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What are the advantages of curved turnouts?

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What are the advantages of curved turnouts?
Posted by IDRick on Wednesday, February 6, 2019 9:28 PM

I found a layout that I really like but the modeler used curved turnouts.  I don't really understand the advantages of curved turnouts, particularly given their very high cost and either very large radius or very small turn radius with no in-between...  Could you more experienced modelers provide an explanation to me, a newb on the subject?

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Posted by Anonymous on Wednesday, February 6, 2019 9:35 PM

Curved turnouts allow you to start a yard ladder on a curve, which could allow a longer track length.

Central Valley makes curvable turnout kits.

https://www.handlaidtrack.com/track-templates-ho-curved-turnouts

Lots of options for different radius, but those are hand layed solutions.

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Posted by Anonymous on Wednesday, February 6, 2019 9:37 PM

The larger radius of a curved turnout can also be used as an easement into a tighter curve radius.

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Posted by Doughless on Wednesday, February 6, 2019 9:45 PM

A 32 inch radius curve takes up a lot of space.  Starting the spur or siding in the middle of the curve allows the diverging track to get straight at the same spot the mainline gets straight. If a straight turnout was placed on the mainline at the end of the curve, you'd get that much less of a siding.  Those few inches might be important when it comes to allowing space for your longest train.

A Walthers #7.5 curved turnout has 32/28 inch radii.  The 28 is fine for heading into a yard, spur, or passing siding.

- Douglas

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Posted by IDRick on Wednesday, February 6, 2019 10:07 PM

Thanks for the explanation.  Do the track planning programs correctly model the curved turnouts or is it better to download a template and play with a 1:1 representation?

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Posted by Anonymous on Wednesday, February 6, 2019 10:14 PM

My preference is 1:1.  Ive seen/heard of programs incorrectly modelling curved turnouts.

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Posted by IDRick on Wednesday, February 6, 2019 10:29 PM

Thanks.  Peco has templates for their curved turnouts, I'll play with it a bit!

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Posted by hon30critter on Wednesday, February 6, 2019 11:19 PM

IDRick
Do the track planning programs correctly model the curved turnouts

Hi IDRick,

I have 3rd PlanIt and the most recent edition has curved turnouts for Peco Code 70, 83 and 100, Shinohara Code 100 and Walthers Code 83. They don't have Atlas curved turnouts yet but I'm sure they will soon.

Before 3rd PlanIt had the curved turnouts I found it was easy to make my own by just drawing two circles equal to the inner and outer radii and then cutting out a segment from each equal to the length of the turnout. I placed the two segments as close together as I could before they automatically aligned and then grouped them and copied needed turnouts from the master. When 3rd PlanIt came out with the curved turnout templates I did a comparison and my hand drawn ones were almost exactly the same. 

FWIW, we used several Peco Code 83 curved turnouts in our club's new layout and they did exactly what Douglas explained:

"A 32 inch radius curve takes up a lot of space.  Starting the spur or siding in the middle of the curve allows the track to get straight at the same spot the mainline gets straight. If a straight turnout was placed on the mainline at the end of the curve, you'd get that much less of a siding.  Those few inches might be important when it comes to allowing space for your longest train."

In each case they made the sidings considerably longer.

Dave

 

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by Tinplate Toddler on Wednesday, February 6, 2019 11:27 PM

IDRick

Thanks for the explanation.  Do the track planning programs correctly model the curved turnouts or is it better to download a template and play with a 1:1 representation?

 

Yes, they do - contrary to what others may tell you from past experience. That past is a long, long, long time ago.

 I have been using track planning programs for almost 30 years now, and only had problems with the representation of curved turnouts in the very beginning.

Happy times!

Ulrich (aka The Tin Man)

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Posted by SeeYou190 on Thursday, February 7, 2019 6:21 AM

Curved turnouts allow you to have a spur or siding in a corner of the layout where there is not enough room to straighten the track for a standard turnout.

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Curved turnouts also look very cool.

.

-Kevin

.

Living the dream.

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Posted by riogrande5761 on Thursday, February 7, 2019 6:53 AM

IDRick

I found a layout that I really like but the modeler used curved turnouts.  I don't really understand the advantages of curved turnouts, particularly given their very high cost and either very large radius or very small turn radius with no in-between...  Could you more experienced modelers provide an explanation to me, a newb on the subject?

