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Help with Reversing Loops Please

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  • Member since
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Posted by rrinker on Thursday, January 23, 2014 2:02 PM

Easier? Wiring it like I do, regardless of the schematic location of the track, ie, say there are 5 tracks going across a section of the tables, the rail to the front of every track would be the white wire, and the rail towards the wall side would always be red (Red Rear). Crossovers would be the same phase throughout, and only the loops on the ends would need gaps and reversers.

 Maybe different for an island layout, but for a shelf layout, this way just seemed more obvious to me when I built my first DCC layout.

        --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 richhotrain on Thursday, January 23, 2014 4:42 PM

I guess that it is a matter of semantics, the use of the word "easier".  It all comes down to how you think about how you wire your layout.  

We haven't heard back from the OP in a few days.  I wonder where he is in his thinking and what he may be planning to do regarding the location and installation of reversing section(s).

Rich

Alton Junction

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Posted by rrinker on Thursday, January 23, 2014 6:39 PM

 It just seemed more logical to me on a shelf type layout to keep the bus wires in the same order. That also avoids wiring a simple passing siding backwards.

         --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 richhotrain on Thursday, January 23, 2014 7:25 PM

Wiring a continous loop poses a different issue, especially with crossovers involved.  In the first diagram below, the OP's initial diagram on this thread, the wiring follows the rails.  Then, the crossovers are gapped in the centers, and the one mainline is gapped to completely isolate the reversing section.

In the second diagram below, the two sides of the mainline are wired the same way, in phase, so there is no points of reverse polarity at the center of the crossovers.  Then, the wiring of the end loops can be either way because the entry and exit points of the end loops are gapped to create two reversing loops.

Rich

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Posted by trafficdesign on Friday, January 24, 2014 11:02 AM

I am back (sorry for the delay) and thanks for all of your excellent thoughts and comments! Hovever, I more confused than ever!  Let me respond to some of your thoughts and questions in hope that I can achieve some clarity.

1. I am using Digitrax DCC so the AR1 shouldn't be an issue.

2. Each of the end loops have 24 inch radii so diameter should be approx. 150 inches or 12.5 feet which is more than enough to hold my max, train length of 10 cars and 2 engines.

3. I do indeed have a short at the crossovers involved as I have wired a continous loop as in the first diagram above, as the wiring follows the rails.

4. I was planning on using richhotrain's EXCELLENT idea of adding a additional left side mainline that could bypass the crossovers altogether, and the gaps in the middle of the two crossovers could be eliminated by wiring the middle track inside the gaps in phase with the right side mainline. 

5. haven't figured out operations completely yet, however I have 2 young boys aged 5 and 8 and each are going to want to run a train so I guess that there will be 3 operators to start!

 

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Posted by richhotrain on Friday, January 24, 2014 12:41 PM

No reason to be more confused than ever.

Go with #4, you and your sons will love it.  The beauty of that arrangement is the simplicity of the wiring.  Just wire it as you first drew it at the beginning of this thread.  The diagram below shows the wiring and the gapping.  The reversing section is easily identifiable, as it is that middle section of track.

Rich

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Posted by trafficdesign on Friday, January 24, 2014 12:51 PM

Is this different than what you indicated before? I thought that if I was adding the third passing mainline section that you didn't gap the turnouts and wired the middle section "in phase" to generate the reverse section.

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Posted by richhotrain on Friday, January 24, 2014 12:55 PM

Yes, my latest wiring diagram is different than that first one that I posted.  In that first one, I was showing the wiring done in phase.  In this current one, I stuck with your wiring protocol.

Rich

Alton Junction

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Posted by trafficdesign on Friday, January 24, 2014 1:09 PM

OK. Is this where I put the 10 foot reversing section in this diagram?

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Posted by richhotrain on Friday, January 24, 2014 1:33 PM

Yes, but recall that it has to be as long as the longest train.  So, not only 10 feet in length on that middle track, but also 10 feet from the top gaps to the crossover gaps and 10 feet from the crossover gaps to the bottom gaps on the middle track.  You need to account for the possibility of a train crossing from one mainline to the other mainline.  Do you have enough space to do that? 

Rich

 

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Posted by trafficdesign on Friday, January 24, 2014 2:42 PM

No I do not have that space available. Would your original idea still work?

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Posted by richhotrain on Friday, January 24, 2014 2:56 PM

That original idea still anticipated 10 feet, not 5 feet.

 

Imagine a 10 foot long train crossing over from one mainline to the other mainline.

 

First, consider a northbound train on the right mainine crossing over to the left mainline.  As it crosses the center of the upper crossover, it flips the AR-1.  Now when it reaches those upper gaps on the left mainline, the trailing car has to clear the crossover gaps.  So there needs to be a length of 10 feet.

 

Next, consider a southbound train on the right mainine crossing over to the left mainline.  As it crosses the center of the lower crossover, it flips the AR-1.  Now when it reaches those lower gaps on the left mainline, the trailing car has to clear the crossover gaps.  So there needs to be a length of 10 feet there too.

 

Rich

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Posted by richhotrain on Friday, January 24, 2014 3:00 PM

It seems that you surely have at least 10 feet of track below the bottom crossover on the left side mainline, correct?

How many feet of track above the upper crossover on that left side track before you reach that turnout to the siding (Middlesex Mfg.)?

Rich

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Posted by trafficdesign on Friday, January 24, 2014 3:32 PM

Below the crossovers I have a clear 20-30 feet. Above it's a max of 5 feet.

