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A flashing signal should always mean the next signal is not g-r-r I believe.

On the NS (ex Conrail), yellow over flashing green is an Apprach Limited indication, meaning to approach the next signal at Limited speed, 45 MPH. Red over Flashing green means Limited clear, proceed through this signal at no more than Limited speed, 45 MPH.

Dajudge wrote:Last night passing MP414 EB track one was yellow over flashing green. So I surmised 412 would be g-r-r. To my surprise it was r-fg-r. So a flashing signal does not guarantee a solid same color at the next BS, right?

Do not forget what yellow over flashing green is ... Approach Limited ... and expect the next signal to be Limited. R-FG-R is "Limited Clear" or as I like to call it "Limited until Clear interlocking". The train would return to timetable speed after clearing CP 412.

"Limited Clear" is not a diverging signal (remember, NS signals give speed not route) but it is likely that the train was set to cross over at CP 412 through turnouts that permit 45 passenger/ 40 freight speeds. If the train was not diverging it would normally get a clear signal. That is the sort of prediction we can make. (The "until clear" signals at interlockings are a clue that a train is crossing over.)

If 412 was Medium Clear 414 should be Approach Medium ... think of Approach Limited as a "speed limit 45 ahead" (45 passenger - 40 freight) and Limited Clear as "speed limit 45 (40)" now. The medium version would be "speed limit 30 ahead". (Understanding that timetable speed should never be violated despite the signalling system.)

Dajudge wrote:And last month at 421 main street was r-r-g. I have to find a rule book......

R-R-G is Slow Clear - 15 MPH until clear interlocking.

Red over Yellow over Green is the one that will blow all you minds lol.

Medium Aproach Medium


See that on eb on 2 Main at CP 360 a lot


That and for a couple of the aspects, there are more then one way to display them. Conrail wasn't consistent on using just one of them ether.

Well and then you have the dwarf aspects.

justalurker66 wrote:Approach Limited ... and expect the next signal to be Limited.

Not necessarily. For short-block reasons, some places you could get an Approach Limited in advance of an Approach. At least on CSX, anyways.

Saturnalia wrote:

justalurker66 wrote:Approach Limited ... and expect the next signal to be Limited.

Not necessarily. For short-block reasons, some places you could get an Approach Limited in advance of an Approach. At least on CSX, anyways.

That was a CSX thing. Conrail didn't do that. They'd use advance approach or approach slow if a short block.

This discussion drift reminds me of the importance of knowing which railroad one is on and the rules for that road. Even NS has "Conrail" vs "Norfolk Western" vs "Norfolk Southern" signalling. Speed signalling vs route signalling.

A few years ago a crew familiar with the signals Amtrak used on the Amtrak owned track approaching Chicago Union station saw a "red over yellow" signal on the NS line. The signal was called out as "slow approach" ... which if true would mean that the train would proceed not exceeding 30 MPH prepared to stop at the next signal. The track would be clear (no obstruction) until the next signal.

Unfortunately it was an NS/Conrail signal. The signal "red over yellow" on NS meant "restricting". Restricting has an entirely different meaning than "slow approach". Restricting allows the train to proceed into a block that IS occupied or obstructed. The crew is under instruction to proceed at "A speed that will permit stopping within half the range of vision, short of train, engine, obstruction, railroad car, men or equipment fouling track, any signal requiring a stop, derail or switch lined improperly and looking out for a broken rail, but not exceeding 15 MPH."

So what is the worst thing that can happen when a train crew misreads a "restricting" signal as "slow approach"? The crew finds a train on the track and is going too fast to avoid a rear end collision.
https://www.youtube.com/watch?v=r2r139F9CUo

And thus ends the lesson on the importance of knowing which railroad one is on and the rules for that road.

(It should be noted that after the engineer called out "slow approach" they treated it as "slow clear" and sped up to 40 MPH before hitting the freight train at 36 MPH. There was more confusion in the cab than simply misreading the signal.)

CSX_CO wrote:

Saturnalia wrote:

justalurker66 wrote:Approach Limited ... and expect the next signal to be Limited.

Not necessarily. For short-block reasons, some places you could get an Approach Limited in advance of an Approach. At least on CSX, anyways.

That was a CSX thing. Conrail didn't do that. They'd use advance approach or approach slow if a short block.

Not always. West side of Fortville IN has an Approach Medium that will show up eastbound if CP 260 Ingalls is showing STOP eastbound.
The signals on the east side of fortville are probably not even a mile away from CP-260.

I guess Conrail didn't want any signals in downtown fortville.

LakeATCS wrote:Red over Yellow over Green is the one that will blow all you minds lol.

Medium Approach Medium

Coming soon to Leesburg?

