With train service largely shut down due to COVID in the spring of 2019, it is time for an infrastructure week and what better infrastructure is there than the remains of the Pennsylvania Railroad Philadelphia and Thorndale low grade freight line! Specifically the P&T junction with the Main Line at Thorndale, PA and the magnificent flyover at Whitford, PA. Not much more to say except that you can find the full set of photos here ( mirror ).
The P&T low grade line extended the Trenton Cutoff about 10 miles from its original terminus at Glendale, PA to Thorndale, PA to avoid a number of significant grades on the original Main Line alignment. Although its hard to notice today. what is now the high speed Keystone corridor has all sorts of grades that often required helpers in the age of steam. Thorndale itself served as a helper base even after the coming of electrification in 1939. Because the PRR didn't want to disrupt the busy Main Line passenger operations flying junctions were constructed at Thorndale and Glendale. Here we see Main Line at Milepost 34 looking eastward as it approaches the P*T flyover that takes the form of a short tunnel on tracks #1 and #2. While originally 4 tracks, track #3 was lifted between Thorndale and Downingtown around 2010.
The P&T itself was reduced to a single track under the Penn Central and then removed entirely in the 1980's. Today only the ballasted right of way remains as an access road. Here is the view from on top of the flyover tunnel looking westbound then eastbound.
Here is the west portal to the tracks 1 and 2 flyover tunnel looking in the eastbound direction. Sheet metal shields were added to the 1906 tunnel to discourage people from coming in contact with the 12kv overhead wire.
The catenary structure dates from the 1939 Harrisburg electrification project and retains many original components.
The P&T junction with the previously covered THORN Interlocking is out of sight to the west.
East of the Thorndale flyover is Amtrak's Thorndale Substation. Built for the 1939 electrification project, it is associated with one of three Phase Breaks on the Amtrak 25hz power system that can isolate the western end of the PRR's electrification system which is chiefly supplied by the Safe Harbour Dam.
Thorndale Substation is also one of only 3 locations on Amtrak's 25hz system to have high voltage oil filled breakers for the 138kv distribution circuits, as the PRR found it easier to switch load on the 12kv side of the breakers. The HV breakers at Thorndale and other places are 1939 pieces of equipment.
Due to multiple rounds of government funding over the years, Amtrak has largely replaced the PRR's 1930's stock of 25hz single phase transformers with updated models. However the Thorndale substation features one of the few remaining 1939 units, with the GE logo still present on the glass globe oil bushing.
Although few if any trains were running, THORN tower was still manned as it had been for every day since 1937.
I also learned that the THORN interlocking plant included a pedestrian underpass.
About 2 miles to the west, CALN interlocking, controlled from THORN tower, was in its last days using its original 1930's relay logic and CTC equipment. A new colorized position light had been installed on the eastbound signal bridge. Until about 2007, track #2 was in place between THORN and PARK interlockings and was used by an occasional local freight serving customers off the old A&S branch west of PARK. It was eventually removed and replaced by a hand operated switch at PARK.
My last stop was the SEPTA R5 Whitford, PA station, notable for being dominated by a massive abandoned truss bridge that carried the P&T low grade extension from the south side of the Main Line to the north side.
Although overshadowed by the Exton Station about a mile to the east with its high level platforms and large park n ride lot, Whitford would definitely be my choice on this part of the R5.
The eye bar construction not only looks cool, but also shows how the load is carried by the truss and not the sides of the deck.
While driving back home I did catch one of the Acela 2's sitting in the Penn Coach Yard at 30th St station.
Well that's it for infrastructure week, next time I'll be making an emergency trip to Greenbelt, MD.
worked there from 1987 to late 89 out of D-town station before the kids torched it. Signal line was still in place and working on the cutoff and branch.
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