Longer cars and curve radii

FlightRisk Dec 19, 2019

  1. FlightRisk

    FlightRisk TrainBoard Member

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    I don't think I ever want cars longer than 60' scale, but looking for input here. I am building a small L shaped layout and the curves will either be 12 and 11" radius, or perhaps up to 15" for the outer track. I'm looking at the Kato Unitrack and was leaning towards their double-track that is super elevated in the curves. Not sure yet due to the fact that the tracks will diverge in places with turnouts. I don't ever want "big boy" engines, but wondering what else I might miss out on if I design track that might never be able to handle 89' cars. 40' seem fine for most with maybe 60' passenger cars or freight on another line.
     
  2. acptulsa

    acptulsa TrainBoard Member

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    Love these questions.

    If you're modeling HO you're shirt out of luck.

    If you're modeling Z you're in tall cotton.

    If I were to make an educated guess that you're modeling in N scale, I'd say 60' passenger cars are either foreign, 19th Century, or rarities (like Talgo cars in the U.S.). Also, 66' six axle locomotives aren't generally as good at curves as cars the same length.

    At 11" radius you really have to check to see if the rolling stock you fell in love with will work. At 15" you can take a lot more for granted. You can also run longer trains without derailing in the curves, and your trains will look more realistic.
     
  3. mtntrainman

    mtntrainman TrainBoard Supporter

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    I am not a fan of superelevated track. 60' cars will make those radius curves just fine. They may look strange doing it. 89' cars may give you problems with overhang and maybe even uncoupling problems. Run trains at a prototypical speed and things should be just fine. Here is a speed calculator...easy to use and will show you how much too fast you are running your trains. ;)

    http://www.stonysmith.com/railroad/speedcalc.asp
     
  4. Inkaneer

    Inkaneer TrainBoard Member

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    When it comes to track radii, bigger is always better. Go with the largest radii that your space will allow. Sometime in the future you may want to run longer cars or more modern cars (which are usually longer than steam era cars).
     
  5. HemiAdda2d

    HemiAdda2d Staff Member TrainBoard Supporter

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    Near as I can remember, my layout curves are 14 and 16" radius. I run autoracks and 80+' passenger cars, and while they overhang a bit more than I like, they still run fine. If you wish to run long cars, 15" is best, but they'll run on 12-13". They just will overhang a lot. I wouldn't go smaller than 11" though. I recommend setting up a small loop and testing out the cars to see if they'll meet your operating expectations.
     
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  6. Grey One

    Grey One TrainBoard Supporter

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    In N Scale in general despite having lots of running room and broad curves I leave my longer cars in the yard for show and run unit trains of short cars such as shorty tank cars, ore cars, 2 bay covered hoppers and such. yes, I will also run 40' to 60' cars in a mixed freight. Sometimes I run 4 bay covered hoppers in unit trains as well.
    They all seem pretty good to me.
    Oh, and I run bullet trains which in general have shorter cars but want 15" curves.
     
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  7. videobruce

    videobruce TrainBoard Member

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    To test parallel curves, take two of your longest cars, place them on adjacent tracks on those curves, staggered, so one end is positioned across from the middle of the adjacent car. Then, keeping that position of both cars staggered, push the cars around the curve. If they don't hit, the curve is good.

    Hope that made sense. IOW's maximize the overhang and underhang of the cars. (y)
     
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  8. randgust

    randgust TrainBoard Member

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    I've got 11" curves on hidden track only and I'd never want to go sharper than that for a variety of reasons for anything bigger than a portable layout module. I have 13"/15" minimum radius on my visible curves, and a 52" general track height. One observation is that if you're on the inside of the curve it looks a whole lot better than the outside of the curve. I have a complete 180-degree horseshoe curve on one end of my layout at 13/15 and I have no operational issues. Standing on the inside at that height it's not bad looking at all. The 90-degree curves visible from the OUTSIDE of the curve of the same radius look much sharper. So how your "L" is visible, and at what height, will definitely change perception.
     
  9. Metro Red Line

    Metro Red Line TrainBoard Member

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    Don't go any smaller than 15" radius and you can run anything in N scale. You never know what future product you'd want in the future, only to find out it doesn't run on your layout. Also, the trend for newer-released rolling stock (regardless of era) is body-mounted couplers so bear that in mind. I learned that the hard way when I was in HO scale. I limited myself to 18" radius and was miserable most of the time because I couldn't run the 89' autoracks I wanted (and even some of the Walthers well car kits I bought wouldn't run on less than 22"). Eventually that led me to dump HO and convert to N (and I've never looked back - 18" radius in N is a luxury). This hobby should be a source of joy, not misery.
     
