On the eastern edge of Germany’s Black Forest, a strange structure, an unoccupied skyscraper, dominates the landscape.
It is called TK Elevator Testturm, and at a height of 245 meters, it is one of the tallest buildings in Germany.
The TK Elevator Testturm is one of the tallest buildings in Germany. (Photo: TK Elevator/CNN).
However, the apparent absence of windows suggests that this high-rise does not house offices or luxury apartments. The main purpose of the tower lies hidden within its core: 12 shafts used to test the latest elevator models.
The German elevator manufacturer TK Elevator, which provides elevators for skyscrapers including One World Trade Center in New York City, also has test towers in Atlanta—a 128-meter tall structure—and Zhongshan, China. The tower in Zhongshan, at 247 meters, is nearly three times taller than the Statue of Liberty.
Elevator test towers can be even taller. For example, the H1 Tower built by Japan’s Hitachi Group in Guangzhou, China, stands at 289 meters. This is one of the tallest buildings in the city known for its skyscrapers, and it also ranks among the Top 25 tallest buildings in New York City, as well as being the third tallest tower in Los Angeles.
The 245-meter elevator test tower in Rottweil, Germany. (Photo: TK Elevator/CNN).
Tomio Pihkala, Chief Technology Officer at Finnish elevator manufacturer Kone, stated that elevator test towers are “like a test track for a Formula 1 racing team.” According to him, “the primary and most important reason for the existence of test towers is to verify certain safety functions that can only be tested in a real-world environment.”
Simulating Operating Conditions
Kone, which installed elevators at Taipei 101 (formerly the tallest building in the world from 2004 to 2010) and The Shard in London, opened its first test tower in Hyvinkää, Finland, in 1967. Since then, the company has built four more test towers, with the tallest completed in 2015 in Songshan, China, at a height of 235 meters.
Aerial view of the Hitachi H1 tower, one of the tallest elevator test towers in the world, located in Guangzhou, China. (Photo: Getty Images).
Mr. Pihkala remarked, “In test towers, we enhance the real operating conditions of the elevators, without the presence of regular users. This is also a great place to verify the quality, comfort, and reliability of the elevators.”
Among the safety tests is a free-fall simulation: “This isn’t a real elevator, but a load equivalent… and that’s when the emergency brake system and safety devices must activate to stop the elevator safely, so no one inside gets hurt,” Mr. Pihkala explained.
The reason some test towers are so tall is that most modern elevators are too fast for the height of the test tower to be sufficient. “With faster elevators, you need a taller test tower,” Mr. Pihkala explained. “High-speed elevators move at more than 9 meters per second, and to test such elevators, you need enough space to accelerate to maximum speed and then decelerate.”
Going Underground
However, building a test tower that reaches into the sky is not the only option. In fact, the longest elevator test facility in the world is located underground. Situated in Tytyri, Finland, it is part of an active limestone mine and reaches a depth of nearly 350 meters.
Kone’s elevator test facility in Tytyri, Finland, reaches a depth of nearly 350 meters underground. (Photo: TK Elevator/CNN).
“This is unique in our industry,” Mr. Pihkala said about this facility. “We have secured agreements to use some deep mines, allowing us to test elevators suitable for buildings up to one kilometer tall.”
At this site, elevators can be tested at speeds of up to 19 m/s, and free-fall tests show that an elevator frame weighing nearly 1,000 kg can reach close to 26 m/s. Overall, the mine has 11 elevator shafts with a total length of nearly 1.6 km.
One of TK Elevator’s test towers in Atlanta, Georgia, USA. (Photo: TK Elevator/CNN).
Like all skyscrapers, elevator towers must withstand strong winds that can cause swaying and affect testing conditions. For this reason, some of them are equipped with mass dampers—large pendulums that counteract vibrations caused by severe weather or even earthquakes.
A Tourist Attraction
The design of the Rottweil tower features an exterior made of fiberglass, giving the building a sleek, opaque appearance. According to TK Elevator, in addition to protecting the building from solar radiation and wind, the façade also helps the building become a local architectural landmark.
The tower has become a tourist attraction since its opening in 2017 and even hosts an annual “stair climbing” competition that attracts over 1,000 participants. However, most visitors come to enjoy the views from Germany’s highest observation deck, which offers unobstructed views of the Black Forest.
