I am working on figuring out signaling for my layout. In looking at the photo below I want to protect the passing siding in the second picturer with the white pushpins heading in both directions. On the right it is entering into a switch, to the left is the balance of the siding. Would I use a single mast with a signal head facing in both directions here (thinking where the S with the arrow is)? If not how would I signal it?
Also would it be prototypical for the train to be stopped on the switch waiting for a green to continue down the siding or would it be stopped some distance before the switches? The first photo shows the entire area in question.
Hopefully these questions make sense, I am just starting to learn enough to even know what questions to ask. Thanks in advance!
- Bill Rutherford Lancaster, NH
Central Vermont Railroad
Depends on whether you want to be prototypical or you just want lights to indicae which way the switch is thrown.
Assuming the two through tracks with the crossover are main tracks, There would be a signal on each of the two main tracks, at the points of the rightmost switch in the crossover. At the "E" near the pliers that would be 4 signals, one for each of the 4 tracks. The angled track and the siding would both probably be dwarf (low) signals and the two on the mains would be full sized masts.
All the signals on the right side would face a train moving right to left and all the signals on the left end would face a train approaching from the left.
Dave H. Painted side goes up. My website : wnbranch.com
dehusmanAt the "E" near the pliers that would be 4 signals, one for each of the 4 tracks. The angled track and the siding would both probably be dwarf (low) signals and the two on the mains would be full sized masts.
I normally wouldn't quibble with anything Dave H. says, but if that angled track is an industry spur, the switch would probably be manually thrown, and outside of the interlocked signals. So the signal could be located between the switch points of the spur switch and the crossover. Three signals for trains approaching from the left side; mast signals for the top two mains, and (probably) a dwarf for the third track - but it can be a full signal too.
This of course still assumes you're trying to do a "proper" realistic interlocking controlling crossovers, and not just switch-position/route indicators for all the switches.
Chris van der Heide
My Algoma Central Railway Modeling Blog
cv_acrI normally wouldn't quibble with anything Dave H. says, but if that angled track is an industry spur, the switch would probably be manually thrown, and outside of the interlocked signals.
I agree but he never said what any of the tracks were other than the "siding". If he redefines the tracks to different things or says he isn't doing CTC it changes the whole arrangement.
Hey Bill-
You've asked a fairly complex question which would require a fairly complex response to answer fully (particularly in writing). Both Dave and Chris addressed the issue faithfully. My rambling answer is also a faithful response . . .
The first thing to ask is do you want to be prototypical, or simplistic enough and practical for model railroading?
The way I understand signals is that they indicate three things: 1) the position of the switch, 2) occupancy of the next block ahead, and 3) occupancy of the following block after the next block ahead, and 3a) the position of the any switches between 2 and 3. These indications would be shown on two sets of signal heads facing both directions. The technical term for these signal masts, signal heads, and occupancy detectors is a signal plant.
Looking at your overall first photo . . . for left-to-right traffic with the train standing about where the white pushpins are, the 'next' block of the through track is only about as long as the little yellow tray holding track joiners (Dave overlooked this, which is practical for model railroading). The next following block for the diverging track is about the same length and is the short section between the crossover turnouts. And then the condition of the following blocks for each route and the position of the switches in between goes beyond the limits of the photo. The right-to-left traffic signals are similar, but understandable if broken down and addressed one thing at a time.
The logic of whatever software you use to set the indications on the signal heads of your system would take this into consideration and turn on/off red-yellow-green lamps in the signal head. This is prototypical. I would suggest you go with the simpler system.
Good luck.
Robert
LINK to SNSR Blog
Yes I want to do CTC and be as protoptypical as possible without giving myself too much of a headache lol.
The bottom left track is a spur track and the other three are passing tracks.
Here is the track plan which should make it a bit clearer. The area in question is just to the right of the word Newport
Thanks everyone!
B Rutherford Yes I want to do CTC and be as protoptypical as possible without giving myself too much of a headache lol. The bottom left track is a spur track and the other three are passing tracks. Here is the track plan which should make it a bit clearer. The area in question is just to the right of the word Newport Thanks everyone!
