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reverse loop complicated

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Posted by richhotrain on Wednesday, March 5, 2014 2:26 PM

I give up.

I am simply trying to replicate the short that the OP shows occurring in his initial diagram.  That is what my diagram does, it shows him why he has the short, where the short occurs, and how to resolve it by moving the gaps.

The OP refuses to tell us how he has wired the track inside the gaps that he has created.  He only recently mentioned that he is using at least one Electrofrog and, if that is true, we need to know that for certain and which turnout is the Electrofrog.  And, of course, you have to question the wisdom of using an Electrofrog in this particular situation.

But, as I say, I give up.  I will leave it to others to debate the issue and continue to ask questions that go unanswered.  Have fun!

Rich

 

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Posted by CSX Robert on Wednesday, March 5, 2014 2:24 PM

The gaps are not outside the loop, the "first" turnout(the one on the left in your diagram) is the one that forms the loop.

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Posted by floridaflyer on Wednesday, March 5, 2014 2:16 PM

Rich, how is the incoming power from the left bridging the gaps and continuing on to the point that you show a short. the only way that would occur is if the op wired the section to the right of the gaps with power from the main buss not routed thru the reverser.

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Posted by richhotrain on Wednesday, March 5, 2014 2:10 PM

CSX Robert

In your diagram where is the second turnout getting it's power?  

 

I don't know.  It is not my thread, and the OP so far has failed to tell us much about his wiring.  If you look at the track diagram at the beginning of this thread, he shows the "second turnout" inside the reverse loop so, presumably it is wired to the output side of the auto-reverser.  But the gaps are outside the reversing loop, so a reverse polarity situation occurs where the end of the divergent track on that second turnout connects to the next section of track.  If left ungapped, a dead short will occur as he powers up the layout.  And, in fact, that is exactly what he says is happening.

Rich

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Posted by CSX Robert on Wednesday, March 5, 2014 2:02 PM

I am referring to the turnout iniside the loop as the "second" turnout.

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Posted by richhotrain on Wednesday, March 5, 2014 1:59 PM

Which turnout is the "second" turnout?

Let me correct something that I said in my last reply.  I didn't mean to say as the loco crosses the gaps.  Crossing the gaps would have no effect.  The problem is that there is a dead short which must be gapped where I placed the arrows.

Rich

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Posted by CSX Robert on Wednesday, March 5, 2014 1:56 PM

In your diagram where is the second turnout getting it's power?  You show it arbitrarily reversed from the rest of the loop.  In your second diagram above, moving the gaps wouldn't help because you would still get a short where the gaps were originally.

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Posted by richhotrain on Wednesday, March 5, 2014 1:52 PM

floridaflyer

Rich, why do you show the same polarity to right of the original gaps as you do on the tracks coming into the gaps from the left? I would think the polarity to the right of the gaps would be determined by the autoreverser.

 

That's the nature of a reverse loop.  As the track folds back onto itself, a point of reverse polarity is inevitable.  That is why you need to gap that point of reverse polarity, not before it, not after it, but at it.

Rich

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Posted by richhotrain on Wednesday, March 5, 2014 1:49 PM

CSX Robert

Your diagram shows the red/blue phase of the track matching across the gaps at both ends of the reverse loop.  The reverse loop phase will swap to match one end or the other, depending on which end the train is passing through.    If fed correctly from the reverser, the enitire loop, including the turnout, would swap and the "short" that you show would occur at either one gap or the other(no longer being a short because of the insulated gap).

 

Because that is the way that he has wired it and gapped it.  

The way that it is wired and gapped, a dead short will occur when he powers up the layout.

Rich

 

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Posted by floridaflyer on Wednesday, March 5, 2014 1:43 PM

Rich, why do you show the same polarity to right of the original gaps as you do on the tracks coming into the gaps from the left? I would think the polarity to the right of the gaps would be determined by the autoreverser.

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Posted by CSX Robert on Wednesday, March 5, 2014 1:35 PM

richhotrain
..and my diagram shows why and where the short is occurring because his gaps are misplaced.

Rich

 

Your diagram shows the red/blue phase of the track matching across the gaps at both ends of the reverse loop.  The reverse loop phase will swap to match one end or the other, depending on which end the train is passing through.    If fed correctly from the reverser, the enitire loop, including the turnout, would swap and the "short" that you show would occur at either one gap or the other(no longer being a short because of the insulated gap).

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Posted by richhotrain on Wednesday, March 5, 2014 1:33 PM

floridaflyer

Rich, I think I am with Bob on this one. How is the main line power carried thru the gaps? If the turnout in question were an Atlas there should be no short. the power coming thru the autoreverser and up to the original gaps. If the turnout in question is a Peco power routing then the turnout should be gapped and the track between the original gaps and the added gaps at the turnout in question would have to be powered thru the autoreverser. Of course I won't bet the farm on this. 