On my last 10x18' layout with limited space, I used curve turnouts to lengthen track train length capacity.

Here, I'll let pictures explain:

First turnout into staging is a curved Shinohara code 100 LH #8

Two more curved Shinohara code 100 LH #8 and a Peco code 100 curved LH (left side of photo).

And at other end of staging there is a Peco code 100 RH curved:

Result, a lot longer storage tracks in staging.

 

I also used curved #8's at each end of my main yard, also to lengthen capacity.  Hard to see in this photo in the distance.

Other end

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by rrinker on Thursday, February 7, 2019 7:32 AM

 For a visual example of how a curved turnout can help you, see the MRVP series with David Popp on designing a layout. In the last or next to last video (so far) in the series, he finds that using regular turnouts mean he doesn;t have room to include the features he wants in the space available, so he redraws it with curved turnouts for a better fit.

 As far as the exactness of CAD programs - I don;t use CAD to cram as much track into an area as possible, I use it to make sure a reasonable idea will fit. I don;t print out the plans to full size and lay the track over them, I just take some measurements and work from thre. If an element as represented in the CAD program is a little too big, or a little too smal, compared with the actual piece of track - no big deal. I never draw anything so that say a 16th of an inch is the difference between the track fitting or it running off the edge of the layout, or into a wall. My CAD drawings are fairly conservative in relation to the available space, allowing for plenty of adjustment as I actually build.

                                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by RR_Mel on Thursday, February 7, 2019 8:11 AM

A couple of years ago I replaced two regular #6 Atlas turnouts with two Peco curved turnouts and gained 30” on a siding.  The siding is hidden for parking a full passenger train and the additional 30” is enough for three more 72’ passenger cars, A&B E7s and 13 Athearn 72’ passenger cars.  Before the mod I was limited to 10 cars on the siding.
 
Well worth the effort. 
 
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by Silverliner266 on Thursday, February 7, 2019 9:08 AM

IDRick

 either very large radius or very small turn radius with no in-between...  Could you more experienced modelers provide an explanation to me, a newb on the subject?

 

 

To expand on this a little bit, it's a practical concern. If you go from 32" to 30" it's going to take a longer run before you have enough clearance to avoid clipping the parked train. Losing the distance negates one of the advantages of a curved turnout, added length on a siding. 

Just an N scale guy in an HO scale world.

Reading Railroad in a small space. 

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Posted by dknelson on Thursday, February 7, 2019 10:09 AM

I am making substantial use of curved turnouts (Peco) on my layout - in some cases it enables the trackwork to flow more smoothly than if I had to abruptly introduce a tangent (i.e. the traditional turnout) into the curve.  

Curved turnouts are useful for track planning for some of the same reasons you might find yourself using the diverging ("curved") part of a traditional turnout as the main line, with the tangent part being the siding or brach. 

In one crossover on my double tracked main layout, one turnout is curved, the other is traditional but the diverging route is the main and the tangent is part of the crossover.  It saved space and placed the crossover exactly where I wanted it.

I fussed and fumed over that crossover problem for hours until I just happened to put some full sized turnouts in place on the plywood and suddenly the solution was staring me in the face.  If the OP acquires a curved turnout or two, I say play around with them a bit before installing and you might discover other good uses (the Peco turnouts came in the blue box that has a photo of the turnout on the cover so cutting out the box photo is almost as good as having a spare turnout).

Dave Nelson

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Posted by riogrande5761 on Thursday, February 7, 2019 11:43 AM

Silverliner266
 
IDRick

 either very large radius or very small turn radius with no in-between...  Could you more experienced modelers provide an explanation to me, a newb on the subject? 

To expand on this a little bit, it's a practical concern. If you go from 32" to 30" it's going to take a longer run before you have enough clearance to avoid clipping the parked train. Losing the distance negates one of the advantages of a curved turnout, added length on a siding. 

It's true if the difference between the inner and outer radius of a curved turnout is not much, then the curved turnout is longer.  But it doesn't negate the advantage by much, which is why I used those #8 curved turnouts on my last layout.  The layout is torn down so I can't go measure the gained capacity but it was worth it for sure.

