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Engineers Develop 'Ultrarope' For World's Highest Elevator 248 writes: Halfway up the Shard, London's tallest skyscraper, you are asked to step out of the elevator at the transfer floor, or "sky lobby," a necessary inconvenience in order to reach the upper half of the building, and a symptom of the limits of elevators today. To ascend a mile-high (1.6km) tower using the same technology could necessitate changing elevators as many as 10 times. Elevators traveling distances of more than 500m [1,640 ft] have not been feasible because the weight of the steel cables themselves becomes so great. Now, after nine years of rigorous testing, Kone has released Ultrarope — a material composed of carbon-fiber covered in a friction-proof coating that weighs a seventh of the steel cables, making elevators of up to 1km (0.6 miles) in height feasible to build.

Kone's creation was chosen to be installed in what's destined to become the world's tallest building, the Kingdom Tower in Jeddah, Saudi Arabia. When completed in 2020, the tower will stand a full kilometer in height, and will boast the world's tallest elevator at 660m (2,165ft). A 1km-tall tower may seem staggering, but is this the build-able limit? Most probably not, according to Dr. Sang Dae Kim. "With Kingdom Tower we now have a design that reaches around 1 km in height. Later on, someone will push for 1 mile, and then 2 km," says Kim. He adds that, technically speaking, 2 km might be possible at the current time. Anything higher would require new materials and building techniques.
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Engineers Develop 'Ultrarope' For World's Highest Elevator

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  • by Noah Haders ( 3621429 ) on Tuesday January 27, 2015 @11:09PM (#48920447)

    i would do away with the motor at the top of the shaft, and instead electrify each individual elevator so it has motive power. seems like the best solution to me.

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      You still need a counterweight or else you are lifting the entire mass of the elevator instead of just passengers. That means a cable.

      • by ihtoit ( 3393327 ) on Wednesday January 28, 2015 @12:00AM (#48920725)

        you can build as high as you want as long as you can build a cable long enough to service the elevator. Cable length isn't a problem, the weight of the cable is. In systems such as this very simplified model of a counterweighted elevator [] it's assumed that the rope weighs nothing, therefore the counterweight only needs to weigh 25lb - even taking into account the rope's weight, all other things being equal it balances itself. That's handy, scaling up you only need a 400lb counterweight for a lift rated at MGW: 1600lb (ten persons (800lb) + 800lb car). This arrangement does of course necessitate four times the length of cable as the height of the shaft, and with another shaft-length you can actually mount the motor at the bottom, negating the requirement for a counterweight - the motor only has to overcome the weight of the car through the system, which practically means it's pulling against a quarter of it. For some reason that's not really practical, so in this arrangement you'd have a counterweight one side, top-anchor the other end of the rope and have the motor roll the cable somewhere in between. FWIW when you see an elevator car with four cables, you're not seeing four cables, it's one cable. It's this arrangement of three (strictly, four, but the car pulley can be and often is a twin) pulleys, a counterweight and a top anchor. Other setups have the anchor point actually on the roof of the car, still others have the car and the counterweight on their own bottom pulleys, both ends top-anchored and the motor in the middle sharing rope between essentially two double systems.

        (grew up in a tower where the elevator spent more time stuck between floors than enough, often with me trapped in it. Hearing firefighters clambering around up there to attach car batteries to the brake solenoids so they can lower the car to the ground after eight hours is a terrifying thing for a four year old. Nerd points for spotting the ropes and asking about them when they were fixing the thing, though).

      • by Hadlock ( 143607 )

        With today's ultra capacitors it seems like you could recapture 70% of the energy on the way down again. Maybe more.

    • Vertical maglev? Why hasnt anyone done that before? Wouldnt be hard to make safe either, in case of power loss, hace a locking system on each floor or each foot or something.
    • by Aardpig ( 622459 )

      And how do you handle the counterweight? What's that? You don't actually understand how an elevator works?

      • you wouldn't need a counter weight cuz of the motors in the elevator itself. got questions? yo I'll solve it.

      • by Jeremi ( 14640 )

        And how do you handle the counterweight? What's that? You don't actually understand how an elevator works?

        If your electric motor is powerful enough, you can dispense with the counterweight. It might not be very efficient, but it's possible.

