# Track Ratios



## jjwtrainman (Mar 11, 2011)

What do you guys think a main line length should be in feet if the following standards were set up for a garden railroad:

10 trains on main line, half going one way, half going the other.
train length no more than 10 feet
single track main line
five places where a passing siding long enough for three trains is on the main line for passing trains



I am going to try and get a math equation to find the answer but I want to know what you think first, you don't need an equation to estimate.

JJWtrainman @import url(http://www.mylargescale.com/Provide...ad.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css);


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## rdamurphy (Jan 3, 2008)

I'm assuming you're talking about a double track mainline and not passing sidings? 

I would recommend 30 feet of track per train, 10 feet for the train, 20 feet between, as a practical minimum to prevent a lot of rerailing rearended trains. 

Thast would mean a bare minimum 150 feet of track per loop. If you're planning on passing sidings, I would recommend the UP-style center track passing siding, it will save you money and track. 

So, for a math equation? 

Train length X Distance between trains X Number of Trains. 

T * D * N = track length. 

You can plug in whatever numbers you'd like, depending on your personal preferences. 

I'm curious, why 10 trains? Seems like a lot of one person to juggle... 

Thanks, Robert


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## jjwtrainman (Mar 11, 2011)

But there is something else that needs to be taken into equation, the speed of the trains. No two trains ever travel at the exact same rate, so how would someone go about estimating potential problems? 
another thing is that i AM talking about a single main line with passing sidings. This is what makes the equation more complicated. 
--JJWtrainman


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## John J (Dec 29, 2007)

Posted By jjwtrainman on 16 Mar 2011 05:49 AM 
But there is something else that needs to be taken into equation, the speed of the trains. No two trains ever travel at the exact same rate, so how would someone go about estimating potential problems? 
another thing is that i AM talking about a single main line with passing sidings. This is what makes the equation more complicated. 
--JJWtrainman 

I think MRC makes a system for model railroads that prevent engines from running into each other on the same track. I saw it at "THE BIG TRAIN SHOW" one year.

JJ


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## rdamurphy (Jan 3, 2008)

DCC should make it easy, just calibrate the locomotives. Of course, that will only work on level track, grades, curves, etc, would make a difference in speed. There used to be a block system that would slow trains down on Yellow signals and stop them on Red Signals until they turned yellow again. That would assume track power, however. 

Thanks, Robert


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## kormsen (Oct 27, 2009)

Posted By jjwtrainman on 15 Mar 2011 04:57 PM 
10 trains on main line, half going one way, half going the other.
train length no more than 10 feet
single track main line
five places where a passing siding long enough for three trains is on the main line for passing trains



that will not work!

i am building just that at the moment (after half a decade of planning) and i had something similar on my last layout.

you can have two, four, eight or twelve trains, but you can't make run a layout with an odd number of passing sidings.

try it out on paper.
step one - from each odd numbered siding trains are leaving in both directions to the nearest two even numbered sidings
step two - from each even numbered siding trains are leaving in both directions to the nearest two odd numbered sidings
and so on.

concerning the distance between the passing sidings - 
i am building each section at least four times the length of the trains. (indoors) my trains are about 7 foot long.


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## rdamurphy (Jan 3, 2008)

Or you could use an odd number of trains... 

It could be done, but the point being, you're going to spend a lot of time starting and stopping trains, throwing switches, and avoiding "corn-field" meets. I can't imagine a prototype with that many trains running that would use a single track main... 

Thanks, Robert


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## jjwtrainman (Mar 11, 2011)

Though not prototypical a railroad like tht would keep the operators on their toes!


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## Totalwrecker (Feb 26, 2009)

On my toes good? Or on my toes PITA? 

PITA and I'll pass on the next invite! 
As in; Didya invite me over to have fun or for you to torture me? How can I enjoy runnining if I'm dodging trains all day? 

