Description: This short-span through truss extends northwest-southwest across a stream in southern Linn County on Bertram Road about a mile east of Cedar Rapids. A plate located on the bridge's south portal notes that the Wrought Iron Bridge Company (WIBCo) erected the structure, using a design that it had patented in 1876. This bridge was presumably constructed shortly after the patent had been issued. WIBCo's patented design was a variation of a standard Pratt truss configuration, employing double-intersecting counter members radiating outward from the center of the span. WIBCo used this unusual Whipple truss configuration on another Linn County bridge, the Upper Paris Bridge, which it constructed in 1879, and on other bridges in the state. The Wrought Iron Bridge Company was established in 1864 and was ultimately absorbed into the American Bridge Company in 1900. It was one of several Ohio companies that provided many of Iowa's that provided many of Iowa's early metal bridges. This early wrought-iron truss features four timber stringer spans at its north approach and is supported by a combination stone/timber substructure. With no alterations of note, the bridge continues to carry intermittent vehicular traffic.
In its extensive dealings with the Wrought Iron Bridge Company in the 1870s, Linn County was simply following a regional trend. In the 1870s, Wrought Iron was one of the largest fabricators in America; its president, David Hammond, distinguished himself as one of the country's most prolific bridge innovators. The period of extensive rural road and bridge construction in the state during the 1870s coincided with the firm's ascendance in the industry, combining to create a booming market for WIBCo's regional sales representatives. The Ohio giant was extremely active in the region at this time. By 1885 WIBCo had installed 21,600 feet of bridges in Iowa, almost equaling the total output of WIBCo across America in its first nine years of business. That year WIBCo's bridges could be found in 41 of the state's 99 counties. The Indian Creek Bridge typifies WIBCo's penchant for the esoteric. Although the company marketed bowstrings and single-intersection Pratt trusses extensively, it also experimented with other forms, such as this double-intersection Pratt. The Indian Creek Bridge is significant as a well-preserved example of an uncommon early wagon truss configuration, built by what was perhaps the most influential bridge building in Iowa in the 1870s
I think Mr. Whipple would just ask you to please don't squeeze the Charmin.
In today's terminology.......Squire Whipple would probably call it a law suit..........lol
If this design is a hybrid of a Pratt and Whipple, wouldn't it make more sense to call it a Pripple Truss? Or Prattple Truss? Maybe Whippratt Truss?
On HistoricBridges.org we made the decision to define this truss bridge type as the "Hammond" truss configuration. Most of the major truss configurations were named after the people who invented them, so continuing this practice with this truss design is logical.
A fascinating story is that although the truss design was patented by David Hammond, there is a Massillon Bridge that appears to have stolen this design: http://www.historicbridges.org/pennsylvania/whitesridge/ I am only aware of this Pennsylvania bridge, the Iowa bridge, and the Indiana bridge as surviving examples of this design. If anyone finds any more, let me know!
Just looked at the Upper Paris (Sutton Road) Bridge, and it is indeed a Whipple truss with double-intersecting diagonals.
There were at least 2 of this rare truss type built in Indiana as well....one of which remains....
Not to be confused with a Whipple truss with diagonals that cross 2 panels, this was a Wrought Iron Bridge Company patented design that extended the counters across 2 panels. It would best be classified as a Pratt variant with the counters being secondary truss members. Apparently the WIBCo. found there to be little benefit from this experiment as only a few of these 1870's spans remain.