The steamy tale behind the composite elevator rope prototype

Elevator World | October 2020 Web Exclusive UltraRope Process

UltraRope Process: UltraRope composite elevator rope

Some of the world’s best ideas originate from the strangest of places. It’s rumored that prolific Nintendo game designer Shigeru Miyamoto developed what became the legendary game Donkey Kong while sitting in the bath. Similar unexpected environments, including the humble Finnish sauna, have also been the source of impressive innovation. Kim Sjodahl, senior vice president of Technology and R&D at composites manufacturer Exel Composites, shares one such story:

It’s claimed that there is almost one sauna for every two people in Finland, so it’s no surprise that they have occasionally been the location for impressive product development and innovation — which was exactly the case for one Finnish elevator engineer. With the growth of megacities such as Tokyo, NYC and Shanghai, high-rise buildings are set to be the future of urbanized living. However, one key element that often restricts the potential height of a building is the distance that an elevator can safely travel before the weight and thickness of the steel rope that holds up the cabin becomes impractical.

In 2007, a KONE elevator engineer saw the potential for the development of a carbon fiber composite rope that could replace steel ropes in elevators that are used in high-rise buildings. In the heat of his sauna, he formed his concept of a . . . product that could take the elevator industry to new heights.

The KONE engineer approached Exel Composites, another Finnish company, which concluded that, while the notion of using composites for elevator ropes was sound, the design needed some development in order to produce a rope that would meet the elevator industry’s stringent requirements. KONE and Exel R&D engineers worked closely together to develop a concept that incorporated flat carbon profiles that would be encased in a soft plastic to form a belt. This was developed into elevator rope prototypes before being rigorously tested and ultimately patented under the product name ‘KONE UltraRope®.

UltraRope weighs around one-seventh of traditional steel elevator rope, meaning it can provide significant energy efficiencies across the elevator mechanical process. It is also more durable and less susceptible to wear and abrasion than its steel-rope counterparts. By using the composite ropes, moving the mass of an elevator with a travel height of 500 m can be reduced by up to 60%. This provides a 15% reduction in energy consumption, as well as opening up opportunities to extend the height of the elevator to additional levels. If the travel height of the elevator were increased to 800 m, the moving mass would be reduced by 90% and the energy consumption lowered by 45%, demonstrating the overall sustainability and energy benefits of this new development.

UltraRope is also less sensitive to a tall building’s sway frequencies, which can be caused by high winds. In strong winds, buildings are designed to sway more, but this causes elevator ropes to sway, as well. This situation often results in the elevators being deemed unsafe, prompting their shutdown until the risk has passed. This new composite rope system also has double the lifetime of a conventional steel elevator rope, meaning it requires less-frequent, easier maintenance. Today, Exel Composites is under contract to supply KONE with UltraRope. The product is manufactured in Finland under strict quality-control standards.

So, it would seem, whether it’s infamous computer games being developed in the bath or composite products having their genesis in a sauna, you just never know where the next great idea will be born.