John


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## kormsen (Oct 27, 2009)

Posted By rdamurphy on 16 Mar 2011 10:25 PM 
Or you could use an odd number of trains... 

please explain how.
i could not find a way to do that.


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## Greg Elmassian (Jan 3, 2008)

What's wrong with the obvious answer that you don't have to use every passing siding? 

You should only need the same number of passing sidings as the half the number of trains if half are going in the opposite direction. 10 trains 5 passing sidings. 

This presupposes that there is enough space between passing sidings to clear the siding/main so the train behind you can get into it. 

Then you could move half the trains clockwise one siding... then move the other half counterclockwise one siding. I think that's the minimum. 

If you wanted to be able to pass the trains on the siding, and then have BOTH head off in opposite directions, then you need twice as many sidings, 10 trains, 10 sidings, so for every siding/mainline "set" there is one clear path to the next siding in both directions. 

If you have an odd number of trains, then one train does not have to pass another train. Just round the number of trains up to the next even number and use that for your number of sidings. 

It isn't rocket science... 

Greg


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## kormsen (Oct 27, 2009)

oh yeah... 

Greg, 
on the ground, that jjwtrainman wants to put 10 trains and 5 sidings: 
as you describe it, he HAS TO move all five trains of one direction allways simoultanious, because not even one train has an empty siding to go to. 
and, for the same reason he never can move trains of different directions at the same time. 

do you really want to call that a "working" layout? 

i agree with you on the number of passing sidings equals number of trains. 
BUT NOT every number of passing sidings DOES WORK for that. 
if the number of trains for each direction is an odd number, you need an additional passing siding. 

look on the pic to see why:


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## DKRickman (Mar 25, 2008)

I'm thoroughly confused... 

First of all, I have no idea why an odd number of passing sidings is supposed to be unworkable. If you assume that every train must move simultaneously, then yes, but why assume that? 

Second, is the layout in question supposed to be operated by humans? A computer? Simple choreography? Trying to time things so that trains always meet at the right location seems like a good way to watch derailments. Having a computer operate the layout might be interesting as a display piece. Having humans operate will likely require a dispatcher to coordinate everything. 

Unless the purpose is to show off an overly complicated operation, perhaps this is a case where less is more?


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## jake3404 (Dec 3, 2010)

Although I think this is an aweful lot of work to just have fun, it is possible. 

You guys failed to see that the sidings are large enough to hold 3 trains. So with a lot of heart palpitating, you could race a train running in the opposite direction to another siding before it "meets the corn" because there is room to run more than one train into a siding. This would only work if your running opposite trains that are not in adjacent sidings. 

Whew way too much work for me.


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## jjwtrainman (Mar 11, 2011)

Maybe the solution is to have a double main line with a few single mainline choke points. That way, as long as an operator is on double mainline, he can go at his own pace and not worry about other trains. And when he comes to a point where single mainline is required, track work, tunnel, narrow valley. he just has to wait until a train in the opposite direction passes through the choke point, then proceed. It would work like a road construction zone, where a certain number of trains have the right of way in one direction, then the right of way flips to the other direction. All it would require is a simple "rules of the road" paper explaining who can go where and when, as well as some communication between operators. for instance: 
operator 1 has eastbound train stop be fore proceeding on to single main line traffic. He radios operator 2 who is piloting a west bound train on the other side of the main line and asks "is single main line clear?" then operator two would respond with, "yes, please proceed." or "No, another westbound a head of me hold until that train is through." 

"you can have two, four, eight or twelve trains, but you can't make run a layout with an odd number of passing sidings"-- kormsen 
This way, operators can have some more operation than just running trains in a circle for 2 hours, but it won't be like operating a switching puzzle for the same amount of time. 


If you do want to run an odd number of trains with the way i described before, move odds first then evens that allows for the trains to exchange sidings with out worry.


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## Greg Elmassian (Jan 3, 2008)

Korm, I think you will see that you and I are in violent agreement, I believe I covered the "odd" number too.. basically I said you had to round up to the next even number if you want trains in both directions to move at the same time. 

