At first, the bridge seems to be a typical steel arch bridge in a small Pennsylvania community of Brownsville, located approximately 40 miles south of Pittsburgh, along the Monogahela River. However, instead of tearing down the structure, as it has been described in a textbook fashion by PennDOT, this bridge is due to be rehabilitated.
So what’s so special about Dunlap’s Creek Bridge, an 80-foot long bridge that reminds the author of the Blackfriar’s Road Bridge in London?
The bridge is definitely older than Blackfriar’s Road Bridge. It was built in 1869 and still serves traffic over the River Thames.
This bridge was built much earlier- 1839, to be exact!
Dunlap was the product of Captain Richard Delafield, the person who designed the bridge. The bridge consists of a Howe Lattice deck arch bridge, made of cast iron that was manufactured by Herbertson Foundry in town. Keys and Searight were the contractors for the bridge. The bridge was built 60 years after the first cast iron bridge in the world was constructed at Coalbrookdale, England, the structure that is still standing today. Yet Dunlap set the standard for the following developments:
1. The bridge set the standard for the introduction of the Howe Truss, designed and patented by William Howe in 1840, one year later. It is possible that Howe either influenced Delafield into using this design or used this bridge as a reference for his design.
2. The bridge was used as references for other arch bridges of this fashion, for hundreds of bridges of this type were used for crossings, big and small, in the US and Europe, built between the 1850s and 1900, a fraction of which are still standing today.
The bridge is the first one to be built in the USA, has been listed on the National Register of Historic Places since 1978 and is one of 76 bridges honored internationally for its unique design and historic significance. Now the 1839 bridge, which took three years to build and is the fourth crossing at this site, is scheduled to be rehabilitated. Plans are in the making to strengthen the arches, replace the roadway, and there is a possibility that the encasement installed in the 1920s will be removed, exposing the covered half of the cast iron arch. No details of how the bridge will exactly be restored, but PennDOT is looking at the restoration cost of up to $3.7 million, according to a report from the Post Gazette in Pittsburgh. The plan is to make it more attractive for tourists once the project is completed.
A link with all the information about the bridge and its history can be found here. The Chronicles will keep you updated on the project as it comes.