Trail: (Satellite, it is still showing the old bridge in 2021)
When the Sylvan Slough Canal was dug in 1871 to provide a tailrace for a powerhouse, it turned the Sylvan Peninsula into an island. Wagon and railroad bridges were built across the canal to provide access to the island. It had some industries including a steel mill.
The railroad bridge is a very rare iron bridge because CB&Q moved the truss from their mainline in Burlington to here to serve as an industrial spur.
According to John Weeks, the wagon bridge was built in 1872. The 1901 date in Bridge Hunter was when the bridge was strengthened. But Bridge Hunter thinks it was replaced in 1901, not just strengthened. It is possible that the piers are from 1872 whereas the superstructure is from 1901. "Built 1901 (Per Arsenal drawing RIA S162-1); Bearing plate repaired 1945, Timber deck replaced by concrete 1953; Floor system repaired 1964; Closed 1969; Converted to pedestrian usage in 1995; Closed 2013, Demolished 2017" [BridgeHunter-wagon]
Was the trail bridge built in 2017 as part of the wagon bridge removal effort?
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| Google Earth, Sep 2017 |
Bridge Hunter generally doesn't document most modern bridges. Normally, it is because they are UCEB (Ugly Concrete Eyesore Bridges). This one they called a MOB. I don't know what that stands for.
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| Retro Quad Cities posted |
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| nathan, Sep 2021 |
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| JohnWeeks-wagon |
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| Public Domain via BridgeHunter-wagon [The building in the background was the Sylvan Steel Works] |
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| Retro Quad Cities posted |
The railroad bridge is now used by the service vehicles of the company that owns the upriver powerhouse.
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| JohnWeeks-railroad "This bridge has a very interesting history. It was built in 1868 in Burlington, Iowa. It was part of one of the very early Mississippi River crossings. The Burlington, Iowa, bridge was being rebuilt, so one 247-foot span was floated up river to Moline. The span had to be cut shorter, so 45 feet was removed. Despite the surgery, the look of the 1868 span was retained." [The building in the background makes John Deere planters.] |
The bridge was originally built in 1868. Metal truss bridges from the 1870s are considered extremely old. Bridges built in the 1860s or earlier are among the oldest surviving metal bridges in the country. Moreover, the bridge is a rare example of a bridge that represents the materials and designs of an early Mississippi River bridge is from the first generation of metal railroad bridges, nearly all of which were lost a few decades after they were built due to a need for stronger railroad bridges which occurred around the turn of the 20th Century. The bridge has cast iron compression members, specifically the top chord (and only the top chord) of the bridge. Any bridge with cast iron members automatically join one of the rarest groups of historic bridges in the country. Most cast iron truss bridges are in the eastern United States, so surviving cast iron bridges in other regions of the United States are regionally even more rare. The end posts and all but the hip verticals of the bridge are another rare type of truss beam, the patented wrought iron Phoenix Column as manufactured by the Phoenix Iron Company. Any bridge with Phoenix Columns is a rare example of its kind and significant for displaying the patented design of column. Phoenix Column bridges are also mostly found in the eastern United States and are less common in this region. The bridge has a Whipple truss configuration. Whipple truss bridges of any kind are uncommon, but are particularly uncommon among surviving railroad bridges.[HistoricBridges-railroad]
John Weeks got the 15th Street Bridge, which was built in 1872 and replaced in 1932, confused with the Republic Steel/Sylvan Island Bridge, which was built in 1901 by the Clinton Bridge & Iron Works.
ReplyDeleteAlso MOB = Mail Order Bridge