So, given the proviso you want all trains to move at the same time (not all clockwise trains, then all counterclockwise trains) yes, odd cannot work. 

My first example was the absolute minimum, and probably the worst looking, with 10 trains, 5 sidings... but you cannot issue a generalized statement that odd number of sidings does not work WITHOUT the proviso of which of the "two operating methods" you are using. 

Method #1, odd # of sidings ok 
Methog #2, odd # of sidings not ok 

Greg


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## NTCGRR (Jan 2, 2008)

What type and era of trains are we ,,,you talking about?? many GRYs grow as $$ comes avalibale. 
Narrow Gauge, Standard?? 
just wondering


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## jjwtrainman (Mar 11, 2011)

This could be any era, and gauge NTCGRR, this is one of those subjects that applies to most, if not all railroads. 
--JJWtrainman


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## kormsen (Oct 27, 2009)

well, gentlemen, i was at fault. 
i have planned so much and so long on my layout, that i - without thinking much - assumed, that jjwtrainman 
would like the same type of layout as i. 
(so what i took as base of thought was a fully automated layout with as much movements as possible at any given moment) 
and from the given length of less than 10 foot per train i thought about an old time or shoestring railroad setting.


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## Greg Elmassian (Jan 3, 2008)

I guess I was guilty too, I assumed with the large number of trains quoted, it would take some form of automated system. 

Yes, if you want to run that many trains, make it mostly double track main... it becomes WAY harder if you have trains going in opposite directions and don't have (scale) miles of space between them. 

It was an interesting discussion though, Korm I enjoyed stimulating the gray matter a bit! 

Greg


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## jjwtrainman (Mar 11, 2011)

Hey, we all have our own visions as what a railroad should be. 
My original thought was whether or not you could have multiple operators, each with their own train, run in different directions at the same time. And it would be possible, however, to make things more effeicant, one should use a double track main line. 
As for my "equation" I have found that track length= (length of trains X number of trains) + (distance between trains X number of trains). 
So 6, 10 ft long trains with 50ft of separation, would require... 360 feet of track minimum. 
And to find how much of that can be single main line: length of track/ number of trains. 
With my example, a maximum of 60 ft of single main line can be on the layout in one place. You can have up to two single line areas on the layout at the same time. this means that the railroad would support 4 trains on double track mainline and 2 trains on single track main line. So long that the average speed of all the trains is the same, this example would work fine. If speeds vary, additonal passing sidings would be needed


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## Greg Elmassian (Jan 3, 2008)

You can do what you are talking about, but it would not be fun for humans. I have a large outer loop (large is subjective!) and two 35 foot passing sidings, running 2 trains basically is constantly ducking into the siding to wait for the other train. To be fun, you want some nice, quiet, running time between to enjoy. 

50 foot separation is too little to really enjoy running. You want a couple of hundred feet I would say. 

Regards, Greg


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## jjwtrainman (Mar 11, 2011)

Well, that is all true, but you can see my point that this little equation would help in determining length of the main line. If you want more enjoyable, relaxed running, just add space between trains and don't fill the main line to capacity. That will allow multiple operators to run their trains without as much [email protected] url(http://www.mylargescale.com/Providers/HtmlEditorProviders/CEHtmlEditorProvider/Load.ashx?type=style&file=SyntaxHighlighter.css);@import url(/providers/htmleditorproviders/cehtmleditorprovider/dnngeneral.css);


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## rdamurphy (Jan 3, 2008)

I guess just because you CAN run 10 trains at once doesn't mean you HAVE to run 10 trains all of the time... 

Thanks! Robert


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## Trains (Jan 2, 2008)

So in the above drawing with the wreck, I take it Stan and JJ are running?
Why did train #1 leave the siding before train E passed. If you have that many sidings
and trains you should never a wreck. Who'd the dispacher?


