Researchers at the Finnish elevator company Kone have developed a super-strong carbon-fiber rope that can replace the steel cables currently used in elevators around the world, allowing architects to design buildings that would tower over those being built today.
Current elevator heights are limited by the strength of steel cables. The new UltraRope, which is as strong as steel cables but much lighter, could allow elevator shafts to stretch over a kilometer. Currently the tallest building in the world is Dubai’s Burj Khalifa, which measures 2,716 feet (828 km) high.
Due to steel’s weight and inability to bend, the energy required to lift an elevator grows exponentially with height. Most elevator makers consider a 1,640-foot shaft the longest that can be effective. Beyond that, there is concern that steel cables could snap under their own weight. In a shaft that long, up to 75 percent of the energy needed to move an elevator is due to the weight of the cables themselves.
UltraRope is made of four bands of carbon-fiber encased in a custom Epoxy coating. That combination increases friction and reduces the risk of slippage. UltraRope resists wear and abrasion, which can lower the cost of repairs and time out of service. It has twice the lifetime of steel cables, is less sensitive to building sway, and can lead to a 60 percent reduction in moving masses and a 15 percent decline in energy consumption.
The researchers at Kone believe UltraRope will allow architects to design more sustainable urban buildings to meet the needs of growing populations in the future.