Tokyo Sky Tree (formerly known as New Tokyo Tower) - the Tallest structure in Japan and the Second tallest structure in the world

The Tokyo Sky Tree, formerly known as New Tokyo Tower, is a broadcasting, restaurant, and observation tower in Sumida, Tokyo, Japan. It has been the tallest artificial structure in Japan since 2010. The tower reached its full height of 634.0 metres (2,080 ft) in March 2011 and the project was completed on 29 February 2012.

The project is being led by Tobu Railway and a group of six terrestrial broadcasters (headed by public broadcaster NHK). Construction of the tower was scheduled to be completed by February 2012, with the public opening on 22 May 2012. The completed structure will be the centrepiece of a massive commercial development located equidistant from Narihirabashi Station and Oshiage Station.

One of Tokyo Sky Tree's main purposes is as a television and radio broadcasting tower. Tokyo's current broadcasting tower, Tokyo Tower, is at 333 m (1,093 ft), and is no longer tall enough to give complete digital terrestrial television broadcasting coverage because it is surrounded by many high-rise buildings.

The Tokyo Sky Tree is the tallest structure in Japan and the second tallest structure in the world, after the Burj Khalifa in Dubai.

Earthquake resistance

The tower also has state-of-the-art seismic proofing, including a central shaft made of reinforced concrete. The main internal pillar is attached to the outer tower structure to 125 meters above ground. From there until 375 meters 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.

Color

The exterior lattice is painted a color officially called "Sky Tree White". This is an original color based on a bluish white Japanese traditional color called aijiro.

Illumination

The illumination design was published on 16 October 2009. Two different illumination patterns (sky blue and purple) will be used, alternately daily. The tower will be illuminated using LED lights.

Naming and height

From 26 October to 25 November 2007, suggestions were collected from the general public for the name to be given to the new tower. On 19 March 2008, a committee chose six final candidate names: Tokyo Edo Tower, Tokyo Sky Tree, Mirai Tree, Yumemi Yagura, Rising East Tower, and Rising Tower, with the official name to be decided in a nationwide vote. On 10 June 2008 the official name of the tower was announced as "Tokyo Sky Tree". 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 have a height that is easy to be remembered. The figures 6 (mu), 3 (sa), 4 (shi) stand for "Musashi" an old name of the region where the Tokyo Sky Tree stands.

Broadcasting use

Tokyo Sky Tree will be used as a communications tower for a number of different media and by numerous companies.

1. NHK General TV / NHK G (GTV)
2. NHK Educational TV / NHK E (ETV)
3. Nippon Television / Nittele (NTV)
4. TV Asahi / Tele-Asa (EX)
5. TBS
6. TV Tokyo / Teleto (TX)
7. Fuji Television (CX)
8. Tokyo Metropolitan Television / Tokyo MX

2008

• 14 July 2008: A ceremony was held at the site to mark the start of construction.

2009

• 6 April 2009: The foundations for the three main legs were completed.
• 7 August 2009: The tower reached a height of 100 m.
• 16 October 2009: The projected height was increased from 610 m to 634 m to make it the highest self-supporting
• 10 November 2009: The tower reached a height of 200 m.

2010

• 16 February 2010: The tower reached a height of 300 m.
• 29 March 2010: The tower reached a height of 338 m, becoming the tallest structure in Japan.
• 24 April 2010: A 1:25 scale model of the Tokyo Sky Tree was unveiled at the Tobu World Square theme park in Nikkō, Tochigi.
• 30 July 2010: The tower topped 400 m, reaching a height of 408 m.
• 11 September 2010: The tower reached 461 m, becoming the tallest structure ever built in Japan, surpassing the dismantled Tsushima Omega tower of 455 m.
• 23 October 2010: The tower reached a height of 497 m, and assembly of the main tower section was completed.
• 20 November 2010: Two tuned mass dampers with a total weight of 100 tons were temporarily placed on the tower tip at 497 m.
• 1 December 2010: The tower topped the 500 m mark and reached a height of 511 m, beating Taipei 101 (509 m). A lightning conductor and two tuned mass dampers were docked to the gain tower, which was gradually lifted within the central shaft.
• 16 December 2010: Ministry of Internal Affairs and Communications approved NHK and five TV key stations in Tokyo's plans to install their broadcasting facilities on the tower.
• 18 December 2010: The transmitting antenna for digital terrestrial television began to be installed.

2011

• 1 March 2011: The tower topped the 600 m mark and reached a height of 604 m, beating Canton Tower (600 m) and becoming the world's tallest tower.
• 12 March 2011: The tower reached a height of 625 m. A full inspection was made, looking for possible damage by the 2011 Tōhoku earthquake and its aftershocks.
• 18 March 2011: The tower reached its final height of 634 m at 1:34 pm JST.
• 23 May 2011: Dismantling four tower cranes one by one, continue till mid-July.
• 7 June 2011: Announced public opening date of Tokyo Sky Tree Town and entrance fee (Adults: 2,000 yen to 350 m level; extra 1,000 yen to 450 m level) to observation floors.
• 17 November 2011: Guinness World Records certified the Tokyo Sky Tree as the tallest free-standing tower.

2012

• 29 February 2012: Tower construction finished. Completion was delayed two months Sourfrom the original schedule because of a shortage of supplies due to the effects of the 2011 Japanese earthquake and tsunami.

Source: wikipedia