Ikitsuki Bridge
{{Short description|Bridge connecting Ikitsuki to Hirado, Japan}}
{{Infobox bridge
| bridge_name = Ikitsuki Bridge
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| image = Ikitsuki Bridge 1031230.jpg
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| official_name = Ikutsuki Bridge
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| locale = Ikitsuki, Nagasaki
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| design = Continuous truss bridge
| material = Steel
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| width =6.5 metres
| height =18 metres
| mainspan = {{convert|400|m|ft|3}}
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| begin = {{dts|1983}}
| complete = 1991
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| coordinates = {{coord|33.3531|129.4380|display=inline,title}}
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The Ikitsuki Bridge is a continuous truss bridge that connects Ikitsuki to Hirado Island. Completed in 1991, it has a main span of {{convert|400|m|ft|abbr=off|sp=us}}.{{cite book|title=Civil Engineering in Japan, Volumes 29-31|url=https://books.google.com/books?id=iM9VAAAAMAAJ&q=%22Ikitsuki+Bridge%22|year=1990|publisher=Japan Society of Civil Engineers|page=183}} It is the longest continuous truss bridge in the world.{{cite web |url=http://www.aisc.org/Content/ContentGroups/Documents/NSBA5/20_NSBA_LongestSpans.PDF |title=Archived copy |website=www.aisc.org |access-date=22 May 2022 |archive-url=https://web.archive.org/web/20020601114245/http://www.aisc.org/Content/ContentGroups/Documents/NSBA5/20_NSBA_LongestSpans.PDF |archive-date=1 June 2002 |url-status=dead}}
History
The bridge allows automobile access from Ikitsuki to Hirado and the rest of Japan.
In 2009, a crack which seriously damaged the safety of the bridge was found in a diagonal member near an intermediate pier during an inspection for determining points to be annually inspected.{{Cite journal |last=Wang |first=Q. |last2=Nakamura |first2=S. |last3=Okumatsu |first3=T. |last4=Nishikawa |first4=T. |date=2017-02-01 |title=Comprehensive Investigation on the Cause of a Critical Crack Found in a Diagonal Member of a Steel Truss Bridge |url=https://trid.trb.org/View/1459787 |journal=Engineering Structures |volume=132 |issue=0 |issn=0141-0296}} The crack grew to be 20 cm long, and was thought to be caused by wind-induced vibrations.{{update inline|date=May 2025|reason="seriously damaged the safety" -- has this been resolved in the meantime and if so, how? And if not, how was it "serious"?}}