This ten panel Whipple truss is a remarkably well preserved and very early surviving example of a Whipple truss that contains the innovative and distinctive details of an early truss bridge built by an obscure bridge company. The bridge is further significant because it contains complex cast iron connection assemblies. Any bridge with cast iron composing structurally important parts is today very rare. The unusual cast iron connection assemblies on this bridge are complex in appearance and creative in design.
The bridge retains amazing historic integrity and also has an extremely high degree of structural integrity with little to no pack rust or section loss present on the bridge.
There are very clear Passaic RM Co. marks on the bridge, identifying the Passaic Rolling Mill Company as one of the metal fabricators for the bridge.
The builder of this bridge, Western Bridge Works was a short lived company formed by two men, one an agent from Toledo, Ohio's Smith Bridge Company. Western Bridge Works apparently built a significant number of bridges during its short period of operation from 1877 to 1885, but little remains today of the company's work. However, a larger, multiple-span example of a bridge similar to the Hardin City Bridge does exist and is the Eveland Bridge, also in Iowa. The Eveland Bridge contains similar cast iron construction details.
In 1989, this bridge was moved from its original location to a location just off the side of a rural road where its sits as a public exhibit.
Information and Findings From Iowa's Historic Bridge Inventory
Discussion of Bridge
In January 1879 the Hardin County Board of Supervisors visited the site of a proposed bridge over the Iowa River at Hardin City. The supervisors conferred with city residents to secure a right-of-way for the structure. After achieving this, the county advertised for competitive bids to design, fabricate and erect the all-iron span. In April 1879 the supervisors awarded a contract to the Western Bridge Company of Ft. Wayne, Indiana. Using wrought iron components produced by the Passaic Rolling Mills of Paterson, New Jersey, Western Bridge fabricated this pin-connected truss and apparently completed its erection that year. The Hardin City Bridge carried traffic until its replacement in the 1980s. After that time, the truss was moved from its original location and re-erected for display on concrete pedestals beside a county road northwest of Steamboat Rock, where it stands today.
Configured as a pin-connected Whipple (or double-intersection Pratt) through truss, the Hardin City Bridge is one of the only eight such structures known to exist in Iowa. First patented by Squire Whipple, bridge engineer and builder from New York, the Whipple truss was a popular choice for long-span crossings between 1850 and 1890. The Whipple truss differed from the more common Pratt in that its diagonal members extended across, not one, but two panels. Although more costly, this variation provided greater lateral support for the diagonals, a critical consideration on deep, long-span trusses. By the turn of the century, Parker and Camelback trusses (Pratt variants with polygonal upper chords) had supplanted the Whipple as the truss of choice for longer span crossings. Accordingly, all of Iowa's extant Whipples date from before that time. With its Whipple web configuration, cast iron hip blocks and bearing shoes and rolled wrought iron components, the Hardin City Bridge typifies wagon truss construction of the late 1870s. Its subsequent move has diminished its locational and historical integrity substantially, but the truss remains a technologically significant, early transportation-related resource [adapted from Crow-Dolby and Fraser 1992].
Bridge Considered Historic By Survey: Yes
Original / Full Size Photos
|A collection of overview and detail photos. This gallery offers photos in the highest available resolution and file size in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer|
Mobile Optimized Photos
|A collection of overview and detail photos. This gallery features data-friendly, fast-loading photos in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer|
Coordinates (Latitude, Longitude):
View Bridge Location In:
© Copyright 2003-2021, HistoricBridges.org. All Rights Reserved. Disclaimer: HistoricBridges.org is a volunteer group of private citizens. HistoricBridges.org is NOT a government agency, does not represent or work with any governmental agencies, nor is it in any way associated with any government agency or any non-profit organization. While we strive for accuracy in our factual content, HistoricBridges.org offers no guarantee of accuracy. Information is provided "as is" without warranty of any kind, either expressed or implied. Information could include technical inaccuracies or errors of omission. Opinions and commentary are the opinions of the respective HistoricBridges.org member who made them and do not necessarily represent the views of anyone else, including any outside photographers whose images may appear on the page in which the commentary appears. HistoricBridges.org does not bear any responsibility for any consequences resulting from the use of this or any other HistoricBridges.org information. Owners and users of bridges have the responsibility of correctly following all applicable laws, rules, and regulations, regardless of any HistoricBridges.org information.