dog bone layout sharing lots of single line between - all autoreverse?

[mumb96]

Hi all, this is my first attempt at a real model railroad.  I'd like to do a dog bone layout with a long stretch of straight track that leads on both ends to turn-arounds.  Picture something like this  0--------0 (nice huh?)  At this point I'm leaning heavily towards HO.

I've seen the bachmann auto-reverse e-z track (both straight and curved).  Is that all I need to use to make this work?
Also, how much of the layout needs to be auto-reverse e-z track?  Does the entire layout need to be auto-reverse (0AAAAA0), or can it all be plain e-z track (or even flexible track) with auto-reversing pieces immediately before each turn-around loop?  0A-----A0

Finally, if I actually plan on having two dog-bones that intersect each other (not reusing track, but just a crossing), do I need to do anything different?

Thanks!

[Desertdweller]

Your proposed layout is not a dog bone.  It is a loop-to-loop.  A true dog bone uses separate routes to connect the loops, and can run continually without reversing.  My own layout uses this plan.

The reversing tracks are used if you want to back up a train on arrival at either end, so it can back up to the opposite end of the layout.  An example of this would be a trolley car layout, or maybe a push-pull commuter train.

I think you are confusing a reversing track with a reverse loop.  A reverse loop needs a section of track that can be reversed, but more than that.  A reverse loop feeds the train back into the track it arrived on, but going in the opposite direction.  This involves turning the train, not backing it up.  In order to do that, the polarity of the main track has to be reversed while the train is in an electrically isolated section of track in the reverse loop.  This means stopping the train in the isolated section and reversing the polarity to match the reversed polarity of the main track.  There are special reverse loop electrical modules that can do this, or your can wire it up yourself using a polarity reversing switch like an Atlas Controller.

This is a bit more complicated than I can explain here and still make sense.  There are wiring books available that explain how to do this.

If you are using DCC instead of DC, I can't help you.  I can tell you the easiest way would be to build a true dog bone, with a continuous track.

Les

[mumb96]

Les, thank you for the prompt reply.  You are correct, I am thinking about a reverse loop.  My thinking was something like this:

https://www.azatrax.com/reverse-loop-system-2.html

And I was wondering if I had to go to all of the wiring work to make it happen, or if there was an easier solution.

[bapguy]

Are you going to use DC or DCC ? If DCC the track still needs to be isolated but you use an auto reverser instead of a switch. The reverser works automatically to reverse polarity. There are several brands of DC auto reversers.   Joe

[mumb96]

Joe, thanks for the response.  I hadn't decided between DC and DCC as of yet.  If I go with DCC, then do I need something like this (http://shop.bachmanntrains.com/index.php?main_page=product_info&cPath=264_274&products_id=1824) at the start of each of my reverse loops?  Is there anything special about the track itself (Bachmann auto-reversing track)?

[Hunt]

You use regular track.   Bachmann auto-reversing track is the wrong product for a double reverse loop track plan. 

[jward]

if you are using dcc you have two options.

1. use an atlas snap relay in parallel with your switch motors to change the polarity of the loop section connected to each switch.

2 easier but more expensive: use a dcc autoreverser (not autoreverse track) to control the single track between the end loops.

if you are using dc, you can use a 3 amp bridge rectifier between the power pack and the loop track to control polatiry on the loop itself. the ac terminals go to the power pack, the dc to the track. if you go this route be aware that you will not be able to change directions while in the loop tracks.

in all cases, your track should be gapped in the places indicated on the web page you linked to.

there ae other options as well which are a bit more complicated to wire.

[Desertdweller]

96:

Yes, I believe the example you gave is correct.  I can't advise you about DCC because I have no experience with it.  Although my model railroad is only a few years old, I decided to stay with DC for several reasons.

You can see why I was unable to explain how to wire it with words alone.  Diagrams are invaluable in situations like this!

The only model railroad you could get away without reverse loop wiring would be something with self-powered locomotives, or three rail AC like Lionel.

Les

[Flare]

I hadn't decided between DC and DCC as of yet.  If I go with DCC, then do I need something like this (http://shop.bachmanntrains.com/index.php?main_page=product_info&cPath=264_274&products_id=1824) at the start of each of my reverse loops?  Is there anything special about the track itself (Bachmann auto-reversing track)?

I'm building a loop to loop layout as well using DCC because reverse loop modules like the one you linked to simplify the wiring dramatically.

The module doesn't necessarily have to be wired to the start of each loop, just to the isolated sections.

You can wire a single module to both loops, or use two modules if you prefer.  Using two will not cause any problems.


Auto-reversing track has more wires than regular track (Which is why it's more expensive).  Two pieces of regular E-Z track are included in Auto Reversing track starter packs, but their purpose is to hold the train when it passes beyond the reversing sections and prevent it from hitting the bumpers.  The train will not continue moving onto a loop.


https://www.youtube.com/watch?v=yzIPjNCsGJI

http://www.bachmanntrains.com/home-usa/dwg/dwgs/N_Scale_Reversing_Track_Instructions.pdf