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Reverse Loop inside another reverse loop

Ed
 

I have a reverse loop that is controlled by a PSX-AR and I have added a quarry at the end of this loop that is controlled by a wye.  I understand that this creates another reverse loop but that I can manually control the turnout at the end of the wye using a DPDT switch. My question is: what does this do to the PSX-AR sensing functions - with or without another loco in the original loop?

Ed Robinson


dvollrath@...
 

Ed,

It makes no difference to the original AR unit unless you cause a short circuit on those tracks. Use a separate DPDT switch in concert with the Wye turnout leading to the loco turnaround stub to flip the polarity to it. Just remember to flip the switch correctly every time. Be sure that that turnout is not of the power routing type and/or make sure the frog rails are insulated from other tracks leading up to it. The main power feed to the switch should be the reversing output side of the PSX-AR. You could also use a 2nd PSX-AR to power the turnout wye stub if the DPDT switch is too inconvenient. Just adjust the timing of the two units to not interfere with each other.


DonV

---In WiringForDCC@..., <lehighman@...> wrote :

I have a reverse loop that is controlled by a PSX-AR and I have added a quarry at the end of this loop that is controlled by a wye.  I understand that this creates another reverse loop but that I can manually control the turnout at the end of the wye using a DPDT switch. My question is: what does this do to the PSX-AR sensing functions - with or without another loco in the original loop?

Ed Robinson


Steve Haas
 

 

Ed Robinson asks:

 

“I have a reverse loop that is controlled by a PSX-AR and I have added a quarry at the end of this loop that is controlled by a wye.  I understand that this creates another reverse loop but that I can manually control the turnout at the end of the wye using a DPDT switch. My question is: what does this do to the PSX-AR sensing functions - with or without another loco in the original loop?”

Ed,

 

It's a bit difficult to answer this question without knowing the lengths of the various tracks, and how you intend to operate engines/trains in that portion of your layout.

 

Having said that, this can be done with only one PSX-AR.  There are several ways to wire this:

 

  1. Control the polarity of the stub end of the wye with contacts on the switch machine for the turnout that controls the access to the stub end of the layout.
  2. Use the PSX-AR on the reversing loop. Beyond the gaps to the wye the wye tracks and stub can be controlled the same as the track entering the reversing loop – the PSX-AR will align the polarity of the reversing section to the main track out side the reversing loop or the stub end of the wye as needed.
  3. Extend the mainline block through one side of the entrance turnout, through the first turnout to the wye, that side of the wye and the stub track. The remaining portion of the reversing loop and (optionally) the other leg of the wye.

 

There are variations on most of those options depending on which makes the most sense for your track plan and how you intend to operate the area.  If I were a better artist I’d draw out some examples for you. 

 

Just remember, the track that creates the ability for a train to reverse itself isn’t necessarily the section that should necessarily be powered by the PSX-AR.

 

Let me know if you need more help with this!

 

Best regards,

 

Steve

 

Steve Haas

Snoqualmie, WA

Ed
 

Thanks Don & Steve. I believe I understand each of your explanations but a short description of operations is in order.

This is a short reverse loop because it only leads to a small quarry where one or two cars would be loaded. Movement of the cars within the quarry is done with a small switcher. Cars would be delivered to/from the quarry from the mainline using mainline locos so they would cross the wye and enter the quarry, drop off/pick up the cars, then exit the quarry via the wye. It is also possible for the quarry switcher to move the cars to/from the quarry by crossing the wye and drop off/pick up on one of the mainline legs of the wye. So, one of my questions is: can you have an operating loco in the mainline reverse loop and at the same time have the quarry loco move across the wye to move cars? If not, then a solution is to never have the quarry switcher cross the wye but this limits my ability to move the switcher to somewhere else on the layout - the engine shed in town for instance.

Ed Robinson

Paul O
 

Ed, a diagram posted in the photo section would sure be helpful.
Paul O

On May 9, 2018, at 2:19 PM, Ed Robinson lehighman@... [WiringForDCC] <WiringForDCC@...> wrote:

 

Thanks Don & Steve. I believe I understand each of your explanations but a short description of operations is in order.

