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11" Minimum radius turns-N-Scale

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  • Member since
    May 2010
  • 42 posts
11" Minimum radius turns-N-Scale
Posted by Dan T on Wednesday, June 30, 2010 2:21 PM

 Hello all,

As many of you know I've been reading and planning for an N-Scale layout based upon industry switching and deliveries.  On my latest sketch and discussion I have a minimum of 12.5 in. radius curves throughout the layout. I also have been using #5 turnouts for turnouts.

As I've been sketching and planning I'm considering removing a couple of industries and making two of the remaining industries a bit larger and more detailed. I'm thinking that 11" minimum radius might allow me to better work my plans.  This is all switching, so I will be using 4-axle locomotives and I don't have any plans for longer than 60' or so rolling stock.

I'm wondering if any N-scale folks have experiences to share with using 11" radius turns with a bit of easement around sweeping curves.  Will it be a reliable radius to use in terms of derailments and so on for the shorter trains I will be using on the layout?

Thanks all,

Dan

  • Member since
    March 2007
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Posted by wm3798 on Wednesday, June 30, 2010 3:28 PM

 You'll be limiting yourself to 4 axle power and short wheelbase cars, but yeah, it'll work for the most part.

The thing that will be most crippling is coupling on the curve, which is a possibility on a switching layout.  This is especially true if you mix the traditional truck mounted couplers with the newer body mounts that are coming out.

If you're doing an urban industrial area, and keep the rolling stock in check, you'll be fine.  Personally, I prefer to keep my minimum to around 15", but I have a little more space to work with.

 

Lee

Route of the Alpha Jets  www.wmrywesternlines.net

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Posted by wjstix on Wednesday, June 30, 2010 4:04 PM

If you stick to your plan (small-medium diesels and freight cars) you should be fine. Most N equipment of that size will go down to about 9-10" R with no trouble. However, more than one modeller has built a "minimum radius" layout and later become interested in passenger trains or big steam and found out they can't run either on their layout because of the sharp curves. 15-18"R and No. 6 turnouts (at least on any mainline trackage) might allow for a later change in desires.

Stix
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Posted by BerkshireSteam on Wednesday, June 30, 2010 4:27 PM

I have a test track piece with a (poorly) done loop thats 11R and juttery (it's not a smooth curve) and my Athearn 57' mechanical reefer went around it fine in a small consist with my Atlas GP9. I imagine a properly done, smooth 11r curve would do fine and your talking about easements and all.

 

P.S. I'm stuck to appartment life so I'm also working on a door sized switching layout. I'm leaning more towards making actual benchwork of open-grid or L-girder (my personal fav) rather than a hollow core door though.

  • Member since
    May 2010
  • 42 posts
Posted by Dan T on Wednesday, June 30, 2010 5:29 PM

Thanks for the responses. I'm hesitant to switch to the 11" radius, even though it would make it much easier.

My thinking here is, this layout will be part of a future room sized around the wall and peninsula arrangement within the next year.  If I drop to 11" then it limits that entire future layout in some way with the advantage of making things work easier on the current. 

Maybe I should lean on the side of caution and keep the 12.5"- 13" minimums, even if they are causing me pain, for that reason alone?

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Posted by WP&P on Wednesday, June 30, 2010 7:21 PM

 I agree with Lee and others who have encouraged broader radii, even though on my own N-scale layout I have used an 11" curve.  It's used for a branch line that leads to a single staging track, where one short local will use it intermittently. There's always an exception that proves the rule, right? The rest of my layout adheres to 15" minimum radius, broader anywhere I can manage it. I think that once you get down to 15 inches or less, every fraction of an inch that you can spare counts!

One thing you might examine is a compound curve that uses 11" radius for the central 30-to 45-degree arc, then spirals/eases out to a broader radius beyond that.  You might be able to get a tighter fit than a true 13" 180-degree curve. It's tougher geometry, since you're basically doing half of an ellipse rather than a standard arc. What you've heard said is that most N-scale equipment can manage the 11"; I think this is true even of longer cars, as long as they are coupled in a consist and just traversing across the curve, rather than being switched on it.  The easements into and back out of the tight spot help cars handle curves that might be difficult otherwise.

We Provide Pride!
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Posted by Jacktal on Wednesday, June 30, 2010 7:44 PM

I'm actually building my layout and I have settled for 15 in.minimun curves for the main lines as I will run rather heavy steamers.I'd love broader curves but space is limiting my options.However,I'm thinking of smaller radiuses  at some places that only my diesels and smaller steamers could use...price to pay I guess.....

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Posted by ham99 on Wednesday, June 30, 2010 8:20 PM

Dan T

 Hello all

As I've been sketching and planning I'm considering removing a couple of industries and making two of the remaining industries a bit larger and more detailed. I'm thinking that 11" minimum radius might allow me to better work my plans.  This is all switching, so I will be using 4-axle locomotives and I don't have any plans for longer than 60' or so rolling stock.

I'm wondering if any N-scale folks have experiences to share with using 11" radius turns with a bit of easement around sweeping curves.  Will it be a reliable radius to use in terms of derailments and so on for the shorter trains I will be using on the layout?

Thanks all,

Dan

I have 11" curves with a piece of 19" easement at each end throughout my layout, and my Athearn Challenger goes through all of them just fine.  Passenger cars [Kato] negotiate all the curves as well.  Note that there are no grades on this layout [the surface of the layout has mountains and valleys, but the track is level].  The only problem I have had is with coupling/uncoupling cars of different lengths running together.

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Posted by CSXDixieLine on Thursday, July 1, 2010 5:20 PM

If you are mostly doing switching and will be limiting the equipment to 4-axle power and shorter freight cars, you are good to go. Just be aware that if you ever do want to use longer locos or cars, you'll probably run into clearance issues and excessive overhang. Jamie

  • Member since
    May 2010
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Posted by Dan T on Thursday, July 1, 2010 5:27 PM

 Thanks for the comments all.  I decided a bit more head-scratching now with larger radius curves is the better way to go.

I completed what I hope is my last design for this layout using 15" mainline and 12.5 industry minimum radii.  On a related note, if anyone feels like checking out the BNSF-Abq. N-Scale topicto make sure I didn't create any derail issues, ugly s-curves or orther mistakes I'd appreciate it.

 Thanks for the thoughtful responses and advice,

Dan

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