Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Resolved - Can I run an Autoreversing Loop inside of an Autoreversing Loop?

1226 views
14 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    October 2020
  • 15 posts
Resolved - Can I run an Autoreversing Loop inside of an Autoreversing Loop?
Posted by Ruckuss on Friday, October 7, 2022 10:14 AM

All,

Thanks in advance for any advice.

I'm creating a new HO Layout.  Backmann EZ Track and Digitrax Electronics.  I plan to automate the switches using either AR1 or BXPA1.

I have a large Reversing Loop and inside that Loop, I want to create another Reversing Loop.  Are there any issues in doing this, or is it just setting up the right blocks to prevent shorting. 

I'll say upfront that I'm a Computer Scientist not an Electrical Engineer or Electrician.  My father was an Electrician and he taught me pretty well, so I do understand the fundamentals..but I can't get it clear whether this is going to work. I've tried looking at many many layouts to see if I can spot a similar set up, but I just don't know.

So, does anyone know why this absolutely would not work?   If not, any suggestions on how to best layout my power blocks to facilitate?

Thanks

Mike

  • Member since
    March 2012
  • 188 posts
Posted by Lakeshore Sub on Friday, October 7, 2022 10:23 PM

Hi Mike.  Welcome to the Forum.

Without seeing the track configuration, it's rather difficult to determine what will or will not work.   Without knowing what you are thinking of for a track plan it's  impossible to determine where the gaps for the reverse sections would need to be.  DCC reverse loop are all about the reversing sections and where to put the gaps.

Theoretically it is possible for a reverse loop to be inside another reverse loop.

Providing a track plan will allow everyone to give you a much better asnwer.

Scott Sonntag

  • Member since
    September 2004
  • From: Dearborn Station
  • 23,187 posts
Posted by richhotrain on Saturday, October 8, 2022 6:39 AM

It is certainly possible to create a reversing section within a reversing section. I use the term "reversing section" because it more broadly refers to situations where tracks wired in opposite polarities connect to each other. Reverse loops are simply one form of reversing section. As Lakeshore Sub has suggested, a diagram of your track plan would be very helpful in giving you advice.

Are there situations where this absolutely would not work? Sure, but those situations would only be caused by the configuration of the two reversing sections. The keys to success are the proper placement of gaps to prevent dead shorts and the length of the reversing sections to prevent confusion between the activation of the two auto-reversers at the same time.

You mentioned both the AR1 and the BXPA1. My advice is to avoid the AR1. It is an older auto-reverser that uses a mechanical relay to trigger the reversal of polarities inside the reversing section. As such, it is slower to react, defeating the whole purpose of reversing polarities.

I have no familiarity with the BXPA1, but it is a solid state device which is quick to react and trigger the reversal of polarities inside the reversing section. Unless you are strongly leading toward the BXPA1, you might want to consider the PSX-AR which many of us are more familar with and use on our layouts.

Let's get back to the two primary considerations to make your track work successful.

To work properly, a reversing section needs to be totally isolated from the adjacent track work by fully gapping the reversing section. The same is true for a reversing section within a reversing section. Both reversing sections need to be totally isolated from each other and from the adjacent track work.

The other basic consideration is the length of the reversing section(s). To prevent confusing the auto-reverser, the reversing section needs to be longer than the longest train that will use the reversing section. In other words, you don't want a train that has already entered a reversing section exiting the reversing section before the entire train is inside the reversing section.

Rich

 

Alton Junction

  • Member since
    July 2009
  • From: lavale, md
  • 4,203 posts
Posted by gregc on Saturday, October 8, 2022 6:49 AM

Lakeshore Sub
Providing a track plan will allow everyone to give you a much better asnwer.

would save a lot of guessing?

greg - Philadelphia & Reading / Reading

  • Member since
    August 2006
  • 52 posts
Posted by santafejeff on Saturday, October 8, 2022 6:23 PM

To my understanding, you can only have one reverse module on a line at a time. If you have two hooked up to the same mainline, they would conflict with each other and would constantly be switching the polarity. Thats how ir was explained to me. 

Now, as far as a reverse section inside another reverse section, yes, you can. You will have to put your gaps far enough outside the second reverse section for it to work. In other words, once you enter one reverse section, the polarity of both would have to change at the same time. Picture a passing siding in your reverse "loop", if you have your autoreverser outside of all that trackage, you could have a big reverse loop with multiple passing sidings in it but they all have to switch together. If you are running two completely seperate mainlines then you can have two reverse modules at the same time but, the second you add a crossover from one to the other, the reverser will conflict with the other one. 

If Im wrong, Ill admit it but, I dont believe you can have more than one autoreverse unit at a time. 

