Danymal

The general departure board does indicate that some trains stop in Jamaica, albeit in a roundabout way. Any train listed on the general departure board at Penn Station with connections to additional trains stops at Jamaica to make those connections.



Using the example of the general departure board in reply number 10, the 5:04 train to Hempstead, the 5:09 train to Speonk and the 5:13 train to Babylon all stop at Jamaica in order to make the connections listed on the general departure board. It’s unclear whether the 5:06 train to Huntington stops at Jamaica. The 5:11 train to Port Washington and the 5:14 train to Great Neck do not stop at Jamaica as the Port Washington line does not pass through Jamaica. Perhaps that’s why trains on that line are colored red on the general departure board?

ijgordon

No, that won't work, because you could see a Babylon branch train connecting to Patchogue/Speonk/Montauk, and those connections often happen at Babylon, not Jamaica (sometimes they happen at Jamaica, mostly for Montauk I'd guess). I think there are other connections at Ronkonkoma for the north fork, and possibly others. I believe, per the image, Far Rockaway and Hempstead transfers (and potentially others) would necessarily have to take place at Jamaica, but I wouldn't rely on this as a method.

I also wouldn't read anything into the red color-coding on the Port Washington branch trains. That's like saying the 1/2/3 subway train is red because it doesn't stop at Grand Central.

nerd

Are you sure you mean Ronkonkoma/North Fork?

ijgordon

nerd

Because that's the only line that goes through Ronkonkoma so I'm confused as to why you'd make a connection there.

ijgordon

If you're taking the train to Greenport, you have to change in Ronkonkoma, not Jamaica. That first train from Penn to Ronkonkoma may or may not stop at Jamaica, so it's another potential example of why seeing [Ronkonkoma] [Greenport] on the departure board at Penn wouldn't be a good indicator that the train stops at Jamaica.

GadgetFreak

If they were color coding for whether the trains went through Jamaica, they would make all the lines that did go through Jamaica red.

guv1976

I believe that the LIRR is not electrified east of Ronkonkoma. So unless the LIRR is running dual-mode locomotives between NYP and Ronkonkoma, it would be necessary to transfer to a diesel for travel east of Ronkonkoma.

Edited to add: https://en.m.wikipedia.org/wiki/Ronkonkoma_Branch

GadgetFreak

I think they started the dual mode quote a few years ago but I remember that they used to have to switch to diesels at some point after they left Penn. I seem to remember some of the switching at Jamaica because one of the problems with the diesel trains was that they couldn't take them into the East River tunnel because of the exhaust.

guv1976

It appears that all of tomorrow's LIRR trips from NYP to Greenport require a transfer at Ronkonkoma.

GadgetFreak

In looking they operate pure diesel and diesel/electric hybrids. So it may depend on things like other needs and scheduled maintenance.

ijgordon

I don't think they have all that many hybrids, and I imagine they're mostly used on the Montauk line, and possibly Port Jefferson / Oyster Bay as I think lines are still not electrified to the ends.

Not sure how we really got to all this, the point is still that you can only tell if a train is stopping at Jamaica from (1) the timetable (printed or online), (2) the station-specific signs above the Penn Station ticket windows, or (3) the train-specific signs at the entrance to each track.
You can't tell for sure based on whether a train offers a connection to another line, as would be shown on the general departure board.

GadgetFreak

You're probably right.

SteveMSflyer

Download traintime from App Store (free). It will give you times and stops for your route.