Hello everyone! It's good to be back here. I am off model railroading to pursue other miniature interests, but most importantly I have started planning for my new layout. And I need some help with Signalling. To give you a brief background, I am planning to build a small junction in the New York Central's Adirondacks division in the dying days of logging - late 1940s. It is basically a long and thin switching layout focussing on slow speed operation. The layout is very simple - NY Central mainline with a passing siding which also double up as a station (I might decide to make it a TO station later, but that's in the future). A couple of nearby logging line interchange with the line here. There is a small quay and a small engine facility. I really want to install proper signalling for the layout and that is where I need help. I have been researching on the internet, looking at videos but I am still not confident that I am on the right track, hence this post calling out to the signalling experts. Plan is to model CTC. The attached schematic will tell you about what's been planned. I am planning to predominantly use G type signals, may be a couple of semaphores. The green/yellow side of the G types, and the orientation of the text denotes direction of journey. Text against each signal head shows what they are protecting. There are a few forks that do not require all 3 aspects (Quay, Engine Facility etc) and those will be made 2 aspects. First, I need validation that I am on the right track (please keep in mind the railroad and the era too), second, I need rectification of whatever mistakes I am making. Any help is appreciated. Thank you in advance and hope you all have extra railroading time this labor day weekend. Kaustav
Are those double-slip switches on each end of the passing track? To be accurate for NYC CTC, there will be a lot of "Restricting" aspects displayed for several of the routes.
Yes, those are double slip switches. This is the best material that I found so far: https://nycshs.org/about-n-y-c/nycs-signal-rules/ What it looks to me is that for each of the routes there needs to be multiple heads - e.g. for my design, both the ends of the siding will have 3 heads for each of the lines - the mainline and the passing siding and station. The problem is that given the layout is small, there is not enough information to put on all three heads - there is valid information only for two heads. So, yes, I am looking at a 'simplified' version as much as possible. How would you correct what I have drawn? Thank you, Kaustav P.S: Multiple heads for one line also increases the cost drastically, and for practical reasons, I want to keep an eye on that too because signals are not cheap. Now, I do have operating switch machines, so I can have "Proper signalling" just for the mainline, and may sacrifice it for the forks. Question is I am not sure how that will look.
These are the two summary pages of the NYC Signal aspects. I am only interested in Double Head Interlocking. So, if I am understanding this correctly, for each of the blocks that the signal is protecting, there will be at least 2 heads. Now how do I model diverging routes? The general rule is for masts with multiple heads, mainline is on top and diverging route is on the bottom. So, for a diverging route, do I have 4 heads in a mast - top two denoting mainline, and bottom two denoting diverging route?
Well, for starters, movements left to right at CP 2 to the Quay or either engine house lead would be Restricting from the mainline or passing siding. Movements from right to left at CP 2 from the Quay and either engine house lead would be dwarf signals, and would display Stop or Slow Approach. Movements from right to left at CP 1 to the logging line or the interchange would be Restricting from either the main or the passing siding. Movements from the interchange or logging line would be dwarf signals, displaying Stop or Slow Approach. I'll have to think about how I can explain the rest, if it is truly a CTC signaling system, But based on your layout of routings, most everything would be a diverging route, so would not have much better than the slow speed signals.
Hi Kaustav I think that it should all be a bit simpler than what you have in your diagram. NYC is a speed signalling system (not route signaling) so you will need to define what the applicable speeds are. If you can avoid slow and medium speeds, and stick to limited for the main line and loop through routes, with restricting for the rest, you should be able to eliminate any need for triple head high masts or double head dwarfs. All the masts will only need a fixed red top head or be dwarf with all the aspects indicated on the lower head (flashing green = limited clear, flashing yellow = limited approach, solid yellow = restricting, red = stop). Exits from sidings can of course just be single head dwarfs because the top head is implied and does not need to be present. If you need to have medium or slow speeds signalled you will need to add a third head to the high masts and dwarfs may need to become double or triple head. The quay line might be exiting through a low speed turnout so might need to display slow clear with solid green rather than flashing green, but that is all down to how the speeds are defined for the turnouts - while you might be able to infer a route from the signal aspect the aspects do not explicitly indicate a route - just a speed. So to sumarise:- Entry signals from the main line = 2x double head inline masts with fixed red top head and red/yellow/green lower head. Gantry signals on signal bridge = 2x gantries each with 2x double inline head dolls with fixed red on top head and red/yellow/green on lower head. Dwarf signals on siding exits = 5x single head dwarf with red/yellow/green. You just need to make sure that you use a signal controller that can do all the flashing! Signalist SC1 would be my choice to make this easier. If you are using JMRI you will be able to create an extra virtual signal mast on each exit route to simulate the off-scene track to allow the exit signals to go from red over flashing green to red over red to red over flashing yellow back to red over flashing green as the train departs. If the line is not very busy there is a good chance that the red over flashing yellow aspect will never actually be seen if the interlocking is put back on hold as the train departs and the hold is not released from the CTC panel until there are at least two clear blocks so you might not need to worry about operating the off-scene signals too much (the virtual signals will need to be there to create the logic). JMRI will allow you to create a timer in LOGIX to automatically change the aspect of the virtual signals if you are keen. Have fun - it is a nice (if a little quirky) prototype from a signalling perspective. Suzie x
I based the speed signal aspects on what is realistically the size turnouts he is most likely using. To properly be able to utilize limited speed signals, he is going to have to have at least #18 turnouts based on the standard that the maximum safe speed through a turnout is 2.5 times the frog number. If he wants to use those aspects because they look neat, that is up to him. My years of railroading tend to make me look at doing things more prototypically on my model railroad. So Kaustav, make sure you enforce Model Railroading Rule #1 in whatever you do.
