Flat Rock Tunnel

Flat Rock Tunnel
Stereo pair view
Overview
LocationLower Merion, Montgomery County, near Manayunk, Pennsylvania
Coordinates40°02′07″N 75°14′39″W / 40.03528°N 75.24417°W / 40.03528; -75.24417
StatusActive
SystemOriginally Reading Railroad
Now Norfolk Southern
Operation
Work begun1836
Opened1840
Technical
Length940 feet (290 m)
No. of tracksOriginally Double
Now Single
Track gauge4 ft 8+12 in (1,435 mm)

The Flat Rock Tunnel is an active railroad tunnel located on Norfolk Southern's Harrisburg Line near Manayunk, Pennsylvania, United States. The tunnel was built by the Reading Railroad for its line along the Schuylkill River.

Flat Rock Tunnel in Pennsylvania, western portal

Construction of the tunnel started in 1836 and it opened in 1840.[1] In 1858-9 the Flat Rock and Black Rock Tunnels were widened to accommodate the wider rolling stock from the Lebanon Valley Branch. The spacing between the tracks was increased from 4 feet (1.2 m) to 6 feet (1.8 m). The widening of the tunnel was the first project to employ electric detonation of multiple explosive charges.[2]

  1. ^ Treese, Lorett (2003). Railroads of Pennsylvania: fragments of the past in the Keystone landscape. Stackpole Books. p. 41. ISBN 0-8117-2622-3. Retrieved November 7, 2009.
  2. ^ "From Branch Line to Main Line: The Story of the Lebanon Valley Branch" (PDF). The RSME Timetable. Reading Society Model Engineers: 5. May 2007. Archived from the original (PDF) on November 20, 2008. Retrieved November 7, 2009.