The "one lamp over three" siding exit signals allow for five aspects:
R-R STOP
R-Y Restricting
R-FY Medium Approach
R-G Medum Clear
R-FG Limited Clear

I'll ignore "Limited Clear" and note that the there are no "Slow until clear interlocking" aspects. Which means the interlocking will be signaled for Medium Speed. The southbound "three over two over three" three headed signal with no green on the center head would allow:
R-R-R STOP
R-R-Y Restricting
R-Y-R Medium Approach (Medium into siding then stop at far end)
FY-R-R Advance Approach, Y-R-R Approach and G-R-R Clear for trains staying on the main
and the special R-Y-G Medium Approach Medium ... which would be perfect for a train taking the siding to pass a train on the main that has already cleared the other end of the siding.

justalurker66 wrote:

LakeATCS wrote:Red over Yellow over Green is the one that will blow all you minds lol.

Medium Approach Medium

special R-Y-G Medium Approach Medium ... which would be perfect for a train taking the siding to pass a train on the main that has already cleared the other end of the siding.

R Y G generally isn't used for siding run thru (though it very well could be, just not worth the logic to put it in)

R Y G is generally used for places where there are interlocking stacked on top of each other without an intermediate between them. And even then Conrail rarely if ever used that signal

It wasn't even possible in PRR territories as it was a Color Light only aspect. Where it was most found was in some NYC era CTC. NS put that aspect to good use on #2 at CP360 so that CPR trains would have the best aspect possible for the next diverging move at CP 358

LakeATCS wrote:R Y G generally isn't used for siding run thru (though it very well could be, just not worth the logic to put it in)

If I understand correctly the current PL signals at CP 19 and CP 21 show Medium Approach when taking the siding and Medium Clear when leaving the siding. Continuing those aspects would be possible but would not require the third head. The green light on the third head only adds two aspects, Slow Clear and Medium Approach Medium.

The current signals are lacking aspects at several locations ... such as no Restricting at Warsaw. Approach Medium is a nice warning to drop to Medium before a Medium Clear the next interlocking, Improvements that are coming with the new signals.

I do not know how often NS does a siding run through at Leesburg. The closest I came to witnessing one in person the opposite train had not cleared the far interlocking so the through train wasn't cleared to leave the siding until after it had already entered the siding. By the time it reached the far end the opposite train had cleared the interlocking and the switch changed and the rout was cleared for the siding train. (I do not get to Leesburg often when there are trains present.)

Speaking of Leesburg, at the first signal north of Leesburg at W900N crossing on the south electronics hut I think I see a GPS antenna? What pray tell would this be for? Part of PTC perhaps?

Also first time to see new interchange at Claypool yesterday. Lots of new signals. Interconnect track looks to be super elevated. Is there really that much traffic WB to NB from the old Nickel Plate? Makes it nice to run 765 to Elkhart!

New signals at Leesburg north switch are awesome. Sad to see changing of the guard. Same way I felt when semaphores where pulled off the Monon.

I posted a photo of CP 19 yesterday in the Marion Branch thread ...
viewtopic.php?f=27&t=32532&p=344687#p344687

I would not expect to see a signal upgrade that did not include PTC.

BTW: Prairie St reopened Friday over the NS near downtown Elkhart. A nice four lane road with sidewalks on both sides over the tracks.
No parking on the bridge or approaches. The closest is on Main St near Prairie.

Along with prairie st project NS also eliminated the Elkhart and Western connecting at cp 421 and its on a hand thrown switch east of prairie now.

justin_gram wrote:On the NS (ex Conrail), yellow over flashing green is an Apprach Limited indication, meaning to approach the next signal at Limited speed, 45 MPH. Red over Flashing green means Limited clear, proceed through this signal at no more than Limited speed, 45 MPH.

Except on the NS (at least the former CR lines), limited speed is 40 mph, not 45.

SD80MAC wrote:

justin_gram wrote:On the NS (ex Conrail), yellow over flashing green is an Apprach Limited indication, meaning to approach the next signal at Limited speed, 45 MPH. Red over Flashing green means Limited clear, proceed through this signal at no more than Limited speed, 45 MPH.

Except on the NS (at least the former CR lines), limited speed is 40 mph, not 45.

NS Operating Rules January 1, 2015 show:
"Limited Speed — For passenger trains, not exceeding 45 MPH; for freight trains, not exceeding 40 MPH."

Perhaps the difference between passenger and freight?

rob46580 wrote:Along with prairie st project NS also eliminated the Elkhart and Western connecting at cp 421 and its on a hand thrown switch east of prairie now.

I was in a hurry when I went through there last week and didn't notice that.

A look from Prairie St ... Note the old Elkhart & Western signal is present but dark.
The new switch and derail between Prairie and Monroe St.
Just add trains ... apparently I picked a slow time to visit. This is a view through the fence of the Prairie St bridge.

Is there any evidence of new crossovers being installed at CP 421? A source had described some future plans for CP 421 and the removal of the Elkhart & Western switch was one of the changes mentioned. It sounds like they are planning on simplifying the crossover arrangement at CP 421.