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__NOTOC__ The Black Hawk Bridge spans the Mississippi River, joining the town of Lansing, in Allamakee County, Iowa, to rural Crawford County, Wisconsin. It is the northernmost Mississippi River bridge in Iowa. Named for Chief Black Hawk, it is popularly referred to as the "Lansing bridge". It carries Iowa Highway 9 and Wisconsin Highway 82. This riveted cantilever through truss bridge〔http://bridgehunter.com/browse/type/truss/through/cantilevered/〕 has one of the more unusual designs of any Mississippi River bridge. Construction started in 1929 and was completed in 1931. The designer and chief engineer was Melvin B. Stone. The McClintic-Marshall Company of Chicago erected the trusses. The steel came from the Inland Steel Company. The Wisconsin approach has a long causeway over Winneshiek bottoms (sloughs, ponds, and backwaters) before ramping up to the bridge itself. The main shipping channel is on the Iowa side. The Iowa approach is rather abrupt, going from a 25 mph city street straight up a steep ramp onto the bridge. Originally a privately built and operated bridge owned by the Iowa-Wisconsin Bridge Company, it was closed between 1945 and 1957, due to damage from ice damming, and lacking funds to repair the bridge, the company went out of business. The two states acquired the bridge and repaired it. In August 2011 the bridge was once again closed for repairs. The bridge has a sufficiency rating of 39.9%, which mainly reflects its obsolete nature. ==Closure== During an inspection on on August 17, 2011, a crack was found in a floor beam under the bridge deck and the bridge was closed.〔(【引用サイトリンク】work=news.iowadot.gov )〕 The bridge was reopened on August 23, 2011.〔(【引用サイトリンク】work=news.iowadot.gov )〕 Image:Blackhawk Bridge 02.jpg|The Black Hawk Bridge at dusk, looking northeast. Image:Lansing IA April 14 2001.jpg|Aerial view looking north, January 14, 2001, with River at floodstage. (USGS, Upper Midwest Environmental Sciences Center) File:Black Hawk Bridge Lansing 1995.jpg|View from northwest, showing Wisconsin shore, with a barge crossing underneath (Library of Congress/HAER) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Black Hawk Bridge」の詳細全文を読む スポンサード リンク
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