For the better part of a decade the Baltimore and Ohio Color Position Light signals at Greenbelt, MD have stood alone as the last main line CPLs in the B&O's home state. The cause is a quirk of GREENBELT interlocking's creation in that it exists solely for the benefit of MARC commuter trains to use high level platforms at the Greenbelt intermodal transpiration center where passengers can transfer between the DC Metro and MARC commuter trains. The CPLs were installed in the 1992 time period at the very end of era when CSX would bother to install precursor specific signals and were likely funded from the same pot of Federal funds that was building the transportation center. In 2013 the entire CSX Capitol Sub, with the exception of GREENBELT, was re-signaled as I assume maintenance and/or replacement of an interlocking with zero utility for CSX was the responsibility of the State. This state of affairs persisted until 2020 when new signaling hardware appeared on sight. With nothing better to do I headed down to catch at least one part of MARC trains on their Covid service patterns, and whatever DC Metro trains were passing near by. The full set of these photos can be found here ( mirror ).
The GREENBELT complex consists of two signaled pocket tracks serving the high level platforms without any other main line crossover. Between here and Hyattsville, MD the MARC Camden Line (CSX Capitol Sub) shares the right of way with the DC Metro Green Line.
Unlike many modern stations, track and ADA access were provided via tunnels and ramos instead of elevators.
There was so little CSX traffic that day that the dispatcher displayed the signals for the first pair of MARC trains almost two hours early. This allowed me to capture a wider variety of CPL aspects than I had been expecting Medium Clear for movements into the pockets, Slow Approach for a Stop at the other end of a pocket and a Medium Approach Medium indication on the westbound dwarf reflecting a back to back crossover at the next interlocking.
Metro Green Line trains were running on a 20 minute headway. All trainsets were made up of 7000 series cars.
I only had enough time to stay for one MARC train, the first three eastbound departures on the Covid schedule. The train of single level cars was headed up by MARC veteran GP39-2H #72 and newer MP36PH-3C #32. Cad car #7759, a familliar face on the Camden Line throughout April, was on the west end.
The CSX signal crew was on site and they were nice enough to allow me some photos of the east end relay hut, which is slaved to the primary equipment hut on the west end. Although much of the logic elements were in the form of digital cards, traditional glass cased plug type relays were provided for track circuits and other field equipment.
Well that's it. Really wasn't much going on due to the Covid lockdown. Next week I'm off to Du Bois, PA for another taste of the old B&O.
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