# Curved TOs and super elevated curves



## Stejones82 (Dec 22, 2020)

Greetings all, 

Thanks again to the many who have given their time and expertise to help me with so many questions and issues. 

My question today is curved TOs and super-elevation. My 'main' will have 22 inch radius curves but will use curved (20-24 Walthers) TOs as part of the curve. Can one 'super-elevate' a curved TO? 

Process I have seen is to step up the super elevation 0.00 -> 0.010" -> 0.020" -> 0.030" And then back down again in the same pattern. But I can't help but wonder that elevating the curved TO is asking for trouble. 

Thoughts? Suggestions? Lessons-learned? Thanks to all! - - - - Steve J


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## MichaelE (Mar 7, 2018)

I believe your outer curve will have to be high enough for the inner curve to continue the elevation in the same plane that the outer curve is in. In other words, don't allow the inner track to run out of vertical room to continue the elevation.

If the inner track gets twisted in the process of exiting the the turnout there will be nothing but problems at this turnout.

As the diverging leg moves farther from the turnout the tracks _could_ return to parallel through the cross section of both tracks.

This is difficult for me to explain without a drawing or photograph. I'm not certain if any of that made sense to you.


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## OilValleyRy (Oct 3, 2021)

What Michael said. 
I had a non curved turnout years ago, which was both super elevated on one side, and on a down grade slant. It was off of a siding so despite being a Walthers #5, there was a slight curve going into it. 
I had daily problems with cars of all lengths, 86’ hi cubes to 2 bay covered hoppers.


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## Lemonhawk (Sep 24, 2013)

Its best to keep any turnout all in a single plane, that is you should be able to lay a flat board over the turnout and it should be touching all point of the turnout. The more the plane can be extended past the turnout, the better it will look and operate. An example would be putting a turnout on a grade where a single track needs to become 2 tracks. As long as both tracks are mounted on the same flat board (but with a grade) there should be no problems. As with any time you want to change to a different plane, like at the top where you level off, then all the same cautions about how to do this apply, especially vertical easement!


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## Thelic (Jan 10, 2018)

You probably shouldn’t be running through turnouts at speeds requiring super elevated corners anyhow. I would lay them flat to avoid problems. Save the super elevation for long sections of unbroken track.


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## mesenteria (Oct 29, 2015)

Super isn't strictly required in our hobby, and it introduces both complexity and problems. Oh, don't get me wrong, I won't have a main line curve without super...but if you want to introduce a turnout along the curve, then good luck to you.

For a curved turnout, the prototype would not super-elevate the inner divergence, or at least not much. Just enough until the frog is cleared so that the main line traffic doesn't have to slow much over a weird frog, at which it would return to level within 10-15 feet.. But no prototype would allow a train to diverge on a curved turnout onto a spur or siding without reducing speed to something like 20 mph or even less.

You can still do this, but keep the super to a minimum, about 1/32" if possible. The problem will come from the now rolled inner route which will want to cant at the same rate, placing those rails below the outer route, and tilting the curved inner rail ends, after the frog, downward toward the main surface of the layout. T'will cause no end of trouble for you if you don't get it perfect. Then, don't be surprised if you simply have to abandon thoughts of running some cars and locomotives over that turnout on the inner route.


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## MichaelE (Mar 7, 2018)

If I just had to have this, I would keep the elevation on the diverging track well past the frog to eliminate geometry problems (twisting) too soon after the frog and make a gradual transition to flat.

Sort of glad I didn't try this.


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## Thelic (Jan 10, 2018)

MichaelE said:


> If I just had to have this, I would keep the elevation on the diverging track well past the frog to eliminate geometry problems (twisting) too soon after the frog and make a gradual transition to flat.
> 
> Sort of glad I didn't try this.


If you keep the super elevation as the legs diverge the inner track is going to be forced to drop significantly in height. Say you are 1/32" super in the point end, by the time you diverge and get past the diverging leg of the turnout the inner track needs to be like 3/32" lower. I mean it certainly could be done, but you wont end up with 2 tracks of same elevation leaning into the corner. A better approach would be to super elevate the entire sub roadbed and leave the cork square with no shims.


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## MichaelE (Mar 7, 2018)

I tried to convey that in my first response to the OP. The outside track would have to start at a higher absolute level so the inner diverging track has enough vertical room to continue in the same plane as the outer track.

I didn't think I was explaining my response clearly though I knew exactly what I was trying to say.


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## 65446 (Sep 22, 2018)

If you are asking 'Can one have a curved TO within a super-elevated (banked) curve ?', I'd say *yes* if, *IF* entire switch is not tweaked... A N Y W H E R E... The degree of slant is not going to be so much that the points or frog are going to 'see' much diff than if switch were completely flat down plumb...So, go ahead and install it on the 'banked' curve as long as all of it and track to and from it are on the *exact same plane* as IF flat down level...Any tweaking or forcing it or approaches to it can cause derailments, false uncoupling, and stall outs...If that starts you can always redo curve without the banking..
It's a hobby..Try it.. No good ? Fix it....


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## Stejones82 (Dec 22, 2020)

Thanks, gents, excellent tutelage as always. I think I will avoid this and keep the curved TOs on the same plane and level.


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## Magic (Jan 28, 2014)

Good choice, curved turnouts are very fussy and if not just about perfect will cause problems.
I have several on my layout, took some work to get them just right.

Magic


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## 65446 (Sep 22, 2018)

I had 1 curved Shinohara switch in the main on my last layout and other then it being 'power routing', needing correct gapping and powering, not only looked great, but caused no problems whatsoever...


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## mesenteria (Oct 29, 2015)

I hand-crafted a long curved turnout perforce on my second layout. There was no commercial product to fit where I needed one, and by then I had made several Fast Tracks style #8 and two #6 double slip turnouts. By the time I had them done, I pretty much realized I could build whatever needed doing, provided I got the geometry right AND the gaps cutting the copper cladding on the PCB ties correctly. It is now in place on my fourth layout, having served on the second, third, and fourth. However, I did use some of the W/S curved turnouts on my main, but I minimized super-elevation. Where I needed a bit more, I had to ensure the diverging route came off at a different vertical cant so that it wouldn't cause derailments. It just took some shimming and some good glue to hold it the way I needed it to be, but it worked fine.


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