Design Philosophy - Passing Sidings

I'm still wrestling with my track plan. I'm likely to have about 40 feet of n scale single track mainline, including a reverse loop at each end. I'm thinking of 3ft sidings to hold a ten car train of short (36ft) old timer cars. My question is how many passing sidings (including the reverse loops) are optimal and how far between sidings.
Oh yeah - My son wants me to add this smiley - :question:

 

Thanks for responding. That's good information about the prototype. On the model, is there a formula, perhaps in an old how-to book? Or is it better to lay out the track on the table and experiment?

 

I remember seeing some formulas of how much of a layout should be devoted to what, in articles 35 or 40 years ago. If I were building a 40-foot-long N loop-to-loop, I would probably want to include a double-ended siding, ie. a passing siding, as part of each end loop- but I wouldn't think of them as passing sidings (though they could be used as that.) I would use them as staging/holding tracks, so I could have a train "go somewhere else." Between the 2 end loops, 2 to 3 intermediate passing sidings would be good. Give a place to schedule meets.

I might also make the layout non-symmetrical in its balance of elements. The two loops would not necessarily be equal in importance or how they are operated. One end loop might be pretty much strictly staging. Not necessarily hidden but disguised a little so it not so obviously a return loop. Might make it look like a junction, with the turnouts open and accessible, but a lot of the back half of the loop half hidden behind a low rise, trees or buildings and building flats. The loop on the other end might include a couple of single-ended spurs inside and in addition to the passing sidings. Make it look like a yard. Maybe let it extend a little further down the line than absolutely necessary for a minimum reverse loop. There might even be short runaround track included in keeping with the terminal operation idea. In this case, two intermediate passing sidings would probably be about right on this size layout.
I would make them "asymmetrical" too. One would be a passing siding with one or two dead-end industry spurs associated with it, the second passing siding would be strictly a passing siding. ("Out in the country.") And along the way, there would be one or two industry spurs with no passing siding immediately in the vicinity. This would give a variety of appearance and operating possibilities.

Course, this is all just my own taste. Plenty of other ways to do it.

 

As a general rule of thumb a layout can support a train for every yard track and siding. On the other hand sidings are required in order to handle meets and passes on single track mainlines. Your layout design and how you intend to operate the layout will set the rules for how many sidings you will need. Unfortunately you will need to make that determination based on knowledge and experience or by using the trial and error method; which btw is what most model railroaders tend to use until they have acquired the former. If you would care to share your track plan and type of operations with us we may be able to give you more specific guidance.

 

Thanks for your interest guys. Below is the plan for my mainline. It is basically a bent dogbone with a reverse loop at each end to represent "somewhere else". I think, loops included, I'll have about 35ft. of N scale mainline with an 11in. minimum radius. The reverse loops will be stacked and slightly staggered, with the rear mainline rising up a 2% grade to provide height and scene separation. It's designed with, and I'm using Atlas code 80 sectional. I had built a smaller layout years ago with a similar theme and save a lot of the parts. I'll need more turnouts. I'd be willing to experiment with flex track. The benchwork will be 14ft long and shaped like water wings.

I have 5 passing sidings of varying lengths and distance apart - one on each loop, one small classification yard, a passing track with a single ended siding, and a junction w/interchange. I've thought about 36in sidings at least 36in (one ten car train) apart. I may include a branch line or two.

For operation, I'm looking at two transcontinental passenger express trains per day, one each way, a fast freight, a through freight, and a local way freight. All trains stop in Albuquerque for crew changes.

Here's my plan. I hope it's not hard to read. I used RTS 10.




Here's a schematic with stations labeled.



Please, let my know what you think, and we'll talk some more.

 

I recommend you read through the "Reality-check math" section of Mark Lestico's Cascades subdivision site for a good argument about how many passing sidings you can have.
http://macrodyn.com/ldsig/wiki/index.php?title=Cascade_Subdivision_-_N_-_Mark_Lestico

 

Your track plan has plenty of sidings built into is as it stands. The reverse loop sidings can actually serve double duty for staging and your yards have an inherent passing siding. The sidings on the right side also serve double duty by offering run around capabilities for switching out the industries. I also like the dedicated yard lead(s).

The right side of your layout unfortunately has twice as much track as needed to serve the given industries. Your Industries should be switched off the straight section of the mainline (back side) rather than off the curves (front side). Your track plan could easily be adjusted to accommodate my suggestion.

Overall nice initial track plan with plenty of operating / scenic potential.

 

CL, all above suggestions are spot on .. I merely wish to say that, it really comes down to what your RR needs to function. You can, same as prototype, add or subtract sidings as you see fit. The 'complete' main line will dictate places where sidings are necessary. You'll begin to see the logic of each choice as you trudge onward. If you build the RR with enough rite of way on either side of tracks, you then can add a siding by simply splicing in switches to accomplish this where and when ever you want. That's how I do it. That's really the way the real one does it if you think about it... It's your RR...There is really no formula on a, say, 223 Mi. branch line as to where theirs will be. It's mainly where you can picture places that trains will typically meet and which need to pass one another.. Or, the siding is for one track to be a ladder track for a yard Situ. while other trains pass right through vicinity on outside track...I find railroading to be built on simple logic of owners, clients and crews of each, finding what they need in track, stations, bridges, tunnels, yards, grades, curves, tangents, Etc... What do you want ?
But remember, as there is no crying in baseball, there is no anger in model railroading !! Mark

 

Thanks guys,
That was good advice. I was concerned that I would need an odd number (three, five, etc.) or risk the middle stretch of mainline turning into a bottle neck. I may sacrifice the middle passing track in exchange for slightly longer sidings. While thirty six inches should accommodate a ten car train of the type expected, I realize that there are clearances required, coupler slack, margin of error, etc. to take into account. It might be preferable to have only two intermediate sidings (the two yards), but slightly long ones. I also allows a little longer run out in the country.

Another option might be to have three full sized intermediate sidings, but sacrifice some mainline distance between sidings by not have a full train length between sidings.

What do you folks think of those ideas?

Finally, Welcome to the forum ssoysal. That was a good recommendation to look at Mark Lestico's work.