Discussion of the past and present operations of the Long Island Rail Road.

Moderator: Liquidcamphor

  by ExCon90
In the quick succession of clips at the beginning of a Retired Railfan video there is a shot of an LIRR diesel passing a color-light signal displaying green over green, which drops to red over red as the head end passes it; it's on single track, non-electrified, and the signal has a small yellow sign on the mast displaying a black C over O. The only time I've seen G/G was on the NYC before MN eliminated automatic wayside signals; is G/G something new on the LIRR, and how does it differ from G/R?
  by gregorygrice
Clear Block: Proceed; Manual block clear.
  by gamer4616
If it's a recent video, the train would be heading west, leaving Patchogue. The signal is a "Clear Block". The track ahead is a "manual block". Trains entering a manual block need to verify the track is clear, prior to entering. One method used to ascertain a "clear block" is a fixed signal, such as this example.

The "CO" on this signal indicates the train is entering an ASC Cut Out loop. The track ahead does not have Automatic Speed Control.

Green over Red is for a "Clear". The indication is "Proceed".
Green over Green is for a "Clear Block". The indication is "Proceed, manual block clear".
  by freightguy
I think patchogue(PD) to "Y" aka Sayville is 261-S with manual block rules still in effect? So basically one train in the block at a time.
  by ExCon90
Thanks -- somehow I had the idea that the Montauk was now automatic block with Rule 261 all the way. But then again I don't know when that shot was taken.
  by DaveBarraza
There is currently a re-signaling project going on the D-251 track and 261MB between the east end of Babylon xlkg and Patchogue. I would expect that the Green/Green will be gone when that project is complete. Highly possible that the WB signal leaving PD will turn into an RAS signal much to everyone's dismay. For sure there will be ASC from Y to PD so no more "CO"

I was speaking about Y to PD with a few old timers, the collective thinking was that when PD got control of the EB home at Y, that was when it became 261 Controlled-Manual-Block, with track circuit detection from end-to-end. Prior to that it was 251MB with BAB (or the cabin at Y) and PD keeping track of the block on paper. No one was quite sure when that happened - old guy memory loss... "CRS syndrome" Can't Remember S%&t.

251MB did use track circuits, for home signal slotting, distant signals, highway crossings; but did not have "directional locking" between Y and PD.
in 261MB ("Controlled Manual Block") the signal system ensures that opposing signals and opposing moves cannot co-exist.
  by gamer4616
DaveBarraza wrote: Sat Sep 24, 2022 7:06 pm There is currently a re-signaling project going on the D-251 track and 261MB between the east end of Babylon xlkg and Patchogue.

Really? I've been hearing about Babylon-Patchogue signalization for over 15 years now. It's nice to hear that it's finally getting worked on.

It would sure be nice to be a patchogue scoot to babylon and not have to wait for the late montauk flyer to clear Y before you can leave patchogue.

As of now, there are a few fixed signals left that can display a "clear block"

Position Light Signal at KO, single track east of Kickerbocker Ave
Position Light Signal at Locust on Oyster Bay No. 2 Track
Position Light Signal at Y on Montauk No. 2 Track
Pedestal Signal leaving Valley on Far Rockaway No. 1 Track
Position Light Signal leaving Oyster Bay
Color Light Signal Leaving PD, single track west of River Ave
Pedestal Signal leaving Far Rockaway on Far Rockaway No. 2 Track