The Shinohara made turnouts had a nominal difference of 4 inches on the centerline, so the #8 were 36/32, and goinig down from there 32/28, then 28/24 etc. 

The Peco OTOH were considerably shorter because the difference is much greater in radii.  The Peco code 100 streamline curved are 60/30 and the Peco code 83 #7 curved are 60/36 radius.

There are advantages and disadvantages to both, depending on track geometry.  You can see in my photo's above how they fit in, and the Shinohara fit into the staging yard throat much nicer IMO.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by BATMAN on Thursday, February 7, 2019 11:58 AM

I have six on my layout, they were a perfect solution to a problem. Two here.

  

Two here, one for the elevator siding and one off the bottom left for the cattle pen siding.

  

One here on my balloon track that also doubles as the yard lead.

  

 One more lower right.

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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Posted by IDRick on Thursday, February 7, 2019 12:39 PM

Interesting replies!  I played with curved peco and shinohara turnouts on AnyRail.  I'm not understanding the geometry of the curved turnouts well enough to use them within the AnyRail software.  Paper templates will clearly be the way to go for me to visualize advantages of varying size turnouts.   A #6 is probably the broadest I can go on my layout table (5x9).

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Posted by oldline1 on Thursday, February 7, 2019 12:40 PM

Ultimately they can save space. I just love the graceful looks of them.

Walthers and Peco have a large selection of different radii turnouts.

oldline1

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Posted by hon30critter on Thursday, February 7, 2019 11:20 PM

Peco has diagrams of their turnouts that you can print. The diagrams have rulers on them that allow you to make sure the printouts are sized properly. You may have to play with your printer properties to get them to the right size.

https://peco-uk.com/collections/turn-out-crossing-plans

Dave

 

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Posted by railandsail on Friday, February 8, 2019 12:14 AM

Full Size Paper Templates of Trackplan

To begin with I am not a computer geek who has ever learned how to manipulate computer track plan softwares. And to tell the truth I never thought it was an idea worthy of extensive study to learn just to singularly design my new layout. I really thought (hoped) that someone would come along and do that computer designing/visualizing for me,....someone who enjoyed doing that sort of thing.
 

Long story short I had to resort to scale drawings / sketches. These can be a little tricky to get 'exactly' to scale, particularly with the variety of turnout brands, and subtle variations in their exact profiles.

 

Paper templates of the turnouts was suggested (these were full size). I also had a good number of the actual turnouts themselves, and some fixed pieces of Atlas sectional track I could use to double check that I was getting a good close fit, and the proper angles.
 

I had a 4x8 sheet of plywood set up as a work table out in my carport. I thought why not lay some drawing paper out on the sheet of plywood and draw up some of the various areas of my trackplan. A contractor friend had an old roll of brown paper that is used to protect new flooring etc during building construction. And it happened to be 4 foot wide.

 

I now lay 4x8 foot pieces of that paper out on my BIG drawing table, and do an exact full size plans of my trackplan for various areas and corners of my layout. I plan on using these patterns to lay down the track on my double decks of the actual layout. Additionally I can simply roll these paper plans up and put them inside during windy or inclement weather,
 

I am actually having FUN creating these full size plans, and I am learning somethings about planning concentric curves, fitting in structures, tight tolerances etc, etc.

http://cs.trains.com/mrr/f/11/t/273575.aspx

http://cs.trains.com/mrr/f/11/t/273575.aspx

 

I'm building all in Code 100 track with Peco turnouts, so I found their EXACT paper templates very handy. You'll also find I have used several different 'double-curved' turnouts in various spots. I found that even the manufacturers got their own designations of the actual curves incorrect, but laying out the full size paper templates (and the turnouts themselves in some cases) brought clarity and exactness to the situation.

These full size paper patterns are divided up into 'areas' simply rolled up for storage until I complete them all. And they will subsequently be used to lay down the track on the plywood benchwork.

example

Hard to tell but there are 2 large radius (60/30) dbl-curves on those 2 mainlines in the upper right had side of that photo.

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Posted by railandsail on Friday, February 8, 2019 8:12 AM

There are 2 double radius turnouts at the head of this freight yard ladder chain of turnouts. These are much tighter curves built by Roco (22/18)

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