I’m stumped and I hope it’s not a bother but I’ve been reading “how to” books like mad and my mind is in a total fog.
I’ve finalized my track plan (see below). This really works for me with the area I have. I’ll be using a Digitrax Zephyr DCC.
I’ve imported the layout into Trainplayer (a cool program, BTW) and when I run trains on it, I (I think) hit a snag.
At the top of the layout there is a reverse loop that reverses by having two turnouts back to back. There’s a second set of switches on the main lines (middle right of the pic), too that will also reverse the train on the other loop. (There’s a third & fourth set of switches coming off one mainline into the storage yard, as well, to act as a “run around”.)
What I’m finding when running trains in Trainplayer is that when the trains go through the 2 switches on the mainline to reverse direction, they go around the loop and then come up on a closed switch. That means that I’ll have to throw them back to open once the train passes the switch. I’d rather not do that manually, as I plan on running one train on the mainlines that’ll be mostly on it’s own and a second switcher in the yard for moving freight around to be delivered at the 4 sidings by the “mainline train.”
I’m looking at both the DCC Specialities Wabbit and Hare units for automatic switch control (I’ll be using Circuitron Tortoise machines for throwing all switches). The wiring for those seems pretty straight forward (fameous last words, lol) so I don’t think they’ll be an issue…The Hare/Wabbit can autothrow the Tortoises for both crossover switches on the mainlines which simplifies things greatly, but that’s not a solution to the problem of the train approaching a point of derailment after it goes through the loop and comes back to a closed switch. Or is it? Do they (Wabbits/Hares) detect that and automatically throw the switches to open?&n
the hare will auto throw the switch for you. you should be able to use 1 hare for a cross over set. you 2 ‘detectors’ for each hare to ensure proper operation.
if your drawing is acurate, 1 auto reverse unit will do the trick. the section of track on the mainline (the section that is on the top right corner farest from the yard area) BETWEEN the 2 crossover switches should be your reverse section, if it is longer than your longest train. this section needs to include both switches at the ends (only the 1st switch in the crossovers). be sure to isolate the rails after the switches (4 gaps total per switch).
i’l try to draw a pic of my idea and post it. or PM me with your e-mail and i can send it to you.
I would go with a pair of auto-reversers for a couple of reasons. First, you said you want to run one train pretty much on its own, while doing switching elsewhere. I assume the yard area on the right side is the “elsewhere,” and that’s where the complications arise. There are enough crossovers there to complicate the auto-reverse wiring, so you will have a lot of places where the auto-reversers could be activated. If you’re switching over one of those spots while your unattended train crosses the gaps up at the top, you’re going to get at least a momentary conflict if you use a single auto-reverser. With two autoreversers, there should be no problem.
Auto-reversers generally don’t support the full power available to your DCC system. They are mostly in the 2-3 amp range. So, you want to use auto-reversers on sections of your layout which will only have one or two trains, particularly if you run multi-engine consists and sound engines, which use more power.
My advice is to go with a DCC friendly double crossover, like the Walthers Shinohara, and scrap the four turnout idea. By time you purchase 4 turnouts and two auto-reverse units, you could have purchased the double crossover and one auto-reverse unit, which is all you need in that case. Operationally, it would be simpler to wire and to operate. You will only need to gap 2 pairs of rails instead of the 6 pairs of gaps required with the two separate crossovers.
Also, the suggestion to go with a double mainline instead of the single mainline is a good one, given the size of your layout. Why limit yourself to one train running at a time? If you already have the four turnouts and decide to go with a double crossover, you can use the four left hand turnouts to get back and forth from the outer track to the inner track. The double crossover would be on the inner track.
The double mainline idea was a good one. Thank you.
And I think that Rich is right, the double crossover not only simplifies wiring, as I initially had suspected, but it also centralizes a single location where the train(s) can swap mainlines to reverse direction. I think it’ll be easier for me, a novice, to keep track of who’s going where on which line if a single double crossover is used VS two seperate crossovers on either end of the layout. I can always add a set in the future, if I find the need is there.
Now, the 64 dollar question is… does a double crossover require 2 Tortoise machines total? I would imagine so, but I’ve never actually owned one.
And I’m still not clear from my initial post… and maybe I’m not explaining it clearly. After a train goes through a crossover (double or single) and it changes tracks from, say, the outer track to the inner track, it travels around the loop and comes back to the that crossover on that different track… but the crossover is in the thrown position from before. Does a Hare or Wabbit sense this potential carnage and throw the switch back to open and allow the train to travel on the new mainline? If not, is there some additional item(s) required to throw that switch automatically? Or do I need to throw it back myself?
Ed, the double mainline will give you a lot of action. Go for it!
As for the double crossover, as you say, it does centralize the crossovers to a single location and, believe me, that double crossover is a sight to behold. I have read where some guys use 2 Tortoises to power a double crossover, but I use four, one on each end of the four-ended track configuration. All four Tortoises are then wired to a single DPDT switch. So, you wind up with straight through routes on each mainline track or, alternatively, all divergent routes crossing over from one mainline track to the other.
