A concrete curved-chord through girder bridge, sometimes known as a camelback bridge,[1] is a type of concrete bridge most common in the U.S. state of Michigan and the Canadian province of Ontario.[2] 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.[2] 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 longest surviving example in Michigan is the three-span, 270adj=midNaNadj=mid US 12–St. Joseph River Bridge, built in 1922 in Mottville.[2]