I have what I believe to be (3) three reverse loops on my layout and need some help in wiring them. I have attached a simplified layout of the area where the reverse loops are. I used colored arrows to identify them (the one with the yard is probably part of the mainline shown with black arrows, but I am not sure of that. I also understand that the turntable is one as well, so that could make it four (4)??. I was thinking of using a Digitrax PM42 or the one that Tony's Trains sells (don't remember the model number right now?) There is more to the layout but that is outside of this area and I am pretty sure there aren't any reverse loops there (it is just a big loop around the layout that ties in on either side of turnouts labeled A and B. I am not sure how to gap the loops and where to put feeders. Also, should I break them up into separate power districts or on separate circuit breakers? Any help will be greatly appreciated.
Bob
Life is what happens while you are making other plans!
You may have what you see as multiple reverse loops, but you only have one "reversing section." That is the S-curve from A to D on your diagram. If you insulate that S-curve at A and D, and use an auto-reverser on that, you should be fine. The Tony's Trains one is the PSX-AR. I have two of the older PS-REV units, and they have performed flawlessly for many years.
I don't see the connection between the turntable and the rest of the layout. Depending on the brand of turntable you use, you may or may not have to provide auto-reverse capability for it.
It takes an iron man to play with a toy iron horse.
May be I'm blind but I can only see one reverse loop that is track related (the S shaped that you pointed out).And yes,if it's not wired for it,your turntable is indeed an occasional reverse loop.Other than this,I can't see any.A reverse loop is a section of track that will reverse the travel direction of the train thus the polarity control requirement.In this case,only the S shaped section does this so is the only part that needs insulated ends and a polarity reverser other than your turntable.
The only gaps you need are at the two ends of the big "Mainline" S - both rails.
If your turntable feeds power to the bridge track through the ring rail and carrier wheels, you can simply leave two dead sections in that rail, exactly opposite each other and long enough so that both carrier wheels on one end of the bridge will be on the dead section at the same time (and at the same time that the carrier wheels on the other end are also both on the other dead section.) Or, since a locomotive on a turntable is standing still when the rails must be reversed, you can substitute a two-for-a-buck DPDT slide switch for the electronic reverser.
Chuck (Modeling Central Japan in September, 1964)
as said above the only reverse loop is the 's' curve through the middle. double isolate at the switches either end and fit a reverser to it. you may have an issue ( i have no idea of layout size or train length here ) IF you decide to a run a train longer than the 's' curve and the trucks have metal wheels. the 's' part can't match both switches at the same time and would try and constantly flick between polaritys. a golden rule of reverse loops is to have them longer than your longest train. in effect the length of the 's' dictates the length of any train you wish to run through it that has metal wheels on the trucks.
If the S-curve is indeed short, that's another good reason for the PSX-AR reverser. It's a solid-state unit, and the "flipping time" is very fast. Some other reverser units, in contrast, use relays. Their flipping time is much longer, although they are still measured in fractions of a second, but even that can be enough to notice.
I have one short reversing section on my layout, and I have a lot of rolling stock with metal wheels. With the Tony's Trains reversers, the fast cycle time allows the reverser to flip polarity many times while the train crosses both ends of the reversing section. Yes, you will occasionally have a situation where a short occurs and the train stops, and you should make an effort to avoid this if possible, but a fast reverser unit will probably let you get away with this more often than you would think.
farrellaa I have what I believe to be (3) three reverse loops on my layout and need some help in wiring them. I have attached a simplified layout of the area where the reverse loops are. I used colored arrows to identify them (the one with the yard is probably part of the mainline shown with black arrows, but I am not sure of that. I also understand that the turntable is one as well, so that could make it four (4)??. I was thinking of using a Digitrax PM42 or the one that Tony's Trains sells (don't remember the model number right now?) There is more to the layout but that is outside of this area and I am pretty sure there aren't any reverse loops there (it is just a big loop around the layout that ties in on either side of turnouts labeled A and B. I am not sure how to gap the loops and where to put feeders. Also, should I break them up into separate power districts or on separate circuit breakers? Any help will be greatly appreciated. Bob
As the other respondents have all indicated, there is only one reversing section in your drawing and that is the section of track running from A to D. The arrows that you added actually illustrate the point. Whenever track feeds back into intself in the opposite direction, you will encounter reverse polarity. For that same reason, the track connection between B and C is not a reversing section, as the arrows show, because the track feeds back into itself in the same direction.
A technique that I use is to draw a track diagram with two rails instead of a single line as you have done. If you draw a track diagram using two rails and color each rail differently (e.g., red and blue), a reverse polarity situation becomes immediately obvious when the red rail tries to connect to a blue rail or vice versa.
Turntables can pose a special problem. Some are factory equipped to deal with reverse polarity situations when the turntable track is rotated 180 degrees; other turntables are not so equipped. In that instance, you may need a second auto-reverser unit.
