Rating:
3 votes

Adair Viaduct

Photos 

Overview

Photos taken November 2006 by Chris Light

BH Photo #109126

Map 

Street View 

Description 

The Rock Island Railroad provided a vital transportation link for Adair, the county seat of Adair County, as it passed through the town. Jesse James knew that, and chose Adair to conduct the first moving train robbery near this location in 1873.

Increasingly heavy rail traffic throughout the turn of the century snarled street traffic and created a dangerous at-grade crossing. In 1908 the county erected an overpass near the spot of James' train robbery. By the early 1920s increasingly heavy traffic required a larger more substantial replacement overpass. In 1923 the Iowa State Highway Commission (ISHC) designed an immense concrete viaduct for the crossing and in May of that year, the Adair County Board of Supervisors awarded a contract to build the Adair Viaduct to the Federal Bridge Company for $42,263.00. The Des Moines contractors began excavating for the concrete substructure soon thereafter; by June 1924 the bridge was ceremoniously opened to traffic, "with the usual accompaniment of music, speeches, and motion pictures," the highway commission reported. After the hubbub of the dedication ceremony died down, the Adair Viaduct functioned as a regionally imported railroad overpass. It remains in use today in essentially unaltered condition.

The Adair Viaduct crossing the Rock Island rail line provided an important entrance to the town from the south. Jesse James notwithstanding, the true significance of this handsomely proportioned structure is technological and aesthetic. Despite an oft-stated preference for concrete for highway bridges, ISHC designed steel trusses for its medium- and long-span structures. As a result, most of Iowa's concrete arches feature relatively short spans and filled spandrel configurations. Less than ten open spandrel arches have been identified by the state historic bridge inventory, of which the Adair structure is a distinguished example. The viaduct is also noteworthy for its aesthetic handling. ISHC rarely embellished its bridges with any architectural treatment, eschewing aesthetics for functionality. With its decorative guardrails and flanking towers, the Adair Viaduct thus marks a rare foray for the state agency into bridge aesthetics. As a regionally important crossing, and a well-preserved example of an uncommon structural type in Iowa - and a site for local lore - the Adair Viaduct is both historically and technologically significant among the state's highway spans. [adapted from Fraser 1992]

Facts 

Overview
Three-span open-spandrel arch bridge over the IAIS Railroad on 5th Street (IA 925) in Adair
Location
Adair, Adair County, Iowa
Status
Open to traffic
History
Built 1923
Builders
- Federal Bridge Co. of Des Moines, Iowa
- Iowa State Highway Commission of Ames, Iowa (Design)
Railroads
- Chicago, Rock Island & Pacific Railroad (RI; CRIP; ROCK)
- Iowa Interstate Railroad (IAIS)
Design
Open-spandrel arch
Dimensions
Length of largest span: 80.1 ft.
Total length: 205.1 ft.
Deck width: 24.0 ft.
Recognition
Posted to the National Register of Historic Places
Approximate latitude, longitude
+41.49683, -94.64333   (decimal degrees)
41°29'49" N, 94°38'36" W   (degrees°minutes'seconds")
Approximate UTM coordinates
15/362834/4595215 (zone/easting/northing)
Quadrangle map:
Adair South
Land survey
T. 77 N., R. 33 W., Sec. 3 (Summit township)
Inventory numbers
IA 60 (Iowa bridge number)
BH 12725 (Bridgehunter.com ID)
Inspection (as of 10/2014)
Deck condition rating: Serious (3 out of 9)
Superstructure condition rating: Poor (4 out of 9)
Substructure condition rating: Fair (5 out of 9)
Appraisal: Structurally deficient
Sufficiency rating: 2.0 (out of 100)
Average daily traffic (as of 2012)
3,910

Update Log 

  • September 14, 2015: New photo from Luke
  • May 6, 2013: Updated by Clark Vance: Added categories "Concrete balustrade"
  • July 3, 2012: Updated by Luke Harden: Added builder
  • July 27, 2011: Updated by Luke Harden: Added description, street view, and photograph
  • September 27, 2007: Posted photos from Chris Light

Related Bridges 

Sources 

Comments 

Adair Viaduct
Posted September 6, 2017, by Billy (jkendic1938 [at] gmail [dot] com)

As of September 2017 , this bridge has been closed over a year. The town said it was being repaired , but it was torn up pretty bad and has sat that way since at least last fall . The concrete railing is falling off and looks in danger of collapse. Trains still go under the bridge daily .