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Reversing Loops

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Reversing Loops
Posted by starman on Wednesday, August 02, 2017 7:59 PM

I have attached a modified track plan that I am attempting to put together. I am really not very good with using the program I used to create this track plan, but I believe you can see what I am trying to do.

 

I am at a point where I need some help with reversing loops. I am afraid I have created a track plan that is beyond what I know how to wire.

 

Please look at the attached image.  Where have I created reversing loops?  Where would they start and stop?  How and where would I install insulators and AR1's to make this work electrically?

 

Thanks for your time and help.

 

Jack

 

 
Modified Track Plan
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Posted by selector on Wednesday, August 02, 2017 8:57 PM

I can't see your diagramme clearly because its size is very small.  However, I believe I see at least two places where you have reversing loops, but apparently four places.  Again, it's only a guess.

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Posted by floridaflyer on Wednesday, August 02, 2017 9:33 PM

Off hand I see three and probably four. After that last fiasco with reversing loops, I'll sit this one out.

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Posted by BigDaddy on Wednesday, August 02, 2017 11:27 PM

floridaflyer
After that last fiasco with reversing loops, I'll sit this one out.

snork (the sound of coffee shooting out my nose)

A bigger picture

From top to bottom label the tracks 1,2,3 and 4  I've labeled the turnouts.  Track 1&4 are the same loop as are 2&3 but work with me here.

My code is the train takes each letter turn out and follows that path. In the 1st reversing loop the train is going counter clockwise on track 1, takes turnout a to track 2 goes around back to near the top of the page where I've called it track 3, takes the switch g & e (it's now reversed on track 2) and if it continues onto track 1 via da it has reversed with respect to track 1

Reversing loops:

#1  track 1  adge track 1  adgeda  track  2  eg track  3 ge track 3 hiadeg
#2 track  2 daihfb   track  2 bf  track  3 fb {same as track 4 from ihfb}
 
The problem with my count is your segments ge and fb are too short to be reversing loops. 

I have no idea where to put AR's but now we have bigger pic, turnouts that we can all refer to and my take on where reversing is going on, feel free to argue with that.

If you made a bunch of copies and traced out each reversing loop with colors for both tracks, it might be more obvious which loops could be shared by the same reverser.

Final edit, is this HO scale?  Are the blocks 1 foot?  If so it looks like 15" radius curves and there is no easy way to get inside the area where I placed the letter i

Henry

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Posted by richhotrain on Thursday, August 03, 2017 6:07 AM

floridaflyer

Off hand I see three and probably four. After that last fiasco with reversing loops, I'll sit this one out.

 

LOL.

I haven't looked at the diagram yet, but I feel the same way.

No good deed goes unpunished.

Rich

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Posted by gdelmoro on Thursday, August 03, 2017 6:25 AM

richhotrain

 

 
floridaflyer

Off hand I see three and probably four. After that last fiasco with reversing loops, I'll sit this one out.

 

 

 

LOL.

 

I haven't looked at the diagram yet, but I feel the same way.

No good deed goes unpunished.

Rich

 

Rich can he avoid reversing loops by the way he wires? Like it was suggested for my layout?

Gary

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Posted by richhotrain on Thursday, August 03, 2017 6:32 AM

I have relented long enough to take a quick look at the diagram.

I see two folded mainlines with crossovers.

The two crossovers on the right pose no problems, as long as both mainlines are wired the same way, but the two crossovers on the left give rise to reverse polarity.

It looks like one reversing section could be created to resolve the problem, if only one train is running on each mainline.

I am feeling very lazy this morning, so I am willing to concede that I may be wrong but, at first glance that is how I see it.

Rich

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Posted by richhotrain on Thursday, August 03, 2017 7:06 AM

gdelmoro

Rich can he avoid reversing loops by the way he wires? Like it was suggested for my layout?

 

Once again, I am reacting quickly, but it seems that wiring the two mainlines opposite one another would create 4 mismatched polarties between the turnouts that make up the crossovers instead of 2, creating even more complexities.

Rich

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Posted by ROBERT PETRICK on Thursday, August 03, 2017 8:55 AM

I like to reduce things to schematics. Makes it easier to see what's what.

