I thought I had it figured out but now I am unsure. I have identified the red track as a reversing section and labeled the gaps A to D. Am I correct? Is there a better way? I run a NCE Powercab with a SB3A and will use a Digitrax AR-1. I hope you can see the photo.
Scott
babefluffI hope you can see the photo.
Can't even see the broken image icon if Firefox. There is a sticky on how to post photos in the forum
if you read it, you missed the line Any site that requires a login won't work, even if visibility is set to Public. Right there on your image is a big sign in button.
I took the liberty of copying your image and modifying it. No reversing is happening until you get to the black arrow I added. I would gap the straight and diverging route of that turnout. I also added the letter E and a vertical red line. You need to gap those tracks going into staging.
Henry
COB Potomac & Northern
Shenandoah Valley
BigDaddyI took the liberty of copying your image and modifying it.
I think Henry has it right.
-Kevin
Living the dream.
Lastspikemike Well, if you're going to do that then remove all the gaps except at D and insert a new gap just to the right of the turnout that actually creates a reversing section. That gets all of the mainline out of the reversing section. Technically, the reversing section doesn't begin until after that turnout. The only really usable reversing section is from D to the turnout.
Well, if you're going to do that then remove all the gaps except at D and insert a new gap just to the right of the turnout that actually creates a reversing section. That gets all of the mainline out of the reversing section.
Technically, the reversing section doesn't begin until after that turnout. The only really usable reversing section is from D to the turnout.
I had thought that originally but then I noticed a second loop and that is why I posted the first picture. The picture below was my original thought but now I am even more confused.
babefluff Lastspikemike Well, if you're going to do that then remove all the gaps except at D and insert a new gap just to the right of the turnout that actually creates a reversing section. That gets all of the mainline out of the reversing section. Technically, the reversing section doesn't begin until after that turnout. The only really usable reversing section is from D to the turnout. I had thought that originally but then I noticed a second loop and that is why I posted the first picture. The picture below was my original thought but now I am even more confused.
Since this is DCC, and the length of the reverse section is not likely to be much of an issue, the only real reverse loop here is short section of track between the turnout at "A" and where it joins the staging yard ladder.
Consider the the whole loop the mainline and just put an auto reverser on that short section.
There is no second reverse loop, that section created the only reverse loop. Think about the layout if you removed that. There is no other way to reverse the train so there is no reverse loop without it.
Once you reverse the train, do you intend to back it thru the loop to reverse it again?
OR
Is there another loop on the upper level that I see a note about?
Sheldon
ATLANTIC CENTRALSince this is DCC, and the length of the reverse section is not likely to be much of an issue, the only real reverse loop here is short section of track between the turnout at "A" and where it joins the staging yard ladder. Consider the the whole loop the mainline and just put an auto reverser on that short section.
Ah... I missed that it was a DCC layout.
I think this diagram reflects what you suggested.
Yup.
The OP mentioned in his first post that he was using an AR-1 which is a Digitrax mechanical relay auto-reverser for a DCC layout. Identifying and isolating the reversing section is pretty simple in this example.
Rich
Alton Junction
SeeYou190 ATLANTIC CENTRAL Since this is DCC, and the length of the reverse section is not likely to be much of an issue, the only real reverse loop here is short section of track between the turnout at "A" and where it joins the staging yard ladder. Consider the the whole loop the mainline and just put an auto reverser on that short section. Ah... I missed that it was a DCC layout. I think this diagram reflects what you suggested. -Kevin
ATLANTIC CENTRAL Since this is DCC, and the length of the reverse section is not likely to be much of an issue, the only real reverse loop here is short section of track between the turnout at "A" and where it joins the staging yard ladder. Consider the the whole loop the mainline and just put an auto reverser on that short section.
I don't know I agree with Sheldon's suggestion. Hard to tell dimensions but that looks fairly short. You could have metal wheels, helper locos or lighted cars in the reversing section and on both sides of it.
BigDaddy I don't know I agree with Sheldon's suggestion. Hard to tell dimensions but that looks fairly short.
I don't know I agree with Sheldon's suggestion. Hard to tell dimensions but that looks fairly short.
Yes, the proposed reversing section may be too short for lack of needed length.
Also, once a loco is reversed, there is no provision to turn it back into the former direction.
Another poor design is the use of two turnouts to join the yard to the mainline at the bottom of the diagram. The yard should be shortened a bit so that only one turnout connects the yard to the mainline.
BigDaddy SeeYou190 ATLANTIC CENTRAL Since this is DCC, and the length of the reverse section is not likely to be much of an issue, the only real reverse loop here is short section of track between the turnout at "A" and where it joins the staging yard ladder. Consider the the whole loop the mainline and just put an auto reverser on that short section. Ah... I missed that it was a DCC layout. I think this diagram reflects what you suggested. -Kevin I don't know I agree with Sheldon's suggestion. Hard to tell dimensions but that looks fairly short. You could have metal wheels, helper locos or lighted cars in the reversing section and on both sides of it.
