In the winter of 2022 I finally made it out to the famous Tunkhannock Viaduct in Nicholson, PA. Although closer in proximity to me than many of the sights in central and western Pennsylvania, Scranton was just not a place I had either the ability or motivation to visit until recently when Subchat buddy Phil N moved into the area. Phil was nice enough to drive me around to both the viaduct and a variety of signal locations over the course of a day, and although I got about 1000 infrastructure photos we scored a goose egg for actual train movements. Fortunately another Subchat buddy, Kevin Painter, was able to bail me out with not only the usual tour of Reading and Northern equipment at North Reading, but also an introduction to the Colebrookdale Railroad in
Boyertown, PA. You can view the lengthy set of photos
here ( mirror )with the non-signal stuff all the way at the bottom.
The
Tunkhannock Viaduct, sometimes known as the Nicholson Viaduct or Nicholson Bridge due to the community it spans, is typically viewed as a singular achievement of railroad engineering. In actuality it was just the showpiece of a far larger project initiated by the
Delaware, Lackawanna and Western Railroad in 1915. The
Clark's Summit-Hallstead Cutoff (aka the Pennsylvania Cutoff or Nicholson Cutoff) was the second great construction project undertaken by the DL&W shortly before The Great War (the first being the famous
Slateford cutoff in New Jersey that proceeded the PA cutoff by a few years) and replaced over 40 miles of the 1850's era alignment with a brand new, high speed and low grade main line. The viaduct, measuring 2,375 feet in length and 240 feet above the ground at its highest point, was necessary to traverse the Tunkhannock Creek at an elevation sufficient to free the railroad from having to follow the path of existing rivers just north of Scranton.
Fueled by the flush profits transporting premium
home heating coal at the turn of the century, the DL&W had the financial resources to not only reconstruct its greater Pocono region main lines, but also use the era's high tech wonder material, reinforced concrete. It would be the bridge's 167,000 cubic yards of concrete that would make it such an iconic and imposing presence compared to a similar bridge of steel beams.
The bridge consists of 10 spans, 9 piers and 2 abutments, all made from reinforced concrete. At the time of construction it was the largest concrete structure in the world and is likely still one of the largest concrete bridges in the world.
Although still branded Lackawanna, the DL&W Main Line did not survive the 1960 Erie Lackawanna merger with most traffic transferring to the Erie side. The Conrail merger of 1976 saw the line pass to the Delaware and Hudson, which was able to abandon its own less efficient Scranton-Binghampton route. In the 90's the D&H was sold to Canadian Pacific before ultimately falling under the umbrella of Norfolk Southern in the 2014.
The scope of the cutoff can be seen at other points along the line where local roads have to literally tunnel through the massive embankments.
The DL&W applied its use of reinforced concrete technology to everything, including station buildings and interlocking towers. Here the station in Glenburn, PA has been repurposes as public works offices with EL caboose #C267 on display nearby.
Moving down to North Reading the next morning, Kevin and I encountered the NRFF lashup awaiting its departure with GP38-2 #2014 on the tail end behind the two NRFF painted SD50s.