Susquehanna Junction

Discussion in 'HO Scale Model Trains' started by Xiong, Jun 22, 2008.

  1. Xiong

    Xiong Member

    Enough theory. At some point I have got to build some real track. Questions, questions.

    Here's a rough preliminary sketch of my idea for a free-mo module -- "Susquehanna Junction", can be used as a corner, straight, or both:


    This was sketched with general-purpose drawing tools; I gather I'll do better using a dedicated track layout CAD application. No easements are yet shown. Track 4 is drawn straight; only optical illusion makes it appear to bend away from the double main.

    The benchwork fits inside a 63" (5-1/4') square. Tracks 1, 2, and 3 are all through mainline. The radius on 1 and 2 is 48"; all other curves are radius 24" -- if your equipment can't negotiate, you don't need to go down those tracks, eh? All track is level, no grades. No track is closer to the benchwork edge than 4"; the mains are all 12" from an edge.

    Track 4 might be modelled as a passenger terminal except that pax cars are just the sort that might have trouble getting around the tight curves -- and long trains will foul the main. Perhaps it will be better as an industrial siding. I see Track 5 as a heavy industrial spur -- literally on the wrong side of the tracks from town inside the corner. Track 6 might be fairly dilapidated, even abandoned. The area to the side of Track 3 might be agricultural.

    I like a road leading out of town to the farms, at the bottom, crossing Track 6 and the double main. Another road connecting the heavy industry to town seems wise. That gives me opportunity for two grade crossings, with attendant annoyance to town drivers.

    I don't think I have enough patience or skill to hand lay track. So, I'm thinking flextrack and bought turnouts.

    Questions, questions:

    * Who likes which manufacturers of track and turnouts? This will be all code 83.

    * How should I handle the easements? Free-mo standards mandate 2" spacing of the double mains at module end but around the big curve, that needs to go up to about 2-1/2".

    * This is a pretty big module. Does it make sense either to (a) shrink it a little for better portability or (b) enlarge it a bit for better operations?

    * Should I account for the optical illusion when planning Track 4? That is, should I build it with a slight curve throughout its length? I don't want to foul the inside main any more than I must; as it is, the siding will only accommodate a few cars.

    * Recall that free-mo has no "front" or preferred viewing angle. Still, the probability seems high that at least at times, the junction will be used simply as a corner and shoved into a room corner. Therefore, the town area will be towards the viewer. Does this work for me or against me?

    When operating this module by myself, I won't have much ability to do anything at all as it stands. This is actually my plan for my *second* module, the first being a long, straight double main with a couple of crossovers. (Maybe in two sections). That will allow me to run a train, say, from Track 5 onto the "first" module, change mains at a crossover, and back on Track 1 or Track 4, perhaps setting out a car on Track 6.

    * Would I be totally insane to consider a curved crossover between Tracks 1 and 2?

    As always, general comments of any nature are not only welcomed but practically demanded.
  2. steamhead

    steamhead Active Member

    Hi....Gotta start somewhere...A couple of thoughts...I presume this is HO, as it's posted in the HO forum..

    Track 6 is going to be "under-used" as its approaches from either end of track 4 seem to be about a foot long...Not much room for a loco and cars (unless they're really small....). Seems like a waste of effort and $$'s to have it abandoned.
    If used as a corner module (and I can't see it as being anything else), track 3 can't be considered as a through mainline, unless it's through a wall..!!! :eek:
    Track 5 is too symmetrical -a little curviness to it would make it somewhat more appealing... would be crazy (IMHO) to add a curved crossover between mains 1 & 2.
    As for which track...I use Peco (Code 100) turnouts and Atlas flex track....It's worked real good for me...

    Please feel free to disregard any or all of the above...After all...IT'S YOUR TRAIN...!!!

    Good luck..!!:thumb:
  3. Gary Pfeil

    Gary Pfeil Active Member

    A few thoughts: The siding which is track 4 is too short to be of much use, think about deleting the turnout leading into from the left, leaving it as a stub ended industrial spur reached from the right side turnout, a trailing point turnout assuming right hand running. Track 6 can be deleted or kept, if kept, extend track 4 to the edge of the module to make it as long as possible.

    Why do the track centers need to be 2 1/2" at the curve? Is that a Free mo requirement? BTW, both tracks can't be 48" radius. With either 46 and 48 or 48 and 50, 2" centers will be fine.

    If you will have crossovers on the module on either side of this one, no need for them here. If you were handlaying, a crossover could be made to operate well and the flowing lines would look great, however, not prototypical.
  4. eightyeightfan1

    eightyeightfan1 Now I'm AMP'd

    Not to rebutt my compadres.....
    Operationally, Track 4 could be a "team track" with Track 6 used for a small industry, that only requires one car, such as a small town oil or coal distributor, or even a small machine shop. Depending on the era, a 40' car looks like it'll fit. For more modern times, you might want to extend that track to close to the edge of the modual, to accomadate a 50' or longer car.

