Tokyo Skytree

 

Tokyo Skytree (東京スカイツリー, Tōkyō Sukaitsurī^?) is a broadcasting, restaurant, and observation tower in Sumida, Tokyo, Japan. It became the tallest structure in Japan in 2010^[2] and reached its full height of 634.0 metres (2,080 ft) in March 2011, making it the tallest tower in the world, displacing the Canton Tower,^[3][4] and the second tallest structure in the world after Burj Khalifa (829.8 m/2,722 ft).^[5]

Led by Tobu Railway and a group of six terrestrial broadcasters headed by NHK, the tower project forms the centrepiece of a large commercial development equidistant from Tokyo Skytree and Oshiage train stations, 7 km (4.3 mi) north-east of Tokyo station. One of its main purposes is to relay television and radio broadcast signals; Tokyo's current facility, Tokyo Tower with a height of 333 m (1,093 ft), no longer gives complete digital terrestrial television broadcasting coverage because it is surrounded by many high-rise buildings. The project was completed on 29 February 2012, with the tower opening to the public on 22 May 2012.^[6]

 

Design

The design was published on 24 November 2006, based on the following three concepts:

• Fusion of futuristic design and traditional beauty of Japan,
• Catalyst for revitalization of the city,
• Contribution to disaster prevention "Safety and Security".

The base of the tower has a structure similar to a tripod; from a height of about 350 m (1,150 ft) and above, the tower's structure is cylindrical to offer panoramic views of the river and the city.^[7] There are observatories at 350 m (1,150 ft), with a capacity of up to 2000 people, and 450 m (1,480 ft), with a capacity of 900 people.^[8] The upper observatory features a spiral, glass-covered skywalk in which visitors ascend the last 5 meters to the highest point at the upper platform. A section of glass flooring gives visitors a direct downward view of the streets below.^[9]

  Earthquake resistance

The tower has seismic proofing, including a central shaft made of reinforced concrete. The main internal pillar is attached to the outer tower structure 125 meters (410 ft) above ground. From there until 375 meters (1,230 ft) the pillar is attached to the tower frame with oil dampers, which act as cushions during an earthquake. According to the designers, the dampers can absorb 50 percent of the energy from an earthquake.^[10][11]

 Colour

The exterior lattice is painted a colour officially called "Skytree White". This is an original colour based on a bluish white traditional Japanese colour called aijiro (藍白^?).^[12]

 Illumination

The illumination design was published on 16 October 2009. Two illumination patterns Iki (chic, stylish) sky blue and Miyabi (elegance, refinement) purple will be used, alternating daily. The tower is illuminated using LED lights.^[13]