Min. radius Q. Switching from N to HO.

Discussion in 'HO Scale Model Trains' started by nolatron, Mar 21, 2006.

  1. nolatron

    nolatron Member

    Hi everyone,

    I searched around but really didn't find a good answer for this so I thought I'd toss it there.

    I'm currently modeling in N-scale but thinking of switching to HO for my next layout. My only real concern is minimum radius for running modern diesels and long cars.

    In n-scale, I tend to stick with 19" radius curves. Everything I have (6-axel diesels, superliners, 5-unit intermodal, auto racks) ran great on it.

    But what's the equivalent in HO Scale?

    I'm dedicating a space that's aobut 18x6 in the garage for a layout and the deciding factor is really gonna be how wide of HO turn am I gonna need to run this stuff. Of course, biggest is always better, but what's the safest min. radius you can go down to?

    I was thinking maybe 24", but probably around 30".

    What do you HO regular's suggest?

    thanks!! :wave:

    LIRRNEAL New Member


    A 19 inch radius curve in N translates into a 38 inch curve in HO. This is a luxury on most layouts. If you have 6 feet of width to work with (72 inches ), I figure on 3 inches from the centerline of the curve to each edge of the layout as a minimum safety barrier. That leaves 66 inches left or a 33 inch radius curve. Still " Broad" by John Armstrong's standards.

    Allowing 2.25 inches between curve centerlines, a second line inside the first would still be 30.75 which is not bad either.

    The safest minimum radius curve is dependent on what you are running, but I would keep it above 24 inches, unless its a deadicated industral switching area. Then you can shrink it to whatever the equipment used there will tolerate.

    The most important thing to remember is that its your railroad, so enjoy!!:)

  3. jim currie

    jim currie Active Member

    well put Neal and welcome to the gauge :wave:
  4. nolatron

    nolatron Member

    Hmm. Good info to know.

    I think I'll stick to N-scale then. Sounds like I could jsut squeeze in some decent curves, but I'd rather stick with N and have "room to play" :)

  5. Will_annand

    Will_annand Active Member

    Shaun, I went the other way.
    Years ago I had an HO layout. Back then it was around the walls of a 12' x 32' attic room with the "door" in the center of the floor.

    When I came to my new apartment, I had 11.5' x 6.5' to play with. To my way of thinking, not enough for HO.

    I now have an "M" shaped N Scale empire to build. Things are documented on my website.
  6. sumpter250

    sumpter250 multiscale modelbuilder

    24" radius may still be tight for something like an SD80/90MAC, and autoracks, or 89' flats. I'd recommend 30" radius as your minimum mainline radius. Industrial sidings will depend on the rolling stock serving the sidings. #8 turnouts, and wide radius curves for the long cars (70-90' ), 24" radius for 60'-70' cars, #4 turnouts, and 18" radius for some 50' cars, and "beercan" tank cars. The industrial areas would be handled by Geeps, or switchers.
    Welcome to the gauge! Where, on the Island, are you located? Are you modeling NY&A? I grew up in Copiague, and spent a lot of time out in the Bridgehampton/Sagaponack area,
    and on Noyack Bay.
  7. wjstix

    wjstix Member

    Generally for HO, 24" R is considered "convential" curves, 30"R is broad, anything 36"R or greater is "superbroad". Most everything in HO will take a 22-24" curve except for full length passenger cars with body mounted couplers, which need 30"+ curves (and maybe a few large steam engines). An HO Spectrum 2-6-6-2 will go thru a no.4 turnout and a 22" radius curve.

    N scale is 55% as big as HO, so 19" radius would be equivalent to about 35" radius in HO.

    LIRRNEAL New Member

    Thanks for the welcomes:)

    LIRRNEAL New Member

    Thanks for the welcomes:)

    LIRRNEAL New Member


    I'm in Miller Place, about 30 miles east of Copaigue, but grew up in East Farmingdale. I model the Long Island around the mid 50s. I guess I'm partial to grey and orange:thumb:

  11. wjstix

    wjstix Member

    I used to have orange hair, now it's orange and gray.
  12. Old 'n' Weary

    Old 'n' Weary New Member

    The conversion from N to HO for 19" radius is 19X160/87 = 34.9"

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