Six-Axle Diesels and Table Top Dimensions

Discussion in 'FAQs' started by Christopher62, Feb 7, 2008.

  1. Christopher62

    Christopher62 Member

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    Okay gang here's the rub... I want to model an HO scale table-top island style layout (I know, I know, I can do what I want a lot better with a shelf layout...) where I can watch the trains go round-and-round. What I want to know is this: what is the minimum allowable dimensions/size of the table I could have yet still run the long, modern, six-axle diesel locos on an outermost loop? Can this be done on an 8x4? Or a 9x5? How close would the track come to the edge with these? And no I don't want to switch to N scale or point-to-point, etc. Thanks everybody!
  2. MasonJar

    MasonJar It's not rocket surgery

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    The minimum radius for your 6 axel diesel will depend on the manufacturer - they often include minimum operational (it will work) and minimum recommended (it will work better, and look better too).

    You can fit about a 22" radius on a 4' table, leaving 2" from the centre of the track to the table edge (radius is measured to the centreline in HO).

    On a 5' table, you can therefore use a 28" radius, which will likely work for almost anything you'd want to run.


    Andrew
  3. Christopher62

    Christopher62 Member

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    Thanks Mason. That helps me out a lot. Do the 22" and 28" inch radius curved track come manufactured? Are there any sizes in between those? I don't want to mess with hand laying and flex track if I can help it.
  4. MasonJar

    MasonJar It's not rocket surgery

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    Flex track is not difficult, and has less joints to solder than sectional. You can also make "easements" (transistions into curves) which make running smoother. And proponents of handlaying will likely tell you it is not all that difficult either...! ;)

    However, yes, 22" radius is available from Atlas, and others. I think that 28" sectional is also available, but probably not from as many. Do a search at Walthers to see what you can find. If you want sizes in between, you are probably looking at flextrack...

    Andrew
  5. Christopher62

    Christopher62 Member

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    Is the easement track called an easement track? Do you buy it that way? How will I know if I need that or not?
  6. MasonJar

    MasonJar It's not rocket surgery

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    No. Easements are no sold as such. You can approximate them by (for example) using a 22" radius section before a curve that uses 18" radius sections (and put another 22"R on the other end of the curve too). But that is definitely not the preferred method.

    The bottom line is basically, flextrack is more... well... flexible. It's really not that hard to use, and Atlas makes the most forgiving (and relatively inexpensive) kind.

    Andrew
  7. Christopher62

    Christopher62 Member

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    Okay, here's a silly question (I know, there are no such things...) When they talk about a 22" curve what exactly does the 22" signify? What's the formula there? ...If you took 22" curves and put them in a complete circle does that mean 22" from the center out?
  8. MasonJar

    MasonJar It's not rocket surgery

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    Usually the measurement refers to the radius. The radius is half the diameter, or the distance form the centre to anywhere on the circle. The diameter is a measure of the distance from one side of the circle, through the middle to the other side.

    You have defined "radius" here:
    In HO scale, the radius is measured to the track centre, so you will always have to add ~1"+ for clearance. So while your 22" radius track technically forms a 44" diameter circle, you need to add a few inches on either side for clearance. Hence the 22" radius curve on a 48" wide table.


    Andrew


    P.S. Just to further confuse things, note that in O scale, notations like O27 refer to the diameter of the circle formed by the track, and it is measured outside to outside, not the centreline of the track.
  9. rogerw

    rogerw Active Member

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    yes if you had 22" radius track in a circle, the center of circle out to the middle of any piece of track would measure 22 "
  10. Christopher62

    Christopher62 Member

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    Thanks guys. That's kind of what I recalled from high school math. That helps me out. I know I can't get too crazy in an HO 8x4 or 5x9 but at least I can have an outer loop of track that can handle those beautiful long diesels.
  11. rogerw

    rogerw Active Member

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    And you thought you would never need it.:mrgreen:
  12. IandOFan71

    IandOFan71 Member

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    Chris,
    I haven't seen it mentioned here but Atlas makes 24" radius sectional track which will more than handle modern diesels. You would have to construct a 5x9 table to allow for the larger radius but you would also gain some extra space. I have a couple C44-9's that do make it around a 22" curve but they don't like it nor do they look good. I started out with 22" radius on my layout but am now changing it all to 24" with wonderful results. Good luck to you and take care.

    IandOFan71
  13. Christopher62

    Christopher62 Member

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    Thanks Fan, et al... Now I just need some HO track plans for a 5x9 table that utilize 22" and 24" inch curves. Anybody?
  14. Nomad

    Nomad Active Member

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  15. Christopher62

    Christopher62 Member

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    Thanks Loren. Yes, I have seen that site before. I don't see any 5x9 sizes though. That's the size I am committed to. Does anyone else know of any HO 5x9 table top layouts that have 22" and/or 24" curves.
  16. MasonJar

    MasonJar It's not rocket surgery

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    If you see something you like in a 4x8 that uses 18" and 22" radius curves, you can "scale it up" so to speak to a 5x9 using 22" and 24" curves. May not look exactly the same, but you can definitely capture the same sort of "flavour".

    Andrew
  17. pgandw

    pgandw Active Member

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    If you are going to use sectional track (22" and 24" radius), download the RTS track planning software (free download) from Atlas. Then, as Andrew suggested, take a 4x8 or smaller plan you like, and redraw it in the software using the bigger curves. Usually, expanding a published plan into a bigger space (and bigger curves) makes the plan that much better.

    In published plans, the designer has usually done everything he can to fit the desired track plan into the smallest possible space. Often, this leaves less than the desirable amount of space for scenery and structures.

    just my thoughts, your choices
  18. IandOFan71

    IandOFan71 Member

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    Chris,
    I agree with Andrew on this as well. You could just change the outer loop on one of the existing track plans and all you would have to do is add a little extra track where the new larger loop meets the inner loop. That's part of the fun of this hobby is taking a track plan and tweeking it to what you want it to be. Operating the layout will also dictate changes. Perhaps an industry doesn't hold as many cars as you would like or you decide that you need a place to service your engines. The plan is just a starting point and the rest is up to you. I started out with a 4x8 layout and I must've changed it a half dozen times before I was happy with the trackplan. I've since dismantled that layout and built a sprawling shelf layout and I've tweeked different parts of it over the years and right now I'm starting yet another change. I would say don't get hung up on trying to find a trackplan that fits a 5x9. Take a 4x8 plan and have fun with it. Good luck to you.

    Tyler
  19. Christopher62

    Christopher62 Member

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    Great ideas, all of you. I think that's what I will do... I've had my eye on the Atlas Yardmaster track plan for some time. Though I'm a little intimidated by the fact that if I enlarge it or tweak it I can't just order the kit; I'll have to buy the track piece-by-piece. I worry about the pieces not lining up right or something like that. I guess if I use that software it will give me specifics. Man, this is complicated... Maybe I should switch to another hobby?
  20. MasonJar

    MasonJar It's not rocket surgery

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