Yes, it will probably take quite a lot of modellers license to pretend that those slips are #18! Triple head masts it should be.
Thank you Suzie! That's very helpful indeed. Yes, I have been doing some research of my own and the fact that I realized that NYC used speed signal vs. route signal made things much simpler indeed! My decision of placing signals came after designing the layout (much like the real railroads did!), so I was pretty confused for a while how to manage those double slip switches. I will be posting my findings in a separate post, and then let's talk further. Thank you! The entire operation will have to be medium to slow speed, however, it seems that given this is a small junction it will be possible to handle it with just two signal heads per mast. I believe in doing things prototypical fashion too, but at times, it gets difficult to get the right documents. Fortunately this time, I think I managed to grab hold of just the thing. However, I am not an expert in america signalling (yet!) and I would definitely need help from you guys to fine tune things a bit, and validate my interpretation of the documents. Thank you both for valuable suggestions - really, very helpful.
While researching about the prototype, I found quite a few websites sharing scanned copies of NYC signalling aspects, however, two documents stood out in terms of providing the information in vivid detail - 1927 NY Central Instructions to manage their newly installed target signals, and an article from Volume 20, Number 9 of the Railway Signalling from the same year explaining the entire system in layman's language (That's my language by the way!). I have attached both the documents here. The biggest bonus of these documents is the route and signal diagram of the actual New York Central lines. I have also attached a document that shows the rules in 1937 and 1956, sort of providing a complete picture of NYC signalling of that era. Now, looking at the three documents and my plan, it seems to me that I can operate this layout with the below aspects: Stop Approach Limited Approach Medium Restricting Slow Clear Slow Approach (Dwarf) Approach Approach Medium Limited Approach Limited Clear Clear The documents say that it is possible to denote all the above aspects with just 2 signal heads, hence my revised signal plan is below: Now, I do not mind getting 3 aspects if required, however, there are two main reasons I am exploring the possibility of 2 aspects first. Cost (signals are costly!) I am going to use Digitrax SE8C and Digitrax Signal masts (already purchased). The problem is that Digitrax's inbuilt logic uses route signalling and not speed signalling. So while they say that 'each signal driver cable can protect one control point and 4 signal heads' what it actually does is that it drives 3 signal masts - one to protect the diverging route, 2 to protect the turnout approach from the other direction. Now, I have decided to use just the 'diverging route' mast in the Digitrax system for all my signals to simulate the speed aspects, but give it drives only 2 heads, I don't know if I can use the same hardware to operate 3 heads. Now, I am ready to add one more signal head per mast where required, if someone can tell me how to use standard Digitrax signalling system to simulate 3 aspect speed signalling. Digitrax uses each signal head as a switch address, and I will be using JMRI, so I 'feel' that it is possible; but I don't want to purchase additional signal heads without knowing for sure that my hardware can support it. Thanks to everyone for all the help - much appreciated.
Two of the files are interesting to me because I operate into Stanley yard, but the track arrangements are slightly different now, and I go by the old dispatcher's tower in Fostoria when I am routed through there.
