PD Tower position light signalling

[DaveBarraza]

Thanks for the commentary above between the difference (on LIRR) between 251/261 and 501 to 509. Is it safe to say that 501-509 have to do with the system that keeps trains safely spaced (between interlockings or block limit signals) and 251/261 have to do with letting trains into an area between interlockings (or block limits) to begin with?

related question:

The remaining sections of dark territory show Manual Block rules 305-373 but also show 251,253,254 but *not* 501, etc.
-Is this because of the rule 295 signals out there? Or maybe because the last home signal before you enter is a "Manual Block and Interlocking Signal"?

Thanks,
Dave

[nyandw]

The PD controlled block MS was also referred to as JJD (James J. Dermody: LIRR Pres. 2003-2006)?? Anyone. Thanks.

[452 Card]

I don't know how many times I've said this, but here it is again: Manual Block Signal System (MBSS) on the LIRR is NOT "dark territory". I went toe-to-toe with an FRA inspector about this and I was defended as correct by a Rules Examiner. There are illuminated MBS signals at the beginning of each block that have the yellow lamp placed next to the track governed.
Dark Territory is defined as the portion of a rail road governed by Track Warrants, devoid of any signal system, which is also assigned by a train dispatcher (although no longer through a block operator) on main track or secondary track without ANY block signals at all. Just a radio transmission or cell phone call gives the superiority to any given train.
In this case, "the first train to the switch gets the block". It has also been the contributing factor to collisions elsewhere.
I don't care what the current rules examiners have to say today. The MBS territory east of SK and KO exists as it did over a hundred years ago. Yard limits still exist, and the RULES ARE THE RULES.

[nyandw]

Thanks, 452 Card.

[ExCon90]

452 Card, I'm very glad to read that about dark territory. I've always believed that where a block system is in place it's not dark territory; whether it's automatic or manual is irrelevant.

[DaveBarraza]

Sorry to offend. I've heard "Dark Territory" used many different ways. If you could point to a document that provides a formally accepted definition I'd appreciate that. My intent was to say "territory where safe separation of trains is not provided for by signals controlled by track circuits"

So let me attempt to rephrase: How does rule 251 apply to the area of the railroad east of Ronkonkoma?

[ExCon90]

There was an extensive discussion of dark territory awhile back, but I can't remember in which forum. To the extent there was a consensus at all it was that the term "dark territory" has no official meaning and can't really be used to convey specific information. For one thing, it apparently means one thing to dispatchers and another to engineers.

As to Rule 251 east of Ronkonkoma, I don't have an ett, but if it's single track I don't see how Rule 251 would apply.

[DaveBarraza]

Thanks again to Plubius Plunkett and 452 card.

After reading and re-reading (from time to time) an old rule book, I think I see what I was missing 4 years ago in this thread. Operation on some model railroads using TT&TO helped as well.

Blocks are divided sections of the railroad. In a Manual Block System, the Block Operator keeps record the movement of trains in a Station Register of Train Movements - so it is known where a train is, or at least which train possesses the authority to move within defined limits. Therefore it's not "dark". Block signals ensure separation of trains. Block Limit signals are just Block signals that don't ever clear from stop. (Part time block stations could have both position light signals and also block limit signals as well.)
Automatic Block Signal systems dispense with the operator and the train register in place of track circuits signal controls. Both Manual and Automatic Block are supplementary to the protection afforded by TimeTable and superiority of trains. This gets me the the question about the application of rule 251 in Manual Block territory.

As was stated up-thread 251/261 are about superiority and not signaling. (300-series rules cover Manual Block signaling and 500's cover Automatic)

Start with all of the rules from about 80-100 that deal with "Movement of Trains"... Timetable Authority and Superiority of trains (1st class trains superior to 2nd, Eastbound superior to Westbound, extras by Train Order -etc.) Under these rules an inferior train has to clear for a superior train in the same direction to pass.
251 says that block signals "supersede the superiority of trains" traveling the in the same direction, relieving crews from having to worry about complying with the requirement to clear for a superior train. -but that's it. East of KO (and East of PD back in the day) you still have to follow the timetable and clear for opposing superior trains, and/or follow applicable train orders.

Sorry it took so long to sink in!

Dave

[Teutobergerwald]

I think the topic that discussed this extensively was called "Signals on the LIRR" or "LIRR Signals."