How to extend diagonal reverse lo

[Cris]

Hi, new 80 old member. Just added a diagonal reverse loop to my layout, but it severely limits train lengths. Need members help! Is there a way to extend my diagonal reverse loop (red track in attachment) within current layout plan on to the main line beyond the top turnout?  The layout is DCC n scale Kato unitrack & both turnouts leading to reverse loop are Kato electrified#6s. All turnouts are manually push button controlled. For loop operation have installed dcc specialties PSX-AR & PSX.
Thanks in advance
Cris

[Bangorboy]

I have a question which will help clarify your needs.

Are you running lighted passenger trains or other trains with anything that draws power?  If not, the only thing that needs to be in the reversing loop is the engine or group of engines.  The unpowered cars can just trail behind and won't affect power or reversing issues.

If you are running lighted passenger cars, you can include the turnouts and half or more of the end loops in the reversing section.  In that case, Double-insulate the rails coming off the straight side of the turnouts, and both rails at the end of the loop section you are including in the reversing section.  Just be careful that the end of the train is clear of the end of the reversing loop, or it will cause a phase short and trip the power.

Does that help?

[C855B]

... Are you running lighted passenger trains or other trains with anything that draws power?  If not, the only thing that needs to be in the reversing loop is the engine or group of engines.  The unpowered cars can just trail behind and won't affect power or reversing issues. ...

Unfortunately, it's not quite that easy. Any trailing cars with metal wheels - powered or not - will bridge the insulated gap and trigger the auto-reverser. The only solution I can quickly arrive at is making the reversing territory large enough to handle an entire train. Here is a possible solution, expanding the reverser district as highlighted in yellow:

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Hopefully somebody will come along with a better solution, or see a potential conflict here that I'm overlooking.

[Maletrain]

I have started setting up a similar layout, and here is how I am handling the problem of the whole train not fitting inside my reversing section:

I  maade 3 isolated sections in the diagonal.  The middle one is on an auto reverser.  The ones on either side of it are wired through a dpdt switch such that either one or the other is powered, but not both at the same time.  Each one is wire so that it is in-phase with the part of the main oval that it connects to.  Those two sections that bound the reversing section only need to be as long as my longest locomotive or lighted car.  The auto reversing section between them should be as long as possible. 

To operate, a train through the diagonal, I set the dpdt switch so that the first isolated segment the locomotives will reach is powered.  That way, when the locomotives get to the reversing section, it will automatically match phase for the locomotive.  When the locomotives have cleared the first section and are completely in the reversing section, I throw that dpdt switch to power the next isolated segment and unpower the first isolated segment.  That accomplishes 2 things.  First, it puts power of the correct phase to get back on the main loop on the next segment the locos will encounter, so that the auto reverser will reverse.  Second, it creates a long enough dead track section where the rest of the train is still coming along behind that no ligthed car (or metal wheel ) can make the reverser reverse back.

That way, you could run a train that is so long that it goes all the way across the diagonal and then around the oval to the point where the turnout to the diagonal is set against it.

It would be possible to do this without using an auto reverser.  I did that on a previous setup with a quad-pole-double-throw switch.  Two sets of poles were wired as described above, and the other two sets were wired to reverse phase on the center section of the diagonal, instead of using an auto reverser.  I did not want to do that on my new setup because throwing a manual reversing switch on the center section causes sound equiped locos to drop the sound and then maybe go through startup gyrations.  I did not have sound decoders when I did this the first time.

There are some limitations to what I am doing.  First, it would be really complicated to use it for a train with pusher or mid-train locomotives.  Also, any lighted cars will go dark when is one of the electrically dead sections.

I looked at C855B's solution, and it is actually much easier to wire.  The concern that I would have with my particular track plan is that I may have a train stopped on the inner loop at a point that crosses the other end of the reverser when my diagonal train needs a reverse.  With DCC, and two operators, I cannot be sure that both operators won't be doing something that requires opposite section polarities at the same time.

But, for one operator, especially if running only one train at a time, C855B's solution looks better.

[Cris]

Hi Mike, thanks for response. Does look like it would work. Question& favor. Could you please mark up on my diagram where you would place ISOLATED joiners & where you would place the LOOP WIRING track connection?
 Will be greatly appreciated!
Thanks Cris
 

[RBrodzinsky]

Personally, I would extend the reversing section, at the lower edge, one switch to the right, keeping both yards within the reverse.

[C855B]

Insulate both rails at each red X, feeders at each blue O. Be sure to follow the proper rails between the two feeders:

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Personally, I would extend the reversing section, at the lower edge, one switch to the right, keeping both yards within the reverse.

That might work, too, (move lower red X to orange X), provided another feeder was added to that right-hand yard leg (green O) so it would have power for a switcher working the yard if the lead off the main was thrown against it (Unitrack power routing). The upper left yard lead might want a similar feeder, too, but less likely than the right-hand yard.

[Cris]

Thanks, To all for your timely replies & solutions to my Reverse loop extension SOS. Forum is a great tool!
 Cris