This is good. The track plan helps. Dave's sketch pretty much captures the essence of the situation, but will need to edit one of the stub tracks. Here's a rough sketch as I see it. Your track plan has a vertical aspect, but the horizontal aspect is easier to see on my screen. Apologies.
Now, what software and/or electronic stuff will you use?
Digitrax along with JMRI and CATS if needed (haven't played with CATS yet)
B Rutherford Digitrax along with JMRI and CATS if needed (haven't played with CATS yet)
I would like to have a train be able to pass from E to A or E to B (or vice-versa) while a train on C works D & F
Tracks A through F can be considered as blocks, and Digitrax has detectors to indicate occupancy. There are also undesignated (and undetected) blocks between turnout 1 and 2, 2 and 3, and 3 and 4, and JMRI would want to know their occupancy status to determine the logic. We can ignore those three blocks for convenience (model railroading), but if we do I don't know how to inform the JMRI logic. There are also additional blocks to the left of A, B, C, and D and to the right of E and F that JMRI would be interested in, but we can ignore those for the purpose of this exercise.
This might come down to the dispatcher providing the logic by visually inspecting the occupancy (from Digitrax block detectors and lit on his screen, or just by eyeball) and then manually setting the red/green aspects of the signals. Workable, but not too elegant. Semi-automatic.
Still thinking about this.
ROBERT PETRICK
isn't a single signal facing right needed as E
while there are signals facing left as A, B and C
greg - Philadelphia & Reading / Reading
gregc ROBERT PETRICK isn't a single signal facing right needed as E while there are signals facing left as A, B and C
Yes. A train heading left on Track E doesn't care whether Switch 1 is thrown or not, it can traverse the turnout safely either way; providing that Track A is clear. Likewise, the alignment of Switches 2 and 4 doesn't matter (but Switch 3 does). A train heading right on Tracks A, B, C, and D need to know the position of Switches 1, 2, and 4 (Switch 3 doesn't matter; providing that Track F is clear) to safely traverse the turnouts.
I need to protect direction of travel both ways on A, B, C
Lets suppose that turnouts 1 and 2 are aligned for a train headed to the left to access track B *BUT* there is a train stopped on B then I would need a red on B for trains headed to the left. That signal needs to be on B side of turnout 2. So the question is would I use a single mast with a signal facing each direction at the entrance to B? Is there such a thing or would there be a different way of doing it?
B Rutherford I need to protect direction of travel both ways on A, B, C Lets suppose that turnouts 1 and 2 are aligned for a train headed to the left to access track B *BUT* there is a train stopped on B then I would need a red on B for trains headed to the left. That signal needs to be on B side of turnout 2. So the question is would I use a single mast with a signal facing each direction at the entrance to B? Is there such a thing or would there be a different way of doing it?
I wish I were a better writer or a clearer thinker to explain this. Some of this is explained in the manual for the Digitrax SEC8; and like all Digitrax manuals, it reads pretty much like Mah Jongg instructions.
All signals on my layout have two heads (except the dwarfs mentioned earlier), and all turnouts have two signal masts, one facing each direction. In all cases, the top head indicates the through route of the turnout and the bottom head indicates the diverging route.
From the facing side (the single track) of the turnout, both top and bottom heads have to be read simultaneously. From the trailing side (two tracks), either the top head or the bottom head (depending on which track the train is on) needs to be read. On my layout, the trailing signal mast is positioned between the fork in the tracks, and the facing signal sits on either side of the tracks (whichever is clearer of scenic obstructions). This could be made simpler by using overhead truss support or overhead cantilever supports of the signal heads.
The SEC8 has ribbons that send aspects to both the leading signals (both heads simultaneously) and the trailing signals (each head individually) as explained in the aforementioned manual. The JMRI logic determines which light (red/yellow/green/flashing yellow) on which head is lit.
Based on the new information, here is how the prototype would signal the location (R= remote switch, M=manual switch):
Obviously you have compressed things more that the prototype would, which complicates things.
The question becomes, what do you do with the leaving signal out of the siding?
