SEPTA Completes ARSENAL Re-Signaling

SEPTA is finally wrapping up its ARSENAL interlocking re-signaling and track reconfiguration project that has been underway since 2019(!).



The primary goal of the project was the allow select trains to turn back at the University City station, instead of 30th St, which required the addition of crossovers and a tail track between the old limits of ARSENAL and WALNUT interlockings. However SEPTA used the funding opportunity to renew the 12kv overhead lines and 1980's vintage ARSENAL interlocking, which unfortunately saw the demise of amber type PRR position lights, some of which were 2000's era LED upgrades.

An extension of ARSENAL southward to include a new trailing point crossover on the West Chester Line resulted in the old northbound signal bridge now serving only the NEC bound tracks. Note that the signal from the NEC can display full indications instead of SEPTA's go-no-go 562 indications.

In the other direction two new automatic exit signals have been furnished as distants to PHIL interlocking. With Approach Medium/Limited being the most favorable indication this could be seen as a downgrade for Airport Line routings that should take place over a Clear signal, however the ACSES speed enforcement doesn't make 45mph possible, let alone the actual line speed, so no big loss..

ARSENAL's southbound limits have been relocated about 900 feet to the south. This will substantially reduce transit time through the interlocking so that an NEC train can follow more closely behind a West Chester Line train .

The big surprise was the complete removal of the WALNUT crossovers in the trench leading up the tunnel approaching 30th St Station. Possibly due to maintenance issues involving water drainage or foul time associated with close clearances, the lack of WALNUT's crossover will risk snarling service if there is ever a need to single track/wrong rail through 30th St Station. Southbound wrong-railing trains at 30th St will have to travel 1.5 miles to ARSENAL whole northbound trains can benefit from the new turnback crossover for a 1.1 mile penalty. I'm not a daily rider, but hopefully I'll have a chance to pick up on how the new configuration help or hurts the user experience (as opposed to the bottom line).