Case Studies / Tokyo Skytree

At 634m the Tokyo Skytree television transmitter and observation tower is the world’s second tallest building. Completed in 2012, the striking quake-resistant giant was designed by Nikken Sekkei and involved more than 100 architects, engineers and planners.

Tokyo Skytree Sensor


The Skytree structure consists of two parts built independently, a steel-frame tower body and a centre column at the core. The centre column stabilises the main structure to reduce swaying during high winds and earthquakes. A five-story pagoda is also stabilised with a centre column (shinbashira). Skytree calls this damping mechanism “shinbashira vibration control.”

Before construction could begin, the designers needed to better understand conditions at an altitude of over 600 metres. They floated a weather balloon to gather extensive wind data, measuring the lateral wind forces that the building would have to withstand. They soon realised that, with very strong winds affecting the building every day, finding a reliable wind sensor to measure wind speed and direction was extremely important.


After extensive research and discussion with our technical team, FT Technologies recommended an FT702LT V22 pipe mount and it was installed on one of the outer walkways. The sensor has so far proved extremely reliable and has withstood the conditions with no need for any maintenance.

FT ultasonic wind sensor used at the top of the Tokyo Skytree in Japan

Image: Nikken Sekkei