Skew Arch Bridge
NBI Information
Location
State: Pennsylvania
County: Blair County
Feature Carried: Huntington, Cambria, & Indiana Turnpike (Abandoned)
Feature Crossed: Incline # 6 of the Allegheny Portage Railroad (Abandoned)
Latitude, Longitude: 40.4531, -78.5429
Toll: On free road
Maintenance Responsibility: National Park Service
Structure Open, Posted, or Closed to Traffic: Open to pedestrians
History
Year Built: 1833
Historical Significance: Bridge is not eligible for the National Register of Historic Places.
Year Reconstructed: 1979
Picture Date: August 9, 2018
Geometry
Lanes on Structure: 0
Lanes under Structure: 0
Skew: Unknown
Number of Main Spans: 1
Main Structure Type: Deck Arch
Main Structure Material: Masonry
Number of Approach Spans: 0
Approach Structure Type: None
Approach Structure Material: None
Condition
Bridge is not on the National Bridge Inventory.
Bridge Information
The historic Skew Arch Bridge sits abandoned in the median of Old Route 22 in Duncansville, PA. However, this bridge was actually vital from 1834 to 1854. During this time, the Alleghany Portage Railroad traveled under the bridge and the Huntington, Cambria and Indiana Turnpike traveled over the bridge. It is actually the only road bridge built along the path of the railroad, and no historic specifications or drawings have been found.
The bridge was skewed to accommodate the bend in the turnpike road. It was difficult for the horse-drawn wagons to make the sharp turn that would have been required to cross the railroad at ninety degrees. The bridge was constructed using broken stone and stone sleepers from the railroad. These stones were perched, fitted, and laid diagonally by hand without mortar. Rectangular stones were cut into an L shape and were placed to reinforce the external corners of the pilasters and walls.
In 1979, the bridge was repaired and stabilized. Nearly the entire exterior of the bridge was repointed. In addition, limited sealing was done and some of the facade was mortared.
References
National Park Service: https://www.nps.gov/alpo/learn/historyculture/the-skew-arch-bridge.htm
National Park Service: http://npshistory.com/brochures/alpo/skew-arch-bridge-2010.pdf