I agree that is a possible problem. It would be good to understand the reasons for the this reverse cutoff in the design.
I also think Rich is correct about moving the one turnout. Or better yet consider a different track arrangement for the reverse loop all together.
LastspikemikePut the LH turnout at C on the other side of where the RH turnout is now. Take that RH turnout out of the "main loop" altogether and put it at the diverging route of the LH turnout you moved. That makes your crossing track longer and removes a turnout from the main running loop putting it into the staging yard where it better suits your purpose.
I cannot visualize what you are proposing.
Please post a diagram.
To answer some questions. The track leading to the upper level has a balloon track for a reversing loop so that I can turn the train back to the other direction. It is stacked on top of the lower loop.
The cutoff track in the lower level is only 30" long, too short for a train to be completly isolated in the loop. Hence the reason to isolate a "section of track" as the reversing section.
The section I see as the second reverse loop is from where the staging yard starts at D and follows the staging, through the main line all around the layout and back to D. My understanding is that if a train can be backed up and then change direction it becomes a reversing section.
I am not sure how to proceed as all this track has been laid and I do not want to have to remove it. I will post a picture of the entire plan later on today to see if it will help.
I appreciate all the help thus far.
Lastspikemike In fact, your original plan will work fine, now that I think it through better. You need more than the minimum two sets of gaps required for a crossing track, as you've realized, and you have them. Gaps located as drawn and your layout will work fine. Gap C is correctly located for what you are trying to achieve. No need to change that at all. Gap C is all that is needed to prevent the circuit from shorting out. Gaps A and B are necessary to run a locomotive over the gap at C. It's the locomotive wheels that short out the gap at C. Hence the need for an isolated section at least as long as the longest locomotive consist. But then there's the metal wheels on the last car in the train which also short the gap at the other end of the isolated section. A normal DCC auto reverser will react to both shorting signals. You do have options as to exactly where gaps A and B and D go but you don't need to change them if you choose not to. You don't need extra gaps at the proposed location E. You can create a longer isolated "reversing section" using the sets of gaps more or less as you have done in your diagram. We have done this on our layout. You just need more than the minimum two sets of gaps, as you have discovered. You can move the gaps at A and B to extend the length of the "reversing section". You can also move gap D to where I suggested in my second "wrong" solution. You don't need to move gap D but operations may be easier if you do.That's the part that only looks like a reversing balloon loop but isn't. It's part of the main line continuous loop that runs through your staging yard. That curved loop back to your staging yard then stays part of the "main line" polarity. That's what the solution proposed by Henry achieves but does not as easily isolate the part of the continuous loop you really need to isolate from gaps A and B to gap C. Steel wheels crossing that gap D will also signal a normal DCC auto reverser. You can move A and B gaps back up the track to the first turnout (towards the top of your diagram) as I suggested in my first solution. That will then include the entire passing siding within the isolated crossing track which is also handy. That also has the advantage of including both sets of sidings in one power district. You always keep the gap at C. Then all should work fine.
In fact, your original plan will work fine, now that I think it through better.
You need more than the minimum two sets of gaps required for a crossing track, as you've realized, and you have them. Gaps located as drawn and your layout will work fine.
Gap C is correctly located for what you are trying to achieve. No need to change that at all.
Gap C is all that is needed to prevent the circuit from shorting out. Gaps A and B are necessary to run a locomotive over the gap at C. It's the locomotive wheels that short out the gap at C. Hence the need for an isolated section at least as long as the longest locomotive consist. But then there's the metal wheels on the last car in the train which also short the gap at the other end of the isolated section. A normal DCC auto reverser will react to both shorting signals.
You do have options as to exactly where gaps A and B and D go but you don't need to change them if you choose not to. You don't need extra gaps at the proposed location E.
You can create a longer isolated "reversing section" using the sets of gaps more or less as you have done in your diagram. We have done this on our layout. You just need more than the minimum two sets of gaps, as you have discovered. You can move the gaps at A and B to extend the length of the "reversing section".
You can also move gap D to where I suggested in my second "wrong" solution. You don't need to move gap D but operations may be easier if you do.That's the part that only looks like a reversing balloon loop but isn't. It's part of the main line continuous loop that runs through your staging yard. That curved loop back to your staging yard then stays part of the "main line" polarity. That's what the solution proposed by Henry achieves but does not as easily isolate the part of the continuous loop you really need to isolate from gaps A and B to gap C. Steel wheels crossing that gap D will also signal a normal DCC auto reverser.
You can move A and B gaps back up the track to the first turnout (towards the top of your diagram) as I suggested in my first solution. That will then include the entire passing siding within the isolated crossing track which is also handy. That also has the advantage of including both sets of sidings in one power district.
You always keep the gap at C. Then all should work fine.
See, great minds do think alike. I have done as you suggested and attached the updated photo. There is also a second photo of the upper level and both photos are a simplified version of my plan.
Thanks to all for the help.