Greetings all! My 5 year old son has mastered the previous 4'x10' layout successfully operating 3 trains at a time (picture below). We are preparing to change duty stations and I have started a new layout design with the dreams of more space 6.5'x 15.5'. In creating this design AnyRail highlighted my inadvertent creation a a reversing loop (highlighted in red) with use of my double cross-over. I know I can use a frog juicer to switch the polarity like I do my electro-frog switches, but is there an optimum place to do the isolation? Also, I think the other side would also create a reversing loop although not as obvious. My son like to run long multi-engine consist freight trains and passengers (with illuminated passenger cars and tail lights). Any suggestions/feedback would be appreciated.
Yes, that double crossover certainly does turn both ends of the dogbone into reversing loops, as any double crossover across the sides of a dogbone would do. What is it for? It isn't a bypass; it takes two crossovers to make one of those. It's not placed conveniently close to any sidings, so they could be worked by a train facing the points of the switch. Any train on the layout goes right to left and left to right across the middle twice each, so being able to swap a train from clockwise to counterclockwise running won't make that much difference. If we knew why that crossover was there, we could better tell you how to wire it for convenient operation.
It's mainly to change the direction of the trains on the loops so a train can be either backed down a siding, or pulled into a siding depending on the location. For example the left inner loop is going to be a passenger station. Ideally the passenger cars would be backed down those runs so the engine doesn't eat into the track in front of the station. Pulling out of that would result in the train running right to left. Directly across the train pulling out of the industrial sidings (inner right loop) would exit leaving left to right for a head-to-head. Essentially I'd want to eventually get all the trains oriented in the same direction. Now that I think about it perhaps I should shift the double cross-over down one position to span runs 2-3 (top to bottom) instead of the current 1-2. That would be a more immediate reversal of the trains exiting those 2 areas which are the primary conflict. Thoughts?
Got it. I'd be more inclined to cross over between 3 and 4. Accessing the station and siding from the immediate vicinity of the yard seems more realistic to me, and if you run a switcher, that gives that yard goat easier access to all the above. Reversing polarity can be done automatically with DCC. Without it, normally a section of track close to that switch that sends trains against the current (in this case, the crossover) is isolated and wired two ways through a double pole, double throw toggle. That toggle is thrown to reverse polarity from normal for that section of track. This gives the locomotive room to move into the "oncoming lane" without shorting the system out. Then the direction control of the power pack and that toggle are both thrown simultaneously, keeping polarity the same where the locomotive is but reversing it everywhere else (because the train is now going the other way). I'd do that to the stretch of Track 3 going right to the siding near the roundhouse, and to the stretch going left to the other siding and the station. These long reversible stretches do two things: You can reverse the one section you're using, and let a train work a siding and go back to running the direction it was before without doing the polarity swap trick. You also have room to reverse a whole passenger train, because lighted cars will short the system out just as quickly and thoroughly as a locomotive will.
I'll move the crossover down one step. Would you place it within the yard stretch or off to the side (left side has more space). Yes, my son and I do use a switcher for all our yard work so that would be ideal. I'm using Piko DCC controller (android based with pictures makes it easy for my kids). I use Frog Juicers on all my electro frog turnouts and was assuming I'd need that for the reversal loops? Based on your reccomendation, could you highligt where you'd isolate the section of track for the polarity switching? Thanks for all the help and feedback. The original board shown in my first post was my first go with DCC and feel like I'm still learning a lot.
How long is the passenger train? If you put the crossovers just left of the yard, and the varnish train fits between it and the sidings in the left loop (passenger station?), and it also fits between the crossovers and the sidings on the right, that's where I'd put the crossover and that's the stretch I'd isolate for the polarity swap. I'd fit it with a DPDT switch even with DCC. You can throw it when working the sidings and save wear and tear on the auto-reverser. Save it for when you're reversing a train. As for DCC, don't ask me. Hopefully someone who knows will chime in.
Tried to incorporate you suggestions. I color coded the 4 blocks for polarity switching, recognizing the whole train would have to be within that block before transiting the next block. Would this work across switches as well as long as I used insul-frogs and still isolated the points end of the switch?
No need to bother with the blue stretch. You may want to extend the green stretch. You never said if your passenger station is down in the end loop, or up where that gray rectangle is. If that's an industrial siding down in the loop, you'll want to give yourself room to pull past the switch and back up. A passenger train runs on the main throttle anyway, so if that's the station down there, you're fine. But I wire industrial sidings in with the main line that feeds them, in case I want to drive the locomotive onto the siding while switching. If you like that idea, you might make the sidings that serve the gray rectangle green, and the sidings on the right pink magenta, to remind yourself. Or you could make the whole stretch and all four sidings green. That way, you'd only need one reversing unit.