    Since its a "Junction", I'm assuming(you all know what happens when we assume anything) that another railroad, or branchline interchanges here at this point. Might I suggest a siding to the right of Track 3(assuming that Track 3 is the supposed branchline, or other railroad) for spotting cars for interchanging.

    BUT.....As Gus mentioned...It's your railroad........
  5. Squidbait

    Squidbait Recovering ALCO-holic

    OK, beyond operational questions, first, the question of reality must be addressed.

    The bad news is, your specs aren't going to work. There's no way you can squeeze in a 48" radius curve and get the rest of it to fit.

    Now, the good news... you can kinda do it. Here's your plan with a 32" radius on track 1, 34-ish" radius on track 2. The mainline turnouts are #8, the secondary tracks have 24" min radius and #6 turnouts.

    I've included the plan file for XtrkCad. It's got a bit of a learning curve, but it's free, and quite powerful. Play around a bit, you'll have a better idea of what you can and can't do in that space.

    Attached Files:

  6. MasonJar

    MasonJar It's not rocket surgery


    Please confirm that Free-mo (as you plan to use it) requires a double main centred on a two foot wide interface?

    If that is the case, I would say you can approach the 48" radius on a 63" square. We (Ottawa HOTrak modular group - trouble with web site currently) use a 42.5" radius on corner modules that have a footprint of 53" x 53".

    With a quick glance, 63" appears to support a 48" radius:

    63" - 13" offset for inside track = 50" This should allow 2" of straight track at either end of the curve at the interface. I do not know if this is enough for joiner track length. Also if you plan to use easements for the curve, it may be advisable to reduce the overall 48" radius to 44" or 42" to all for this.

  7. Triplex

    Triplex Active Member

    The issue is that the plan
    shows turnouts as continuous-curve-meets-straight. Real commmercial turnouts appropriate for these curves are much longer. The turnouts for track 4 are curved on both legs, and would have to be hand-laid.
  8. Squidbait

    Squidbait Recovering ALCO-holic

    What he said. :)

    You might be able to get away with Walthers curved turnouts, but with straight turnouts (even #6's) you're not going to get a 48" radius in that space. Easements make the radius even tighter.
  9. MasonJar

    MasonJar It's not rocket surgery

    So, if it was just the curve, you might get away with it. BUT...

    - Standard commercial turnouts (one straight leg, one diverging) will reduce the radius
    - Easements will reduce the radius
    - Setbacks required for Free-mo "spec" joiner track will reduce the radius

    My example above of a 42.5" radius on a 53" square is indeed based on an uninterrupted curve - no limitations as above... wall1

    Squid - in your XTrkCAD plan, the tracks leading out the the left do not seem to have the same relative spacing as the ones at the bottom. Although Xiong has not confirmed yet, I believe the double main Free-mo standards call for the track to be 2" apart, centred on a two foot end (i.e. each track is one inch to the left or right of the module centreline). I also think that track 3 will need a slight wiggle, in order to be on the centre to meet with a single main Free-mo module. This is probably less critical, since the entire module can be shifted slightly (as long as alignment pins or bolts are not used).

  10. Squidbait

    Squidbait Recovering ALCO-holic


    It's an optical illusion... they're both 2 1/4" apart. I was less concerned with the finer points of Freemo standards than with a proof-of-concept plan demonstrating that the original specs ( like 48" radii) weren't going to work.
  11. Xiong

    Xiong Member


    Yes, free-mo is an HO modular standard. Track 6 may not be used at all; perhaps it will be a place to set out just one car. Perhaps it will be a run-down dining car used as a diner... Waste is American.

    Free-mo doesn't seek to form a big module loop; small layouts tend to be "snake" shaped. A corner module might end up in a room corner or in the middle of the floor. Susquehanna is intended to allow some flexibility by allowing the choice between continuing straight or turning a corner. If there are enough modules and enough floorspace, perhaps it works truly as a junction, with three lines taking off from it, you choose which you want to call main or branch, but all up to mainline standard.

    Code 83 is required.

    Gary Pfeil:

    That is the other thought, delete Track 6 and run Track 4 as a spur as long as possible.

    Track spacing on curved double track is an NMRA standard ( S-8 ) incorporated by reference in the official free-mo standard:

    To be exact, any radius between 40" and 53" requires 2-3/8" centers. This radius is measured at the inside track centerline. So, in the simple case, one could build a conforming layout consisting of a perfect 40" circle with a concentric 44-3/4" circle. The more cautious 2-1/2" centers are my choice.

    Both tracks certainly can be 48"; if so, though, they won't be concentric. Since they must, as a free-mo requirement, exit the module on 2" centers and increase spacing through the curve, the tracks can't be completely concentric anyhow. At least at this stage of design, it's easier for me to sketch both radii equal.

