Pittsburgh's light rail system is descended from PCC-based streetcar lines running south of the city that had the good fortune to have both their own rights of way and the use of a dedicated tunnel through Mount Washington. These advantages earned the system a light rail style conversion in the 1980's complete with a downtown subway and dedicated bridge across the Monongahela River. While the rebranded Mount Washington Transit Tunnel continued to underpin the network, the Allegheny Port Authority and its predecessors had recognized the Mount Washington Tunnel as a single point of failure and therefore maintained an alternate surface route up and over the hill. Christened the 52 Allentown in 1984, this alternate route, terminating at South Hill Jct, would see declining levels of service until it was discontinued entirely in 2010. However tunnel diversions kept the old 52 Allentown in service as a ghost line, light rail trains running doors closed through the eponymous neighborhood on an as-needed basis. For out of town railfans catching a ride over the 52 was particularly difficult as the diversions were not often scheduled in advance, however in 2025 the tunnel was to undergo a long term renovation with Route 47 and 42 trains diverted over the 52 for the better part of a year. This allowed me to schedule a trip to Pittsburgh to get photos and videos of this rare occurrence.
My arrival in Pittsburgh was too late in the day to properly ride the 52 Allentown, but I was able to catch the arrival of westbound Amtrak Pennsylvanian Train 43 with P42DC leading the usual consist.
It was at this point I had my first ever encounter with a Rule 280a "Clear to Next Interlocking" signal indication displayed eastbound on Track #1 at the former CP-EAST PITT. Displayed as a flashing white marker light next to a standard Medium Clear, the signal us used in cab signal territory without wayside intermediate signals for train movements that are not cab signal equipped. In this case said movement would be Train 43 shoving back to CP-HOME where the turning wye is located.
By displaying Rule 280a instead of a Restricting, the shove move would be able to operate at speeds up to 45mph, saving considerable time across the 8 mile round trip.
The following morning I caught a light rail train at Steel Plaza and was in place to get photos as it crossed over at Panhandle Interlocking and onto the short single track that would lead to the street running up and over Mt. Washington via Allentown.
The whole trip takes about 8-10 minutes, about 5 minutes longer than the trip through the tunnel. The ride was downright exciting as my LRV's operator was really flooring it up the twisty grade. A temporary infill station was also added along the route in the Allentown neighborhood.
My outbound SD400 LRV, running on a 47S service, at South Hills Jct
South Hills Jct is built around a large double track scissors crossover. Although from the point of view of the platforms the crossing routes over the diamonds are in a geometrically straight path, from a railroad interlocking point of view those would be the diverging routes. Normally the light rail trains get a solid yellow lamp for a Restricting indication into street running track. However for the "diverging" route, they get a flashing yellow.
In its original configuration trains from the Overbrook and Beechview lines would merge into the transit tunnel with the option to use the 52 Allentown Route.. With Overbrook Line trains making use of a new flying junction since 2004 and the 52 being discontinued in 2010, the scissors crossover sees rather limited use in its role as a crossover. Here SD400 LRV #4221 crosses northbound over from the Beechview Line to the 52 Allentown line.
Pride month pay have been over, but SD400 pride unit #4239 was still roaming across the light rail system in early July, along with 4202.
Here we see SD400s #4227 and #4201 along with CAF LRV #4317 running out of the junction and up the incline towards Allentown.
CAF LRV #4315 descending southward from the Allentown route. The CAF LRVs were a supplemental order of vehicles to support the re-opening of the Overbrook line, which was closed between 1993 and 2004.
Like the northbound trains, southbounds would roll towards the junction and get a Restricted Diverge flashing yellow signal on the dwarf.
View along the axis of the scissors crossover route from the Beechview/Overbrook lines to the Allentown Line with CAF LRV #4317 and SD400 #4253.. While this routing is physically straight, as far as the interlocking is concerned this a diverging route.
In this video we see an inbound 42S South Hills Village (via Beechview) train with SD400 LRV's #4231 and #4235 passing an outbound 42S with CAF LRV's #4310 and #4313 with #4310 sporting the new "Pittsburgh Regional Transit" paint scheme.
In my previous visit to South Hills Junction in 2023, both PCC loops were still present for short turns both from the north and south. Since that time the southward loop for PCC's coming off the 52 Allentown has been removed along with its boarding platform. PCC's were used through 1993 as the old Overbrook line had wooden trestles that could not support the weight of LRVs.
On the other hand, the old Route 47/52 platform had been re-paved. Before the Overbrook Line rebuild this platform had served the PCC's using the 47 route as well as all 52 Allentown cars which terminated at South Hills Jct.
Another view of LRV's crossing over to the Route 52 with SD400 #4250 and CAF LRV #4308.
The tunnel closing also affected local bus traffic which also had to detour up and over Mt Washington. Here bus #6236 passes inbound SD400 #4227.
All of the construction miscellany made getting a view into the tunnel a bit difficult, but I was able to manage a photo.
Back to the South Hills Jct platforms where I caught SD400 #4224 passing #4201 and #4206 arriving southbound.
The return trip was not quite as exciting, I'm guessing the operators know they have a bit more leeway for speed on the steep ascent since the grade will quickly bring the car to a stop without use of brakes.
Heading north across the Panhandle Bridge I encountered CAF LRV #4314 painted in the new "Pittsburgh Rapid Transit" branding.
Final photo of this set if SD400 #4224 after dropping me off at the Honorable United States Steel Plaza.
All in all Pittsburgh Light Rail is a great little system that still presents a lot of heritage due to the early date of its light rail conversion. If the MWTT ever shuts down again I urge you all to schedule a visit.
