BRIDGESPOTTING

One of the more prolific constructors of iron truss bridges in the late 1800s was the Wrought Iron Bridge Company of Canton, Ohio. The company constructed at least seven bridges in York County, Pennsylvania, including three through-truss bridges spanning an important date transition, and in various states of preservation. They also constructed at least three prominent through-truss bridges in adjacent Harford County, Maryland, and four prominent through-truss bridges in adjacent Baltimore County, Maryland, during the same timeframe.

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The date transition occurred in about 1892 or 1893, and was made visible through a change in the type of constructor’s plaque used over the portal of the bridge. Prior to the change, the constructor’s plaque displayed the name of the company, and the location of Canton, Ohio, but no date. The date was displayed, instead, on a sort of cast iron medallion, used as a joint cover on crossing bar supports. In York County, this was done on the 1888 York Haven Bridge, and the 1888 Sheep Bridge. On the later bridges, such as the 1898 Bishop Road Bridge, the style of the main constructor’s plaque over the portal had been changed, and the date was included on the plaque.

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What did not change was the type of font used for the date. Certainly stylish at the time, the font on both the earlier and later versions had one quirk that has led to confusion regarding the actual construction dates on several Wrought Iron Bridge Company bridges. The quirk was that the “9” was given a long, curly tail that curved upward to meet the upper part of the number. On the new, clean builder plaques, the design was gorgeous, but after the paint had peeled for a while and the plaque had rusted, the “9s” became difficult to distinguish from the “8s.” This was made worse by the fact that the plaques were placed high above the roadway, so they were difficult to read in normal circumstances. If the end chords framing the portal were slanted, then the plaques were also often angled upward, away from the viewer, making it even more difficult to read.

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These last three conditions happened on the York Haven Bridge, crossing Conewago Creek just before the creek enters the Susquehanna River. The 1898 date of the Bishop Road Bridge is clearly visible on the plaque above the portal, although even on a plaque such as this in good condition, it can be easy to misread the “9” as an “8”. On the Sheep Bridge, the 1889 date is clearly visible on the joint cover plate, but it could also be confused. However, on the York Haven Bridge, where the joint cover is rusted, very high, and slanted upwards, the date 1889 is easily confused as 1888.

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This difference of one year may not be serious on the 1880s bridges, but can cause most serious ripples in the historical documentation for bridges constructed in the 1890s. While researching builder plaques on Wrought Iron Bridge Company bridges for my book Bridgespotting Part 2: A Guide to Even More Bridges that Connect People, Places, and Times, I examined a number of plaques from the Wrought Iron Bridge Company, I wrote a detailed analysis of the effect of the font used for the date on the Nobles Mill Bridge in Harford County, Maryland. The situation here was more complicated, because the original plaque, which showed the actual construction date of 1893, had been severely rusted, and was replaced during a recent renovation with a new plaque. The problem is that the renovators misread the date on a photo of the original plaque, and produced two new plaques, one for each portal, providing an incorrect date of 1883, thus making the bridge appear to be 10 years older than it actually is. This 10-year error then became integrated the documentation of the history of the surrounding Nobles Mill Historic District.

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A more detailed discussion of the unusual errors is provided in Chapter 2 of my book, Bridgespotting Part 2: A Guide to Even More Bridges that Connect People, Places, and Times.