        • I have been down a 2km mineshaft(the shaft is deeper, but they only go down in +/-2km sections) in a 'cage'. There is no counterweight, but the AC winder that drops (yes, 'drops' is the right word) you and hauls you back out is pretty powerful. They account for cable weight and extension because there are rails in the cages and they need precision to match them up. They get about +/- 1cm. Operator skill is important..

          Yes. It is possible even with old style cables, but to get anywhere in a reasonable time, y

    • Why do you suppose they generally never do that?

      • Re: (Score:2, Funny)

        by Dutch Gun ( 899105 )

        All the engineers who actually have to build these devices obviously never had the brilliant flash of insight after a few minutes of thought that our intrepid slashdot armchair engineers had, of course!

    • by gl4ss ( 559668 )

      slower speeds, more noise, more danger, I would imagine.

      btw KONE means MACHINE.

  • by 140Mandak262Jamuna ( 970587 ) on Tuesday January 27, 2015 @11:12PM (#48920473) Journal
    So I guess the space elevator is not coming any time soon.
    • 2km for a building full of usable space like offices and hotels. A space elevator only requires a cable. That said, no, no space elevator any time soon.
    • Instead of a two kilometer tall office building they should build a two kilometer tall railgun. Then design a super aerodynamic, heat-shielded carrier with a late-firing chemical rocket for satellites and spacecraft payloads that can be launched from the rail gun. If there were stability issues (could be tied down with cables, I suppose, like a radio tower) they could build half of it underground, though I don't know how much momentum they'd lose from having to travel the extra distance.
    • by jrumney ( 197329 )
      2km? I'm pretty sure I heard somewhere about an ancient construction technique that can support structures up to 8,848 m.
      • But that isn't vertical construction. Anyone can make a big pile of stuff and I am pretty sure my kids have made a bigger pile of their things.

        Yes I get the reference, and yes I am sarcastic.
    • We'll have the space elevator, just as soon as we find someone who's a bit too rich with a dick that's a bit too small that wants to build a monument to themselves.

  • ... we may have use the 2km long ultra strong ultra light cable to dredge the Saudi economy from the bottom of the Persian Gulf.
  • by fuzzyfuzzyfungus ( 1223518 ) on Tuesday January 27, 2015 @11:24PM (#48920541) Journal
    Does anyone know why they wouldn't sidestep the infeasibility of particularly long cable runs by having the elevator climb the walls of the shaft directly, rather than being raised and lowered on a cable? I imagine that a cable and counterweight arrangement is more energy efficient for shorter runs; but if that isn't an option wouldn't a cog railway style mechanism, with 'track' on one or more walls of the elevator shaft, result in a system where the weight that has to be moved doesn't change at all with the height of the building? There would be some additional weight per unit height from the track structure; but that would be static and connected to the building's frame rather than being forced to support its own weight.

    Too energy intensive? Wears too quickly? Safety breaks infeasible leading to risk of sickening plummet to doom?
    • It's mostly the counterweight issue, which you can resolve by using electric motors in the cars and large battery banks.

      Draw power on the way up, generate power on the way down. There are losses, of course, but it's doable and not terribly inefficient.

      The regulations for battery maintenance make it prohibitively expensive. I think there's only one or two such installations in existence.

      • "It's mostly the counterweight issue, which you can resolve by using electric motors in the cars and large battery banks."

        Cuonterweight is there to avoid the need of hugh power-hungry engines, since they only need to lift the load. Take out the counterweight and you will need to lift the whole load requiring a much bigger engine. Put the engine on the car and then you'll need an even biigger engine (much bigger) to lift its own weight too.

        • Agree, but a hybrid approach is likely the most efficient. Get 50% of the power/braking from the rope and 50% from a cab-mounted motor. Batteries aren't needed; just regenerate into the rails.

          The other interesting challenge is water. Every 200m you need a pressure break because the welds in the pipe reach pressure limits. An extremely tall building needs to deal with these issues cost effectively, and efficiently-- think water treatment every 40 stories to recover grey water, treat potable water, recove

          • Hell, from an IT perspective you reach the limits of multimode fiber risers pretty quickly.

            Yeah, but the lag on the satellite broadband suddenly drops away...

            Actually, if you're building a tower that high anyway, you'd be just as well using it as a pseudo-satellite broadband provider -- the horizon is over 100 km away when you're a kilometre up. You can serve wireless internet to a small country from up there....

