What is the Smallest Radius a 6 Axle Diesel Can Negotiate?

Discussion in 'N / Z Scale Model Trains' started by Hoss, Nov 13, 2003.

  1. Hoss

    Hoss Member

    I'm in the layout planning stages and I have a couple of curves that are 13.75" radius. Will this cause problems for my Kato Dash 9's and SD70MAC's? If so I'd rather fix it now than after I have track in place. I'll be using easements so that will help, but I still want to know before I start laying track.

    Also....even though I've also asked this in another thread....will these locos negotiate the PECO small radius turnouts (12" radius)??
  2. hemiadda2d

    hemiadda2d Member

    Anything above 10-11"r should handle any 6-axle engine fine, even 90MACs.
  3. roryglasgow

    roryglasgow Active Member

    I've run a Kato SD90 Mac on 9 3/4" radius curves without any problems. It hangs over quite a bit, but it still works!
  4. Hoss

    Hoss Member

    I knew Kato advertised that their 6 axle diesels would run on 9-3/4", but I didn't think they actually would! I guess that pretty much answers my question.
  5. hemiadda2d

    hemiadda2d Member

    I dunno how tight it is, (7-9"r)but the LL power-loc track that came in a starter set, put together into a loop, is too tight for SD40-2's. I have tried it, even nailed the stuff down to plywood...
  6. Hoss

    Hoss Member

    I don't plan to have anything as tight as 7-9". In fact, I'm trying to find a way to make my 13.75" radius turns wider. The only place I have it is at the dogbone ends of my turnout where the benchwork is 3' wide. I've got it double tracked at those locations with the outside track at 15" radius and the inside at 13.75". I just want to make sure the 13.75" will work if I have to leave it like that. Everything else is 20" or greater.
  7. hemiadda2d

    hemiadda2d Member

    13"r should be more than enough for even the 90MACs. But autoracks may give you trouble--restrict them to the outside main.
    Anything 15"r+ is best for autoracks. Besides, the overhang of an autorack on a 13" r curve will knock other adjacent trains off the tracks, on curves......... *speaking from experience!*
  8. Agatheron

    Agatheron Member

    That's wise counsel... I've been considering doing my first layout based around the auto industry in Southern Ontario. It's pretty obvious that Auto Racks are a part standard trains in the area. The problem for me is space. I've been developing plans to fit on doors mostly to try to simulate the industry. However, if I also want a continuous loop, the trains will need to turn around in an appropriate space. So far, I've been working with plans with a minimum radius of 11" for the inside loop. Given my spacial limitations, the outside loop will be 12.5" to an absolute maximum of about 14". Even with that I'm as close to the edge as I am comfortable with on my outside loop... Realistically I could possibly push the exterior loop to around 13.5" before I have less than an inch between the edge of the track and the edge of the board...

    Any suggestions? Or do I simply try to keep autoracks on a reasonable display and make sure that I am careful when running other trains beside autoracks?
  9. zeeglen

    zeeglen Member

    My Kato SD40-2 and Mikado runs fine on 9 3/4 " as long as I use curved sectional track (Atlas) - the gauge is wider (but still within NMRA spec) and forgiving. When using Atlas flexible track (code 80) the SD40-2 had trouble on both 9 3/4 and 11". Checking with a NMRA track gauge showed the flextrack gauge to be just slightly too narrow.
  10. rcwatkins

    rcwatkins Member

    I run SD80's on 12 3/8" curves (Kato) & they run fine. :D
  11. marc gast

    marc gast Member

    6 Axle Radius


    Don't run it on anything less than an 18 inch radius. They may negotiate a smaller radius, but, look hokey! From the looks of your layout plans, etc. this looks like a very nice design. Don't ruin it with tight radius, etc. When you get less than an 18 inch radius and running long engines, passenger cars, auto carriers, etc. it really looks toyish with all the overhanging of the rails. Looks like you have plenty of room for wide radius; don't hokey it up! Also, think about the transition into the curves, don't go straight then whan into the radius. Using transision curves makes for nice running and looks more prototypical.
  12. Hoss

    Hoss Member

    Re: 6 Axle Radius

    Hey Marc.

    When I originally started this thread I was working on totally different benchwork and a totally different track plan than the one I'm in the process of building now. Due to the space constraints on it, it was going to require a maximum radius of about 15" to 16" at each end to turn trains around.

    I dismantled that benchwork because I could never settle on a track plan I liked (sharp curves being part of the reason for that).

    The layout I'm now working on...and probably the one you're referring to...has a MINIMUM mainline radius of 21", and that is only on the circle at the bottom where the coal loading operations are going on. The rest of the mainline radii are primarily 24" and 30"...with one curve being 26" and one being approximately 42".

    I also plan to ease all of my curves....so no need to worry about me hokeying it up. ;)

    Thanks for your comments. :)
  13. marc gast

    marc gast Member



    Thanks for the update!!!!!!!!!! Sounds like some really nice prototypical running. Ya put your right foot in, ya put your right foot out, and do the Hokey Pokey! LOL

    Keep us posted on the progress.

  14. Hoss

    Hoss Member

    Prototypical running is what I'm shooting for. I guess we'll just have to wait and see how it turns out. ;)

Share This Page