Saturday, 17 November 2018
LIFTjournal Logo

Born in the depths

Other lift manufacturers test their installations in towers. Kone tests its new technologies in the (still active) Tytyri mine in Lohja in Finland, just 50 km as the crow flies from Helsinki.

The visitor zone of the Kone test centre has been redesigned. (Photo: © Kone)

The test centre has undergone extensive renovation in the last two years to increase its capacities and be able to test even more elaborate high-rise systems. Workers have hewn over 60 km of roads and paths into the limestone, which today is mined at a depth of 370 m at a continuous temperature of 8° C. It is an unreal location, where time seems to have come to a stop.

What most visitors of the mine museum do not suspect: only a few metres away in the depths of the Tytyri mine, Kone operates one of the most modern tests centres “That was a really clever idea,” according to Antti Hoppaina, Quality Manager in the group’s Research and Development Department. “After all, the shafts had already been dug. All we had to do was use them.”

Number of shafts increased from four to eleven

HandwerkOf course, the company could have also built test towers, like the Hyvinkää research centre or at Kunshan in China. In 2014, the facility here was opened with a height of 236 m and twelve lift shafts. “But the conditions here in Lohja are unique,” said Hoppaina. “The constant microclimate with its low temperature and high humidity is ideal for experiments where our engineers depend on consistent conditions.

“In addition, a test tower is difficult to expand – a system embedded in rock, like Tytyri, by contrast can be. The expansion, during which the number of shafts was increased from four to eleven, took two years. The overall length is 1.16 km. Maximum depth of a shaft: about 200 m. In this connection, four shafts were designed for low and medium-high lifts, seven lifts for high and the highest lifts. This shows what is intended.

Deep shafts for the highest buildings

“The world’s population is growing, people are moving to cities, their buildings are getting higher and increasingly large traffic flows have to be managed,” said Kone Technology Director Tomio Pihkala, outlining the situation. We are developing solutions for this, which we can test to the limits under realistic conditions.”

An example is the UltraRope, a high performance belt for lifts with polyurethane-clad carbon fibre strands, which at conveyance heights of 200 m and more can replace conventional steel ropes and from conveyance heights of 500 m actually must replace them. For example, in the 1007 m Jeddah Tower.

There the world’s fastest double-decker lifts will travel at 10 m/s (36 km/h) from 2019 and at the same time overcome the previously unparalleled conveyance height of 660 m – a two-fold record. “Previously, a 500 m conveyance height was the limit and passengers had to change. Now, we can overcome 1000 m non-stop if necessary,” said Pihkala.

Testing very specific lift configurations

HandwerkThe tests in Tytyri provided the foundation for this. The engineers tested the long-term stress, temperature and friction characteristics and much more of the conveying belts exhaustively in the mine. Specific structural projects are also prepared in Tytyri.

The latest example: at 528 m the future highest tower in Peking, the China Zun. Seventy-nine lifts and twenty-one double-decker lifts are to be installed, of which eleven with UltraRope high performance straps. “Tytyri is ideal for this, because we have the capacity and option to test very specific lift configurations,” said Pihkala.

Tytyri itself was set up in response to the height compulsion of architects and investors. In the 1970s, Kone acquired the European branches of Westinghouse to which the Australian EPL was added in the 1990s. “We became an actor in the high-rise segment with these two acquisitions: in new construction and maintenance. And that’s why we need completely new test options,” explained quality expert Antti Hoppaina.

Nothing that is not tested

The “normal” test mode comes on top of the work on the prestige projects: a lot of relatively unspectacular work, which ensures that large and small lifts worldwide run smoothly. “This is a very wide-ranging programme,” said Hoppaina. “We conduct comfort tests where we measure noise development and vibrations of lifts. Then we have trials to test new components. And then there are of course acceleration tests with drives, which we continuously further develop.”

HandwerkThis includes the testing of brake systems, which is anything but “normal.” Anyone who has been at a free-fall test – of course, not in the car – who has experienced the enormous forces that arise when the car accelerates up to 26 m/s (93.6 km/h) before being brought abruptly back down to zero a few metres from the bottom of the shaft pit, will never forget the experience.

“That is definitely the most extreme thing we do here and of course the high point of the tours,” revealed Technology Director Pihkala. It is mainly customers who get access to the redesigned visitor area of the test grounds. Almost 1,500 guests are expected in 2017.

What really interests men

What question is asked most frequently? “How fast do the fastest lifts travel,” said Pihkala. “For men in particular, that is obviously an important question,” he added and laughed.

Things do actually move very fast in the shafts. The cars travel at up to 19 m/s. That is equivalent to five to six storeys a second. Or 68.4 km/h. “These are the stress tests for the technology with which we explore the limits of what is technically feasible, but with which we also want to optimise the aerodynamics of the car,” said Pihkala. In addition, the simulation programmes study how speeds and pressure changes affect the human body.

Intelligent systems for lift and user control

Nevertheless, it is (currently) rather unlikely that users will in future be brought to their flat or office at such a speed. “At such high speeds, especially at great heights, we would have to equip the cars with systems for pressure compensation to prevent users getting earache,” noted Pihkala. “That would be rather expensive and therefore it would make sense to stop at 10 m/s.”

HandwerkYou can also see that maximum speed is not the measure of all things from London’s Leadenhall Building. The lifts there “just” travel 8 m/s (28.8 km/h) and nevertheless only need 30 seconds for a maximum 225 m conveyance height.

“To ensure that users make fast progress, planners rely on connections without changing, such as those made possible by the UltraRope, and intelligent systems for lift and user control. Such systems, which Kone also provides as people-flow intelligence solutions, are likewise tested in Tytyri. But that is another fascinating story.

nach oben