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.[6] 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 seven kilometres (4.3 miles) northeast of Tokyo Station. Sumida Aquarium is in the Tokyo Solamachi complex.
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.[10] There are observatories at 350 m (1,150 ft), with a capacity of up to 2,000 people, and 450 m (1,480 ft), with a capacity of 900 people.[11] 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.[12]
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.[13] According to the designers, the dampers can absorb 50 percent of the energy from an earthquake.[14][15]
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).[16]
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.[17]
The cross-section of the tower forms an equilateral triangle on the ground, gradually rounding to become circular at 320 m elevation.
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, "Tokyo sky tree"), Tōkyō Edo Tawā (東京EDOタワー, "Tokyo Edo tower"), Raijingu Tawā (ライジングタワー, "Rising tower"), Mirai Tawā (みらいタワー, "Tower of the future"), Yumemi Yagura (ゆめみやぐら, "Dream lookout"), Raijingu Īsuto Tawā (ライジングイーストタワー, "Rising east tower"). 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".[18]
The height of 634 m (2,080 ft) 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.[19]
30 July 2010: The tower topped 400 m, reaching a height of 413 m (1,355 ft).[27]
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.[citation needed]
23 October 2010: The tower reached a height of 497 m (1,631 ft), 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.[28][29]
1 December 2010: The tower topped the 500 m (1,600 ft) mark and reached a height of 511 m (1,677 ft), beating Taipei 101 (509 m (1,670 ft)). A lightning conductor and two tuned mass dampers were docked to the gain tower, which was gradually lifted within the central shaft.[30]
1 March 2011: The tower topped the 600 m (1,969 ft) mark and reached a height of 602 m (1,975 ft), surpassing Canton Tower and becoming the world's tallest tower.[32][33]
12 March 2011: The tower reached a height of 625 m (2,051 ft). 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 (2,080 ft) at 1:34 pm JST.[34]
23 May 2011: Dismantling four tower cranes continues until mid-July.[35]
7 June 2011: Announced public opening date of Tokyo Skytree Town and entrance fee (Adults: 2,000 yen to 350 m (1,150 ft) level; extra 1,000 yen to 450 m (1,480 ft) level) to observation floors.[36]
17 November 2011: Guinness World Records certified the Tokyo Skytree as the tallest free-standing tower.[37]
2 March 2012: A ceremony was held to celebrate the completion with a kannushi priest and 70 people from Tobu Group, construction, broadcasting and other companies.[41][42]
6 March 2012: First Light-up during the Tokyo Hotaru Festival
16 January 2013: Snow falling from the tower knocked a hole in the roof of a nearby house. No one was reported injured.[45]
13 May 2013: Tokyo MX continued transmission from Tokyo Skytree and stopped transmission from Tokyo Tower with a gradual decrease in power since 12 November 2012.[46]
31 May 2013: On 9:00 a.m., formal transmission of broadcast in channel 1 to 8, except 3, start from Tokyo Skytree after number of test transmission with off for minutes to hours from Tokyo Tower since 22 December 2012.
22 May 2022: the 10th anniversary of the opening of Tokyo Skytree was celebrated with Kabuki by Ichikawa Ebizo XI who performed a signature technique called the "nirami" glare on a special stage atop of the tower.[47]
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.[48] 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.[49]
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.[50]
^高さ610メートル電波塔「スカイツリー」本体が地上に姿 [The height of 610 meter radio wave tower, "Skytree", the main body of tower appeared on the ground]. Sankei Shimbun (in Japanese). Tokyo. Archived from the original on 9 April 2009. Retrieved 28 July 2009.
^"東京スカイーツリーの最高高さを634mに決定しました。" [Maximum height of Tokyo Skytree to be 634 m] (PDF) (in Japanese). Tokyo: Tobu Railway and Tobu Tower Skytree. Archived from the original(PDF) on 16 October 2009. Retrieved 16 October 2009.
^総重量は約100トン。制振装置が塔体の最頂部へ [Total weight 100 ton, TMD placed on tower tip.] (in Japanese). Blog from construction site, Obayashi Corporation. 25 November 2010. Archived from the original on 16 July 2011. Retrieved 25 November 2010.
^世界一ツリー604メートル到達 東京スカイツリー [Tokyo Skytree reaches 604 m] (in Japanese). Nikkei Inc. 2 March 2011. Archived from the original on 6 March 2011. Retrieved 3 March 2011.
^東京スカイツリータウンの事業概要が決定しました [Decided the business outline of Tokyo Sky Tree Town] (PDF) (in Japanese). Tokyo Skytree Town. 7 June 2011. Archived(PDF) from the original on 26 June 2011. Retrieved 8 June 2011.
^東京スカイツリーで竣工式 [Completion ceremony for Tokyo Skytree] (in Japanese). Tokyo. NHK TV. Archived from the original on 2 March 2012. Retrieved 2 March 2012.
^10月1日、東京スカイツリーから放送開始 [Start broadcasting from Tokyo Skytree on 1 October 2012] (PDF) (in Japanese). Tokyo MX. 27 September 2012. Archived from the original(PDF) on 4 March 2016. Retrieved 2 June 2013.