Robert

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Posted by floridaflyer on Friday, August 04, 2017 5:37 PM

Tried to resist but gave in. I agree there are two reversing loops as described by Big Daddy and Robert. I also agree with Rich that one isloated section with one AR can get the job done. Using Daddy's diagram I would isolate both rails on the divergent track between turnouts B and F, and both rails between the divergent track between  turnouts C and E. Next I would go a few feet to the left of turnout B and isolate both rails. Next I would go to the right of turnout C a few feet and isloate those two rails(probably at the point end of turnout D). This will make the track section with turnouts B and C islolated from the rest of the layout. Power the section from a few feet to the left of B to the point a few feet the the right of C with the AR. Although it is desireable to have the reversing section longer than you longest train it is not absolutely mandatory. I would stagger the cuts in the rails on the straightaways to reduce the chances for a short. It is also possible to be parking one loco on a part of the isloated section while another makes the crossover. That is not a desireable and is a weakness in the plan, but doeable.  Idea is not set in stone and other comments are welcome as I may have missed something.  

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Posted by rrinker on Friday, August 04, 2017 10:31 PM

When you simplify it to the schematic that Robert did, B-F is the left most crossover, and C-E is the middle crossover. Schematically it can be treated as a dogbone layout, so you can actually get away with putting gaps to the left of B and the left of E, and making the loop between those points the reversing section. Then you get a reversing section larger than the largest train and should have no problems.

                            --Randy

 


Modeling the Reading Railroad in the 1950's

 

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Posted by richhotrain on Saturday, August 05, 2017 5:10 AM

I always use a 2-rail color system to identify and resolve reverse polarity issues.

If you look at the upper portion of the diagram below, with both mainlines wired the same way, blue rail on top and red rail below, you can see that the two crossovers on the right have matching polarities with their connecting tracks. But, in the two crossovers on the left, blue meets red and red meets blue, reverse polarities.

One way to resolve the problem is to gap the rails on either side of those two crossovers and wire everything inside the gaps with the blue rail on top and the red rail below, as shown in the lower portion of the diagram. Add an auto-reverser to control this single reversing section and you are all set. To make the reversing section longer than the longest train, simply extend the gaps, as needed, at the far left in the diagram.

Rich 

 

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Posted by ROBERT PETRICK on Saturday, August 05, 2017 7:59 AM

Okay, good. No fiasco here.

I see two reversing loops. I'd call them the 'right inner loop' and the 'left inner loop'. There is another outer loop that should be wired exactly like the right inner loop and has no bearing on the subject, so Henry's ADHI and the right side of Rich's two-rail two-color sketch can be ignored.

Both the inner loops are pretty long, so train lengths can be pretty long. I'd gap the rails at the crossovers like Rich suggests. But since each crossover is made up of two turnouts, and since all four turnouts face each other, there might need to be some more internal gaps depending on the style of turnout (live frog or dead frog) and/or manufacturer. To minimize the number of insulated rail joiners, I'd try to coordinate those internal gaps with the gaps required for reversing.

Tony's Train Exchange makes some pretty nice, reliable, reasonably-priced devices that combine the features of auto reversing and power management. I'd buy two.

Robert

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Posted by richhotrain on Saturday, August 05, 2017 8:32 AM

No argument here, Robert. If you use one auto-reverser, there will need to be some additional caution with the operation of more than one train through the reversing section. If you use two auto-reversers, the wiring and gapping gets a bit more complicated, but then two trains can be entering and exiting the entire reverse complex at the same time. 

Since two trains could traverse the straight through routes at the same time but only one train can use the diagonal routes without a collision, I would opt for one auto-reverser, treating the entire complex as one reversing section. A second train would need to stop outside of the reversing section to prevent a polarity conflict.

Rich

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Posted by ROBERT PETRICK on Saturday, August 05, 2017 10:20 AM

richhotrain

Since two trains could traverse the straight through routes at the same time but only one train can use the diagonal routes without a collision . . . 

Yes. Because of the proximity of the two crossovers, some sort of interlocking protocol would be needed. And by definition, cross traffic in either direction would have to wait. Also because of the proximity, the two crossovers could be effected by a single store-bought double crossover manufactured by ME or Shinohara or somebody (there are many threads devoted to these). I've never used one, but I assume the internal wiring and jumpers and whatnot can be set to solve any electrical/mechanical issues or conflicts that arise.

Robert

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Posted by richhotrain on Saturday, August 05, 2017 11:15 AM

ROBERT PETRICK

because of the proximity, the two crossovers could be effected by a single store-bought double crossover manufactured by ME or Shinohara or somebody (there are many threads devoted to these). I've never used one, but I assume the internal wiring and jumpers and whatnot can be set to solve any electrical/mechanical issues or conflicts that arise.

Yep, at one time I had three Walthers Shinohara Double Crossovers on my layout, although I only have one in use today. The W/S Code 83 are DCC Friendly.

If you include the entire double crossover inside a single reversing section, it is easy to wire.