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## jjwtrainman (Mar 11, 2011)

Exactly Robert! If everyone who operates a layout wants to operate with some challenge, fill er' up to capacity! But if you want to have easy running, and relaxed rules, then cut down the umber of trains and have people take turns for running on the road. 
--JJWtrainman 
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## kormsen (Oct 27, 2009)

Posted By Trains on 19 Mar 2011 03:26 PM 
So in the above drawing with the wreck, I take it Stan and JJ are running?
Why did train #1 leave the siding before train E passed. If you have that many sidings
and trains you should never a wreck. Who'd the dispacher?



the two wouldn't even get a chance to produce a crash on my layout!
aren't there enough accidents, where "human failure" gets blamed? - since i discovered the EPL system from LGB i build full automated layouts only.

the indoor two-level layout i am building will have four trains in each direction, eight passing sidings and a little more than 400 foot of track (including the sidings)
the longest line between sidings will be about 70 foot, two with about 60 foot length, the others shorter.
using backgrounds and mountains with tunnels most of the short radius curves will be hidden and most of the layout will look like a couple of dioramas. each with a passing siding/station of eight foot length (plus turnouts) and about 27 foot of single track line.
when i'm finished with tracklaying and electricification, either the Mayas will let the world end, or i will be able to model and landscape, while the trains are running all around me.

and for an automated system, i can stagger the moment of departure a bit (with the location of the triggering switches), but it would get too complicated, if i didn't let every train run once, before the next phase starts.


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## Allegheny (Jan 2, 2008)

Designing a new railroad, or evaluating an existing one, for operational possibilities and problems has a long history in the smaller scales. The first systematic approach to this was an article written by Roy F. Dohn in Model Railroader back the late 60's. For those of you that don't know or remember him, Dohn was a physician up in Canada that built one of the largest and most complex HO scale railroads ever built - The Victoria Northern.

I don't know if his article is available online, but an updated version is. Joe Fugate - one of the driving forces behind the online E-zine MRH (that's Model Railroad Hobbyist magazine) - updated Dohn's original work with additional thoughts and tailored it to match the evolution of track planning from the "spaghetti bowls" of Dohn's time to the more common "linear" or "walk-a-round" layouts of today. It is not an easy read, and is quite math intensive, but it WILL give you a lot of food for thought if your goal is to design or to reconfigure a layout for prototypical operation.


Here it is:

http://siskiyou-railfan.net/e107_plugins/content/content.php?content.32.3

You might also consider looking into the NMRA Layout Design SIG - they have a YahooGroups List:

http://groups.yahoo.com/group/ldsig/

and even a website with an online design guide, among other resources:

http://ldsig.org/ 
Brian
Taxachusetts


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## jjwtrainman (Mar 11, 2011)

What the purpose of this article was, is not to copy or model prototype, though I do find your suggestions very interesting, I to am an indoor railroader, My original question was to find a ratio of single to double line track for X number of trains. it is really interesting what you've got there, but I figured out an equation for this somewhere in this fourm. 
--respectfully, JJWtrainman.


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## Allegheny (Jan 2, 2008)

Hi JJW,

If I misunderstood your question, I apologize. I think if you tinker with JoeF's equations, I think you will see that you can basically configure them for any possible scenario you would like to dream up. Of course, if you already have a workable equation or solution, none of this is necessary.

Cheers,

Brian
Taxachusetts


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## jjwtrainman (Mar 11, 2011)

Brian, 
Hey, its okay, those equations are very good for applications, and this fourm is as good as any to have a link to them. I found the equation from my previous post: 

Track length= (length of trains X number of trains) + (distance between trains X number of trains). So 6, 10 ft long trains with 50ft of separation, would require... 360 feet of track minimum. 

Try it out! Because all of the most basic variables are included, train length, train number, space separation. And then half of that should be double main line for trains running in opposite directions. 
--JJWtrainman


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