The final part of my trip on Amtrak's 2016 Autumn Express will cover Amtrak's Harrisburg Line, aka the former Pennsylvania Railroad Main Line between Philadelphia and Harrisburg. Amtrak would use the old PRR route to return the Autumn Express to New York City and with speeds up to 110mph the travel time would be a fraction of what it took to get out on the overall shorter freight route. Because of the faster travel time, Amtrak was able to schedule a special photo stop at Lancaster to allow the passengers to get out and take photos of the giant Autumn Express trainset as it backed up and then made a repeat arrival. After that it continued on to Philly, utilizing the famous New York->Pittsburgh Subway to access the westbound NEC. Unfortunately a North Philadelphia stop was not provided for those passengers needing to return to the philly area or points south.
You can find the photos from this section of the trip here, just scroll down about half way until you see the Harrisburg Station.
The Harrisburg Station complex had recently been rebuilt with a new layout, new signaling and concrete ties on all the station tracks. Here we see the catenary inspection car sitting on track 5, just behind the PRR caboose and GG1 #4859 that are on display under the Harrisburg trainshed.
Departing through the new, simplified STATE interlocking. In addition to the tower being closed, parallel routes were eliminated and others were raised to 30mph from 15mph. Track 8 was also eliminated as a through track leaving track 4 as the only other through track aside from the high level platform tracks 6 and 7. This was likely necessary to support wide freight and equipment movements.
Here we see the graceful curve leading up to the Royalton flyover that allows the old log grade freight tracks to relocate to the west side of the right of way in order to branch off towards Columbia, PA. Located at the end of Harrisburg International Airport's single runway, the hulk of a a Convair VT-29B Samaritan used for fire training can be seen in the background.
After crossing over at ROY interlocking, we met Amtrak P42DC #96 with the westbound Train 43, Pennsylvanian waiting for its turn to proceed.
This squat structure is actually the old PRR LANDIS interlocking tower in Landisville, PA. A small table type interlocking machine installed controlled a diamond crossing with the Reading Company's Columbia branch. Long removed, it was one of the few at grade diamond crossings on the eastern part of the PRR Main Line.
Because we were running early and due to platform availability issues at Lancaster, we had to wait for both the eastbound Pennsylvanian and a westbound Keystone to pass before we were able to proceed through CORK interlocking. Train 42 was being hauled by P42DC #97 and the Keystone was being trailed by Metroliner cab car #9638.
So the final "rare mileage" part of the 2016 Autumn Express was run over the NS Harrisburg Line between CP-WYOMISSING JCT, just west of Reading and CP-CAPITOL in Harrisburg. Of course this segment of track had been trodden before by the 2014 Autumn Express, that actually came and went over the route in both directions. Of course this year I was able to take photos out hr back whereas before I was not. You can find the full series of photos at the top of this photo set here.
After running up the ramp from the Reading Line, out train entered the Harrisburg Line at CP-WYOMISSING JCT. The Harrisburg Line between Reading and Harrisburg had been run under Rule 251 ABS up through the Conrail era, but a CTC project was one of the first orders of business for NS due to the 40-50 trains a day that traversed the line to serve both the New York and Philadelphia markets.
Although not as well known as the Reading Main Line between Philadelphia
and Reading, the old Lebanon Valley Branch, as it was called, boasted a
lot of Reading station infrastructure for both New York and Philly
bound passenger services. Here we see old Reading stations in
Wernersville and Lebanon.
After crossing over at CP-DORF, we passed an eastbound merchandise train with a trio of NS locomotives including former Conrail C40-8W #8396 and a 5000 series SD40-2, and one unidentified Reading and Northern EMD.
The Penn Supply Milard quarry has a small fleet of ex-road power to shift the long aggregate trains through its loading facility. Here we see long time power B23-7 #250 and SD40M-3 #6521 along with a newly acquired ex-UP SD40.
A short distance away in the receiving yard was NS C40-9W
#8865 and SD60E #6916. Both classes are common in the Harrisburg area.
In Palmyra, a cut of cars was being prepared for set-out by some road power including NS C44-9W #9519 and SD60 #6707. Note the osage oranges all over the track.
NS GP38-2 #5303 was working the Hershey yard with a former Conrail cabin car. As you might surmise, the Hershey yard mostly supports operations for the Hershey company that has many plants in and around the Hershey, PA area.
At CP-BURN, located in eastern Allentown, Amtrak's Autumn Express turns onto the former Conrail Reading Line, which runs between Allentown yard and a junction with the Harrisburg Line just outside of Reading, PA. For a named "Line" (under the Conrail system), it is actually quite short, only about 30 miles from end to end, but as a link in the east-west trunk to the Port of New York and New jersey is handles a large volume of traffic.
The timing of this trip was especially important because the double track Reading Line was slated to be re-signaled from ABS Rule 251 to CTC Rule 261 and taking a train over it allowed me to survey all the classic searchlight signals in one go.
A spike of railfans had set up at CP-BURN to watch the special rise out of the hole and then cross over to westbound track 2.
The nominal subject of this photo is the eastbound MP33
distant signal to CP-BURN, however way back at the crossing is former
West Jersey informal railfan trip specialist Kevin Painter.
Large group of railfans out for the train in East Allentown.
Some cars wait for interchange on the Perkeomen Branch that diverges at Emmaus Jct.
Another big crowd is on hand at a railfan park in Macungie, PA, the home of Mack trucks.
Power crossovers at CP-ALBURTIS. This interlocking was re-signaled around 2007 and will be re-signaled again for the CTC.
Former Reading Mertztown Station building.
The new crossovers at CP-LYONS will help fill the gap between Alburtis and Blandon.
They will replace the single trailing crossover at the old LYONS Temporary Block Station, seen here with an eastbound autorack train.
