These days elevators can carry you up 500 meters (that's nearly a third of a mile) in one go. But the sheer weight of the steel cable that hoists them prevents elevators from going any higher in a single run. The key to revolutionizing high-rise design will be the development of a super-light, super-strong hoisting cable. New Scientist reports.
In Dubai’s Burj Khalifa tower, currently the world's tallest building at 828 meters, people have to switch elevators to go above the 500-meter mark. Kingdom Tower in Jeddah, Saudi Arabia, is due to top out above 1 kilometer in 2019.
With at least 20 skyscrapers over 500 meters high expected in the coming years, Kone Corporation in Finland has been engineering ways to move people up and down a kilometer in convenient, less energy-intensive ways. Last month, they unveiled UltraRope (pictured), which gets elevators to heights of 1 kilometer:
- Instead of interwound steel thick ropes or cables (called hawsers), Kone's hoisting line comprises four carbon-fiber tapes sealed in transparent plastic about 4 centimeters wide and 4 millimeters thick. (Looks more like a belt or a ruler than rope.)
- UltraRope beats steel for tensile strength but weighs only one-seventh as much. And it will last twice as long as steel.
- Simulating its use in a 640-meter-high building, Kone found that the elevator used 11 percent less electrical power than with a steel-cabled version.
- With its special coating, no lubrication is required to maintain it.
The material has been tested in a 333-meter-deep mineshaft since 2004. As well as repeatedly heating and cooling it to tropical and arctic temperatures to accelerate the ageing process, they also tested its fire resistance and the effect that tools dropped down a lift shaft could have on it. UltraRope has now passed all European Union and U.S. certification tests, the company says.
With 200,000 people moving to, or being born into, urbanized environments every day, building upwards in megacities might be a valid solution.
Correction: an earlier version included incorrect conversions.