Wow! That is interesting! Never thought that I would be able dig up a 90 years old piece of history so close to your home, from halfway around the world. That is the power of the internet my friend. Hope you enjoy the articles, I sure did. So, once you manage to read through that, please let me know about your thoughts on the revised design. I am keen to make it as close to the real thing as possible while staying within my constraints. Thank you again for all your help. Kaustav
A great page (which is now defunct, unfortunately) to push you through that journey is: http://web.archive.org/web/20160313144451/http://alkrug.vcn.com/rrfacts/signals/signals.htm
Very nice! Thank you for sharing! I will take a back-up of all the information, and may be consolidate them and create a fresh document when I have time. Thank you for sharing.
I'm slowly trying to pick my way through what would be needed. There are 2 types of signaled passing sidings, controlled and signaled. Controlled sidings get a Restricting to enter and "Could" get a medium speed signal to leave. It appears that the sidings on the example you provide are Controlled sidings, with Slow Speed signals to leave. That was common around here on both the NYC and the B&O. Signaled sidings would give you a "speed" signal aspect to enter and to leave. So would setting moves up to enter the passing siding at either end, from any track, with a Restricting signal make things easier for you?
In an "ideal" world, this is how I would do it, based on the aspects I expect each signal to need to show, for what I've seen of the track layout: I have decided/designated all of the switches are SLOW speed, except for [4] and [8] which are MEDIUM speed. I've never heard tell of a particularly-fast double-slip, but then I've not heard tell of quite a few things, I am sure. The use of MEDIUM speed requires three signal heads, so three heads are needed on several signals. Entering any of the unbonded tracks (names marked in red, with asterisks) should show a Restricting indication (R/Y or R/R/Y). In this diagram, no signal lights need to flash. Note that I've planned for a few fancier aspects, such as Approach Slow on [3E] when switch [2] is normal and [10] is diverging. [1E] and/or [7W] could show Medium Approach Slow when traveling through via [2][4][8][10] or vice-versa. Otherwise, all signals before a diverging movement signal show Approach (or Medium Approach; Restricting for dwarfs and 2-head signals). No flashing aspects also means any of these colorlight signals could be replaced by semaphores with little else changing. Except for dwarfs, I would avoid any 1-head/arm absolute signals, however. I don't know when the NYC phased those out, but always better to have 2+ lamps lit.
You're quite welcome. I can't "explain signals" much better myself, though I've threatened for years to create a similar guide. One important thing to keep in mind is he mentions there are three ways to show Restricting on a signal. But there are four. And it's a bit odd to me that he doesn't mention that fourth method since he's more-or-less following the NYC aspects he saw as a kid, which did not use Lunar White nor Flashing Red. Instead, Yellow in the lowest position indicates Restricting—Red over Yellow for a 2-head signal, or Red over Red over Yellow for a 3-head (plus, Yellow alone or Red over Yellow on a dwarf). Since SLOW speed is always shown with the lowest head on regular signals, it means that Slow Clear always downgrades to Restricting, as Slow Approach cannot be shown on such a signal (in this schema). Other/newer railroads would go on to have flashing that Yellow indicate Slow Approach, but the NYC never did this to my knowledge. These are the types of subtle differences that exist across various signaling systems in the United States.
Jovet, this is absolutely fantastic. Thank you for taking time to draw this - it is fabulous! I read through the link you shared (and also saved it in a PDF for future reference), and tried using that to understand the NYC instructions and documents that I gathered. No need to mention that that article helped me understand my research material much better - so thank you! The main reason I was confused as to why I cannot use just two head instead of 3, was because of how the diagrams of the signals appear in the NYC instruction booklet that I found, I was under the impression that a 2 headed signal shows a 'medium and slow' aspects as opposed to 'high and medium' aspect. That's why I kept on thinking that if I do not even have a high speed route, why do I even need to have a signal for it, especially when most indications of a three head signals can be provided in a 2 headed signal by flashing (which I am OK with for most signals I will be using). The understanding that a 2 headed signal is for 'high and medium' and not for 'medium and slow' made thing clear, finally. One question though, most high speed heads in your diagram show a single search light type head as opposed to a larger target signal head - in the pictures of the old NYC signals, I have never seen that - I have seen two/three color/lamp for medium, and two or single color/lamp for slow as the most common heads. The high speed head always had three colors in all the photos that I have noticed. So in your diagram are those heads meant for just denoting the red aspect and in the actual model you expect to see a larger target signal type head, or is there something that I am missing here?
NYC would standardize on the "bowling ball" triangular pattern head and just use the colors needed at a particular location. Unused colors would be "blanked" with no light box, just a plate over that particular hole. So you would use a triangle head with green and yellow blanked out.
