660-Ton Pendulum Protects Taiwan’s Tallest Building From Earthquakes

Due to its location in one of the most seismically and volcanically active regions in the world, along the Pacific Ring of Fire, the building must have fairly robust defenses against earthquakes.

The skyscraper was designed by CY Lee & Partners, a local architectural firm, to be flexible enough to withstand earthquakes and typhoons common in Taiwan.

And the cherry on top of the building is a massive steel sphere called a tuned mass damper. It weighs 660 tons and has the power to reduce, or “dampen,” building movements by up to 40 percent, according to the company A+H Tuned Mass Dampers, which helped create the device.

About 18 feet in diameter, the tuned mass damper is made of 41 layers, each nearly 5 inches thick, of solid steel plating that are welded together to form the golden sphere, explains Taipei 101 on its website. It hangs on 92 steel cables, each about 3.5 inches thick and 138 feet long, between the 87th and 92nd floors in the center of the building.

A “bumper ring” at its base helps limit the range of the ball’s back-and-forth movement to approximately 59 inches during extreme typhoon-force winds and powerful earthquakes.

And although tuned mass dampers are found in other buildings around the world, such as the Central Park Tower in New York and the Dublin Spire in Ireland, what makes Taipei 101 unique is that spectators can watch it in action from an indoor public observatory.

Other buildings in Taiwan did not perform as well as Taipei 101 on Wednesday.

More than 100 buildings were damaged across Taiwan, about half of them in Hualien County, CNN reported.

Taiwanese authorities said 70 people were trapped in rock quarries and more than a hundred in road tunnels.

The earthquake killed at least nine people and injured more than 900 others, the Associated Press reported.