 

Forget about what kind of turnout it is and look at my last diagram.  It shows the track, blue one rail and red the other rail.  Auto-reverser or not, where the OP has placed the gaps, the reverse polarity situation remains, although flipped, when two ungapped rails of different polarities meet.

Rich

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Posted by floridaflyer on Wednesday, March 5, 2014 1:27 PM

Rich, I think I am with Bob on this one. How is the main line power carried thru the gaps? If the turnout in question were an Atlas there should be no short. the power coming thru the autoreverser and up to the original gaps. If the turnout in question is a Peco power routing then the turnout should be gapped and the track between the original gaps and the added gaps at the turnout in question would have to be powered thru the autoreverser. Of course I won't bet the farm on this. 

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Posted by richhotrain on Wednesday, March 5, 2014 1:21 PM

WardR

I just have to make a decision if i want to deal with trains causing possible shorts or make some serious track modifications to avert this whole thing, although that would be a royal pain. I’m at the point where I want to cut all lower feeders and just attach the loop itself and go from there.  
 

LOL

Oh, like that is gonna work......not.

Do us and yourself a favor.  Show us the entire track plan and mark the turnouts as to type (Atlas, Peco Insulfrog, Peco Electrofrog, etc., and don't guess.  Otherwise, you are wasting everybody's time even though we are still trying to help you.

Rich

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Posted by richhotrain on Wednesday, March 5, 2014 1:14 PM

This thread is a mess because the OP is feeding us piecemeal information.

First, he draws a diagram different than that drawn on his previous thread.  Then, he fails to answer our questions or follow our advice.  Then, he tells us that his turnouts are Pecos, Electrofrogs no less, and thinks that the Electrofrogs are gapped.  Which makes me think that, perhaps, he has Insulfrogs.  Who knows? Who cares?  The only thing that we are getting from the OP is more and more questions without, apparently, doing anything about what we have already told him.  Hopeless!  Pointless!

Rich

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Posted by richhotrain on Wednesday, March 5, 2014 1:09 PM

CSX Robert

The diagram you show doesn't make sense because you show the second turnout isolated from the main, yet with it's polarity matching the main.  

 

 

The diagram, although abbreviated, makes perfect sense. You are just not reading my comments correctly. It is the track arrangement that Ward drew at the beginning of this thread, and my diagram shows why and where the short is occurring because his gaps are misplaced.

Rich

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Posted by floridaflyer on Wednesday, March 5, 2014 12:27 PM

Ward, is the turnout where the short occurs a Peco or an Atlas?

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Posted by CSX Robert on Wednesday, March 5, 2014 12:25 PM

No, they do not come gapped.  An elctrofrog turnout will cause a dead short on the leg of the turnout that it is aligned against if power is being fed from that leg.

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Posted by WardR on Wednesday, March 5, 2014 12:10 PM

dont the electro frogs come gapped? they pickup thier power from the points and feed the frog that way, im not sure where else i would need to cut gaps.

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Posted by CSX Robert on Wednesday, March 5, 2014 12:06 PM

WardR
...i though by putting them all inside the loop and cutting the gaps after the first turnout that it would be fine, but as the other image shows from the other user the polarity does seem to fall back on itself, i traced my feeder wires and the + on one side goes into the - in that area, at least it appears to..


WardR
...It looks to me like I formed another mini reverse loop when the upper siding comes back through that turnout...


When you trace around the loop, the + on one side does go into the -, that is what creates the reverse loop, but it is a single reverse loop, you have not added any reversing sections with your movement of the gaps.

WardR
...The turnouts in that area are pecos and one atlas, the pecos are electro frogs...


Well, Peco eltrofrogs are power routing and can cause shorts even without having a reversing loop. I suspect the porblem has something to do with not having the turnouts gapped and powered correctly. Again, are there any other gaps other than the ones for the reversing loop(if not, then you definitely do not have the turnouts gapped and wired correctly)?



