# The more i read, the more confused I am - Signals



## Therios (Sep 28, 2008)

*The more i read, the more confused I am - Signals* Sorry to those ahead of time that will tell me "go read this". My head is swimming. Eventually, I plan to put signals on my system. Now I have several questions that I can't seem to get answered. And digging it out of reading is killing me. So I plan to ask a couple of questions for clarification.

I would bet that I am just overthinking things again. But this can't really be all that tough. It is just a bunch of really primitive logic. Don't know why I can't get a handle on it.

SWITCHING
Ok, so there are dwarf and pole(?). I know the difference and I know there are differing styles and sizes and such. I think that I pretty much have all that down. Except for yellow. A-entrance. B and C are legs. Approaching A there are two heads. Approaching B and C there are single heads. I understand the red and green. Some have yellow, right? When would you see a yellow?

BLOCKS
I also know that there are a plethora of kinds. So each block is or should be longer than the longest train you will run. Obvious in real life but could be harder in some cases in scale. I can handle this. So red means the block ahead has a train on it. Green means not. Is there a directional thing or do you just slam on the brakes if you approach a red signal. Is there Yellow? What does that mean?

COMBINED
So what if I have a switch aligned to a crossing that has a train on it? Would signalling tell me that? How and where? This would mean the two would have to talk in some method right? 

So the next and most complicated of it all, since JMRI will be handling all the above, is the hardware and wiring.

Check me if I am wrong:
1) Need to separate blocks and feeders and run them through a block sensor board. Any alternatives to the 8 block sensor from digitrax? My long main will be 8 blocks. I have 54 sections of track on the main. So that is 7 or so per block or 21' per block. I really think thayt will be enough even for me.
2) obviously I need switch position sensing. I know digitrax has those boards with little heads that make signals as well. Better solution anywhere? Can I do this manually with a switch somewhere that senses the position of the switch? I am planning on using manual push/pull until I can dump a load of money on tortii. These boards work independant of JMRI or do they require it?

Thanks for any assistance. Sorry for being a lazy idiot but I am floating in information and just a little confused.


----------



## Scottychaos (Jan 2, 2008)

For a Garden Railroad (or any model railroad really) you basically have to ignore prototype practice! 90% of it anyway..
prototype practice is WAY too complicated for the average model railroad..


SWITCHING
Ok, so there are dwarf and pole(?). I know the difference and I know there are differing styles and sizes and such. I think that I pretty much have all that down. Except for yellow. A-entrance. B and C are legs. Approaching A there are two heads. Approaching B and C there are single heads. I understand the red and green. Some have yellow, right? When would you see a yellow?


Sounds like you might be getting bits and pieces from different prototype railroad's practices..Many railroads had VERY different signal systems, and protocalls..there was no one universal signaling system, or universal type of signal systems..So if you are looking at prototype signal systems all over the internet, from all over the world, from all kinds of different eras, its definately wont make any sense!  You have to pick just one railroad, during one era, and maybe then you can work out how their signals worked..


We have some "Z-stuff for trains" signals on our club displays, like this:

Z-stuff signal

They have sensors..they light "green" when no train is nearby..as a train appraches and passes the signal, the light immediately turns red (because there is now a train *ahead* of the signal..it turns red to warn any second train coming up behind that there is a train in the next block, and they have to stop) after a short period of time..30 seconds or so, the signal turns briefly yellow, then back to green..then stays green until a train passes again..this is a simple prototype practice used on many red-yellow-green "mainline" signals..

of course its possible to get more complicated than that!  if you want to..
but first figure out what you want signalling to do, on your own railroad..you cant mix-and-match hundreds of conflicting prototype systems..that will get you no where! 

Scot


----------



## Greg Elmassian (Jan 3, 2008)

If you use JMRI, it can control the signals, and give you the prototype operation you are asking about. 

(by the way, it's my opinion you are making the right choice using jmri, rather than some proprietary system of hardware) 

The first step though, is the block detection, how you are going to do it and feed it back to jmri. 

Once you have that, then it's simple to program how you want your signals to respond, and you can use simple decoders, like the $14 FL4 to control the lights. 

Greg


----------



## toddalin (Jan 4, 2008)

For a garden railroad, the blocks should be arranged in some logical fashion, (e.g., turnout to turnout), but this is not always ideal if you intend to run operations. It is then easiest to toggle the turnouts using an electrial switch either attached to the turnout(e.g., LGB EPL system), or you can use relays to activate the signals that are toggled using the turnout toggle switch.

If you want to incorporate sensors to toggle/deactive the signals, you can use magnets and reed switches, track gaps, or some optical/electrical detector. The simplest dectectors can be just a track gap or reed switch and a relay with a wall wart for power. If you just want the signals to change as the train proceeds around the layout, this relay circuit that I came up with is probably the easiest way.

Tortoise Bump Block Detection:


----------



## bnsfconductor (Jan 3, 2008)

Here's a quick primer on prototype signals. 
Red - Stop 
Yellow- Approach prepared to stop at next signal 
Green- Clear block proceed at track speed to next signal 
Now here's more confusing signals 
Red signal with a station name -Absolute stop, need dispatchers authority (not permission) to proceed past red signal 
Red signal with number plate or Grade sign- stop and proceed at restricted speed (prepared to stop for obstruction on track) 
Flashing yellow- Approach medium next signal will be yellow, or could be crossing over at next signal to another track, reduce speed to 35 
Yellow- Reduce speed to 30 prepared to stop at next signal 
Yellow over Green- Advanced Approach- proceed at track speed prepared to crossover at next signal, (reduce speed for turnouts 50mph) because turnouts generally have lower speed limits then the track speed limit) 
Yellow over flashing Green-Approach Limited (same as above, but higher turnout speed 70mph?) 
Flashing Red- proceed at restricted speed 
Lunar (white)-proceed at restricted speed 
Lunar over Red " " 
Red over Lunar- " " technically but when a lower signal head displays an indication it means your crossing over. So in this case you would be going into a yard track or other unsignaled 10 mph track 

Hope this doesn't confuse you more. Only the first 3 would most likely been seen on a garden RR, with the possible addition of the Approach Medium (Flashing Yellow) 

Craig


----------

