grades

Discussion in 'FAQs' started by Charliethecat, Jan 21, 2002.

  1. Charliethecat

    Charliethecat New Member

    Ok i have spent the last year and a half ,fighting for the spare bedroom, building oak book cases and a desk. Trains run on top of book cases and throught the desk . Track is laid plaster is done, moutain is finished.
    Started to do rolling stock " Back woods logging train" Great kit having a blast.
    So here is where my problems begin I went to Sierra West Scale models site and ordered the Big Logging Mill ( in one word "awesome" )You guessed it ,I have to redesign the layout.
    1) So my first question is how do I get the grade? What is the formular(1 inch up in 36 inches for 1%) I have gottin four different answers.
    2)Is the Bachmann HO Shay to big for 15 in radius,
    and can you use 15 inch radius for a helix
    Thanks in advance Kevin
  2. roryglasgow

    roryglasgow Active Member

    Kevin,

    The grade is calculated like this:

    height/distance * 100

    So, if you went up 1.7 inches over a length of 60 inches, that would be 1.7/60*100 = 2.83 percent. (I used that example because the N-scale piers sold by Atlas, if used every 5 inches, work out to about that grade.)

    When I started this message, I thought I knew the answer to the Shay minimum-radius question...but now I'm not sure! But I bet someone else here on the board does!

    Good luck on the layout. Post some pictures! We all like to see what each other is doing!

    -Rory
  3. billk

    billk Active Member

    Welcome to the Gauge, ttc. I can answer your grade question. Grade (G) = vertical distance (V) divided by horizontal distance (H), where V and H are in the same units and G is expressed as a percent. So, if you want to climb 1 inch using a 1% grade, you'll need 100 inches (1/100 = 1%).
    Usually, as a rule of thumb, 2% is as steep as you want to go, but for logging railroads you can go to 4 or 5% (there's a recent thread from Shamus showing this).
    By the way 1 in. in 36 is 1/36 or about 2-3/4%.
    I'm not familar with the Shay to answer the minimum radius question, but am sure someone here is.
    For helixes, the more distance per revolution, the smeller grade needed. For 15 inches, you will get about 94 inches per revolution. Assuming you need to rise 4 inches per rev, you will need a grade of about 4%. That's pretty tight and steep,
    generally tight curves and steep grades don't mix well.
    If you have room, you can make the revs oval instead of circular and bty a little bit that way, or you can just use a larger radius.
    Regards, BillK
  4. kettlestack

    kettlestack Member

    Hi and Welcome Charlie,

    I assume you are contemplating buying the Bachmann Shay for your layout but want to know if it can handle the curves?

    My out-of-the-box Bachmann 3-truck Shay is happy as a piggy in dirt on 15" radius curves.

    Redesigning in this hobby is called "Evolution" .. :D :D

    Would love to see pics of your layout.

    kettlestack
  5. shamus

    shamus Registered Member


    Hi Kevin and welcome to the gauge, let me answer your questions for you.
    1 - As a general rule 1" in 48" is ideal for a helix for the grade, you only need (IN H0) 3" clearance where the two meet on the helix, around 20" radius to be able to climb easy.
    2 - the Bachmann 3 truck shay will go around a 15" radius, mine do on my logging layout.
    One of my grades is 8.5% on my new Badger Creek
    Shamus
    [​IMG]

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