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Reverse Loop Control with DC Power

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Reverse Loop Control with DC Power
Posted by SeeYou190 on Wednesday, March 31, 2021 3:28 PM

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Posted by doctorwayne on Wednesday, March 31, 2021 5:52 PM

My original 4'x8' layout had two reverse loops, one within the main oval, and one which could be switched to track outside the oval, which was then elevated and crossed the oval on a truss bridge and a wooden trestle, then returned to the other side of the oval, at ground-level.

Each reversing loop was electrically-isolated (both rails) from the rest of the layout, and there was a double throw switch which controlled direction within both of those loops, as only one would be in use at any time. 

Before the train entered either loop, the direction switch for the loop needed to be aligned for the proper direction.  While the loco was within the isolated loop, another switch, which controlled direction for the rest of the layout, would be re-positioned to allow the train to continue without need of stopping.

Here's a rough sketch done from memory (click on photo to enlarge)...

The layout, built by my father, was Atlas brass flextrack on fibre ties, with all but one turnout also Atlas, buit from kits.  The non-Atlas turnout was a scratchbuilt #8, again done by my father.
All turnouts were remotely controlled by use of choke wires, which rotated an under-table mechanism to move the points (I wish that I had taken photos of that mechanism, as it was very easy to use, and included rotating targets on the switchstands.
All locos and rolling stock had Kadee K-type couplers, and there were multiple uncoupling ramps, also remotely activated from the control panel. 

Wayne

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Posted by SeeYou190 on Wednesday, March 31, 2021 6:30 PM

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Posted by mbinsewi on Wednesday, March 31, 2021 8:30 PM

In the late 80's, I built this:

The "Y" needed a reversing switch, so I used the Atlas #220:

Mike.

 

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Posted by RR_Mel on Wednesday, March 31, 2021 9:31 PM

I started out in HO in 1951 as a 14yr old.  I pretty much self taught myself how to wire my layout.  I used blocks back then and still do.  All blocks have a DPDT center off toggle switch with a home run from the track to the switch.

When I started my current layout in 1989 I went with block control, I guess after using block control for 38 years I was comfortable with throwing switches.

When I cutover to dual mode DC or DCC I made an attempt at following the DCC Guru way but it dinged all my signaling so I rewired it back to original DC block control.  The DCC operation works as well as the DC block operation.

I purchased an MRC Prodigy Advance² DCC System, I had used MRC power DC packs for 50 years without a single problem.

The DCC system has worked perfect on my block wiring since day one.

All that to get around to saying if it was my layout I would go with the DPDT toggles, simplest way, KISS!


Mel
 
Modeling the early to mid 1950s SP in HO scale since 1951



My Model Railroad    
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

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Posted by SeeYou190 on Wednesday, March 31, 2021 9:33 PM

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Posted by SeeYou190 on Wednesday, March 31, 2021 9:35 PM

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Posted by Dave K on Thursday, April 1, 2021 7:22 AM

Kevin,

 

Great article.  I will keep it simple but ultimately move to some form of automation.

 

Dave K.

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Posted by mbinsewi on Thursday, April 1, 2021 8:31 AM

SeeYou190
Can you help me understand the Atlas 220 switch.

Here's an instruction pdf from Atlas.

http://download.atlasrr.com/pdf/Item220Instructions.pdf

To keep the flow of the train smooth, I remember I had to be watching, and ready at the switch.  Nothing was automatic like todays DCC auto reverse controlers are.

Mike.

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Posted by SeeYou190 on Thursday, April 1, 2021 9:11 AM

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Posted by SeeYou190 on Thursday, April 1, 2021 10:12 AM

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Posted by mbinsewi on Thursday, April 1, 2021 11:13 AM

It's up to you Kevin.  I had the 220 hooked up to 3 #215 selectors, and used common rail, with 2 cabs.

I installed it as per Atlas instructions, and had no problems.  I think the instructions were on the back of the package, plus I had a book by, I think, Linn Wescott, describing and showing examples of wiring methods, use toggles, and a section on setting up Atlas components.

Mike.

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Posted by SeeYou190 on Thursday, April 1, 2021 11:35 AM

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Posted by mbinsewi on Thursday, April 1, 2021 12:05 PM

Actually, I had to go look for the book.  It's called "HO Primer, Model Railroading for All", by Linn Westcott.

His perferred method is the 2 toggles, like what you show, and using the Atlas Twin #210.

Mike.

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Posted by SeeYou190 on Thursday, April 1, 2021 12:20 PM

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Posted by SeeYou190 on Thursday, April 1, 2021 12:21 PM

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Posted by SeeYou190 on Thursday, April 1, 2021 12:51 PM

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Posted by SeeYou190 on Friday, April 2, 2021 9:33 AM

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Posted by Dave K on Tuesday, April 6, 2021 7:06 AM
I have attached pictures of my two DPDT switch arrangement for the 1st turn back polarity reversal.  Switch on left controls mainline while the one on the right controls the turn back section polarity.  I've attached pictures of the mainline feeders, turn back section feeders and the switch setup.  I've wired the switches in an X formation to control polarity.  What is strange is the left switch has power when switch is in the center and up position but shorts in the down position.  the right switch has no power in the center off but has power at up but also shorts in the down position.  Is there something wrong with the cross wiring?  I've checked for touching wires but cannot figure it out.
 Dave

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Posted by mbinsewi on Tuesday, April 6, 2021 8:06 AM

Your picture is not working.

