Reinventing the elevator
Traveling more than 500 meters, or 100-odd floors, in a continuous elevator trip is challenging and doesn’t really make sense using conventional technology. At that point, the weight of the several kilometers of rope needed to hoist the elevator becomes an obstacle. More ropes are needed just to lift the weight of the ropes. In a building this tall, the moving masses of a single elevator hoisted with steel ropes can be some 27,000 kilograms. This is equal to fitting ten off- road vehicles inside the shaft and shifting them along with the elevator. Using KONE UltraRope for hoisting in a similar shaft, the moving masses are roughly 13,000 kilograms, or about the weight of four off-road vehicles.
Limits set by ropes are a major reason why most very tall buildings have sky lobbies served by shuttle elevators from the ground. Separate elevators take people higher from these lobbies in the sky. In the future, KONE UltraRope will enable elevator travel all the way from ground floor to penthouse in a kilometer-high building in one continuous journey.
KONE UltraRope is compatible with all other KONE high-rise solutions so it can be used to replace conventional ropes in old buildings. And with the new technology, the higher you go, the bigger the benefits. For example, the energy savings for a 500-meter elevator journey are around 15 percent versus conventional rope. For an 800-meter journey, the savings are over 40 percent.
In addition to being very light, carbon fiber is strong and durable. It has already revolutionized products in several other industries, including aviation and sporting equipment. At KONE, the idea of creating a carbon fiber rope came in 2004. The first prototypes were made by hand. Actual research and development began a few years later. It wasn’t long before the rope was fitted into a shaft at KONE’s Tytyri high-rise testing laboratory in Southern Finland.
The rope has since been tested thoroughly both in real elevators and in laboratories. Properties like tensile strength, bending lifetime, material aging and the impact of extreme temperatures and humidity are just some of the qualities that have been measured.
No rust, no wear
Unlike steel, carbon fiber does not rust, stretch or wear. The special coating of the new rope makes lubrication unnecessary, meaning environmentally friendlier maintenance. Carbon fiber also resonates at a completely different frequency to most building materials. This means KONE UltraRope is less sensitive to building sway, and elevator downtime during strong winds and storms can be reduced.
While typical high-rise elevator ropes need to be changed at regular intervals – no easy task in a tall building – the new technology enables a rope lifetime twice that of conventional ropes. KONE has also developed a real-time rope condition monitoring system.
The high rise developments are spearheaded at KONE’s Tytyri Elevator R&D center in Lohja, Finland, which incorporates the world’s tallest elevator test tower. The KONE test facility is situated in a limestone mine and extends 333m (1090ft) below the surface of the Earth. Tytyri constitutes the only mineshaft in the world where elevator speeds up to 17 m/s (56 ft/s) can be tested.
Some of the installations using KONE UltraRope technology around the world are:
Jeddah Tower, Jeddah, Saudi Arabia – On going – Year of completion – 2018. Height over 1 KM
KONE Test Tower, Kunshan, China. Completed in 2015. Height 235.6 metres
Sky Tower, Auckland, Newzealand. Modernised in 2015. Height 328 metres.