Tokyo Skytree (東京スカイツリー), also written as Tokyo Sky Tree, is a broadcasting and observation tower, located in Sumida, Tokyo, Japan. It is the tallest tower in Japan since opening in 2012, and reached its full height of 634 m in early 2011, making it the tallest tower in the world, displacing the Canton Tower, and the third tallest structure in the world (behind Merdeka 118 (678.9 m) and Burj Khalifa (829.8 m or 2,722 ft)). The tower is the primary television and radio broadcast site for the Kantō region; the older Tokyo Tower no longer gives complete digital terrestrial television broadcasting coverage because it is surrounded by high-rise buildings. Skytree was completed on Leap Day, 29 February 2012, with the tower opening to the public on 22 May 2012. The tower is the centrepiece of a large commercial development funded by Tobu Railway (which owns the complex) and a group of six terrestrial broadcasters headed by NHK. Trains stop at the adjacent Tokyo Skytree Station and nearby Oshiage Station. The complex is 7 km northeast of Tokyo Station. Sumida Aquarium is in the Tokyo Solamachi complex.

Design

The tower's design was published on 24 November 2006, based on the following three concepts: The base of the tower has a structure similar to a tripod; from a height of about 350 m and above, the tower's structure is cylindrical to offer panoramic views of the river and the city. There are observatories at 350 m, with a capacity of up to 2,000 people, and 450 m, with a capacity of 900 people. The upper observatory features a spiral, glass-covered skywalk in which visitors ascend the last 5 metres to the highest point at the upper platform. A section of glass flooring gives visitors a direct downward view of the streets below.

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 for the first 125 metres above ground. From there until 375 metres the pillar is attached to the tower frame with oil dampers, which act as cushions during an earthquake. Additional resilience is achieved through an "added mass control mechanism" (or tuned mass damper) – a damping system which, in the event of an earthquake, moves out of step with the building's structure, to keep the centre of gravity as central as possible to the tower's base. According to the designers, the dampers can absorb 50 percent of the energy from an earthquake.

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).

Illumination

The illumination design was published on 16 October 2009. Two illumination patterns alternate daily. One is the sky blue Iki (chic, stylish), and the other is the purple Miyabi (elegance, refinement). The tower is illuminated using LEDs.

Naming and height

From October to November 2007, suggestions were collected from the general public for the name to be given to the tower. On 19 March 2008, a committee chose six final candidate names: Tōkyō Sukaitsurī (東京スカイツリー), Tōkyō Edo Tawā (東京EDOタワー), Raijingu Tawā (ライジングタワー), Mirai Tawā (みらいタワー), Yumemi Yagura (ゆめみやぐら), Raijingu Īsuto Tawā (ライジングイーストタワー). The official name was decided in a nationwide vote, and was announced on 10 June 2008 as "Tokyo Skytree". The name received around 33,000 votes (30%) out of 110,000 cast, with the second most popular name being "Tokyo Edo Tower". The height of 634 m was selected to be easily remembered. The figures 6 (mu), 3 (sa), 4 (shi) stand for "Musashi", an old name for the region where the Tokyo Skytree stands.

Broadcasting use

Tokyo Skytree is used as a radio/television broadcast and communications tower.

Television broadcasters

Radio broadcasters

Timeline

2008

2009

2010

2011

2012

2013

2022

Opening

As the Skytree's opening approached, people reportedly waited in line for a week to get tickets. By the opening, trips up the tower were fully booked for the first two months of operation. The opening day drew a crowd of tens of thousands, despite rainy conditions which blocked the view from the tower's observation deck. Strong winds also forced two elevators to be shut down, leaving some visitors briefly stranded on the observation deck. According to Tobu, 1.6 million people visited Skytree in its first week. Local residents reported that the influx of visitors disturbed the peace of their community and had, so far, generated little economic benefit for the local area.

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