The invention of the modern elevator in 1853 allowed buildings to rise higher and higher, becoming the statuesque skyscrapers of today. Now, in June 2013, a fresh breakthrough in elevator technology will allow skyscraper to built taller still. The Finnish elevator manufacturer Kone has announced that, after a decade in development at its lab in Lohja (which sits above a 333 meter deep mineshaft that is used as a testing ground), their carbon fiber elevator cable, dubbed UltraRope, is ready for production.

Kingdom Tower

Elevators are currently suspended from steel cables (known as "ropes" in the trade) which are very heavy. In an elevator shaft 500 meters tall the steel ropes represent three quarters of the total moving mass. Though this has an huge impact on power consumption, more importantly every bit of this long cable has to support not only the elevator as well as the travelling electricity and communications lines, but also all of the cable beneath it. The weight of the cable therefore places an enormous strain on the cable itself. This limits the maximum height of elevator shafts to 500 meters; any higher and the steel would come dangerously close to breaking under the load.

UltraRope, on the other hand, isn't made of steel. Kone manufactures the rope by embedding tubes of carbon fiber in epoxy resin and then covers them in a highly friction resistant coating, so as to reduce wear and tear. The final product is a super-light and super-strong (particularly tensile strength) elevator cable that opens up a world of construction opportunity.

elevator shaft 2

Indeed UltraRope is stronger and 90% lighter than its steel equivalent and is therefore capable of raising an elevator more than twice as far, to heights of a kilometer or more. Since the maximum possible height of elevators is one of the main limiting factors on the height of skyscrapers, these should double in height too.  In Jeddah, Saudi Arabia, work is already progressing on the Kingdom Tower, which will be at least one kilometer tall. Now the main constraint on the height of skyscrapers is simply the cost. With a big enough budget it would be possible to build a mile-high tower. As you will see below, the very sky is no longer a limit.


Besides allowing for the construction of far taller buildings, UltraRope also has a number of other advantages. As mentioned above, lighter ropes reduce power consumption. Lighter ropes also make braking an elevator easier and reduce maintenace bills, since they last twice as long as steel cables. Lastly, since carbon fiber resonates at a different frequency than other building materials, carbon ropes will sway less as skyscrapes move in high winds, meaning that elevators won't have to shut down as often due to high winds. All of these advantages mean that the futuristic skylines of concept art are much closer to reality than they once were.

Coruscant skyline

UltraRope doesn't stop with a new generation of soaring skyscrapers, it also has the potential to bring humanity one step closer to the stars. Carbon fiber elevator cables could one day be used to construct a space elevator, a way of ferrying people and equipment into orbit without having to use a highly inefficient rocket. Building a space elevator would involve lowering a 35 thousand kilometer long cable from a satellite in geosynchronous orbit above the Earth's equator, all the while simultaneously deploying another cable attached to a large mass (such as an asteroid) outwards into space to serve as a counterbalance. The competing forces of gravity (stronger at the Earth end) and the outward centripetal force (stronger at the space end) would create a tension that would hold the cable up and keep it stationary over a single position on Earth. Amongst other difficulties, the material required for a space elevator would have to be extraordinarily strong and light. Kone's UltraRope might just be this incredible material.

Space elevator


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