Without some additional sensing equipment wired in, once a single crossover (two connected turnouts) is thrown to the divergent route and a train crosses over from one track to the other, the divergent route remains in place. So, a train approaching such a crossover from the other direction is in danger of derailment unless the route is set back to straight through after the train traverses the crossover.
With a double crossover, you have a different situation. After a train traverses a double crossover on a divergent route, the divergent route remains in place. However, in this case, a train approaching such a crossover from the other direction is not in danger of derailment if the route is not set back to straight through after the train traverses the crossover. Instead, the approaching train will take the divergent route, traverse the double crossover, and wind up back on the other track.
I have no sensing equipment installed to change the routes back to straight through. I have to remember to flip the DPDT switch controlling the double crossover (or single crossover) to change the routes. However, I have installed my DPDT switches on control panels with bi-polar LEDs, green to indicate straight through and re
Thanks for the reply, Rich. When I picture a double crossover in my mind, I’m visualizing 4 switches that are connected - and I’m not understanding how it would differ when a loco enters that when it’s thrown VS entering a single crossover created from 2 switches when it’s thrown.
But, you own one & I don’t, lol, so I’ll take your word on it that it’ll be OK. [:)]
You could however fit in more yard track on the right side if you put it to the outside the curve. (Obviously) I like doing this because then I can use background buildings to act as a scenic block and operations area.
(This is if that section of your layout is in a populated area)
As to your double crossover question:
The only benefit to having a double crossover is that you can enter the loop from either side and still come out on the track you want. With a single crossover you may not be able to do that.
For example (single crossover):
Enter A->Exit A or B
Enter B->Exit A only
(Double crossover)
Enter A->Exit A or B
Enter B->Exit A or B
How important this is will obviously be entirely up to you. You can get around this problem IF you are willing to backup on the single crossover back into the loop. Once you pass the switch, you can then throw the crossover points and resume on same track you entered on.
Thanks for your ideas. It’s going to be a rural setting, I’m leaning towards a southwest desert look at this time.
I hear what you’re saying about putting the yard on the other side of the mainlines, but the drawing doesn’t show the footprint of the room, only the layout. The double mainline is close (6 inches away) to a wall on the right side. Moving the yard there means moving the bulk of the layout left (inward), and that would block the doorway entering the room.
I’m also factoring full wheelchair access into the plan because I use a wheelchair, (I did architectural design for wheelchair access in homes for 15 years) which forces me to need a 36 inch wide point entering between the 2 loops and a 48+ inch turnaround area when inside the loops. Strategic support leg locations on the loops can help with that, and the l
In the first drawing at the top, visuliaze a single crossover with a train moving from right to left entering a divergent route to cross over from the lower track to the upper track, as shown with the green arrow. As it returns around the loop moving from left to right to the crossover on the lower track, if the divergent route remains in place, the engine will derail when it reaches the crossover, as shown with the red arrow.
In the second drawing at the bottom, visualize a double crossover with a train moving from right to left entering a divergent route to cross over from the lower track to the upper track, as shown with the green arrows. As it returns around the loop moving from left to right to the double crossover on the lower track, if the divergent route remains in place, the engine will not derail but, rather, the engine will merely cross over to the upper track and continue to move to the right, as shown with the green arrows.
I agree about the double mainline. And I will suggest an idea that gives the “feel” of reversing train directions (but each keeping on “correct” side of double track) with no reversing polarity problems! I am not saying to build THIS layout but look at it for ideas. This is “loosely” based on the area around Houston Union Station (part of the old station structure is now incorporated as the Houston Astros Minute Maid Stadium!) as it existing about 1970. Note you can run a train counterclockwise around the dogbone loop at top and no polarity problems. Right hand running, train stays on right hand track on the portion of continuous loop that is squeezed together to look like double track.
What about reverse loop at bottom? Not really a reverse loop, polarity wise! Outer track is just a dogbone end loop. Inner track is just an alternate route (like a disguised passing siding) around the dogbone, that crosses itself to run with flow of traffic in apparent opposite direction from outer loop. But once back on apparent double-track section, it is plain to see it is really running the same direction. (I once was in a train club that rebuilt a discarded layout for a children’s hospital. It had what appeared to be a reverse loop, and for the longest time, members tried to figure out what it would run without worrying about throwing a reversing switch. And of course they needed it to run without a reversing switch for many o the kids to use it…)
The stub passenger terminal seems to have a wye that introduces a polarity reversing situation, doesn’t it. NO IT DOESN’T. The south leg and north leg attach to di
The blue track functions as arrival and departure track, and becomes part of the yard.
The other train has to run around it, independent from what is going on in the yard. Two cross-overs are needed, it can be done using the bright red tracks.
If you do not like a reversing section like that, an other passing track could be your way out.
BTW the crossing in the upper leg need some special wiring.
Not contributing anything new, but reinforcing some already-expressed opinions.