  10. MK

    MK TrainBoard Member

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    In T-Trak, the two curve radii standards are 11" and 12-3/8" Kato Unitrack, inner and outer, respectively. We run everything on it, including GS-4 locos and auto racks. They do run fine but appearance wise it's whatever your tolerance is in what "looks right". :)

    On my home mini layout I've run SD70 locos and 50' cars on 9-3/4" with no problems. Appearance wise I just squint. :D
     
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  11. Maletrain

    Maletrain TrainBoard Member

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    Model railroading is almost always a set of personal choices from among an lot of compromises. What you end up choosing is determined by what is really most important to you. And, usually people really find out what is important to them by trying some things and being disappointed, then redoing it more to their liking with new knowledge. That can cost some money and a lot of time. So, my advice is to get some exposure to the things you are considering before going going whole-hog. Going to train shows and looking at operating layouts can give you a good idea of how equipment you like looks on the curves on those layouts, and talking to the people running them can give you some ideas of the limitations that they have had to contend with to get their displays to run reliably. This is the best time of year to do that, due to all the Christmas related displays and club open houses.

    You could set-up test loops of Kato track, but Kato track isn't cheap, so finding that you don't like a particular radius would be lost funds. If you do decide to do that, you could at least pick a mid-level radius and see if you want to go larger or smaller. At least that way, you maximize your chance of being able to use the track you buy first as either the inner or outer radius for your double track, or, if really too tight for either, perhaps as some industrial area switching track that never sees large cars.

    For what it is worth (not much to others), I picked 13.75" Kato track as my minimum radius, and did not like what the Kato Mikado looked like going around those curves - too much overhand. So, I squeezed-in 15" minimum radius on the mainline, with an approximation of 16.5" on the outer curve by judicious alternation of 15" and 19" track sections (because Kato doesn't make single track sections in radii between 15" and 19").

    I also found that putting an "easement" on the ends of curves does a lot for making things look more realistic. For one thing, real railroads use easements, so they just look more realistic. But, more importantly, easements reduce the amount of overhand/offset between the ends of a car that is totally on the curve and a car that is totally on the adjoining straight section. That will be especially important if you are using body mounted couplers. Nobody makes real spiral easement sections of sectional track, but approximating the effect by using a larger radius track section at the ends of the curves gains a lot of the visual and operational benefits. I use 19" 15-degree sections to lead into 15" and smaller radius curves.
     
  12. FlightRisk

    FlightRisk TrainBoard Member

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    Thanks for all that! MtnTrainMan, why are you not a fan of superelevated? I am using N Scale. And not married to elevated twin track, but considering it.

    And why are they going to body mounted couplers? Something else to complicate things now. I know on tight curves, if the engine has a body mount, you would want the car behind it to have body mounted, but the truck mounted couplers stay in the center of the track.
     
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  13. mtntrainman

    mtntrainman TrainBoard Supporter

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    The biggest reason I am not a fan of superelevated track in model railroading >>>>>>>

    To many guys use it mistakingly thinking they can run their model trains faster and they wont derail in a 180 curve due to centrifugal force issues. A model layout has no real need for superelevation; there simply is not enough mass for it to have a noticeable dynamic effect.

    If everyone ran their model trains at 1:1 speeds for their class of track...they wouldnt need superelevated track for any reason ;)

    I will agree superelevated track looks pretty cool on a toy train layout. If its used for that reason...than (y)(y)(y)(y)(y)

    Model trains and track are NOT Matchbox Cars & Race Track
    :LOL::LOL::ROFLMAO::ROFLMAO::ROFLMAO::ROFLMAO::whistle::whistle:


    Just my humble opinion of course....:whistle:
     
    Last edited: Dec 21, 2019
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  14. Metro Red Line

    Metro Red Line TrainBoard Member

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    Superelevation done right is very subtle and not too obvious to the eye (unless you have hight-clearance cars like autoracks and doublestacks). I use Evergreen .020" strips on my outside rails, which is pretty close to prototypical dimensions for superelevation, and have never had any problems.
     
  15. mtntrainman

    mtntrainman TrainBoard Supporter

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    Like I said...it may look cool but otherwise serves no practical purpose...like the abilty to run trans faster on a Model Railroad...JMO ;)
     
    Last edited: Dec 21, 2019
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  16. Grey One

    Grey One TrainBoard Supporter

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    I have the Kato V11 set with super-elevated double track but will keep that strictly for my bullet trains. The freight will run on single track and no fancy curves. Note, I will be running the bullet trains in what on paper will be a long oval. The freight will be more point to point with switching along the way. Occasional excursion trains will be run over the freight line but that is just to keep it interesting.
    So, if you are running double track freight line with trains in both directions and limited switching then the curves might be nice but only for visual reasons.
    Just my thoughts.
     
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  17. NtheBasement

    NtheBasement TrainBoard Member

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    Looks-wise, IMO long cars on small radius is OK as long as the cars overhang the rail on the outside of the curve. It looks bad if you see the outside rail exposed to the light.

    Running-wise, small radii are OK if you have truck mounted couplers. A superelevated curve in combination with body mounts would be an invitation to stringline.
     
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  18. Inkaneer

    Inkaneer TrainBoard Member

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    A good rule and one I have never seen stated, probably because of its obviousness, is this; Do not overcomplicate things. Employ the K.I.S.S. method and avoid a lot of frustration.
     

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