Rating:
2 votes

Herring Viaduct

Photos 

Photo taken by Jason Smith

Enlarge

BH Photo #213295

Map 

Facts 

Overview
Cantilevered deck truss bridge over Des Moines River and B Avenue on Kenyon Road in Ft. Dodge
Location
Fort Dodge, Webster County, Iowa
Status
Open to traffic
History
Built 1935; rehabilitated 1977
Builder
- Iowa State Highway Commission of Ames, Iowa (Design)
Design
Cantilevered Warren deck truss with sub-panels
Dimensions
Length of largest span: 136.2 ft.
Total length: 562.0 ft.
Deck width: 32.8 ft.
Also called
Kenyon Road Bridge
Approximate latitude, longitude
+42.49393, -94.18861   (decimal degrees)
42°29'38" N, 94°11'19" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/402326/4705303 (zone/easting/northing)
Quadrangle map:
Fort Dodge South
Inventory numbers
IA 52081 (Iowa bridge number)
BH 49546 (Bridgehunter.com ID)
Inspection (as of 09/2015)
Deck condition rating: Good (7 out of 9)
Superstructure condition rating: Satisfactory (6 out of 9)
Substructure condition rating: Fair (5 out of 9)
Appraisal: Functionally obsolete
Sufficiency rating: 60.2 (out of 100)
Average daily traffic (as of 2015)
7,350

Update Log 

  • June 4, 2015: Updated by Luke: Edited name to local name
  • March 27, 2013: Updated by Fmiser: added "catilevered" to design description
  • March 27, 2013: New photos from John Marvig
  • September 8, 2011: Updated by Jason Smith: The bridge is on Kenyon Road which also carries business route US 20

Sources 

  • Jason Smith - flensburg [dot] bridgehunter [dot] av [at] googlemail [dot] com
  • Historicbridges.org - by Nathan Holth
  • John Marvig - marvigj27 [at] gmail [dot] com
  • Fmiser - fmiser [at] gmail [dot] com
  • Luke
  • IowaHighwayEnds - Info

Comments 

Herring Viaduct
Posted June 4, 2015, by Nathan Holth (webmaster [at] historicbridges [dot] org)

I think this may be continuous vs cantilevered. Its hard to see in the photos to confirm, but the reason is typically, aside from the usual presence of suspended span in a cantilever, a cantilever deck truss would typically not "bear" on the pier at the ends in the traditional sense of the word... what we typically see with a cantilever is that this area is in tension and the end is in fact anchored (often by eyebar chain embedded in the pier)... whereas I think this looks like its just a regular bearing sole plate/masonry plate... but again I can't actually see for sure. Here is an unusually obvious example of cantilever anchorage (Deception Pass Bridge) http://historicbridges.org/washington/deceptionpass/deceptio... although other bridges its not this obvious.

Kenyon Road Bridge
Posted March 27, 2013, by Fmiser (fmiser [at] gmail [dot] com)

I agree with Robert. The clue is the end of the span. And while Jason took some good pictures, none are titled or commented so I'll refer to John Marvig's photos.

"Second pier from west" and "Span" clearly show the arc is not at the end. In other words, the high strength, wide part of the web is above the bents. This is a characteristic of a cantilvered truss.

So I'm changing the design field.

Kenyon Road Bridge
Posted March 27, 2013, by Robert Elder (robertelder1 [at] gmail [dot] com)

I would classify this one as a cantilver deck truss.