The fairly large pile of Alco locomotives that are rostered on the PV&T are the results of years of motive power decisions.

Alcos started to arrive on the PV&T’s constituent railways in the traditional way of dieselization; replacing steam in the yards, then colonizing the mainlines until no steam was left. Since both Alco & MLW were online shippers (MLW directly, via a TdM switching district, Alco indirectly, via D&H transfers across town) they were both the obvious preferences for motive power suppliers.

The 244 engine was a bit of a disappointment, that didn’t stop the system from trading in all of their 244-equipped power for (briefly; Worthington shutting down Schenectady abruptly at the start of 1969 came a bit of a shock, even though they telegraphed it by completing the LT&L’s last order (of T-6s) in Montréal) new locomotives with 251s.

After ‘69, General Motors & GE made a big push to try and get the LT&L and TdM (the PV&T was already lost to them, having completely electrified a decade and a half earlier) to purchase their power, but weren’t able to make their case, and orders kept going to MLW (and, in the middle of the 70s, ILW.)

When the two original DL-109s were kept on the roster instead of the LT&L’s 700s and then PC DL-109 #PP716 was purchased out of the old New Haven’s Boston deadline and carefully rebuilt as a freight locomotive, it became obvious that at the very least the TdM’s shops were full of honest to g-d railfans, so the sales visits from GM & GE fell right off a cliff.

It was not a particular surprise when, after the D&H merger, the Parsons Vale dumped most of their GP-38s and replaced them with AC motors (the D&H’s trackage rights from Harrisburg east) and the went out and bought 22 C&NW C-628s when that railroad flushed the last Alcos out of their system.

As of 2020, there were still over 300 Alcos & MLWs running on the Parsons Vale, while all of the non-Alco power coming onto the roster ended up being sent to (storage on) the BAR until either scrapping or resale.

The TdM shops & ILW are still asking locomotive brokers for even remotely salvable Alco or MLW units, though the few that remain are almost all in such bad shape that they’re only good for a complete remanufacture into an ILW eco-a unit.