|
}} Fallasburg Bridge (alternatively Fallassburgh Bridge) is a span Brown truss covered bridge, erected in 1871 in Vergennes Township, Michigan, United States, north of Lowell on the Flat River. Carrying Covered Bridge Road across the Flat, it is located in the Fallasburg Historical District south of Whites Bridge and Smyrna. It is listed on the National Register of Historic Places, and along with Whites Bridge, Langley Covered Bridge, and Zehnder's Holz Brucke, is one of only three Michigan covered bridges open to vehicle traffic. ==Design== The bridge uses the Brown truss system, a through truss consisting of diagonal compression beams and (optionally) almost vertical tension members (slanting in at the top toward the center of the span). This system was patented by Josiah Brown of Buffalo, New York, in 1857. The Brown truss is similar to the Howe arrangement of "X" bracing and counter bracing, but uses lighter members and less timber. It contains no upright compression members and uses no iron except for bolt connectors at the timber intersections. Builders〔Bresee for this bridge, Bresee and Walker for Whites Bridge, William Holmes for Ada Covered Bridge〕 used the Brown truss successfully in at least four covered bridges in Michigan, three of which (Ada Covered Bridge, Whites Bridge and this one) are still in existence. The Brown truss was thus briefly popular in Michigan but did not gain wide acceptance elsewhere. The bridge currently rests on concrete and fieldstone footings at each end put in place in 1905. As is typical for covered bridges, it is a frame structure with a gabled roof that is covered with creosote shingles. Its construction is of the through-truss type, and the white pine (sourced from Greenville, Michigan) trusses are completely sheathed on the outside with rough pine boards.〔 The floor is wide and long and the bridge has an inside clearance of . The bridge has warning signs on each portal: "$5 fine for riding or driving on this bridge faster than a walk." 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「Fallasburg Bridge」の詳細全文を読む スポンサード リンク
|