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15 inch radius

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15 inch radius
Posted by Rooster70 on Sunday, March 2, 2014 8:31 AM

Will 40 foot cars handle a 15 inch radius well, very likely to derail? 

Also are there any curved turnouts with a 15 inch radius on the inside with an 18 inch radius on the outside, or a regular turnout with a diverging 15 inch radius, like a snap switch only tighter? 

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Posted by mlehman on Sunday, March 2, 2014 8:43 AM

Handle it well? Nope, 15 min radius will cause you no end in headaches. Some cars will make it, many won't, if you're talking about standard RR cars.

Now, if you're prepared to run it as a specialized logging, mining, industrial or otherwise strictly limited prototype with the right motive power and cars, you could make this work and still be believeable. This will require a short wheelbase loco and cars shorter than 40', perhaps with some special attention to coupler swing.

Couplers will be the limiting factor here, as they may pull cars off the tracks or make it difficult to impossible to couple on a curve without human intervention.

Even with short cars, etc, 15" radius curves will prove to be an aggravating limiting factor.

Mike Lehman

Urbana, IL

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Posted by jrbernier on Sunday, March 2, 2014 9:08 AM

  Most 40' freight cars will go around a 15" radius curve, some may have problems due to underbody drtails that limit the swing of the trucks.  Highly detailed models with lots of underbody details and extended shock control coupler should be avoided.

  There are no curved turnouts available with the combination of radius you are mentioning.  I think some European track may have something like 17/13" radius, IIRC.  Atlas makes sectional Snap Track with a 18" radius diverging route, and a 22" radius route.  Again, some of the European stuff may have sharper curves - But I would expect 'Sticker Shock' when you see the prices!

  My old layout had an 18" radius curve on a house track and really limited what cars/engines could access it.  Running a single car around it was OK, but pushing a string of cars around it would rally bind up the train.

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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Posted by gregc on Sunday, March 2, 2014 9:49 AM

V8Vega
For people who put off building a layout because of no room let me incourage you that 15" radius is sure better than no layout. I had a lot of fun with that layout.

greg - Philadelphia & Reading / Reading

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Posted by IRONROOSTER on Sunday, March 2, 2014 10:11 AM

Make sure your trucks swivel freely and your couplers as well.  Lay the track with care to avoid kinks, dips, and bumps.  40 ft and less should work just fine on 15".

Enjoy

Paul

If you're having fun, you're doing it the right way.
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Posted by b60bp on Sunday, March 2, 2014 12:15 PM

Howdy,

you should have no real problem with 40 footers on 15 inch curves. As others have said, just be careful to do your best track laying.  I used to have some industrial curves of 12 inches and one even tighter. Traction modelers used down to 9 inch radius regularly.

 

And none of that is unrealistic. The Reading Company used t list minimum radius for their switchers in the Philadelphia terminal area. The early box cab had a minimum radius of 50 feet (about 6.9 inches in ho), while an HH900 Alco was rated at 60 feet, or about 8.25 inches in HO. The largest any switcher called for was 75 feet.  Of course this was all yard trackage with very low speeds.

Point is, if the prototype did it, so can you, on a slightly smaller that is.

 

Benny

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Posted by Fergmiester on Sunday, March 2, 2014 1:20 PM

I once saw a layout that used 15" curves.It was a real gem! However as stated above you will be limited to what you want to model and run. There are some great suggestions for layouts with 15" curves in Lynn Westcotts 101 Plans published by Kalmbach.

Fergie

http://www.trainboard.com/railimages/showgallery.php?cat=500&ppuser=5959

If one could roll back the hands of time... They would be waiting for the next train into the future. A. H. Francey 1921-2007  

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Posted by Javelina on Sunday, March 2, 2014 1:30 PM

Rooster,

I've had no problems with Athearn 40 footers, Athearn GP-7/9's, Con-Cor MP-54 passenger cars and Roundhouse cabooses on 10" radius curves. These were part of a "micro" layout, the curves were eased to tangent. Forward, backward, fast or slow, no problems or derailments. The locomotive growls a little louder than normal, but only because its universal joints are making more rapid changes in angularity due to the sharp curve. Don't be afraid of tiny radii for switching, as one of our other respondents has noted, the prototype wasn't either. Reasonably careful trackwork does wonders. This is a case where it may not pay to take "the rules" as gospel. Try it yourself and decide if the result is acceptable to you. Genchi Genbutsu, Go and See.

