- Source: Kawazu-Nanadaru Loop Bridge
The Kawazu-Nanadaru Loop Bridge (河津七滝ループ橋, Kawazu-Nanadaru Rūpu-kyō) is a bridge located in Kawazu, Shizuoka on Japan National Route 414 connecting Numazu to Shimoda, in Japan's Izu Peninsula southwest of Tokyo.
Description
The Kawazu-Nanadaru Loop Bridge is a double spiral bridge with a height of 45 m (148 ft), 80 m (260 ft) in diameter, and a total length of 1,064 m (3,491 ft).
From the direction of Shimoda/Kawazu Station, it goes uphill counterclockwise, and from the direction of Izu/Amagi Tunnel, it goes downhill clockwise.
It loops 720 degrees (or 360 degrees twice). The carriage is one lane on each side, but the speed limit is limited to 40 km (25 mi) per hour to prevent the danger of vehicles passing through this bridge, and overtaking is prohibited. In addition to cars and motorcycles, bicycles can also pass through.
History
In the past, National Route 414 used hairpin turns along the mountain, but it collapsed due to the 1978 Izu Ōshima earthquake and the road on the hillside was cut off. After that, the convenience of passage and the height difference were eliminated, and a construction method was adopted stemming from the lessons learned from landslides caused by the earthquake. In 1981, the Kawazu-Nanadaru Loop Bridge was opened. In the same year, it won the Tanaka Award from the Japan Society of Civil Engineers.
Notes
References
浅井建爾 (2001-11-10). 道と路がわかる辞典 (初版 ed.). NIPPON JITSUGYO PUBLISHING. ISBN 4-534-03315-X.
小川秀夫; 栗栖国安; 田宮徹 (2016-04-10). "河津七滝ループ橋". In 中村純一 編 (ed.). ニッポン絶景ロード100. エイムック. EI Publishing. p. 76. ISBN 978-4-7779-3980-0.
中村純一 編, ed. (2017-04-10). "河津七滝ループ橋". 日本の絶景道100選. エイムック. EI Publishing. p. 76. ISBN 978-4-7779-4572-6.