A skyscraper’s amazing 728 ton stabilising ball

[The Judge]

The enormous steel ball you see in the photos (and the incredible video below) is the world’s largest ‘tuned mass damper’ and sits near the top of the world’s largest completed skyscraper on earth, Taipei 101 in Taiwan. The idea behind a tuned mass damper is quite simple: as a building sways (resulting from high winds, earthquakes etc), its tuned mass damper, essentially a finely tuned and ridiculously heavy pendulum, will move in opposition to the structure’s oscillations and minimise any movement. If that makes no sense, watch the crude gif below.

Due to both the immense size of Taipei 101 and the fact that it sits just over 600 feet from a major fault line, engineers had no choice but to install one of this size at a cost of $4 million. Too heavy to be lifted by crane, the damper was assembled on site and hangs through 4 floors of the skyscraper. it can reduce the building’s movement by up to 40%.

Now for an incredible video. On May 12th, as the horrendous earthquake occurred in China’s Sichuan province, tremors were felt for miles, including in Taipei 101. YouTube user phuaalvin was in the building at the time and said that as the building started to shake, dozens of people ran to the damper to watch it in action. Here’s the video he took…

[Davydave]

Wow! Amazing stuff! That was significant motion for something of that weight.

[westcoastO]

i had this exact same idea like 6 years ago, just got lazy and it never materialized.