    The major issue for me is how to figure the easements that make it all work. Precise plans depend on exact measurements of included turnouts -- and that's why I want to get recommendations on those.


    A siding next to Track 3 is appealing to me; as you might guess, I want track, not trees. I did feel that I'd crammed enough track in there already but thanks for the idea. I like the prototypical operations feel of "Track 7".

    I'll forget about crossovers on the curve; maybe not insane but silly. However, I do want to plan for the possibility that my module gets clamped between single mains. With the current plan, that would leave the town area isolated.


    Thanks for taking a crack at drawing the junction with XtrkCad. I mean to get that app, just as soon as I get a box that can run it. However, 32" radius is out of the question. Free-mo insists on minimum 42" and RP is 48".

    Unlike some roads, I'm planning the track first; then I'll figure out how big the benchwork needs to be. So, there's not going to be any question of squeezing the radius into a specific square.


    Free-mo requires a *single* main be centered on a two-foot endplate. Double mains are on 2" centers on a 26" endplate, so each center is still 12" from an edge.


    You're right.

    * * *

    I think the main issue here is that I can't do accurate track planning until I make my choice of turnouts. So, I'll ask again who would choose which manufacturer of code 83. Squidbait mentioned Walthers with curved turnouts and I may need one or two, so that's a plus.

    Thanks for the comments but *please* keep them coming.
  12. Squidbait

    Squidbait Recovering ALCO-holic


    If you want 48" curves, you're going to have to handlay your turnouts. The Walthers #8 curved is the largest RTR turnout out there (that I"m aware of). The outside radius is 36".

    Also, 48" is the preferred radius for mainline track - the minimum is 42". Both are incredibly generous by modeling standards.
  13. Gary Pfeil

    Gary Pfeil Active Member

  14. pgandw

    pgandw Active Member

    In the past, I have tried designing a home layout around some Free-mo modules. Eventually, I gave up because the differences in purpose and practical standards were too great.

    I have been challenged to produce an HO/HOn3 Free-mo module set for Sept 2009. I have been leery of accepting because all work on my home layout would have to be given up for the next 15 months. And the module set would not be usable at home due to space constraints.

    Free-mo is built around making and operating realistic module sets where space is not a primary constraint. Module size is limited primarily by transportability. Most Free-mo setups emphasize realistic transition-era or later operations, using large locomotives and long trains.

    A home layout typically has space as the ultimate constraint, with maximum utilization of the space for the desired purposes being the prevalent design philosophy. To this end, train length, era, and size of motive power are often adjusted downwards to gain more operational or scenic features in the given space.

    Modular and club members typically have even less space than most for home layouts, so they join the groups as a means to let them run big power and long trains.

    Free-mo with its generous curves, turnouts, and other unspoken standards, meant to operate big, modern trains does not fit well into a limited home space. The best one can hope to do is provide a "docking station" for a Free-mo module set at home to allow reasonable use away from setups.

    More practical matters:
    • Transportability. Most SUVs and minivans can take about a 4x6 to 4x7 ft layout with the seats folded down. If your module won't fit your vehicle, you can't get it to a setup easily. Your planned module isn't going to fit easily into any likely vehicle I know of. It will have to be broken into at least 2 pieces for transport. Note that you do not have to meet Free-mo specs at the joints internal to a module set - only at the external interfaces. But you might want to consider what kind of environment you will typically be setting up in (how even are the floors, how much time to get exact alignment, etc) before you commit to multiple track joints on curves at internal module set separation points.
    • What non-national standards (written and unwritten) does your local Free-mo group use? Examples are fascia and skirting, public barrier ropes, NCE wiring, etc.
    • What does the local run chief expect from your module? If it doesn't match with what he can use or fit, or fit in reasonably with the other modules or operating styles, you may tend to get left out of some setups. Again, talking with other Free-mo'ers in the area in advance is worthwhile.
    • Free-mo requires track be straight and level for 6" from the module interface.
    • I didn't review the branchline module specs before writing this, but I don't think any curves below 30" radius are allowed on through tracks, period. Even if the substandard curves and turnouts are limited to industrial tracks, if there is insufficient operating potential within the proposed setup and operating scheme, your module may not be used (or at least limited to mainline ops as a through module).
    • No track is permitted to be less than 4" from a module edge.
    • A run chief planning a setup needs an electronic plan of the module as actually built. Dimensions and angles, as well as the track plan with car and train capacities are critical to plan a setup. Typically, 3PI is the software used, but I think others can be.
    As you can see, a junction is not a simple 1st Free-mo module set to design and build. First time Free-mo module builders are often encouraged to build a straight, run-through module for the first attempt, and as a way to lay the groundwork for greater efforts.

    For more information and support, join the Free-mo Yahoo group.

