Dead train set on the Needham Line?

Today, just west of Forest Hills on the Needham Line there was a set of 6 doubles and an HSP46 (I didn't get the number) sitting dead this morning and still there on my trip home this evening. The HSP is uncoupled from the set of cars, and about a car length away, perhaps to keep the crossing to the Orange Line work area clear at Forest Hills. Anyone have an idea of what's going on there? Maybe related, there's an utterly demolished shopping cart next to the tracks at Roslindale.

the 2025, had a bearing issue. Separated from the set so that the crane could get at it and do a change out

2025 is on the 1834 set which is 6 doubles. That’s the set that you are talking about with that hsp bearing issue.

In any case, it was gone this morning so I guess it's sorted, or at least was sorted enough to move it back to a shop.

What does HSP Stand for?

Presumably it's "High Speed Passenger" though the concept that they're anything close to high speed is pretty hilarious.

HSP is shorthand for the locomotive, which in this case would be an HSP-46.

https://en.wikipedia.org/wiki/MPI_HSP46

Google is your friend, folks, nobody would credibly argue that any commuter rail system operates a high speed passenger service.

Had read the article on wikipedia before posting but it never stated what HSP stood for.