IA3 West Fork Des Moines River Bridge
Located on State Highway 3 just west of Humboldt, this long-span steel beam bridge spans the West Fork of the Des Moines River. The structure consists of two 140-foot, variable depth plate girders, with two shorter plate girder approach spans, all supported on a 33-degree skew by a concrete substructure. The Des Moines River Bridge was designed in the spring of 1939 by engineers of the Iowa State Highway Commission. Designated Federal Aid Project 73C, the contract for the bridge's construction was let to the E.A. Kramme Company, Inc. Kramme completed the bridge that year for a total cost of almost $60,000. Since that time the bridges has carried vehicular traffic, in unaltered condition.
In the 1930s that state highway commission began using variable depth plate girders for its long-span beam bridges. These typically employed straight girders with arched or curved haunches at the abutments and piers to help withstand the increased shear forces at the bearing points. The girders were rigidly joined to form a continuous-span structure. ISHC built several such beam bridges with spans in excess of 100 feet in the 1930s and 1940s. With a span length of 140 feet, the Des Moines River Bridge in Humboldt County represents the longest example of steel beam bridge design identified by the historic bridge inventory. It is thus distinguished as the ultimate extension of this relatively common structural type [adapted from Johnson 1992]
- Plate girder bridge over West Fork Des Moines River on Iowa Highway 3
- Humboldt County, Iowa
- Replaced by a modern bridge
- Built 1939, replaced 2007
- - E.A. Kramme Co. of Des Moines, Iowa
- Iowa State Highway Commission of Ames, Iowa (Designer)
- Deck plate girder
Length of largest span: 140.1 ft.
Total length: 403.2 ft.
Deck width: 24.0 ft.
- Approximate latitude, longitude
- +42.73190, -94.25790 (decimal degrees)
42°43'55" N, 94°15'28" W (degrees°minutes'seconds")
- Approximate UTM coordinates
- 15/397025/4731810 (zone/easting/northing)
- Quadrangle map:
- Land survey
- Twp. 91 N., R. 29 W., Sec. 3
- Inventory numbers
- IA 28980 (Iowa bridge number)
BH 13668 (Bridgehunter.com ID)
- March 12, 2012: Updated by Luke Harden: Corrected lost date
- July 26, 2011: Updated by Luke Harden: Added description
- July 31, 2010: New Street View added by Jason Smith
- December 1, 2009: Updated by Jason Smith: Updated- replaced in 2009
- September 27, 2007: Posted photo from Jason Smith