You have plenty of room to double-track your main line, go for it. Will more than double the fun, especially since I sense that this will generally be for a single operator.
Get the double crossover. It saves space, simplifies wiring and control, and centralizes the crossover activity. BTW I don’t get your beef about the $. The double crossover lists for $80. The four switches it replaces list for $25 apiece.
Definitely automate the polarity change when reversing track direction.
I recommend moving your main line entirely to the rear of the yard section. This rationalizes the yard and will allow you to do most of your yard switching without getting tangled with the main line. While in your planning it may seem fun to have to cross the main to get to one of your spurs, I think you’ll find in practice that that gets old in a hurry.
If the grid is one-foot squares, your mainline radius looks to be about 20 inches. That’s pretty tight if you plan to operate modern equipment or large steam locomotives. I realize that you also want the width of the “throat” between the two loops to be fairly generous and this is admirable, but increasing the minimum radius will have a dramatic effect on the look of your models in operation. You can afford to have the aboslute narrowest part of the throat 24 inches - bear in mind that interior doors can be as narrow as that. You wouldn’t want all your clearances to be that narrow, but we are talking about just one relatively small area. At that, I estimate that you can easily expand your minimum radius to 26 inches and quite possibly to 28 inches.
It looks it, but I really don’t have room for a double main.
The loops are drawn with 22 inch radius, all other turns on the outer main are 24. If I go outside with a second main, it’ll increase the benchwork size, which in turn closes the access path between the loops to a point where it’s very tight for a wheelchair. Inside means 18 inch radius, which I don’t want at all.
As I said earlier, the room itself isn’t drawn in, only the square feet. There’s a closet door near the entry door & both are 36 inch doors. So that blank floor area on the left really can’t be utilized. Make sense?
Here’s what I did… (see above) The double crossover is below the single crossover used for entering the yard. Doing so allows a train(s) to operate on the outside main without interferring with a switcher operating in the yard. The trouble is that now the yard is much smaller, which cuts freight car storage capacity down by about 40%.
I dunno. There’s lots of helpful ideas given, and I certainly appreciate them, but I’m up against the wall needing floorspace for access. Not only do I need room to enter, turn & move - but I need to factor in reach, too. Or maybe I’m just an idiot and not thinking this through clearly? [:)]
I have to agree a double track main would look alot better, plus you could even add a spur line that you could develop later into a industry or something.
You mention two issues in your latest post: (1) problems with adding a second mainline and (2) problems with adding a double crossover to a single mainline.
Let’s deal with the double crossover issue first. You say that if you add a double crossover that it reuslts in a shorter set of yard tracks because of the placement of the double crossover,. However, in comparing your track plan in your first post back on 2-28-11 with the track plan in your most recent post, you placed the double crossover well below the position of the single crossover that it was meant to replace. Why not simply place the double crossover higher up on your track plan? That way, you can leave the crossover to the switching lead track at the beginning of the yard where you had it in your original track plan.
Regarding the issue of adding a second track to create a double mainline, you indicate that space considerations will not allow you to do so. If you can post a track plan showing the doors and other obstacles, we may be able to come up with some possible solutions. In any event, you know your situation best, namely the room and configuration, the bench work, and the effect of your disabilities.
So, I don’t mean to be presumptuous, but if the concept of a double mainline appeals to you, it may be possible to do it with your current track plan. I say that because the addition of a second mainline track, as the outer track, should only add an additional 3 inches all around the current track plan.
Granted, the bigger challenge may be the additional space need to install single crossovers to get from the outer track to the inner track in order to reach the yard. A lot depends upon the placement of those single crossovers.
If you want to provide a revised track plan showing the position of the doors and other obstacles, I am up to the challenge if you are.
You could however fit in more yard track on the right side if you put it to the outside the curve. (Obviously) I like doing this because then I can use background buildings to act as a scenic block and operations area.
(This is if that section of your layout is in a populated area)
As to your double crossover question:
The only benefit to having a double crossover is that you can enter the loop from either side and still come out on the track you want. With a single crossover you may not be able to do that.
For example (single crossover):
Enter A->Exit A or B
Enter B->Exit A only
(Double crossover)
Enter A->Exit A or B
Enter B->Exit A or B
How important this is will obviously be entirely up to you. You can get around this problem IF you are willing to backup on the single crossover back into the loop. Once you pass the switch, you can then throw the crossover points and resume on same track you entered on.
Hi DG,
Thanks for your ideas. It’s going to be a rural setting, I’m leaning towards a southwest desert look at this time.
I hear what you’re saying about putting the yard on the other side of the mainlines, but the drawing doesn’t show the footprint of the room, only the layout. The double mainline is close (6 inches away) to a wall on the right side. Moving the yard there means moving the bulk of the layout left (inward), and that would block the doorway entering the room.
I’m also factoring full wheelchair access into the plan because I use a wheelchair, (I did architectural design for wheelchair access in homes for 15 years) which forces me to need a 36 inch wide point entering between the 2 loops and a 48+ in