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Posted by Dave K on Tuesday, April 6, 2021 8:21 AM
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Posted by SeeYou190 on Tuesday, April 6, 2021 8:32 AM

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Posted by SeeYou190 on Tuesday, April 6, 2021 10:27 AM

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Posted by richhotrain on Tuesday, April 6, 2021 10:41 AM

Interesting and worthwhile thread.

But, I have a one word reaction to DC reverse loops - - ugh!

Thank goodness for DCC.

Rich

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Posted by SeeYou190 on Tuesday, April 6, 2021 10:48 AM

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Posted by richhotrain on Tuesday, April 6, 2021 10:50 AM

SeeYou190

Absolutely true... DCC makes reverse loops so much simpler.

Maybe I should add a fourth question to my DCC or DC questions about reverse loops. 

I have often thought that a Sticky on DCC reverse loops and reverse sections should be authored - - much like this thread on DC reverse loops.

Rich

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Posted by ATLANTIC CENTRAL on Tuesday, April 6, 2021 11:14 AM

richhotrain

Interesting and worthwhile thread.

But, I have a one word reaction to DC reverse loops - - ugh!

Thank goodness for DCC.

Rich

 

Well Rich, my new layout only has one, and it is not part of mainline operation, it is just a staging return on the WESTERN MARYLAND branch line. And it will be easy and logical to operate. And, you will not see it, it will be hidden.

I do have the wye, but that too will be semi automatic. If you are in the staging yard, and want to leave that leg of the wye and come back out on the main, all you is set the wye for the direction you want to go on the main, east or west, which only takes one button. Than you just set the direction on your wireless throttle to that same direction.

Your train will pull out of the staging and proceed on the main. Going in you just set the turnouts and pull in, nothing to do. 

To leave, you just have to think "when I reach the mainline which way am I going?" That is the way your throttle direction needs to be set.

Relays and turnout position do the rest.

So let's say I'm headed west on the main with a train and I want to turn the whole train on the wye and go east.

My steps are:

Push one button to set the wye to allow the west bound diverging route into the wye/staging.

Make sure I am pulling into a staging track that is available, push one button if needed to select a track.

Pull the train in until it clears the wye.

Push one button to align the wye for west bound exit from the staging.

Now, which way is my train going? It is still going west. So I don't change my throttle direction. Start the train, it will now back out of the staging and move west bound in reverse around the wye.

After you are fully on the mainline, reset the the wye turnouts to the main, again done with one button. Which way is your train facing now? East. 

Change your throttle direction to east, and proceed.

You have not pushed one more button, or flipped one more toggle switch (in fact no toggles were flipped), or aligned one more turnout, than you would have with DCC.

You just have to think in terms of east and west, not forward and reverse.

The throttles have two buttons side by side with little arrows, pointing left (west) or right (east), easy enough.

As you move around the layout, left is always west, right is always east, the trains never turn themselves around in relationship to your view.

That is why you are "inside" the benchwork at all times.

Even If I used DCC I would build my layout that way, always viewing the trains as if I am facing "north". Layouts built for operation are much easier to understand and learn if you do this.

Sheldon

    

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Posted by SeeYou190 on Tuesday, April 6, 2021 11:50 AM

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Posted by richhotrain on Tuesday, April 6, 2021 12:57 PM

ATLANTIC CENTRAL
 

My steps are:

Push one button to set the wye to allow the west bound diverging route into the wye/staging.

Make sure I am pulling into a staging track that is available, push one button if needed to select a track.

Pull the train in until it clears the wye.

Push one button to align the wye for west bound exit from the staging.

Now, which way is my train going? It is still going west. So I don't change my throttle direction. Start the train, it will now back out of the staging and move west bound in reverse around the wye.

After you are fully on the mainline, reset the the wye turnouts to the main, again done with one button. Which way is your train facing now? East. 

Change your throttle direction to east, and proceed.

You have not pushed one more button, or flipped one more toggle switch (in fact no toggles were flipped), or aligned one more turnout, than you would have with DCC.

Sheldon, my reply, which follows, is not meant to be argumentative but rather observational.

The operation of that part of your layout seems complex. I count four buttons to be pushed in addition to throwing turnouts. I haven't stopped to figure what would be required to conduct that same operation in DCC.

On my DCC layout, it is essentially a dogbone with reverse loops at both ends. But, visually, you would not see any "reverse loops" because the layout is large and the loops at both ends don't appear to be loops because the middle of the layout (which is the bulk of the layout) is a 4-track mainline controlled by four double slips, all wired in phase.  

What I actually have to deal with the loops are what I call four "reversing sections" of straight track that end with gaps leading into and out of the loops. Four auto-reversers controls the four reversing sections. So, I have to do nothing as the mainline trains enter and exit the loops. It is all handled automatically by the four PSX-ARs.

Whenever I want to switch a train from one mainline track to another, I manually throw spring-loaded Peco turnouts and/or double slips. But those movements don't happen often because in that area of my layout it is mostly high speed mainline running of trains.

That is the beauty of DCC.

Rich

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Posted by Dave K on Tuesday, April 6, 2021 3:52 PM
I have two sets of insulated joiners, one at the beginning of the turnback and one at the end of the turnback

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