# Track configurations for multiple trains in operation?



## BigRedOne (Dec 13, 2012)

I'd like to hear some thoughts / experience on what you've done to run multiple trains simultaneously. I know that two parallel tracks allows two trains to run unattended without interference; this is what I'm used to doing in HO. An alternative is single track with passing tracks - which would require automation or manual control to avoid collisions. I'm leaning toward a combination of the above, such that the parallel tracks allow two trains in opposite directions, while any manually controlled trains have to maneuver around to complete their task (e.g., a freight is manually controlled and has to avoid disrupting a passenger train.)

I'm contemplating an indoor G gauge railway using my old HO tables. Using the structures I already have, I have two grids of 6' x 10' with ply tops in 78" width; I can connect the grids in a variety of configurations, such that a single, rigid structure is formed. The arrangement which best fits my space is an "L" shape with a long leg of 238" (6 m) and short leg of 150" (3.8 m), and leg width of 78" (2 m). The short leg and 7' of the long leg fit into a corner against walls, so the viewing and operating range is the entire inside corner and much of the long leg. 78" allows R2 with some room to spare, so I can get an "L" shaped parallel track loop. 

My thought at the moment is to have a "first level" consisting of a parallel track "main line" which crosses itself at the inside junction of the "L". I'm running short and articulated prototypes, so the R1 + R2 are fine; switches are R1. I'd like to have (or at least keep the option for) catenary.

Then a "second level" of a long loop folded over itself twice (therefore reaching three elevations.) This allows three independent trains without conflict, and additional manually-operated trains. I plan on having the ability to connect the three loops in series as well as parallel, in which configuration the track is a single loop of much greater length. I believe the best way to accomplish this is a helix buried in the outside corner of the "L" (against the wall) to carry the upper level of the folded loop track back down to the "main line."

Hope that all made sense!


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## toddalin (Jan 4, 2008)

Read this month's _Garden Railways Magazine_ for Kevin Strong's dissertation on how to do this and what to use.


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## ThinkerT (Jan 2, 2008)

This sounds like an expanded version of Vics multi-level pizza layout. 

The bottom level sounds a bit like the design I set up for my 'Pizza Pile-Up' thread.


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## Garratt (Sep 15, 2012)

Can you draw a rough sketch? 

Andrew


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## BigRedOne (Dec 13, 2012)

This is what I have so far for the parallel-track main line. It is still close to 5% (to reach 225 mm.) I think I will test the train on a grade before deciding if it makes sense to try to build something this steep. If it doesn't, then the lower lever will have to stay flat, in which case I will go with an "L" shaped oval, to avoid crossing tracks. 

The spur at the left hand of the picture is a provision to connect all the loops in series instead of parallel, which allows one long run.


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## Garratt (Sep 15, 2012)

Yea, that's what I thought you meant but I'm in Australia so it was upside down.








I wasn't sure if you were having double track crossings







or crossing over the top on a different level. 
The bottom right hand corner will be hard to get to unless you crawl under from your description.
So the 'circle' is where you actually want another loop folding over itself, starting already up one level therefore getting up to three levels?

What locos/prototype railroad do you wish to run/model? 
You have stacks of room. Surely you can design something to keep closer to 3% grade. 
If you already have R1 switches can't you use them for the upper mountain loop and use wider switches for the mainline?

Andrew


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## Garratt (Sep 15, 2012)

I had a fiddle with your design idea for some creative entertainment. Measurements are in centimeters. (aprox 20' x 12' 6" overall, 6' 5" deep)
You should be able to get about 4% grade with 200mm height difference between levels. Use very thin upper support where your tracks cross. 
The minimum radius is just under 600mm on the upper level. The main line radius are greater than 600mm except the inner bottom left and inner tunnel ones which are 600mm. 
The switches are Train-Li R3 (3ft radius) with one Train-Li curved and one 600mm long one. (The switches on the upper level are drafted with flexi track because I ran out of parts in the evaluation version of the software). The upper level loop drops down partly to the joining switch (lower right). The track near this switch would be ideal for a long trestle over the main line. Trains can run either way on the upper level via the section in the middle to make a reversing loop. This will have a polarity wiring issue. 
There is a scenery/clearance issue with the tight tunnel portal lower left. Clearances would be critical, probably more suited to shorter-medium length cars. I left some room in front of the lower section for extra sidings etc.