    The above is not meant to discourage you. On the contrary, Free-mo attempts to take modular model railroading to a higher level of realistic appearance and operations than most other modular standards. It takes more effort than the continuous run module systems. You should be commended and encouraged for attempting a Free-mo module. From all I hear, it's great fun. I know I have enjoyed the Yahoo group. And if you are in Colorado Springs in Fall 2009, I'll see you there.

    as always, my thoughts, your choices
  15. Xiong

    Xiong Member

    I think I'll need to handlay anyway. As I do the research and planning, I can feel my head swell with details of trackwork. I know that if I try to use flex and RTR, I'm going to be frustrated with dozens of little discrepancies.

    Fred Wright: I don't think it's practical to think of a free-mo module as a home layout. Yes, it might be nice to fire up a train and fool around with it but as you say, free-mo is not about that.

    For obvious reasons, corner/junction modules are difficult. That's why I'm planning one now. I don't want to show up at a run with a straight module and everyone else has also brought straights and we don't have any flexibility as a group. With the junction contemplated in this thread, even if every other module is straight, there will be some opportunities for interesting operation.

    Transport of a five-foot square module is an issue. I don't think it's practical to hope to fit *any* module inside my hatchback. Rather, it will have to go on the roof, inside a protective box. I'm sure some readers are appalled by the thought but I routinely move a lot of stuff on my roof. I may get a lot of stares but if you saw my car, you'd understand that I get stares even when all I'm moving is a cup of coffee and my own fat rear. Internal joints over curved track seem unwise.

    My local free-mo group doesn't even exist yet; I'm the one defining the standards. I've made the rule that the only standard for ARMS is the Official Free-Mo Standard. While I realize there is are many reasons for local standards, I think openness and inclusiveness is more important.

    Susquehanna Junction is *not* intended to be my first module. The first module will be a double main, with some crossover work. It may well be a set of two -- I'll just duplicate the first. The Junction will be done much later but I'm planning now. I like to lay track before the train gets there.
  16. Russ Bellinis

    Russ Bellinis Active Member

    Have you considered a small trailer dedicated to module transport? You can pick up small utility trailers from the various home centers or Sears for under $150.00 the last time I priced them. They are limited to a 1000 pound gross weight, but you shouldn't get anywhere near that weight with freemo modules. You can build a body that would easily accommodate your module and make it weather proof as well. It might even serve as a storage space for your modules when not in use.
  17. Xiong

    Xiong Member

    That is an *outstanding* idea, Russ. A small trailer, with appropriate shelving installed, would allow the transportation of perhaps a dozen modules of various sizes; weight is hardly an issue, I'd think.

    Or, a flatter trailer might haul fewer modules with less air resistance.

    This is worth giving serious thought. Thanks for the idea!
  18. Xiong

    Xiong Member

    Let it never be said that planning is in vain. Now that I have at least halfway accurate track templates to plan the layout, it's clear that it will be rank insanity to build this as a single module. I haven't finished the double main easements and it's already looking like a 6 foot square. Trailer, yes; wide load, no.

    So, like it or not, this would have to be two modules with an internal joint. I don't like that. Internal joints force a commitment: use both modules or none. But if the modules are to be -- perhaps -- independent, then each needs to work alone.

    Looking over the original sketch, I'm thinking that the *junction* is mostly in the right half. Maybe the right answer is a single main (Track 3) with a double main curving off at 45° only. I might be able to throw off another branch in the spirit of Track 5, too. That may just be enough for the one module. There might still be room to put in a siding along Track 3.

    Track 4, with its curved turnouts, looks more and more questionable. The left-hand module might just be the double curved main -- no turnouts or other special work. Or, make the module longer and run a stub-ended Track 4 from a regular #8 turnout. There might also be room to finish out the length of Track 5, which will only be a short bit past the turnout on the right-hand module. At least that module will be easy to build -- put it on the list before the complicated junction module.

    With two modules each turning through 45°, they'll both be narrower. There'll be less room inside the curve for the town but that's fine. This is free-mo railroad modelling, not Sim City.

    One thing grieves me. With just a 45° angle and taking into account the requirement that track run straight for 6" from module endplate, it seems that the entire curve will be easement -- there isn't room for a section of constant radius! This is due in large part to the fact that at the endplate the track spacing must be 2", while it widens in the curve. Well, it beats blasting through granite.
  19. Russ Bellinis

    Russ Bellinis Active Member

    The trailer does not have to be as narrow as your car. In fact, it is easier to back a trailer that is slightly wider than your car. The width limit in Ca. is 105 inches, but you probably don't want to go over 78 inches or so if you are not used to pulling a trailer. The other thing to remember about pulling a trailer is to take it slower and leave a bit of extra room between you and any traffic because your braking distances will be a bit longer. Most small cars will have no problem pulling an extra 1000 pounds.

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