Dewitt Road Bridge

Key Facts

Bridge Name	Facility Carried / Feature Intersected	Location	Structure Type	Construction Date / Builder or Contractor
DeWitt Road Bridge	DeWitt Road (Old Alignment) Over Stony Creek	Merle Beach (Rural): Clinton County, Michigan	Metal Pinned Queenpost Pony Truss, Stationary	1880 By: Unknown

Technical Facts

Structure Length	Bridge Width	Roadway Width	Main Spans	Approach Spans
40 Feet (12.19 Meters)	18 Feet (5.49 Meters)	16 Feet (4.88 Meters)	1	None

This bridge is one of the oldest bridges in Michigan, with a construction date of 1880. This is also the last known remaining pin-connected queenpost truss bridge in Michigan, and is forty feet in length. Clearly, this is a small bridge with great importance. Unfortunately, the bridge sits severely rusted with so much growth on it that it is not difficult to imagine the vines eventually collapsing the bridge. Although the bridge is a privately owned structure today, the bridge however appears to be in its original location, as an old alignment for DeWitt Road. Regardless of who owns the bridge, funding from a government level should be made available to preserve this last vestige of early metal truss bridge construction in Michigan.

Information and Findings From MDOT

his single-span wrought iron bridge crosses Stoney Creek on an abandoned road segment in rural Olive Township. Spanning about 40 feet, the Stoney Creek Bridge is a pin-connected Queenpost pony truss.
The queenpost’s origins are ancient and obscure. Its symmetrical form lent itself naturally to timber roof framing, where the truss was first used in the Middle Ages. Early American carpenters constructed kingpost and queenpost bridges at minor crossings throughout the eastern United States. The technology for these two truss types spread to Michigan with the pioneers in the 18th and 19th centuries. As a result, uncounted timber kingposts and queenposts were built on the region’s early roads. The truss forms remained the same as their construction evolved from the vernacular to the industrial in the 19th century, with the principal changes involving materials used: timber/iron, iron, steel.

All-metal versions were marketed to the counties and townships by bridge fabricators as inexpensive structure types for short-span applications. This relatively narrow span range limited their use, however. As steel beam bridges received widespread acceptance after the turn of the 20th century, erection of kingpost and queenpost trusses declined correspondingly. Kingposts were far more frequently employed than the inherently longer queenposts.

The later truss type was superseded in its all-metal configuration by the three-panel Pratt, which closely resembled he queenpost in all ways except the composition of its verticals. Subsequent attrition has eliminated all of Michigan’s queenposts but this one diminutive span in Clinton County. Apparently built in the 1880s, it is thus technologically significant as the last example of its kind of what was once a mainstay structural type. The Stoney Creek Bridge is today distinguished as a well-preserved, early illustration of small-scale wrought iron truss construction.

Visit MDOT's Historic Bridge Website

About the Martin Road Bridge, From Michigan Historic Sites Online

Narrative Description:

This single-span wrought iron bridge crosses Stoney Creek on an abandoned road segment in rural Olive Township. Spanning about 40 feet, the Stoney Creek Bridge is a pin-connected Queenpost pony truss, with web members comprised as follows: upper chord and inclined end post - two channels with cover and batten plates; lower chord and vertical - two punched rectangular eyebars; and diagonal - two round eyerods with turnbuckles. I-beam floor beams are hung from the lower chord pins by U-bolts and support steel stringers, which carry a timber deck. The truss is supported by concrete abutments with stone masonry wingwalls. The bridge has been superseded by a concrete culvert and now stands abandoned and in deteriorating condition. main span number: 1 main span length: 40.0 structure length: 42.0 roadway width: 16.0 structure width: 18.0

Statement of Significance:

The queenpost's origins are ancient and obscure. Its symmetrical form lent itself naturally to timber roof framing, where the truss was first used in the Middle Ages. Early American carpenters constructed kingpost and queenpost bridges at minor crossings throughout the eastern United States. The technology for these two truss types spread to Michigan with the pioneers in the 18th and 19th centuries. As a result, uncounted timber kingposts and queen posts were built on the region's early roads. The truss forms remained the same as their construction evolved from the vernacular to the industrial in the 19th century, with the principal changes involving materials used: timber, timber/iron, iron, steel. All-metal versions were marketed to the counties and townships by bridge fabricators as inexpensive structure types for short span applications. This relatively narrow span range limited their use, however. As steel beam bridges received widespread acceptance after the turn of the 20th century, erection of kingpost and queenpost trusses declined correspondingly. Kingposts were far more frequently employed than the inherently longer queen posts. The latter truss type was superseded in its all-metal configuration by the three-panel Pratt, which closely resembled the queenpost in all ways except the composition of its verticals. (Pratt verticals act in compression; queenpost verticals in tension.) Subsequent attrition has eliminated all of Michigan's queenposts but this one diminutive span in Clinton County. Apparently built in the 1880s, it is thus technologically significant as the last example of its kind of what was once mainstay structural type. The Stoney Creek Bridge is today distinguished as a well-preserved, early illustration of small-scale wrought iron truss construction.