Lou

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Posted by Texas Zepher on Sunday, March 2, 2014 1:55 PM

Rooster70
Will 40 foot cars handle a 15 inch radius well, very likely to derail?

I had a dual track loop with the inside being 15" radius for several years.   It was the same set of cars that had derailment problems on the inside 15"  or outside 18".  So tune your cars and there should not be an issue.  And for certain do not mix truck mounted couplers and body mounted couplers.

Also are there any curved turnouts with a 15 inch radius on the inside with an 18 inch radius on the outside, or a regular turnout with a diverging 15 inch radius, like a snap switch only tighter?

Not that I know of.   Peco has the smallest in code 100 that I know of.

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Posted by tomikawaTT on Sunday, March 2, 2014 2:23 PM

There is one 'large' loco that will take 15 inch radius and laugh - the so-called Mantua Logger, standard gauge edition 2-6-6-2.  Mine (with a modified superstructure but no chassis mods other than removing the American pilots) has been run down to 300mm (a bit under 12 inches) radius and routinely runs on 400mm radius curves and 4% grades.  The longest cars used on the route are not quite as long as a US 40-footer over couplers - everything longer or stiffer is embargoed.

As for the turnouts, I have the 'makin's' available at all times for any size no matter how odd.  My tea tray has lengths of raw rail, pre-cut (to length) tie stock, spikes, solder, flux and the necessary tools.  If I can bend flex track to the configuration I want for each route I can build the specialwork to merge them.  Handlaying is not really that difficult to learn - and once you master the methods you will never again have to search for that elusive size or shape of turnout.

Chuck (Modeling Central Japan in September, 1964 - on 400mm curves and handlaid specialwork)

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Posted by angelob6660 on Sunday, March 2, 2014 2:50 PM

I know my 40 foot freight cars run very well in 15 inch curves in N Scale, but their are questionable on HO equipment that depends. I believe it well work with hoppers and boxcars. You would know if you don't try.

Modeling the G.N.O. Railway, The Diamond Route.

Amtrak America, 1971-Present.

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Posted by galaxy on Sunday, March 2, 2014 3:51 PM

Rooster70,

Welcome to the forums!

DOn't listen to the nay-sayers:

First, let me say that I have a 3.5 foot x 5.1 foot HO scale layout. It consists of a 15"R inside oval interconnected with Atlas Snap switches to an outter 18"R oval. Inside the inner oval is a 4 spur yard and a 2 spur engine storage/sevicing facility.

I have had no problems with short steam or 4 axles diesels. No problems with 40' cars, and pretty much my few 50's will take it, but not like it {meaning they will do it ,but look funny and are strained}.I have mostly body mounted couplers and a few talgo couplers{swivels}. Only the 68' odd passenger cars will not take them, but will the 18"R curves..

There are no curved turnouts, BUT if you do what I did, put the diverging curve of a Snap switch on the curve of the 15"R turn, and the straight section out to the outside {where on mine it connects to the diverging curve of another switch wihtin the 18 R oval} you can curve off the straight section or do what I did.

NOW: the caveat:

I am doing what I can to rid myself of the 15 r and make it a 4 x5.5' layout with two interconnected 18"R ovals, or one 18R and one 22"R If I make it 4.2x5.5-6'.

WHY? because: The 15 R curved oval IS VERY LIMITING. NO respecatable 6 axle locos are going to like the 15R. NO big steam is gonna like it. It was fun while it lasted, but now i wnat an inner oval of 18R!

I want the smallest to be 18R, as most ANY loco is desingned to run on 18"R but NOT on 15" R!!!

Unless you are severely limited in space {in which case I would consider N scale}, I would not go with 15r and favor 18r.

Geeked

-G .

Just my thoughts, ideas, opinions and experiences. Others may vary.

 HO and N Scale.

After long and careful thought, they have convinced me. I have come to the conclusion that they are right. The aliens did it.

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Posted by dknelson on Sunday, March 2, 2014 6:01 PM

gregc
 
V8Vega
For people who put off building a layout because of no room let me incourage you that 15" radius is sure better than no layout. I had a lot of fun with that layout.

 

 

Ho ho! John Allen's original Gorre & Daphetid!   which he incorporated into subsequent layouts, proving that it can be done.  One problem with tight radius curves is that you need good coupler swing action, most likely particularly on the locomotive.  Sometimes even short engines have inadequate coupler swing.  But yes there have been many many layouts built with curves that sharp. 

Dave Nelson

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