one reason or another. The problem isn't in coming up with the concept (or, now, making animated 3D renderings), it's in making it actually work well.
This, incidentally, is why so many of us are so ecstatic about SpaceX -- because they've made something amazing that actually works.
And it has it's first production project in the OVG East Side Tower Berlin (though not yet finished building)
What are the seismic implications - the tolerances on the XY intersections are surely tight.
How the hell would you inspect some of the complex systems.
You would need a sensor car that just roams the tracks measuring tolerance levels - make it a service car that repairmen can be in which has no walls. You'd be more cost effective putting all your large sensor objects in a car as opposed to thousands of them throughout the system
What happens when a rotating intersection piece fails and its the only route a car can take/the piece fails with a car on that portion of track - there is no door/escape/access to the passengers in that scenario.
Also - the building would require extra height to accommodate horizontal passages if the intersection between XY cant happen at ingress/egress points. If they DO happen at such points - what happens when E1 wants to go right and E2 wants to go left. one car need to give way, then get back on track to go... routing conflicts could occur frequently - like the skyway connectors between towers where that Sim takes the car from tower1 to tower2 but he gets out of the middle of a row of doors....
And as mentioned, elevators are already not that cheap - I don think all but the Nakatomi Plaza and Ono Sendai HQ buildings could afford these yet...
Actually - There are buildings with primary structural elements on there external (HSBC Building in Hong Kong, for example) -- So I could see this as an external bolt-on layer to the side of a building - as opposed to a network of tunnels and shafts throughout - but then that eliminates a majority of the horizontal movement, unless it wraps onto two sides of a building...
Plus, in this system all the elevators are centrally scheduled and therefore there won't be any concern about human drivers fouling up the system :)
Apparently traditional linear elevator systems are really limiting as far as what can be accomplished with skyscrapers, to the point that a famous architect sees fully flexible 3D people mover systems inside a building as being the next big innovation to radically change what cities look like.
Still, elevators in general are more like ridesharing than public transit: they move according to the requests they receive in real time (with some central planning influence), rather than on a schedule set by committee months or years prior.
Wonder what tech they use for traction while moving vertically.
http://www.newyorker.com/magazine/2008/04/21/up-and-then-dow...
And it has it's first production project in the OVG East Side Tower Berlin (though not yet finished building)
-the Paternoster (http://www.audioguideportal.de/assets/Foto/thumbnail520x397/...)
The post title is just clickbait for a ThyssenKrupp commercial, plus it only shows animations of these new elevators. Yawn.
not sure there's anything "revolutionary" here.
There's going to be several layers of safeguards, like there are with current elevators.
That would be able to take me up a 100 yard high building in 11 seconds.
Why can't real elevators be like that? Why must the doors move slowly, and wait for 5 seconds before even starting moving? Why does the elevator reach a sluggish top speed, even with very little load? Why when arriving at the destination floor does it take a further 2 or 3 seconds for the door to open?
1- no one has bothered.
2- it's been tried, something terrible happened and now they don't try it anymore.
3- it's been tried, but the extra cost doesn't cover the extra benefit. No one wants to pay for it.
All that said, I was at a hotel once that had, to my mind, perfect acceleration like you describe. No one else cared, but I was blown away by it.
More tellingly: fast closing doors are absolutely a thing, so clearly the safety issues are not insurmountable, but I only see them in more modern/expensive locations. I suspect it's a price grading move and if you wait another century fast-closing doors will be everywhere.
Also, most of the improvement would come from replacing the worst offenders (5-10 second closing times) rather than from shaving 1 second times to 1/2 a second, and there's tons of precedent for the former from the faster-closing 10% or so of existing installations.
Doors that have sensitive rubber edges that can detect hitting something and engage a lock within milliseconds are also trivial.
The two methods combined mean that you have safety for soft human fleshy bits incase either malfunctions, yet the door can still be moving at 15 mph or more and close in 100 milliseconds.
My favorite bit, though, is where they lock the escape hatch from the outside and provide no "alarm will sound" override mechanism. That way if the elevator dies you'll be stuck there for hours until they can get the fire department on the scene.
So my guess is that the slowness has to do with safety.
Doors have to close slowly for safety. There's a limit on how much kinetic energy (7 foot-pounds, from memory) can be in a closing door. Opening can be much faster, and on high-speed elevators, it usually is.
At the destination floor, there's often a delay for precise leveling. Position feedback for leveling is just limit switches until you get to the really fancy high-speed elevators, so it works by shifting to slow speed and inching until the switch trips. Fancier elevators used analog optical systems and inductive systems that gave an analog signal of leveling error. Here's a modern elevator position sensor, with a bar code strip running the height of the shaft.[1]
Precision position and speed control of large motors was really hard in the 20th century.
[1] https://www.cedes.com/documents/produkte/Broschueren/108783e...
As beautifully explained by xkcd[0], "If your building has lots of floors, you need lots of different elevators, since there would be so many people trying to come and go the same time. If you make a building too tall, the whole thing gets taken up by elevators and there's no space for regular rooms."
But if one elevator shaft can have multiple independent cars, suddenly you've got a huge capacity multiplier without the space costs.
The horizontal motion part is cute, but I don't think it will matter nearly as much.
You need a sideways dimension of movement to avoid this problem.
you mean like the elevator system being discussed here?
> But if one elevator shaft can have multiple independent cars, suddenly you've got a huge capacity multiplier without the space costs.
> The horizontal motion part is cute, but I don't think it will matter nearly as much.
My point is: 1. Stacked cars are not independent. 2. Horizontal motion matters a lot.
And/or have horizontal transit floors. You don't need horizontal transit at every floor, just sufficiently frequently to accomplish lateral transfers.
the reason elevators exist is because people cannot easily climb 100+ vertical ft, especially while carrying stuff.
on the other hand, humans are well adapted for horizontal travel - 15mi per day without breaking a sweat. and when they're not, there are movable walkways like in airports.
this whole thing is a solution looking for a problem, IMO. we don't yet live in Matrix-style human incubators with miles of horizontal travel in buildings that are also miles high - it's usually either/or, and not because we've been lacking these revolutionary elevators.
with a lot of cars in uni-directional shafts, is this really an issue?
> all cars must wait each time a car reaches a floor
maybe solved by a 2-lane shaft with a passing lane. very doable with rails or towing cars.
Elevators have a natural height limit, due to the weight of the rope, which is why taller buildings need sky lobbies. You also can't (really) increase the capacity of a single elevator shaft with a traditional rope-based system.
With a linear motor system, more elevators can be added without adding shafts. Part of making that possible is allowing elevators to change shafts.
you can solve this by having the cars on rails and having unidirectional shafts where the cars only travel horizontally at top and bottom. this would allow muliple elevators per shaft.
TLDR: the manufacturer can't do much about the owner not maintaining their product properly.
And back on-topic, googling to find the details instead of just a flashy video, here's Tom Scott on MULTI: https://www.youtube.com/watch?v=kdTsbFS4xmI
[0] https://en.wikipedia.org/wiki/ThyssenKrupp