Andrew


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## BigRedOne (Dec 13, 2012)

Thanks, Andrew. You raised a number of questions, so I'll take them in order. 

I'm hoping to avoid grade-level track crossings, since those call for automation or manual operation to avoid collisions. I'm still overwhelmed by the range of product offerings in digital control for G, and I assume I would have to settle on a digital system prior to designing a track plan which depends on automation (I do not want the abrupt stop / start and loss of illumination caused by a relay-based automation.) I want the ability to run the independent loops without intervention, and then manually control additional train(s), working around the running trains. 

You're exactly right that the bottom right hand corner is against the walls; I do have a port in the table top, and yes I have to crawl under the table to get to it. I can accept that, because I gain a lot of surface area and flexibility if I push the tables close to the wall. 

The R1 circle in the bottom right is one possible position for a helix affording four or five levels. I'm hesitant about this, because it is steep, and running a steep helix could limit operation to one direction. 

I am running narrow gauge European prototype in 1:22.5 scale; the largest equipment I plan to run is the RhB Crocodile with the "Alpine Express" passenger cars - I deliberately want to stay in shorter or articulated prototype, and don't intend to run anything which can't handle R1. I do want to keep the ability a have catenary. 

I want to have the ability to switch between a number of short loops and a single long loop. 

Your mountains and tunnels really fit the space well.


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## toddalin (Jan 4, 2008)

I hope that you don't intend to run this on simple track power using the commercially available passing devices without lots of head scratching. This presents an electrical nightmare and is certainly not for the beginner or electrically challanged.


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## Greg Elmassian (Jan 3, 2008)

It is simple in DCC.... even for a beginner.. you can run trains, and add automated control as you go...


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## Garratt (Sep 15, 2012)

Posted By toddalin on 09 Apr 2013 08:49 PM 
I hope that you don't intend to run this on simple track power using the commercially available passing devices without lots of head scratching. This presents an electrical nightmare and is certainly not for the beginner or electrically challanged.

It was primarily a layout concept at this stage, to have 3 loops with 3 trains running continuously. How to fit it all in a given space. The electrical wiring issues have not even been considered yet although the obvious one is the return loop on the upper level. All a progressive conceptual discussion at this stage. 
The OP specified a double mainline with an upper loop, all connected that could be run as one long run. That is going to create wiring issues, I agree unless of course it is DCC as Greg has pointed out. The OP has not specified.









Andrew


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## Greg Elmassian (Jan 3, 2008)

Actually he did talk about operational goals in his first post: 

"I know that two parallel tracks allows two trains to run unattended without interference; this is what I'm used to doing in HO. An alternative is single track with passing tracks - which would require automation or manual control to avoid collisions. I'm leaning toward a combination of the above, such that the parallel tracks allow two trains in opposite directions, while any manually controlled trains have to maneuver around to complete their task (e.g., a freight is manually controlled and has to avoid disrupting a passenger train.)" 

So, I did not want the discussion to stop because of Todd's "electrical nightmare" statement, the task with that layout and DCC is simple to wire and operate, so keep those creative "juices" "unfettered" by worrying about the electrical issues right now. 


Greg


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## Garratt (Sep 15, 2012)

BigRedOne,


A 7ft circular helix in the corner, would give a grade 0f 3.4% with a rise of about 9". It would effectively cut your space in half not allowing any track to pass unless going through the helix.
It would be quite a large portion of the space and much track could become a hidden. If designed right you could overlay each 'loop' of the helix in such a way so there was nothing above all of the track, all of the time. It would lend itself to a track popping in and out of tunnels. You could use the helix as just a means to get from each level or use the helix as a part of each running loop too. For the moment consider these plans where entering the helix at 'A' and exiting a whole level higher at 'B'. A train could also exit the helix at 'C' not an entire level higher, then grade back down outside the helix and back to where it started which would be half a running loop. You would do the same on the other side. Of course trains would have to give way to any other train going up the helix past that particular level. This method would be a possibility if space for tracks getting past the helix was a problem.