If you move the signal to the left of the switches, then you are going to need a signal leaving each track really complicating things. Or you could move the leaving switch up next to the frog on the siding switch.
For a movement to the left assuming no other trains:
Main track normal = G over R
Main track reverse, siding for siding = R over Y
Main track reverse, siding for industry = R over Lunar
ROBERT PETRICKYes. A train heading left on Track E doesn't care whether Switch 1 is thrown or not, it can traverse the turnout safely either way;
Yes it does make a difference. Lined normal (A to E) it will be a clear signal. Lined diverging it will be a a more restrictive signal such as a diverging or medium signal.
Likewise, the alignment of Switches 2 and 4 doesn't matter (but Switch 3 does).
From a prototype perspective it's the opposite of what you have said.
If switch 2 is lined for the siding, assuming the siding is "bonded", has detection in it", if switch 2 is lined for the siding, signal A can give an indication better than restricting. If switch 2 is lined for the industry tracks the best indication it can give is restricting and it doesn't matter how the other tracks are lined.
Dave,
Thanks . So how would the crew handle the manual switches? Would the conductor manually inspect the switches to determine how they are lined? Assuming the train where taking the diverging side off the remote switch the train would need to stop to determine how the other switches were lined, and/or change them?
cv wrote: "I normally wouldn't quibble with anything Dave H. says, but if that angled track is an industry spur, the switch would probably be manually thrown, and outside of the interlocked signals"
Back when I worked Oak Point Yard (South Bronx) in the 1980's, there was a customer that received cars of flour in the Woodlawn area (north Bronx).
The switch to their (short) siding was within Woodlawn interlocking limits, where the New Haven line joins the Harlem line.
The switch was hand operated, but there was a low signal governing movements from the spur track back to the main track.
You didn't need a signal to open the switch, you were already inside the interlocking limits. But after you placed the car at the bakery, the dispatcher would display the signal for you to come out of the siding and BACK INTO interlocking limits.
I recall it as being underneath the 233rd Street bridge (which crosses right over Woodlawn). After 40 years, it's almost certainly gone now.
B Rutherford So how would the crew handle the manual switches?
So how would the crew handle the manual switches?
Yes, the crew would manually get on the ground and manually line the manual switches.
Would the conductor manually inspect the switches to determine how they are lined? Assuming the train where taking the diverging side off the remote switch the train would need to stop to determine how the other switches were lined, and/or change them?
Switches are required to be left in the "normal" position, typically for straight away movement. The switch into the siding would be left lined for the siding.
A train heading into the siding would get a a diverging or medium speed signal at E. That would tell them the switch was lined for the siding and they wouldn't stop to line that switch because it would already be lined for the siding.
If the switch to the siding was lined toward the industry tracks, reversed, the signal would display restricting which tells the crew to proceed prepared to stop short of obstructions or switches not properly lined. They would know that they have to line switches or be prepared to stop and line switches.
[/quote]
Thanks!
ROBERT PETRICKThe way I understand signals is that they indicate three things: 1) the position of the switch, 2) occupancy of the next block ahead, and 3) occupancy of the following block after the next block ahead
Actually, for 3) it's the next SIGNAL, not the next block.
e.g. if you are approaching an interlocking/control point you might be seeing something like an "Approach Medium" or "Approach Diverging" indication, showing that the block is clear, and the next signal down is showing some sort of medium-speed or diverging indication through switches at the interlocking.
If it's a "speed signalling" system, the signal indication infers up to TWO potential pieces of information: the speed at THIS signal (based on switch position and block occupancy) and the speed at the NEXT signal (based on switch position and block occupancy), if applicable (if this signal is Stop or Restricting then the next one obviously doesn't come into play).