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Posted by WardR on Wednesday, March 5, 2014 11:45 AM

If its not clear I am running dcc using MRC, with a  dcc specialties psx-ar reverse unit. It shorts when i go over that turnout, does not matter which way its thrown, i even removed feeder wires to all the inside tracks as a test and it still shorts. originally those inside tracks were not included in the reverse loop, i though by putting them all inside the loop and cutting the gaps after the first turnout that it would be fine, but as the other image shows from the other user the polarity does seem to fall back on itself, i traced my feeder wires and the + on one side goes into the - in that area, at least it appears to. I appreciate everyone’s input, I just have to make a decision if i want to deal with trains causing possible shorts or make some serious track modifications to avert this whole thing, although that would be a royal pain. I’m at the point where I want to cut all lower feeders and just attach the loop itself and go from there.  The turnouts in that area are pecos and one atlas, the pecos are electro frogs. It looks to me like I formed another mini  reverse loop when the upper siding comes back through that turnout.
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Posted by CSX Robert on Wednesday, March 5, 2014 11:07 AM

richhotrain

 

 
CSX Robert

I don't know why people keep telling you to move the gaps, where you have them is fine  

 

 

 

The reason that the gaps need to be moved is because where he has them now, a dead short is created where the ungapped divergent end of the turnout is joined to the track in the loop.  

Rich

 

The diagram you show doesn't make sense because you show the second turnout isolated from the main, yet with it's polarity matching the main.  The turnout would get it's power from the loop and should not cause a short, unless...

What I strongly suspect is happening is he has power routing turnouts wihtout having them properly gapped and powered.  If that is the case, then there still is no need to move the gaps for the reverse loop, but you would have to add additional gaps between the two turnouts that are facing each other and additional feeders(from the reverser, not the main bus) to the section of track between those turnouts.  There are other solutions, but leaving the reversing gaps where they are only uses one reverser and is the only one that insures you never have more than one train crossing the boundaries at the same time(even the two reverser solution could still have trains crossing both ends of one reversing section at one time).

I really can not be sure what is going on unless WardR answers the list of questions I possed eralier.

 

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Posted by richhotrain on Wednesday, March 5, 2014 8:14 AM

Ward,

I see two issues in this thread.

One, what is causing the short in your initial track diagram.  The short can be eliminated by moving that one set of gaps to the divergent end of the turnout.

Two, how to operate two trains in opposite directions without causing a short.  For that, you likely need two reversing sections, each with its own auto-reverser.

Rich

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Posted by WardR on Wednesday, March 5, 2014 8:10 AM

Bingo, thats exactly the way I see it too! i like the idea of the 2 reversing units on each siding, that would help solve the short issues with trains going in and ot of the loop, or at least minimize it.

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Posted by richhotrain on Wednesday, March 5, 2014 8:09 AM

WardR
ok, so that short piece of track you are referring to, doesn't the reverse loop have to be able to hold your longest train in the loop? otherwise you would have part of the train in and out both sides of the loop section?
 

Who are you asking?

 

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Posted by WardR on Wednesday, March 5, 2014 8:07 AM
ok, so that short piece of track you are referring to, doesn't the reverse loop have to be able to hold your longest train in the loop? otherwise you would have part of the train in and out both sides of the loop section?
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Posted by xdford on Wednesday, March 5, 2014 5:12 AM

I wrote a piece about growing a layout with a return loop and a simple "fix"  I have a problem getting graphics to show but ttransposing what I have written, the short length of track between A and B is double insulated in the reverse fashion to mine. This might help you and feel free to contact offline should you need clarification

http://www.meltonmrc.org.au/newsletters/issue22-september13.pdf

Hope this helps

Regards from Australia

Trevor  www.xdford.digitalzones.com for yor interest

 

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Posted by richhotrain on Wednesday, March 5, 2014 4:23 AM

CSX Robert

I don't know why people keep telling you to move the gaps, where you have them is fine  

 

The reason that the gaps need to be moved is because where he has them now, a dead short is created where the ungapped divergent end of the turnout is joined to the track in the loop.  

Rich

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Posted by CSX Robert on Tuesday, March 4, 2014 10:48 PM

I don't know why people keep telling you to move the gaps, where you have them is fine and, as you have already mentioned, with them there there is no possibility of crossing both ends of the reversing section at the same time.

 

Some questions:  When do you get the short and why do you show it at the turnout?  Is it because you get a short when you throw the turnout, when a loco crosses the turnout, anytime power is on?  What kind of tunrouts do you have?  Are they power routing? Are both sets of gaps in both rails? Are there any other gaps?

 

 

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Posted by richhotrain on Tuesday, March 4, 2014 8:09 PM

WardR
Rich, thanks for drawing that up, makes sense, but what happens if two trains enter the loop at different ends? Is there a way to avoid this? The reason i tried to put the gaps where i did was to avoid a short based on the fact that only one train can go through a turnout at a time. If this is the only way than ill have to try and see how to avoid this or modify the track to avoid this all together.
 

Well, then, lengthen the passing siding and add a second auto-reverser to create a second reversing section.  In the following diagram, one set of gaps are colored red and one set of gaps are colored black. In between the red colored gaps is one reversing section, and in between the black colored gaps is the other reversing section.

Rich

Alton Junction

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