Andrew 











Smaller radius but more room to get past the helix and to go around the back avoiding using 'C' and 'D'. 
If you bypassed the helix at the front also, it would remain clear for trains to go up and down each level without interrupting any loops. 
The point being is that a helix can be used in a number of different ways rather than just being conveyance to different levels. When space is tight or saving turnouts, the helix can be used as a part of a level's 'loop'.


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## BigRedOne (Dec 13, 2012)

I plan a single electrical circuit on the track and digital control; no reversing loops or other fancy wiring. My base premise is that three trains can be run with no oversight on the three independent loops (parallel track main and single track mountain branch.) These loops can be switched in such a way that they can run in series (this calls for the switch configuration in my photo with the spur connecting the "end" of the "final" loop with the "beginning" of the "first" loop. This concept uses switches to select between parallel and series running, with the "spur" crossover to make the "end to beginning" switch. It can be a grade crossing or elevation, with the latter creating a single long run without the collision risk of a crossing. An out-and-back long run is interesting, but the reverse loop is then a problem. 

(As an aside, I understand the basic premise of a reverse loop is to align the polarity of the loop with the main, allow the train to enter the loop and then reverse the polarity of the main so that the polarity of the main is now aligned with the exit instead of the entrance of the loop ... what I don't understand is how this concept works while other trains are in operation on the main?) 

Andrew, thanks for the idea of stretching out the helix - it helps a lot on the grade. I can add some table in the inner join of the "L", up to perhaps two feet, and this could give the needed clearance. I don't want to go below R1, since I can depend on LGB product running successfully on R1. 

Some goals: 

- No crazy grades that end up with a locomotive and one car. 
- Parallel and series option, since this affords a laissez faire mode of operation or an operator intensive mode. 
- Three or four distinct themes for modeling and photography - heavy industry, large passenger station, isolated industry, small passenger station ... (probably the easiest goal.) 
- A carload of cute girls asking me out (maybe asking too much?) 
- No derailments, ever, especially if they are hard to reach! 
- Each time the train brings a beer wagon, and it's full. 

What I wonder about is whether the parallel track main is a better plan than a single track main with automation to allow two trains running in opposing direction without manual supervision?


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## Garratt (Sep 15, 2012)

Ooops, I messed up the helix pictures. Here they are again.
Having to squeeze the helix into an 'oblique?' oval helps to make room. Depends on the rest of the layout but instinct tells me to do it that way for now. An oval helix actually helps with adjusting things at the design stage too. It is only a matter of changing the straight sections to adjust the grade which might help to fit other things in the overall plan.
With a helix run of 300" (762cm) for a rise of 9" (22.5cm) the grade will be 3%. 
To go to a 3.5% grade shorten each straight section by 21.5" (546mm).
To go to a 4% grade shorten each straight section by 37.5" (940mm).
I hope I got all that correct









With the first layout design, the upper loop was tricky to fit in and I had to do the reverse loop idea basically because it was easy to draft and facilitated the train returning that way. 


This is all an exercise and reference for myself. There is a logical way of putting all this into perspective. Space is always a premium in this scale unless out in the expansive great outdoors. Even a layout table of the size you have has it’s limitations it seems. Still pondering...

Andrew


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## toddalin (Jan 4, 2008)

Posted By BigRedOne on 10 Apr 2013 06:45 PM 
I plan a single electrical circuit on the track and digital control; no reversing loops or other fancy wiring. 

What I wonder about is whether the parallel track main is a better plan than a single track main with automation to allow two trains running in opposing direction without manual supervision? 

Then that's not the track plan for you.

To run two train in different directions is simply a matter of doing a "leap frog" and having one engine equipped with a switch so that you can reverse its polarity. You can see where we do it here.

Tortoise & Lizard Bash In Operation


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## Garratt (Sep 15, 2012)

BigRedOne,

I know it isn't necessarily the plan for yourself but I got rid of the upper level reverse loop situation that some would find a problem.









Andrew


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