While I am not necessarily disagreeing with with Chris has said might cause a particular signal, I will mention that what I was taught and we covered in prototype rules classes in not to "infer" anything. Don't guess what might be happening at the next block or couple of blocks. Do what the signal tells you to do and don't try and out guess the system. It's amazing how many cews have gotten into trouble thinking that the "next block" or the "next signal" is going to be one thing and it turns out it's something else.
dehusman While I am not necessarily disagreeing with with Chris has said might cause a particular signal, I will mention that what I was taught and we covered in prototype rules classes in not to "infer" anything. Don't guess what might be happening at the next block or couple of blocks. Do what the signal tells you to do and don't try and out guess the system. It's amazing how many cews have gotten into trouble thinking that the "next block" or the "next signal" is going to be one thing and it turns out it's something else.
I'm an engineer on the outfit Dave H. retired from. Once, almost in Dave's backyard no less, I had a student engineer running the train. We went past an approach signal. That block was 3 miles long to the next signal. The signal we went past was on an upgrade that crested about the middle of the block. The next signal was on the downgrade, steeper than the upgrade side, on a curve and depending on the time of year and what crop the farmer planted in the adjacent field, you wouldn't see the signal until you were on it.
We crested the hill about 25 mph or so when the student said, "I think the next signal will be another approach." I said, "And I think I'm going to pull the air (open the conductor's emergency brake valve) unless you get us down to a crawl, prepared to stop at the next signal until we can see it."
I then explained that he was probably correct that the next signal will be an approach. But you can't think that way because one day the train ahead might've stopped for some reason. (It's a location close to our away from home terminal and trains would sometimes bunch up waiting to get in.) That preceding train might only be a foot beyond the insulated signal joint and you wouldn't know it until it was too late.
Jeff
Jeff's story reminded me of this incident outside Chicago in 2007:
https://www.youtube.com/watch?v=r2r139F9CUo
https://www.jonroma.net/media/rail/accident/usa/ntsb/RAR0901.pdf
[from the report]
The engineer said that when he saw the red over yellow signal, he called out slow approach in the cab and announced slow approach on the radio to the conductor riding in one of the passenger cars. A slow approach signal would have required the engineer to not exceed 30 mph and to be prepared to stop short of the next signal; a slow approach signal also would have conveyed that the section of track beyond the signal was not occupied.
The relief engineer told investigators that after the engineer had miscalled the signal at Englewood, she had thought to herself, “… maybe [the engineer] just called it wrong but he knew it was a restricting.” She said that she had “wanted to see what he was going to do.” She also said, … when the vision came clearer, I could see it was a red over yellow which is a restricting, and when the engineer called slow approach, I started questioning what I knew of signals, and I started going through my head what all the signals are in the NS [Norfolk Southern] and what their aspects are.
Once the train cleared the curved track at MP 516.3, the engineer accelerated the train to more than 40 mph. The relief engineer said that she had become uneasy about the speed of the train and that she had challenged the engineer.
She said that she had asked the engineer what signal he had called at the Englewood interlocking. She said that he responded that it was a slow clear. (A slow clear signal would have allowed the engineer to accelerate to a maximum authorized speed of 40 mph after clearing the crossovers and the curve restrictions.) During postaccident interviews, the relief engineer said that she told the engineer, “You called a slow approach at Englewood, right? … Even if it’s a slow approach, you have to be down to 30.”
Sounds like the relief engineer (IIRC only recently certified) knew more about situational awareness, and NS signals, than the engineer at the throttle.
Regards, Ed
Ed wrote: "Sounds like the relief engineer (IIRC only recently certified) knew more about situational awareness, and NS signals, than the engineer at the throttle."
Seems to me that the signal aspects were the same but the indications were different, considering that the two engineers came from different territory.
On the NYC/Penn Central/Conrail (was this particular piece of track former CR?), red-over-yellow was "Restricting".
The [brand-new] engineer was probably taught this way for the territory she was working.
But I believe the other [older] engineer had previously been working in other territory, not of the NYC/PC/CR lineage, and the red-over-yellow aspect in that territory had a DIFFERENT indication.
I remember posting someplace (perhaps "Misc.tranport.rail.americas"?) that in a time when railroad t&e folks get moved around all over the place, and work in different territories, that there should be an effort by the FRA and RR's to bring all signal aspects and indications into "conformity". That is, a particular aspect should have the same indication everywhere. Things "out there" could be confusing enough at times as it is...