Lastly, no one mentioned the Digitrax AR1 auto reverser unit. I have two on my layout and they are great. The objections to the AR1 are that (1) it makes an audible click (oh, spare me, stick it in one of your structures or under the layout - - - it is all but inaudible) and (2) it reacts too slowly based on old technology but I have never had a situation where the reverser was slow too act. It is an urban myth.
Rich
Alton Junction
Thanks for all your comments and suggestions. NOW that you pointed out that there is only 1 reverse section (from A to D) and the turntable is a second one, I feel a lot better.. I didn't show the entire yard layout for simplicity (there are about 10 tracks in the yard) but the turntable is actually fed by 4 tracks coming from the yard. The S curve is about 10 feet long so I don't think I will be running any trains longer than that. This is quite a relief as I was expecting to have a nightmare of a wiring project. I will isolate the S curve and feed it from the auto reverser. I know I have to use one on the turntable as well. The turntable is a Walthers 130' fully automated model (not the DCC version).
As always you guys come through with all the answers. I love this forum.
thanks again,
When you say that your turntable is fully automated,it tells me you should investigate a little further.It likely has polarity control,even if not specified DCC friendly.But I don't know this product so can't be sure.....
farrellaa Thanks for all your comments and suggestions. NOW that you pointed out that there is only 1 reverse section (from A to D) and the turntable is a second one, I feel a lot better.. I didn't show the entire yard layout for simplicity (there are about 10 tracks in the yard) but the turntable is actually fed by 4 tracks coming from the yard. The S curve is about 10 feet long so I don't think I will be running any trains longer than that. This is quite a relief as I was expecting to have a nightmare of a wiring project. I will isolate the S curve and feed it from the auto reverser. I know I have to use one on the turntable as well. The turntable is a Walthers 130' fully automated model (not the DCC version). As always you guys come through with all the answers. I love this forum. thanks again, Bob
Bob,
The Walthers 130' turntable has an auto-reversing unit built in, so you won't need to add an auto-reversing unit or isolate a section of track for this purpose. Only the S-curve needed to be isolated and powered by an auto-reversing unit.
Rich,
Thanks for the updated info on the TT. I have the manual but haven't taken the time to look into the reversing issue, but I believe you are right about it having it built in. I ran the TT when I first got it but haven't installed it on the layout yet. I am researching the auto reversing units now and it looks like it is between the AR-1 and the PSX-AR, since I only need one.
bob
farrellaa Rich, Thanks for the updated info on the TT. I have the manual but haven't taken the time to look into the reversing issue, but I believe you are right about it having it built in. I ran the TT when I first got it but haven't installed it on the layout yet. I am researching the auto reversing units now and it looks like it is between the AR-1 and the PSX-AR, since I only need one. bob
A lot of guys will tell you to pick the PSX-AR over the AR1. The argument is that the PSX-AR trips faster and quieter than the AR1. Whatever. My AR1 trips so quick you don't notice it, just like the PSX-AR. As far as a clicking noise goes when the auto-reverser trips, the click is all but inaudible on the AR1 and if you hide it inside a structure as I do, or under the layout as most do, there is no way you hear a click.
Thanks for the info on the AR1. I was originally going to use it until I though I would need more than one, in which case I was going to use the PM42, which has 4 reversing/circuit breakers. Since I only need one now I will most likey go with the AR1 as it is half the price of the PSX-AR and I don't mind if there is a slight click when it operates. I can put it under the layout in a plastic instrument box (like the PSX-AR suggests to do with theirs). That should keep the clicking to a minimum!.
farrellaa Rich, Thanks for the info on the AR1. I was originally going to use it until I though I would need more than one, in which case I was going to use the PM42, which has 4 reversing/circuit breakers. Since I only need one now I will most likey go with the AR1 as it is half the price of the PSX-AR and I don't mind if there is a slight click when it operates. I can put it under the layout in a plastic instrument box (like the PSX-AR suggests to do with theirs). That should keep the clicking to a minimum!. Bob
Good decision and, believe me, that click is more like a tick.
Farrell, I'd suggest that you pick up a copy of Andy Sperandeo's book, "Easy Model Railroad Wiring". It's a Kalmbach book, and you can order it from MR's home page, or a good bookstore should have it.
Marlon
See pictures of the Clinton-Golden Valley RR
farrellaa,
Did you test that TT for any reverse polarity problems?
I don't have the turntable set up yet. I read the manual and it says it will reverse polarity automatically and there is another thread on the forum about this very problem with the Walther's turntables. I don't expect to have a problem with the TT but will most certainly be checking all my wiring before I turn it on. I did have it running on DC when I first got it but just to try programming the track stops and the loco ran correctly when I turned it 360 degrees and everything in between.
Thanks,