I saw there already is an current auto reverser question topic, and I’m sure many older ones, but I think my situation is enough different I started a new one; plus I didn’t want to hijack someone’s topic.
My situation is that I am designing my first N-sacle 4 x 8 DCC layout that I will be running by myself and I like to complicate things. I have posted my question on other forums, and yet have a good answer to my question. My design started with a “simple” reversing loop with it starting at the top of a 4-turn helix, where I go from a single main line to a double for the helix. After the 4-turn helix I have a five-track staging area, then back up the helix and back to the single line main. My plan was to use a PSX-AR and have it control the turnout at the split, with the gaps in the rails close by, so I wouldn’t have to worry about preventing a misaligned turnout short. This also would allow me not to have to worry about using right or left hand running, I would use whichever way the turnout was. BUT… now that I have been testing out my design on the computer, I have figured out that if I add a crossover at the base of the helix I can have a way to fix a head on situation without having to back up a train in the helix, or move the power from one end of a train in staging to the other end. Now after a long-winded explanation, my question is how many AR’s do I need (I’m thinking two) and where do I put the gaps?
The helix is still part of the main, and a double crossover presents no need for an AR. You do, or will, still need that one AR at the pinch point of your looped staging if it’s served by one turnout.
You have to post your screen shot in one of the free photo hosting sites like Imgur.com or Flickr.com
Then the easiest way to share on the forum is to get the BB Link (bulletin board link from the earliest days of the internet) and control V directly into your post.
I don’t see a reverse loop in that. A train coming in on one side, going through the crossover, up the helix, then reversing on the single track and back through has not changed the direction it is facing.
Okay, lets try this a third time. This time I posted what the staging level, helix, and a section of the single mainline looks like. Can you tell I’m new at this…
On my Flickr account, when I hit the arrow at the lower right, I get this choice for sharing, and I choose BB code
Then we can see it here
A train that enters the helix at the top, right to left, eventually comes back to the single track facing the opposite way. That, as you say, is the first reversing loop. I would gap after that tunout.
If I understand correctly, the arrow new crossover, is the proposed new crossover, you are not adding another crossover between the arrow and the outer loop.
From the outer loop of the helix, into the yard, is another reversing loop. I would put the gaps where the elevation 0 arrows are. Two AR’s by my count, but I’m better with pics than with reversing loops. [:D]
I might not be reading your elevations properly, but I still see the need for the AR at the pinch point caused by the new crossover. It appears also that the point of intersection at the single tail at the higher elevation presents a phase conflict, and you’ll need to reverse that as well.
If you have two trains, both running in either the helix or in staging, and not crossing one of the two reversible points, you can serve both places with the one AR.
Gee, I’m just having way too much fun trying to post my track plan… [banghead] I thought I followed the steps on, “How to Post a Photo to the Fourum” correctly, guess not.[sigh]
Thank you for the count of AR’s needed, at least I got that part right.
Selector, The single tail goes onto the second elevation of the layout; if I had shown that it really would have gotten confusing. With that said and I’m guessing the odds of two trains crossing the “pinch points” near the same time are low, could one AR work for both locations?
Thanks, Scott
Why not just treat the 5-track staging area as a single reverse loop? Place gaps where the arrows point (marked Elevation = 0"). That way, all of the track work, including the turnouts outside the staging area could be wired the same way so that no reversing sections would occur outside of the staging area. Everything outside of the staging area would be in phase, the mainline tracks at the top of the helix, the helix, and the track work at the bottom of the helix.
What Rich said. This is how my layout is designed, though it doesn;t go right to the helix, it goes fromt he multri track loop around the room to the helix at the other end of the run, then up the helix, back around the room, to a second multi-track loop stacked above the first one. The loops at the ends are the only reversing sections.
Since there can be many trains in the staging loop, perhaps the best way to do it would be to use a booster that can do autoreversing to power the staging loop. Though some autoreversers can handle fairly high currents. This is one case where the simple relay of the AR-1 would not be suitable, the current of a staging yard full of sound locos would exceed the relay contact ratings.
Not to be pushy, but you should do more than consider it.
You should do it for several reasons. One, it would only require one auto-reverser instead of two. Two, it would simplify your wiring protocol. Three, the single reversing section will be long enough to accommodate an entire train whereas the proposed two shorter reversing sections will raise problems with longer trains that cannot fit in the shorter reversing sections.
Oh be pushy, I want to learn as much as I can. What I’m not understanding is how the crossover and the turnout at the top of the helix won’t create short. Following the rail it turns back on it’s self.
That’s why you would place gaps where the arrows point (marked Elevation = 0"). By placing gaps on those two track spots, you will isolate the entire staging area from the rest of the layout. All of the track work, including turnouts, that is outside of that gapped area would be wired the same way in that track diagram. Under that arrangement, no track folds back onto itself, so no shorts.
Maybe this will help. The following track diagram shows both rails on each piece of track, colored red and blue. If you follow it from top to bottom, there are no mismatched colored rails which means that there are no points of opposite polarity to cause a short.
The red and blue only connect together through the yard tracks, each of the yard sidings is its own reversing loop because it connects to the entrance and exit tracks. Those two tracks join at the crossover turnouts. Isolating at the points indicated treats all those reversing loops as one reversing loop, polarity wise.
The tracks also connect at elevation 8" which makes it look like there may be two reversing loops and there are in a sense. But gapping the loop only there would not solve the reverse loop shorting that occurs at elevation 0".The shorting points are in series if you like.
Installing a new crossover inside a reversing loop requires its own set of gaps. Once gapped there however, the original gaps closer to the old reversing loop entry and exit become redundant. Unless you also loop that end back on itself using a return loop to that single track at 8" creating a return reversing loop from a return loop elsewhere.
Our layout does that so we have three blocks: the connecting double track with a crossover at each end and two reversing loops each created by one of those crossovers. Without the crossovers that’s a dogbone. Add one crossover which allows a train to cross to the opposite track anywhere in the dogbone and you create one reversing loop. Add a crossover facing the other direction and you create another reversing loop.
You could also just gap the crossover at the connecting diverging routes and again at elevation 8". That would provide the option of turning a much longer train if you wished, using the reverse loop created at elevation 8". Automating that would probably require two AR units.
