Signal Complexity

This forum is dedicated to Riding Scale Railroading with propulsion using other than steam (Hydraulics, diesel engines, gas engines, electric motors, hybrid etc.)

Moderators: Harold_V, WJH

rkcarguy
Posts: 1240
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: Signal Complexity

Post by rkcarguy » Wed Jan 02, 2019 4:16 pm

+1 John, it's pretty hilly in my area too. While I'm basically doing the signals for my own amusement unless I have a guest, I'm still going to do it right, and size the blocks for the grade, visibility conditions, and expected tonnage I'll be moving.
As for multiple trains in a block, if the "light" was following the "heavy" I don't see an issue as long as everyone is paying attention. The other way around though, and you have the ingredients for a wreck. I agree though, that one train per block is highly preferable.
Don't forget though, that even that "light" can get heavy with more passengers. My dad, my uncles, and I are all 6'-2" + and just the 4 of us is easily over 1000#'s.

User avatar
ChuckHackett-844
Posts: 113
Joined: Wed May 03, 2017 3:54 pm
Location: Tampa, Florida

Re: Signal Complexity

Post by ChuckHackett-844 » Wed Jan 02, 2019 5:29 pm

johnpenn74 wrote:
Wed Jan 02, 2019 3:41 pm
Why have the signals at all if you are sectioning....

The signals are there to prevent three things, front end collisions and rear end collisions and derailments from too much speed in a route change. So I have to ask, if you not going to stop at a red signal for the occupied block in front of you, or start slowing because you have a yellow approach, then what's the point? Basically operators are just blowing off the very devices that were put into service to help protect the system in the first place. So signals are just there to be pretty and ignored?

I just don't get it. So many people at the clubs have a mentality of "This is a hobby so what can I get away with". Signals are designed and placed to improve safety, too bad if that's inconvenient. Maybe after we plow enough cabooses people will get to the point to ether slow or obey signal protection on a blind curve.
One thing I forgot to mention about us allowing "Second Sections". The rule is: "If you want to follow a train as a second section you must NOT pass a red signal UNLESS you can SEE the train in front of you and it is your responsibility to maintain safe separation from the train ahead"

This ("see the train ahead") is so that there is no chance that the Stop (Red) signal is due to a train headed TOWARDS you :-)

Now, as I said, this requires the following train to maintain a rational following distance just as he would have to do at a railroad that had no signals and just went round-and-round so, this "following" is nothing out of the ordinary.

I do not encourage it (I prefer that we have more meet/pass opportunities) but, at a large meet, it is kind of a fact of life for some with short trains who like to travel together.

I also think that this (allowing second section) is a club/track decision and should be followed without question.

When I am running my Northern I ask that people NOT follow as a second section because I don't want to have to worry if someone is going to ram me if I derail and/or have to stop suddenly (those automatic air brakes can bring a 120-foot train to a stop pretty fast) but, in the un-signaled (dark) territory all I can do is ask them to not follow closely.
Regards,

Chuck Hackett, UP Northern 844, Mich-Cal Shay #2
Owner MiniRail Solutions (http://www.MiniRailSolutions.com)
"By the work, One knows the workman"

User avatar
ChuckHackett-844
Posts: 113
Joined: Wed May 03, 2017 3:54 pm
Location: Tampa, Florida

Re: Signal Complexity

Post by ChuckHackett-844 » Fri Jan 04, 2019 3:10 pm

johnpenn74 wrote:
Wed Jan 02, 2019 3:41 pm
The signals are there to prevent three things, front end collisions and rear end collisions and derailments from too much speed in a route change.
In their common usage on ride-on railroads (in my opinion) signals are almost 100% "Route" and/or "conflict" (as you point out above) indications - not "speed" indications.

The average 7.x" engineer can easily handle that Yellow boils down to "the block ahead is clear but the block ahead of that is occupied" but it is not 'normal' in his experience that it's telling him to slow down (remember, 7.x" stopping distances are much shorter than prototype).

Even at a turnout, an engineer is way more likely to use his judgement on the correct speed for a turnout (right or wrong) rather than thinking "yellow means I need to use X speed" so you might as well present green or yellow based on track ahead rather than "speed" - but, I see no harm in using yellow when it would have otherwise been green - just don't get upset when 90% of engineers don't treat it as a "slow down".

Most times in 7.x" practice the signals are not located at separation distances dictated by scale stopping distances or scale train lengths (EPRR may be different, I don't know) but more based on where a track is going (double-head at a facing point move) or single-head to de-conflict (guarding a diamond, trailing point move/merge, etc.) - again, nothing really to do with speed in 7.x" practice.

In my experience, most railroads are not fully signaled - in other words, there are areas of "dark territory" (single uni-directional trackage, sidings, etc.) where the engineer is still responsible for maintaining separation distances even at a track with signals. This also holds when a train is pulling in behind another train at a passing siding (he needs to see and slow down to avoid rear-ending the train in front) unless you are going to place extra signals to control movement into the siding itself.

