Concrete curved-chord through girder bridge

A concrete curved-chord through girder bridge, sometimes known as a camelback bridge,[2][i] is a type of concrete bridge most common in the U.S. state of Michigan and the Canadian province of Ontario.[1] C.V. Dewart, the first professional bridge engineer of the Michigan State Highway Department, designed the type.[3] By the early 1920s, the Michigan State Highway Department had produced standardized designs for these bridges in lengths of 50, 60, 70, 75 and 90 feet.[1] The first such bridge in Michigan was built in 1922 over the Raisin River at Tecumseh. By the end of the decade, the design fell out of favor since it could not be widened to handle increasing traffic.[4]

The first camelback bridge in Michigan over the Raisin River near Tecumseh
The three-span US 12–St. Joseph River Bridge in Mottville, Michigan, the longest remaining camelback bridge in the state[1]
Looking down the length of the Ten Curves Road–Manistique River Bridge

As of 2012, the longest surviving example in Michigan is the three-span, 270-foot-long (82 m) US 12–St. Joseph River Bridge, built in 1922 in Mottville.[1]

List of bridges edit

Notes edit

  1. ^ The term 'camelback' is more commonly applied to a steel Parker truss with five segments.

References edit

  1. ^ a b c d Staff. "US-12 St. Joseph River Bridge". State Historic Preservation Office. Michigan State Housing Development Authority. Archived from the original on December 24, 2012. Retrieved August 30, 2012.
  2. ^ "Historic Indian River bridge to be no more". Petoskey News-Review. October 25, 2011. Archived from the original on January 31, 2013. Retrieved August 31, 2012.
  3. ^ "Overview: M-32 Spur Bridge". Michigan Department of Transportation. Retrieved August 31, 2012.
  4. ^ "Wadhams Rd. / Pine River". Historic Bridges. Michigan Department of Transportation. Retrieved August 31, 2012.