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Posted by richhotrain on Friday, January 24, 2014 4:01 PM

Well, then, we are back to wiring the reversing section in phase so you don't have to gap the centers of the crossovers.  Now, you only need 5 feet up and down the mainlines.

Rich

 

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Posted by trafficdesign on Friday, January 24, 2014 4:17 PM

Yes! That is what I was thinking too! That way the entire gapped middle section of the centre and the right track become the reversing section.

Just curious is there a reason that you changed the wiring from red (positive) outside on the mainline? I know that the middle gapped section needs to be wired in phase but can I still keep my red outside/black inside convention for the rest of the mainline?

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Posted by richhotrain on Friday, January 24, 2014 5:59 PM

Oops, sorry about that.  How about this?

Rich

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Posted by trafficdesign on Friday, January 24, 2014 10:30 PM

That looks great!

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Posted by richhotrain on Saturday, January 25, 2014 3:22 AM

Keep us posted on your progress.  What is your timetable for laying track and wiring the layout?

The thing that intrigues me about the third track is the ability to keep trains moving even when two trains are traveling toward each other on the same track. For that reason, the longer you can make that third track, the better.  Here is another thought.  Add a fourth track on the right side.  Oh yeah!  With three operators, this just adds to the fun.

Rich

 

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Posted by bagal on Sunday, January 26, 2014 4:36 AM

richhotrain

Oops, sorry about that.  How about this?

Rich

 

Isn't there a risk of two trains in the reversing section at once with this arrangement?

 

Bill

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Posted by richhotrain on Sunday, January 26, 2014 5:17 AM

bagal

 

 
richhotrain

Oops, sorry about that.  How about this?

Rich

 

 

 

Isn't there a risk of two trains in the reversing section at once with this arrangement?

 

Bill

 

There is a risk.  There is a risk in any reversing section, but the problem with this configuration is that two passing trains on the mainline tracks would cause issues as they enter and exit the reversing section even though they are not using the divergent routes on the crossovers.  For that reason, I really prefer the 4-track configuration as opposed to the 3-track configuration.  That way, no train would enter the reversing section unless it planned to use the divergent routes on the crossovers to reach the other mainline.  In that case, I would consider the outer two tracks as the mainlines and those two inner tracks as the reversing section.

Rich

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Posted by trafficdesign on Sunday, January 26, 2014 6:52 AM

Unfortunately I don't have the room to add the 4th mainline right hand side track. I can fit in the 3 track configuration as originally proposed. Guess I'll have to be careful!

I have already built this section and will have photos up soon. Haven't bought the AR1 yet nor have I built the track north of Middlesex, so I have not tested it out yet. Stay tuned....

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Posted by gregc on Sunday, January 26, 2014 7:02 AM

it seems unfortunate that the electronics to control the trackwork is affecting the layout design.

greg - Philadelphia & Reading / Reading

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Posted by trafficdesign on Sunday, January 26, 2014 7:43 AM

Do you have a suggestion/solution?

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Posted by richhotrain on Sunday, January 26, 2014 8:00 AM

trafficdesign

Unfortunately I don't have the room to add the 4th mainline right hand side track. I can fit in the 3 track configuration as originally proposed. Guess I'll have to be careful!

 

 

Actually, the more that I think about it, the 3-track design is quite satisfactory because two oncoming trains won't have have to pass each other on adjacent tracks.   With the 3-track design, the left most track becomes the main line and the center track is only used to cross over to the right side main line.  Or, when trains headed north on the right side main line want to cross over, any train headed south would use the left most track as the main line.   So, the 3-track design is perfectly satisfactory.

Rich

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Posted by gregc on Sunday, January 26, 2014 10:16 AM

trafficdesign
Do you have a suggestion/solution?

no.   It's just an observation that trackwork that may be prototypical can be impractical to model because of the electrical aspects.

i was impressed how Rich managed to control two reversing loops with just one auto-reverser.   I haven't  been following the thread.   did you consider moving one of the crossovers to the other end of the dogbone and have two separate but convention reverse loops?

greg - Philadelphia & Reading / Reading

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Posted by richhotrain on Sunday, January 26, 2014 11:03 AM

gregc

It's just an observation that trackwork that may be prototypical can be impractical to model because of the electrical aspects.

 

greg, that is a great point and one that I have thought about quite often.

I have a lift out section that spans an aisle and it holds two bascule bridges, an impressive sight, if I may say.  The purpose of this section is to return the double mainline back onto itself so that I can reverse the directions of the trains and send them back in the direction that they came from.

So far, so good.  But, it takes two auto-reversers to control two separate reversing sections and a lot of complicated wiring, particularly because it is a lift out section.

Rich

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Posted by rrinker on Sunday, January 26, 2014 1:34 PM

 The electronics don't really affect the track plan. The wiring is affecting the electronics placement which is affecting the track plan. Were it wired as I suggest, all parallel tracks the same phase regardless if they are the northbound track or the southbound track, then the end loops would be the reversing section and you could have any arrangment of crossovers and runarounds along the mains as you wanted.

        --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 zstripe on Sunday, January 26, 2014 1:43 PM

I have been following this thread, but I did not want to get involved, for the simple reason, too many hands in the pot so to speak. But I agree with you RANDY.

Frank

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Posted by richhotrain on Sunday, January 26, 2014 1:49 PM

Yeah, but Frank, as Randy would have it, the electronics do affect the track plan, so, in effect, you agree with greg and me.

Alton Junction

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