Which brings up another point: In my opinion (during a meet where there are lots of visitors) all signals should be absolute. I don't think we can rely on everyone to stop and proceed at 'dead slow' into a siding given a red at the entrance and yet know to "Stop and Stay" at a head-end signal - even with the use of a number plate being there or not. This means that (in the siding example above) we have no way to tell him to pull into the siding slowly because of the train ahead (if red means stop and yellow and green mean go). We have to rely on his observation of following distance.

Now, if a railroad absolutely wants/needs to have "permissive signals" and they want to use them for visitors I would think that a 50% flashing red could be used (like a flashing traffic signal at road crossings) because the average person has some familiarity with that or by placing a sign on each permissive signal that says something like "On red you may stop and then proceed at low speed to the next signal".
johnpenn74 wrote:
Wed Jan 02, 2019 3:41 pm
So I have to ask, if you not going to stop at a red signal for the occupied block in front of you, or start slowing because you have a yellow approach, then what's the point? Basically operators are just blowing off the very devices that were put into service to help protect the system in the first place. So signals are just there to be pretty and ignored?

I just don't get it. So many people at the clubs have a mentality of "This is a hobby so what can I get away with". Signals are designed and placed to improve safety, too bad if that's inconvenient. Maybe after we plow enough cabooses people will get to the point to ether slow or obey signal protection on a blind curve.
I guess it boils down to the philosophy of the railroad. Just as some railroads have designated themselves as "Steam Only" a given railroad can state that their signals closely follow prototypical practice and must be followed as such. This is easy to do on a private railroad or one where only members run. If the railroad wants to be open to general visitors (meets, etc.) and even if you offer extensive classes compressed for time (remember, what seems simple to you may be very complex to visitors) you need to be prepared for accidents (they forget or miss-interpreted something), and/or ask them to leave if they are not following the rules. Not "friendly" or practical in my opinion.

This is one reason I advocate solid-state signals for large tracks - it allows you to have one operating mode for "the gang" who want's to adhere to prototypical practice as closely as possible and another mode to be used during a meet, etc. (where "Green or yellow means go, anything else means stop") - no changing of wires, diodes, etc. just a software command ... Your mileage may vary :-)
Regards,

Chuck Hackett, UP Northern 844, Mich-Cal Shay #2
Owner MiniRail Solutions (http://www.MiniRailSolutions.com)
"By the work, One knows the workman"

User avatar
johnpenn74
Posts: 386
Joined: Tue May 04, 2010 12:54 pm
Location: Waiting for next assignment!

Re: Signal Complexity

Post by johnpenn74 » Fri Jun 07, 2019 11:42 am

Check it out fellas. Eaglepoint Railroad is turning to the Dark side....

Vader hoods on the new ABS route signals.

JP
Attachments
dark side.gif
CSME Vader Collage.jpg
John Pennington

Logging meets that actually move logs

Project
2 Mich-Cal Shays
Allen 4-4-0 Narrow Gauge Conversion
Two Reading A5a Camelback 0-4-0
USRA 0-6-0
Clishay
4 Western Wheeled Scraper NG Dump Cars
N&W 4-8-2
ICM 2-10-2
4 Modern Stake Cars
L&N Caboose
4 Big Four Conversion Gondolas

Like I'm actually gonna build all this stuff :-P

rkcarguy
Posts: 1240
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: Signal Complexity

Post by rkcarguy » Fri Jun 07, 2019 12:34 pm

Looks good John!
What are the buckets for?

I'll add that I had some conversations regarding the block sensing and leakage between the rails in wet conditions. Due to the variances in these factors from moisture to tie material type, distance between rails and length of the blocks, the detection circuit pretty much has to be "tuned" to each block. I think the ticket is going to be using fairly sensitive relays yet "dumbing them down" with resistors and playing with the resistor values to get the proper results. The level of power used across the rails can also be played with if the resistors and/or relays are getting too hot during wet operations. I can get my old Tech II out of my HO train stuff box and use that as an adjustable power supply during the tuning process, before buying, building, or repurposing power supplies for the detection circuits.

Something else I changed, is that when I built my first signal I used some conduit boxes and lenses that were all glued together and bedded in silicone sealant. They wouldn't be serviceable without grinding all the sealant out of the conduit box if an LED burned out. I found that by getting conduit boxes with pipe threaded ports:
https://www.lowes.com/pd/Sigma-Electric ... dy/1100323
….that the lens and LED light assembly can be bedded into a plastic threaded adapter and then is far easier to replace. I figure a nearby lightning strike or voltage spike, or maybe just LED burnout is inevitable so best to make the units serviceable.

User avatar
johnpenn74
Posts: 386
Joined: Tue May 04, 2010 12:54 pm
Location: Waiting for next assignment!

Re: Signal Complexity

Post by johnpenn74 » Wed Jun 19, 2019 3:58 pm

Buckets are a temporary electrical cabinet for the relay board. (pictured earlier)

This system uses led trailer marker lights. Best part is they are water proof. You have to take the head off to disconnect / reconnect when changing them out. Two screws pretty easy.