Rich

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Posted by starman on Sunday, August 06, 2017 10:47 AM
I want to thank you all for your time and effort you have taken concerning the reversing loops I created for my track plan.  I knew I could count on this group for excellent help and advice.  However, it is easy for me to see that these reversing loops are getting way too complicated for what my son and I want to do, way too expensive, and may limit some other train operations that we are more interested in than being able to operate a train in either direction on one track.  As a result, my son and I have decided to simplify the track plan by removing the reversing loops that have been discussed.  You can see from the attached picture what we are going to do.  If we want a train to travel in the opposite direction on the red or blue track, which we don’t believe will be all that often, we will simple lift up the train and turn it around.  This hobby is supposed to be fun, not a headache! Big Smile
 

 

There is, however, a new question I have.  As you can see in the attached picture, a train traveling on the blue track in the direction of the arrow can easily enter the area marked as the yard by using one simple reversing loop.  I think I understand this simple loop.  However, if the train is traveling on the blue track in the opposite direction of the arrow, how would I set up the entrance to the yard so that a train traveling in either direction on the blue track can enter the yard? 
Yard 
 
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Posted by richhotrain on Sunday, August 06, 2017 5:02 PM

starman, as to the first part of your most recent reply, there is nothing all that complicated about setting up a single reversing section with those two left side crossovers wired as part of the reversing section. That would only require one auto-reverser. The only "complication" would be coordinating multiple trains on the same track, but even that is no big deal. Before you give up on that track plan, give your decision some second thought. We are here to help you through the process.

As to the second part of your most recent reply, speaking for myself, I am not at all sure that I understand your question or your track diagram. If others are also confused, you may want to redraw the track diagram and rephrase the question. Is the loop that you have drawn considered the yard? If so, where are the yard tracks?

Rich

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Posted by BigDaddy on Sunday, August 06, 2017 5:23 PM

These postage size pics make it too hard.  I'm not quite sure how you managed to do that, but  if you are entering dimensions in with the picture icon in this forum, don't.

Also I expressed concern in my previous post about the access to your layout.  In your new plan there is a peninusla on the left.  If there is aisle access to the right of that in a U shape to the other side of the layout, you better not be a supporter of the obesity epidemic

This sounds snarky, my apologies, because I don't mean it to sound that way, read it as tough love

Henry

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Posted by starman on Sunday, August 06, 2017 6:50 PM
Henry - I agree that my pictures are miniscule, but I am not sure what to do about it.  I create the track plan in AnyRail.  I will readily admit I am not very good at using it.  Once the track plan is complete, I download it to my desktop.  I then open Flickr and drop my AnyRail download when it says drop.  I copy the Flickr file address and go to the forum and inset it in a reply.  Any help as to how to control the size will be appreciated.
As for the actual track plan, I have not drawn it to scale.  I guess I should do that but it will probably take me days.  I’ll begin working on it tonight.  Once it is complete you will see exactly how it fits in the room.  Don’t be concerned, I have not taken any of your remarks as snarky.  I appreciate your help.
 
Rich - I will give a second thought to the reversing loops.  After I have my track plan drawn to scale, I will hopefully know how to send a full size picture and I will have some specific questions about setting up the reversing loop.  I also appreciate your encouragement.
I also appreciate all the others who have replied.

 

Jack 
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Posted by BigDaddy on Sunday, August 06, 2017 7:07 PM

Jack

I have used Flickr but not Anyrail.  I guess they produce thumbnail pic.  Glad we are OK.

Henry

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Posted by richhotrain on Monday, August 07, 2017 5:27 AM

starman
 
Rich - I will give a second thought to the reversing loops.  After I have my track plan drawn to scale, I will hopefully know how to send a full size picture and I will have some specific questions about setting up the reversing loop.
 
Jack  

Jack, draw a track plan that suits your needs and objectives. Don't try to avoid reversing sections simply because they seem complicated. Any track plan can be successfully wired and operated, although some track plans required more time and attention to operate efficiently.

Rich

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Posted by rrinker on Monday, August 07, 2017 7:05 AM

 Especially with DCC, there's no real reason to avoid reverse loops and such, because it can be easily handled automatically, no extra toggles or whatnot you might need with DC. As an operator, you just need to make sure the turnouts are lined properly and drive the train, nothing to flip or adjust. If it makes sense in the track plan for there to be a connection that happens to cross polarity, just do it, and install an auto reverser.

                       --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by floridaflyer on Monday, August 07, 2017 7:51 AM

In a quick look at your new plan it appears that the yard is a reversing loop. Bigger picture would help though.

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Posted by richhotrain on Monday, August 07, 2017 8:16 AM

floridaflyer

In a quick look at your new plan it appears that the yard is a reversing loop. Bigger picture would help though.

