Bridges are a part of everyone’s lives, we walk across them, drive across them, and use them for cover in the rain. But do we ever really stop to appreciate the history of these bridges? My internship this summer focused a lot on historic bridges, especially stone arch bridge, and helped me to appreciate their value in the community.
As part of my internship, I was tasked with updating the National Register of Historic Places Eligibility of masonry arch bridges in PA-SHARE. The masonry arch bridge reevaluation is part of a bigger reevaluation of important bridge types in Pennsylvania using an objective point system to look at the remaining population of bridges that were part of the 2001 Statewide Historic Bridge Inventory.
Mechanicsburg Waterworks Bridge (Resource # 1985RE00750) built in 1899 and located within York County, remains eligible as a part of the 2022 Masonry Arch Bridge Reevaluation and is an example of a stone arch bridge with exceptional overall length. Photo courtesy of PennDOT.
The point system awards points to all bridges with distinctive characteristics, special features, or innovations, as well as early and rare bridges. The system subtracts points for loss of distinctive characteristics or lack of integrity of materials, design, or workmanship. Those bridges that maintain a minimum threshold of points are considered eligible for the National Register. To date, the point system has reevaluated the population of metal truss bridges, concrete arch bridges, concrete slab bridges, and now stone arch bridges.
Goshen Road Bridge (Resource # 1986RE00790) in Delaware County is an example of a masonry arch bridge designed by Theophilus P. Chandler and built by J.A. Morris in 1905, both are important bridge designers, builders, and engineers in Pennsylvania. Photo courtesy of PennDOT.
One of the earliest bridge types in Pennsylvania, stone arch bridges were seen as a more durable solution to timber bridges which were often damaged or destroyed by periodic flooding. Stone arch bridges consist of curved blocks, referred to as the arch ring, placed between two abutments. According to Pennsylvania’s Bridge Technology Context, the arch ring compresses together when carrying a vertical load and the outward thrust from the base of the arch is countered by the abutments.
Stone arch bridges are constructed using false work and earthen fill. Many stone arch bridges are made from local stone with technology originally brought over by early settlers. Stone arches can be found throughout the state, although more common in the southeastern part of Pennsylvania.
The National Register Listed Frankford Avenue Bridge over Pennypacker Creek in Philadelphia (Resource #1986RE00517) was built in 1697 and is known as the oldest surviving roadway bridge in the nation. Photo courtesy of PennDOT.
A subtype of the masonry arch bridge is the brick arch, which uses similar construction methods as stone arch bridges. Brick arches provide layers of brick and mortar alongside a stone frame. Although not as old as stone arch bridges, the use of brick arches dates to the last quarter of the 19th century when improvements in bricks and Portland cement mortar made them easier to construct comparted to stone arches. The reevaluation looked at 34 brick arches which were awarded points under the methodology as an uncommon and distinctive type of arch bridge.
Old Falls Road Trolley Bridge (Resource #2004RE05822) is a pedestrian bridge over a former road and contributes to the National Register Listed Fairmount Park (Resource #1972RE00013). The bridge was determined individually eligible under the masonry arch reevaluation and exhibits offsetting arch ribs which is a characteristic more commonly found on brick arches. This characteristic is a highly important and unusual variation that shows a difficult method of construction employed to provide a skew in an arch bridge.
Both stone and brick arch bridges were reevaluated under the Masonry Bridge Reevaluation and a total of 41 masonry arch bridges were elevated as National Register Eligible as a result of the reevaluation. The methodology and the update in eligibility have been updated in PA-SHARE for each of the bridges in the reevaluation.
In addition, to my projects with historic bridges, I was able to complete multiple site visits alongside SHPO staff which allowed me to visit parts of Pennsylvania I had never seen before. Some of my favorite site visits were to Pithole City in Venango County with the entire SHPO staff. While there, I advanced my working knowledge of archaeology while learning more about a small part of Pennsylvania that was new to me.
I also participated in site visits to places that received Keystone Grants. The Lansdowne Theatre peaked many of the summer interns’ interests as we learned about new and creative methods being taken to restore the building to the Secretary of the Interiors Standards for Rehabilitation.
My favorite site visit was to Lancaster County to the Hans Herr House (PA-SHARE Resource #1970RE00020), a 1719 Mennonite home and meetinghouse. The National Register Listed property is touted as the oldest Mennonite Meeting house still standing in the Western Hemisphere. This site visit was my favorite as I am native to Lancaster County but had never seen the beauty of this house.
The Hans Herr House, the oldest structure and Mennonite meetinghouse in Lancaster County, dating back to 1719. Summer interns participated in a site visit here July 19th visiting Keystone Grant recipients and seeing historic homes in Lancaster. Picture by Rachel Fuhrman.
While having a full-scale replica of a Native longhouse on site to pay homage to the Indigenous Peoples who lived there before, I was most interested in the Mennonite aspects, as a part of my family grew up in the Mennonite Church. I am grateful for these site visits as they expanded my knowledge and love of Pennsylvania’s history.
While my internship this summer comes to an end, I am grateful for the experiences to intern with PennDOT in the SHPO office. I have a new found appreciation of historic bridges and was able to visit many places in the state I had not seen before.
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Today’s guest contributor is Rachel Fuhrman. Rachel is a graduate student at Shippensburg University studying Applied History concentrating in Community History and Preservation. She is local to central Pennsylvania, growing up in Lancaster County. After graduation Rachel is hoping to pursue a career in historic preservation and is hoping to pursue a doctorate’s degree in history.
Rachel,
I read your article regarding stone arch bridges in Pennsylvania. The Warwick Township Historical Society is in possession of such a bridge built in 1804 and variously referred to as Petit’s Bridge or the Eight Arch Bridge. It is listed on the National Register. It is located at Bridge Valley in Warwick Township, Bucks County. I am wondering if you examined it and if you applied your point system to it.
Rachel–Thanks for your informative & well written article! Keep up the great work & best of luck in your future historic preservation endeavors!