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ThyssenKrupp Multi – world’s first rope-free elevator [video]

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Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#131

The elevator industry has been playing around with multi-cab systems for many years. The Otis Odyssey system (1997) [1] had cabs that could move both horizontally and vertically. The cabs were more like containers carried vertically in ordinary elevators and slid out sideways for horizontal movement. Otis built a full-sized prototype, but nobody ever ordered one. Otis considered ropeless elevators, but in 1997 it loo…

> Worse, they're on vertical surfaces in the shafts, where maintenance will be difficult.

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.

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#132

My ideal elevator would accelerate at a pleasant 4 m/s^2 and have a jerk not exceeding 4 m/s^3. It would have doors that close instantly when the doorway is clear, and start right away. 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…

If the elevator ascends too fast, riders' ears will pop, and some people, especially those with colds, will experience ear pain. Some high speed elevators (Tapei 101, at least) pressurize the elevator cab so they can control the rate of air pressure change. But that runs the cost way up. 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…

I love that position sensor. It doesn't say how the code on the strip is determined, but I'd like to imagine it's some kind of gold code so the sensor can find the position even if 99% or more of the code is occluded with dust or dirt.

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#133
post #99

The big benefit is that you get more than one elevator per shaft. For skyscrapers the amount of floor space wasted by elevators grows exponentially by the number of 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,…

That's polynomial growth http://www.wolframalpha.com/input/?i=100+*+f+*+ceil(f%2F10)

I deserved that.

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.

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#134

Earlier quoted context omitted.

> That means that all cars must traverse the entire distance 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.

How can you have multiple cars in a single shaft, using the rope system? To what would the second car from the ceiling be hanging on?

> very doable with rails or towing cars.

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#135

Earlier quoted context omitted.

How can you have multiple cars in a single shaft, using the rope system? To what would the second car from the ceiling be hanging on?

> very doable with rails or towing cars.

Ah, right. But then, isn't that what they've done here?

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#137

The follow up video https://www.youtube.com/watch?v=8OBHUZetYIU was a bit more interesting. It shows the mockup system running through a variety of transitions. 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.

It's explained in another video. Those "tracks" are linear motors, with periodic electro magnetic coils.

Looks like it will be crazily expensive.

https://www.youtube.com/watch?v=kdTsbFS4xmI

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#138
post #84

Accelerating and decelerating in line with gravity is a lot more forgiving on the occupants than lateral accelerations. Seems like this would put a big limit on horizontal movement.

True, but I guess that enough value will lie in just being able to put a whole fleet of cabins into a small number of one way shafts. Horizontal travel with people inside is a gimmick, but a very illustrative one. I expect early adopters to overuse it for showing off and later regret it quite a bit, for the reasons you stated.

Actually they say that horizontal movement is critical. Because in the morning when all elevators go up, they need another shaft to return them down and make a loop.

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#139
post #122

The big benefit is that you get more than one elevator per shaft. For skyscrapers the amount of floor space wasted by elevators grows exponentially by the number of 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,…

Perhaps you could just hang two elevators on one set of cables in the same shaft? They will have to move in sync and the range will be cut in half, but the throughput will nearly double during the rush hour. In a tall building could be an acceptable tradeoff.

https://en.wikipedia.org/wiki/Double-deck_elevator is like that, but right on top of each other so the range isn't reduced.

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.

Re: ThyssenKrupp Multi – world’s first rope-free elevator [video]

#140

Earlier quoted context omitted.

In an n floor building, nobody is being transported in n-1 floors.

No one is using 100% of the space in the rest of the building either. Restrooms aren't a waste of space even if they're not constantly filled. Not everything has to be at 100% utilization to be worth the investment.

But as you make a building larger the number of restrooms increases linearly. A building twice the size uses twice the space for restrooms.

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.

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