Do you think using a single cross-over would simplify the solution? And yes, the grey building on the left was planned to be the passenger station, the sidings below that for industrial, the sidings to the right with the Tram track the commercial area. I'd like the option for one reversal just to enable the ability to back the passenger trains down the lines to the station regardless of the main line flow. I don't really need 2 reversal loops, the passenger train sidings are really the only ones that are opposite the rest. Thanks for all the help and feedback so far.
I'm not sure I follow all of what you are trying to achieve, but would only having 1 reversing loop put you in the situation, where once a train is reversed the only way to reverse it back would be to back it through the single reverse loop? Sumner
I believe using this version I can get away with only two blocks that might need to switch polarity. And in theory I'd only need the blocks to be as long as the trains that could fit within the lines that might be reversed, most often the passenger terminal line. Not sure what all you're asking Sumner, but yes, I'll have to always back my passenger trains back down the line to achieve what I'd like. The industrial and commercial lines exit their branches in the same flow as the mainline already. Does this appear like it would work?
He's saying the latest version with a single crossover allows you to turn a train that's running the outer loop counterclockwise so it runs clockwise without stopping. But once the train's running the outer loop clockwise, you can't turn it without backing up. The double crossover allows you to turn any train without stopping. In the latest version, the green reversing section is needed, but the other one doesn't do anything at all. It's only needed when a double crossover is used. That single crossover can only direct a train to the green track or take a train from the green track, so the green track is all you need to reverse polarity. You could make the whole thing the reversing section to make switching easy off to the right, but there's less than zero reason to make those two separate electrical zones.
Ah, you are correct Sumner and I want this to be as versatile as possible for my kids, the double cross over is back in. I know none of what I'm doing is anything close to prototypical, but want to offer enough variation and options for them to not get bored with things always running the same direction. I also like seeing them work through the puzzle of coordinating track changes without crashes. I'm trying to learn the art of block detection and signals on this layout as well. Here is the layout, just not sure if I've identified a 'smart' reverse track plan. I'm trying to incorporate all your feedback.
The track plan will certainly make them have to think. Good plan and great what you are doing with them , Sumner
Hopefully this is the last of the changes. I went back and noticed that pulling engines from the turntable would require a long round about trip to get to the yard so I put a single cross over from the run in to the turntable over to the reverse loop. Does this plan still work with my polarity swap sections or is this just a bad idea? Thanks again for the help. Next will be block detection ideas Dale
I'll be interested in other's view's but without trying to figure out the implications polarity wise of the crossover I'd spend the money on some frog juicers, like Tam Valley's, for those two turnouts. They might not be needed but they aren't that expensive and I was too lazy to really look at the total polarity issue and it is your money . Since the reversing section starts just after them my gut feeling is they aren't needed but they also might be creating another reversing section but after doing a quick look I don't think they do. Looks like the only way they would is if you ran through the purple reversing section and then the polarity change on that section would take care of it. I do think that it is wise putting the crossover in for the reason you stated, Sumner
Yes, that new switch would involve a polarity swap too. Each track has the opposite polarity of the track next to it. Instead of entering the loop around the roundhouse the usual way as you have done, you could come off the next loop up and get to the roundhouse via a crossing.
Sumner: Yes, I love Tam Valley frog juicers. That's what I currently have on my double crossover and all my electro-frog turnouts that aren't connected to a tortoise machine. ACPTulsa: I understand I'd need to make the loop around the roundhouse and the track leading to it as a block as well. I'm not understanding the second part of your post with another way to get to the roundhouse. I'm open to any ideas that makes this more feasible. I'm starting to think I'm over complicating it and should get rid of the double cross-over and all and just have to manually flip the engines around if I want to run trains the opposite direction. (K.I.S.S.) If I'm making this a wiring nightmare for myself please let me know.
The crossover makes life easier overall. Wiring in a DPDT with the feeds reversed is easy as pie, and I don't think DCC reversers add that much complication either. You can simplify even more by combining the purple and green into a single reversible block; only one train can use a double crossover at a time anyway. My alternate way in involved a left hand switch in the loop very close to the end of the commercial district sidings. The through track uses the curve and the straight track diverges toward the roundhouse. Of course, it's outside the end loop. But one crossing will let it in to where the roundhouse is.
