Builder Obayashi, which recently announced plans for a space elevator to start services by 2050, declared the Sky Tree complete. While the world’s tallest building remains the Burj Khalifa in Dubai at 829 meters (2,720 feet), the Sky Tree tops the list of the tallest free-standing towers at 634 meters (2,080 feet).
It’s 34 meters taller than the Canton Tower in Guangzhou, China, and nearly twice the height of its predecessor, Tokyo Tower (333 meters). Operated by Tobu Railways and a consortium of media companies, the Sky Tree will serve as a digital terrestrial broadcasting center for Tokyo and the surrounding Kanto region.
The land is known to be relatively unstable and much of the area was reclaimed from Tokyo Bay long ago. But engineers say the Sky Tree will be able to withstand even the strongest of earthquakes. They point to a traditional building technique that was incorporated in the structure. The Sky Tree makes use of a shinbashira, a central column that features in the architecture of Japanese pagodas. The column acts as a stationary pendulum to counterbalance seismic waves, greatly reducing the sway in the surounding structure. Indeed, there are virtually no records of pagodas being toppled in quakes in Japanese history. The tallest wooden tower in the country, the 55-meter (180-foot) pagoda of Toji temple in Kyoto, has been standing firm since 1644.
The Sky Tree’s shinbashira is a hollow concrete tube housing elevators and stairs. It’s structurally separate from the exterior truss but is joined by oil dampers, which help reduce quake shaking.