The Wrought Iron Bridge Company of Canton, Ohio was one of the most prolific bridge manufacturers during the late 19th century in the United States.
The company specialized in designing bridges for locations throughout much of the Midwest (as well as Canada and Mexico), fabricating the bridge parts and shipping the parts and plans via rail for assembling by local labor at their ultimate destinations.
Today, there are maybe a dozen of the nearly 4,300 spans manufactured and erected in this way by the company that still exist.
The Maple-Foster Bridge over the Huron River near Ann Arbor in southeast Michigan is one of two surviving Wrought Iron Bridge Company spans standing within a few miles of each other.
I wrote about the nearby Delhi Bridge here a couple of years ago, but we recently took another ride out to Ann Arbor so I could take pictures and learn a little more about this similar span on Maple Road just off of the scenic Huron River Road.
The Delhi Bridge was the first one of these two spans to catch my eye years ago because of its head-turning bright orange paint job, while the Foster Bridge wears a little more sedate coating of forest-green paint, which it first wore during the 1940s.
It's also easier to capture a decent image of the Delhi Bridge because there seem to be fewer power wires obstructing views of that span.
These two bridges are among the oldest metal bridges in the state, although it appears that the Foster Bridge may predate the Delhi Bridge by a few years.
The Delhi Mills area was a thriving community with flour, woolen, plaster and saw mills during the mid-to-late 1800s. Early bridges in the area made it easier for residents and those traveling to and from the mills by allowing them a drier way to cross the Huron River, rather than fording the river with their horse-drawn vehicles.
A mill closing next to a mid-1800s wooden bridge in the area moved Washtenaw County to contract with the Wrought Iron Bridge Company of Canton to replace half-dozen spans there with metal truss bridges during the late 1800s. This explains the proximity of the Foster Bridge to its sister bridge at the Delhi rapids.
The Foster Bridge is a pretty typical example of the earliest bridges by the company that display a plaque with an 1876 patent date, but no construction date, and decorative cresting atop the bridge. Based on this fact, one historic bridge site speculates that this bridge may have a construction date closer to 1880, as opposed to the slightly later construction dates I've found assigned to the Delphi Bridge.
Much like the Delphi Bridge, the Foster Bridge faced possible demolition and replacement with a new two-lane bridge in around the turn of this century, but citizen intervention and support led to its rehabilitation in the first decade of the 2000s.
The Foster Bridge had an eroding deck, peeling paint and severe weight limitations before its rehabilitation. Washtenaw County set a 6-ton weight limit for the bridge, meaning that the span could not accommodate larger and heavier traffic like school buses or emergency vehicles, severely limiting its usefulness to its community.
Washtenaw County studied the idea of demolishing the bridge constructing a new two-lane bridge just upstream or downstream of the site. The trouble was that all of the demo and new construction options meant that some residents north of the river in the area might lose part of their properties, and there was also the little matter of a projected bill of $1-$4 million to complete the job.
Area residents prevailed upon the Road Commission to explore the idea of rehabbing the bridge and organized the non-profit Citizens for Foster Bridge Conservancy to raise money to hire a group of consulting engineers to inspect the bridge, test materials, do a load rating analysis and identify rehab options.
The studies proved that the bridge was sound enough, and that it would be far more economical to rehab and strengthen the bridge. The end result was a rehabilitation which strengthened the bridge with structural components like additional tension cables and guard rails to bring it up to modern safety code--an option costing $525,000
The rehab took place over six months in 2003.
Today the bridge has a 20-ton weight limit and could have another century of service life.
Even better, the presence of the old bridge helps maintain the area's rural character and serves as a record of its nineteenth-century history.
Be sure to check out my story, Wrought iron bridge links Michigan and Ohio, to learn more about this area and the two Canton bridges.
Interested in learning more about the history of Michigan's other historic truss bridges? Check out Historical Highway Bridges of Michigan by Charles K. Hyde.
© Dominique King 2015 All rights reserved