    • that was my first thought as well, until someone pointed out that it's not the cable to the motor that's the problem it's the up and over then attached to the counter balance that is the problem.

    • by quenda ( 644621 )

      Such lifts certainly exist, and are used on construction and industrial sites.
      I expect noise, speed, power use and maintenance cost might be areas where cable wins out. []

    • by ihtoit ( 3393327 )

      car weight. Bear in mind you're lifting a deadweight vertically potentially through several hundred feet. That is a LOT of gravity well to overcome. The lighter your car, the better. If your combined car+rope is lighter than car+cable+attached motor for the same shaft, it makes sense to go with the cable and offload the motor to the building that isn't moving.

    • Cog railways are way too slow...

    • I think one of the reasons is that it is possible for fire fighters to manually move the winding drum in the event of a power failure to move the lift car to the nearest floor. Without a drum and cable any rescue attempt during a power loss would require lifting equipment and would involve climbing into the lift shaft to reach the car with all the related falling from height issues.
  • LSM (Score:5, Interesting)

    by jklovanc ( 1603149 ) on Tuesday January 27, 2015 @11:40PM (#48920623)
    • That was a cool article, thanks for the link, this part made me think StarTrek style turbolift:
      from the linked article (emphasis added):

      Flexible configuration: LSM elevators can propel a vehicle in any direction, and cabs can be switched from hoistway to hoistway, enabling the creation of “one-way” hoistways with multiple cabs in each. Modular stators allow the height of the elevator to be customized at installation and extended in the future with minimal disruption. LSM elevators can also ac
  • by localroger ( 258128 ) on Tuesday January 27, 2015 @11:43PM (#48920637) Homepage
    Highest skyscraper is a hell of an expensive way to show your ability to get an erection. How much of the Burj Dubai is even occupied? Or for that matter even the *cough* whatever they're calling it now in NYC which gets a third of its patriotic 1776 feet from a totally nonfuctional dick-waving spire.
    • I went to the top of Burj Dubai* in May last year, and I couldn't see anything that made it look useful for anything other than a tourist platform. If such buildings eventually bring in more tourist dollars than they cost to build, then I suppose they serve their purpose.

      * Does that mean that I mounted Dubai's... oh, let's not go there.

  • Many posts suggest doing away with the cable by putting the motor on the elevator car; but this overlooks the fact that the elevator needs to be connected to a counterweight for efficiency reasons.

    However, here's a thought: you put motors on the elevator *and* the counterweight. As the elevator goes up, the counterweight goes down and uses its motors as generators to partly power the elevator's motors. And vice versa.

    Sure, you're not going to break even due to electrical losses; but it'll be a damn sight be

    • While such an elevator system would use more power one of the inherent abilities of any electric motor system is the ability to use regenerative braking. You'd probably have a bank of super-capacitors in a utility room, when the elevator was going up it would use the capacitor bank and some power from the mains, when it was going down it would refill the capacitors. Even if you had to put the motors on the elevator car itself this shouldn't be an issue as we have centuries of technology (subways, trains,

  • A frictionless cable (as described by the summary) would be practically useless. TFA says the cable has high-friction coating, which makes a lot more sense.
  • Better Way (Score:5, Interesting)

    by Jim Sadler ( 3430529 ) on Wednesday January 28, 2015 @01:47AM (#48921269)
    The RCA building in NYC uses compressed air and the elevator is effectively a dart flying up the shaft. With an accelerometer installed to trip the brake if too rapid a descent occurs there is no need at all for cables.
  • There are examples of cable that are strong enough in long stretches (2.5km), light (~10kg) and have a high break strength. Such as used in a glider winch []. I guess there are extra demands to an elevator.
  • Would a vertical maglev be feasible? ... It would be worth a try. ... However, I guess a handful of buildings becoming to high for our current tried and trusted elevator technology is a luxury problem.

  • Rope and cable for elevators is a century old technology, I'm surprised they aren't using linear motors, standard electric motors or something else for record breaking skyscrapers. I can understand continuing to use cable for normal skyscrapers as it is a tested, widely available and is cheaper due to current production. But when dealing with such immense heights (1km) you would think someone would have the sense to develop something better suited rather then putting a small metal box on the end of a gian

Statistics are no substitute for judgement. -- Henry Clay