This is a short reverse loop because it only leads to a small quarry where one or two cars would be loaded. Movement of the cars within the quarry is done with a small switcher. Cars would be delivered to/from the quarry from the mainline using mainline locos so they would cross the wye and enter the quarry, drop off/pick up the cars, then exit the quarry via the wye. It is also possible for the quarry switcher to move the cars to/from the quarry by crossing the wye and drop off/pick up on one of the mainline legs of the wye. So, one of my questions is: can you have an operating loco in the mainline reverse loop and at the same time have the quarry loco move across the wye to move cars? If not, then a solution is to never have the quarry switcher cross the wye but this limits my ability to move the switcher to somewhere else on the layout - the engine shed in town for instance.

Ed Robinson

dvollrath@...
 


I agree. Post a sketch showing the track layout and things you name so we can mark it up and send more thorough suggestions.
But... any loco that stays inside the A-R controlled section while another loco/train enters/exits over A-R/main boundaries will not be affected by a change in A-R section polarity. Trouble occurs only when two different A-R boundaries are being crossed at the same time. The polarity of a wye stub can be selected by the position of the last turnout leading up to. If the sub-bus feed for that stub and turnout happens to be an A-R section controller... so be it.

DonV 

---In WiringForDCC@..., <pomilian@...> wrote :

Ed, a diagram posted in the photo section would sure be helpful.
Paul O

On May 9, 2018, at 2:19 PM, Ed Robinson lehighman@... [WiringForDCC] <WiringForDCC@...> wrote:

 

Thanks Don & Steve. I believe I understand each of your explanations but a short description of operations is in order.

This is a short reverse loop because it only leads to a small quarry where one or two cars would be loaded. Movement of the cars within the quarry is done with a small switcher. Cars would be delivered to/from the quarry from the mainline using mainline locos so they would cross the wye and enter the quarry, drop off/pick up the cars, then exit the quarry via the wye. It is also possible for the quarry switcher to move the cars to/from the quarry by crossing the wye and drop off/pick up on one of the mainline legs of the wye. So, one of my questions is: can you have an operating loco in the mainline reverse loop and at the same time have the quarry loco move across the wye to move cars? If not, then a solution is to never have the quarry switcher cross the wye but this limits my ability to move the switcher to somewhere else on the layout - the engine shed in town for instance.

Ed Robinson

Ed
 

OK. A picture has been uploaded to the files section titled "Quarry wye.jpg"  Hopefully this helps.

Ed Robinson

dvollrath@...
 


I certainly does, Ed. Thanks.

Isolate both rails between turnouts 1 & 2 and 1 & 3. [easy to do using 4 insulated rail joiners at #1]
Wire the entire turnout #1 and the Quarry rails at the point end of the turnout through a DPDT switch, OR a 2nd PSX-AR, to switch power according to the position of turnout #1... but the INPUT side of the switch should be to select power from the main reverse loop rails.

If turnouts 2 & 3 are of the power routing type, add an insulating joiner on the frog rails between them.

Then when a train flows through either 2 or 3 to get to/from the Quarry stub it will automatically be at the correct polarity to exit/enter from the main reverse loop. If 2 and 3 are set to bypass the Quarry it doesn't make any difference what polarity exists on turnout 1 or the Quarry stub.

A loco already in the Quarry or even in the process of entering/exiting via 1, 2 or 3 will see the polarity quickly flip if there is a polarity change of the main reversing loop. This should not interfere in any way.

You can still get short circuits, and derailments, if both turnouts of either desired path are not set up correctly before attempting to run a loco through it. But that is operator/engineer error.

DonV 

---In WiringForDCC@..., <lehighman@...> wrote :

OK. A picture has been uploaded to the files section titled "Quarry wye.jpg"  Hopefully this helps.

Ed Robinson

Ed
 

Thanks Don. This is just what I needed to finish up my layout wiring.

Ed Robinson