Staple Bend Tunnel

The Staple Bend Tunnel was constructed from 1828 to 1834. It was the first railroad tunnel and the third tunnel of any kind built in the United States (the first two tunnels were along canals in PA). It was located between Inclined Plane Nos. 1 and 2 of the Allegheny Portage Railroad.

The tunnel is approximately 900 feet long and was cut through solid bedrock using black powder blasting. The tunnel grew about 18 inches per day, with both sides moving toward the center. The middle 600’ is left as bare bedrock, but the first 150’ on each end is lined with cut stone for safety. Each opening was surrounded by a classical facade consisting of four Tuscan pilasters supporting a full entablature (the official word for the moldings and bands which lay horizontally above columns) of ashlar sandstone. This was done to impress travelers and the general public, and was nearly half of the cost of the project. Unfortunately, only the west portal remains intact, as the east portal was repurposed as building supplies.

After the decline of the Pennsylvania Railroad, the tunnel became a popular carriage route. This continued until the Flood of 1889, when flood damage and other concerns made it a less desirable driving spot, although local residence continued to visit the tunnel. In the 1940’s, large water lines and a water vault structure were constructed and used by Bethlehem Steel, and the tunnel was sealed at both ends with concrete-block infill and steel plates. Fortunately, the National Park Service took control in 1994, and restored the tunnel. It opened as part of the Allegheny Portage Railroad National Historic Site in 2001. Along this path, you can still see the cut-stone “sleepers” that once anchored the railroad rails.