The relays are not any more or less sensitive. I have had good luck with heavier relays (run of the mill ice cubes) as it requires more amps to get things to move and has less problems with the relay sticking "on" when the train has passed.

You only have to get into resistors if you are making an intrinsicly safe detection circuit (break in operational circuit, rail etc will cause the track clear occupancy rail to drop out. Of course you could still have contacts weld in so maybe you need redundant series relays).

Or you could just accept a non safety circuit that works like a switch and move on. I'll insert the disclaimer here as I been witness to a rear ending where a diesel ate a caboose because the non safety detection circuit failed. It was a temporary wire that had been screwed down to the tops of the ties, and then a derailment cut the wire... So its a matter of setting the expectation.

JP
Attachments
ADJUSTABLE_RESISTOR_Railroad_Signal_International_LLC_038_40.jpg
An adjustable railroad resistor
John Pennington

Logging meets that actually move logs

Project
2 Mich-Cal Shays
Allen 4-4-0 Narrow Gauge Conversion
Two Reading A5a Camelback 0-4-0
USRA 0-6-0
Clishay
4 Western Wheeled Scraper NG Dump Cars
N&W 4-8-2
ICM 2-10-2
4 Modern Stake Cars
L&N Caboose
4 Big Four Conversion Gondolas

Like I'm actually gonna build all this stuff :-P

John.can
Posts: 45
Joined: Wed Dec 23, 2015 12:39 pm
Location: San Diego, CA
Contact:

Re: Signal Complexity

Post by John.can » Wed Jun 19, 2019 5:01 pm

Hey everybody, if you want to see complex, the society I'm currently apart of has a full operating system with shunt capabilities against the normal flow on our system. We have 3 signal boxes, one of which can control our entire system with 96 levers in total. It's located in SW London and it is an amazing feat of engineering with all the interlocks and time out relays that exist on the system. I have provided two links and a set of time stamps for one to show what our society is set up as.
https://www.youtube.com/watch?v=8j0blzTZlZg
@ 1:50 Hampton Court Signal Box can be seen, that is the main signal box.
@ 2:45 Angel Road Signal Box.
@ 7:15 Willowbank Signal Box.
@ 7:37 Interior of Willowbank Signal Box
@8:29 Interior of Hampton Court Signal Box
@10:28 Interior of Angel Road Signal Box
https://malden-dsme.co.uk/
Then open Railway Info
Then select the respective signal box.
Each page has the full history of the levers and where they originated from. It's a pretty good read.
Hampton Court can control everything, or by way of two controllers, can send control to the other boxes accordingly. However the interlock is set so that one can't return and one can't take away control with out both speaking on the phone and perform a task at the same time. Angel Road and Willowbank boxes also have the ability to run absolute blocks via bell signals between the boxes to control all train movements between their respective track territories.
Hope y'all enjoy the video and weblink and if ever in London, reach out and I will probably be able to show y'all around.

rkcarguy
Posts: 1240
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: Signal Complexity

Post by rkcarguy » Thu Jun 20, 2019 2:01 pm

johnpenn74 wrote:
Wed Jun 19, 2019 3:58 pm
Or you could just accept a non safety circuit that works like a switch and move on. I'll insert the disclaimer here as I been witness to a rear ending where a diesel ate a caboose because the non safety detection circuit failed. It was a temporary wire that had been screwed down to the tops of the ties, and then a derailment cut the wire... So its a matter of setting the expectation.
Ouch! I think its doubly important to make sure the wires are tucked out of harms way, possibly doubled up on the same, or different joiners for insurance if the system is wired default = green.

User avatar
johnpenn74
Posts: 386
Joined: Tue May 04, 2010 12:54 pm
Location: Waiting for next assignment!

Re: Signal Complexity

Post by johnpenn74 » Thu Jun 20, 2019 6:36 pm

Yes, well this is why industrial electrical codes (NFPA, NEC, Etc.) requires safety things like redundant mechanical devices (IE control relays), severing of power for emergency applications (stop and etsop break the power), and intrinsically safe design of the circuit (a correct Robinson detection circuit, in our case for the railroad you get a high signal for clear - not a high signal for occupied). This all goes back to the fundamental layout of the circuits to the relays and plc, sourcing and sinking circuits, and hardware selected. PLCs vs Relays doesn't change this, as even a Safety Rated & qualified PLC can still be wired up fundamentally wrong to the track and panel. It boils down to what kind of system failure is acceptable, tolerable.
JP
John Pennington

Logging meets that actually move logs

Project
2 Mich-Cal Shays
Allen 4-4-0 Narrow Gauge Conversion
Two Reading A5a Camelback 0-4-0
USRA 0-6-0
Clishay
4 Western Wheeled Scraper NG Dump Cars
N&W 4-8-2
ICM 2-10-2
4 Modern Stake Cars
L&N Caboose
4 Big Four Conversion Gondolas

Like I'm actually gonna build all this stuff :-P

Post Reply