  • Member since
    July 2009
  • From: lavale, md
  • 4,203 posts
Posted by gregc on Saturday, October 8, 2022 7:24 PM

santafejeff
you can only have one reverse module on a line at a time. If you have two hooked up to the same mainline

of course a layout can have multiple reversing sections and ARs.   the AR only controls the polarity of the reverse loop -- not the mainline

of course a reverse section can have many sidings (e.g. a yard)

there's 3 ARs (larger boards)in the image below

Lakeshore Sub
Providing a track plan will allow everyone to give you a much better asnwer.

speculation until then

 

greg - Philadelphia & Reading / Reading

  • Member since
    September 2004
  • From: Dearborn Station
  • 23,187 posts
Posted by richhotrain on Sunday, October 9, 2022 5:38 AM

santafejeff

To my understanding, you can only have one reverse module on a line at a time. If you have two hooked up to the same mainline, they would conflict with each other and would constantly be switching the polarity. Thats how ir was explained to me. 

Now, as far as a reverse section inside another reverse section, yes, you can. You will have to put your gaps far enough outside the second reverse section for it to work. In other words, once you enter one reverse section, the polarity of both would have to change at the same time. Picture a passing siding in your reverse "loop", if you have your autoreverser outside of all that trackage, you could have a big reverse loop with multiple passing sidings in it but they all have to switch together. If you are running two completely seperate mainlines then you can have two reverse modules at the same time but, the second you add a crossover from one to the other, the reverser will conflict with the other one. 

If Im wrong, Ill admit it but, I dont believe you can have more than one autoreverse unit at a time.  

I have four auto-reversers on my layout. I use PSX-AR units. The keys to avoiding conflicts between multiple auto-reversers are gapping and wiring.

First, each reversing section needs its own auto-reverser, and each reversing section needs to be totally isolated from any other reversing section and totally isolated from every non-reversing section. Properly placed gaps will accomplish this objective. Also, you need to be sure that each totally isolated reversing section is longer than the longest train that will pass through it. Show us your track plan and we can help you with the proper placement of the gaps. 

Second, the wiring is critical. Each reversing section will have two wires from a non-reversing section connected to the input side of the auto-reverser. Any output wires from the auto-reverser should only be connected to track inside the reversing section. Any wire from the output side of the auto-reverser that connects to track outside the reversing section will result in a short. Also, any wire from a non-reversing section that connects directly to track inside the reversing section will cause a short. It sounds complicated, but once you lay it out all on a diagram, it is really quite simple, especially if you color code your wiring.

Rich

Alton Junction

  • Member since
    July 2009
  • From: lavale, md
  • 4,203 posts
Posted by gregc on Sunday, October 9, 2022 10:54 AM

greg - Philadelphia & Reading / Reading

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 1,972 posts
Posted by jjdamnit on Monday, October 10, 2022 7:47 PM

Hello All,

There seems to be two (2) parallel (excuse the pun) threads generated by the OP approximately seven (7) minutes appart on Friday- -according to the time stamps.

Bachmann Crossover Causing Short

created at 10:07 am.

And this thread created at 10:14 am.

Without a track plan, it is difficult to answer with any certainty or clarity.

Can the moderators combine these two (2) threads?

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    September 2004
  • From: Dearborn Station
  • 23,187 posts
Posted by richhotrain on Tuesday, October 11, 2022 5:25 AM

Our OP, Ruckuss, posted three similar and somewhat related thread on Friday morning. We need to hear back from him, so we can further help. And a track plan would be most helpful so that we can visualize his track work.

Rich

Alton Junction

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 20,715 posts
Posted by MisterBeasley on Tuesday, October 11, 2022 12:29 PM

Way back when dinosaurs ruled the earth and the layouts of modelers with little kids, it was understood that connecting one reversing section to another wasn't a good idea.  When you do that, both autoreversers will try to flip polarity at the same time, which would result in another short.  I suppose more modern autoreversers might have adjustable delay timing that might alleviate this.

It takes an iron man to play with a toy iron horse. 

  • Member since
    October 2020
  • 15 posts
Posted by Ruckuss on Thursday, November 24, 2022 9:51 AM

Simple question and simple answer is yes. An autoreversing loop can be installed within an autoreversing loop. At least using BXPA1. I have this installed and working perfectly thru a little trial and error. I didnt try the AR1 because i wanted solid state and to take advantage of the track detection feature

simple questions need simple answers. My layout is irrelevant to the questio

Mike

  • Member since
    October 2020
  • 15 posts
Posted by Ruckuss on Friday, November 25, 2022 8:22 AM

Thanks. This was helpful. I chose BXPA1 for solid state and have 3 reversing loops working perfectly. One inside another has no issues. Its all about the wiring...and of course gaps

Mike

  • Member since
    October 2020
  • 15 posts
Posted by Ruckuss on Friday, November 25, 2022 8:26 AM

No issue. Works perfectly. The more I thought about it the clearer it came.  Proper wiring is the key to success and its very simple

Mike

  • Member since
    October 2020
  • 15 posts
Posted by Ruckuss on Friday, November 25, 2022 8:33 AM

Thanks Scott. But I wasnt asking for specifics on how to set this up. I simply wanted to know if it was possible 

Some posted that it was feasible so I forged ahead. With a trial an error I was fully operational 

I appreciate the response. But I was just looking for a simple Yes or No

thanka

Mike

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!