 

Yeah, that "yard" loop would be a reverse loop.

I am guessing that he wants to also enter the yard from the left side coming down on the blue colored track, but it is not clear from his question.

Rich

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Posted by floridaflyer on Monday, August 07, 2017 9:43 AM

I think he also has one in the lower right of the plan. But without a larger picture it is hard to tell. Maybe yes maybe no

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Posted by richhotrain on Monday, August 07, 2017 10:21 AM

floridaflyer

I think he also has one in the lower right of the plan. But without a larger picture it is hard to tell. Maybe yes maybe no

 

Could be. I was just looking at that yard area.

Rich

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Posted by starman on Monday, August 07, 2017 11:41 AM

I have drawn my track plan to scale using AnyRail, at least the best I could do.  It is pretty close to scale.  Using flickr.com the only picture sizes I could come up with were postage stamp size or what you see below.  At least the picture below can be clearly seen. Smile  

Please note that track 1 and track 2 or both loops.  My yard is a little more complicated to draw and I will include that in a separate picture, probably tomorrow.

Some of my curves look tight, but I can run an articulated steam engine over them.  I was limited in AnyRail, as far as I could determine, as to the exact size curves that were available to me.

I have labeled what I think are the important turnouts using the same scheme that Henry used. I hope I got it all right.  Please note that b-f and g-c could be moved anywhere along the top of the track plan as I have laid out this plan, but not fastened anything down.

I am using a Digitrax system.  Now, exactly where would I install insulators and where would I connect AR1's.  I assume I would use AR1's.  Also, I would like to run rather long trains and more than one train on the same track at a time.  How will reversing loops affect my operation?

Please ask if you have any questions.  I won't be offended.  This is the first layout I have ever built.  The overall my idea is to have N&W trains, from the 1950's to 1960's, travel from the coal mines in western Virginia (along the bottom of the plan), through the Pieidmont area (along the right side of the plan, through the South Norfolk yard (along the top of the plan - I grew up in South Norfolk about a block from the yard), and finally through Norfolk and into the Lamberts Point yard (in the center of the room).

Again, sorry for the large size of the picture, but it was that or postage stamp size!  Perhaps someone else can tell me how to send a more appropriate size image.

I appreciate all comments and help.

Jack

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Posted by ROBERT PETRICK on Monday, August 07, 2017 4:53 PM

starman

I am using a Digitrax system.  Now, exactly where would I install insulators and where would I connect AR1's.  I assume I would use AR1's.  Also, I would like to run rather long trains and more than one train on the same track at a time.  How will reversing loops affect my operation?

If installed properly, the ARs will be completely transparent to the users and should give many years of trouble-free service.

Regarding cost (from your earlier post), auto-reversers cost about  $25 or so for a basic unit. A little more, depending on whether any advanced features are wanted. Not a whole lot in the scheme of things, and actually a bargin for the amount of work they do.

Robert 

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Posted by richhotrain on Tuesday, August 08, 2017 5:28 AM

starman

I am using a Digitrax system.  Now, exactly where would I install insulators and where would I connect AR1's.  I assume I would use AR1's.  Also, I would like to run rather long trains and more than one train on the same track at a time.  How will reversing loops affect my operation?

The input side of the AR1 would be connected to your track bus. The output side of the AR1 would be connected to the rails inside the reversing section.

You added a bit of a complication in your latest drawing with those two passing sidings, one above and one below those two crossovers. I placed dots where the gaps need to be cut in order to isolate the entire reversing section, as shown in the upper portion of the diagram.

If that configuration is not longer than your longest train, then expand the reversing section by extending the gaps to the left. But when you do that, you also need to add gaps to the divergent side of the turnouts on the left side of the passing sidings, as shown in the lower portion of the diagram.

Make sure you wire the two mainlines the same way. Any and all feeders inside the reversing section should be wired to the output side of the AR1.

If you are running multiple trains, you have to be careful about more than one train entering and or exiting the reversing section simultaneously. When the AR1 automatically flips the polarities to avoid a short, the train that set off the AR1 can pass through the reversing section unhindered, but a second train might encounter a mismatched polarity and cause the AR1 to flip polarities which then adversely affects the first train.

So, the proper protocol would be to halt the second train outside of the reversing section until the first train has cleared the reversing section. That said, it may be possible to have two trains on separate tracks passing each other simultaneously in the reversing section. It all depends on where the trains are located at a given time and what action has been taken by the AR1. For that reason, it may be best to follow that halting protocol that I just mentioned.

Rich

Alton Junction

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