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Double Crossover with a Double-curve Turnout

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Double Crossover with a Double-curve Turnout
Posted by railandsail on Sunday, February 10, 2019 8:14 PM

Double Crossover with a Double-curve Turnout

I'm proposing to build this particular double crossover arrangement between my 2 mainlines as they enter/exit the upper deck of my double deck layout. Three of the turnouts are Med radius Peco's (nominal diverging radius 30”). The 4th turnout is a double-radius Peco with nominal radii of 30/60”).

I was hoping to insert a very short radius track between the crossover itself and the larger radius of the curved Peco. As I have it mocked up here that short radius piece is 22” radius. Would that work?,...or maybe 24”r piece??

 

 

 

 

It looks smooth enough to me. I'm just not sure how such a change in radius can effect things?

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Posted by Doughless on Sunday, February 10, 2019 8:46 PM

I don't think it will be a problem, long as the train is moving relatively slowly.  And since its a short piece, the typical minimum radius issue for long cars doesn't really come into play since only one truck is on the sharp curve at a time.  However, the truck needs to be able to swivel that sharply, obviously.

It looks like there is a kink in the joint to me.  

This is where laying curved turnouts can be complicated. You may have to curve the long piece of flex slightly more and pivot the turnout.  Or, you might be able to shorten the sharp short piece a 1/16th or 1/8th of an inch.  If you shorten it too much, it will throw off the angle heading into the turnout.

- Douglas

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Posted by peahrens on Sunday, February 10, 2019 9:01 PM

Certainly do-able.  

a) consider flex track section(s) as you can optimize the length and also vary the radius along that section slightly for smooth transisions.  The radius of a piece does not need to be constant

b) as noted, ensure joints have zero kinks

c) recognize you can trim the legs of the turnouts as that helps the custom arrangement, as long as you do not cut off any electrical jumpers (such as on my Walthers-Shinohara turnouts)

d) of course, trim ties as needed.

Paul

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Posted by hon30critter on Sunday, February 10, 2019 10:01 PM

Hi Brian,

I would do as Paul suggests. Use flex track for both pieces that join the curved turnout to the crossover. A 22" or 24" radius piece will probably work but IMHO having larger radii, if possible, would be better.

Something that I would suggest that you do before you make a final decision on the crossover arrangement is to check if the track coming out of the curved turnout will end up where you want it to without any tight curves. (I probably didn't need to tell you that. I'm sure that with the level of detailed track planning that you are doing you have already thought about it.)

Dave

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Posted by railandsail on Sunday, February 10, 2019 11:02 PM

Actually Dave I was trying to get the total radius a bit tighter originally.

I first placed a 18"r section in there, then I discovered I had a short piece of 22"r to experiment with. I didn't have a short, larger radius, piece to experiment with.

Its such a short section of track I wonder if the use of a piece of flex track there would make much of a difference over the fixed track??

I think I also saw just a bit of a 'kink' there myself, but by then I had been looking at it so much, I was wondering if I was seeing things. And of course going from the extreme of 60"r to the much smaller radius would give such an illusion.

 

 

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Posted by hon30critter on Sunday, February 10, 2019 11:12 PM

railandsail
Actually Dave I was trying to get the total radius a bit tighter originally.

Hi Brian,

I kind of figured that given that you don't have tons of space to work with. If you don't have any kinks and you restrict your speed through the crossover just like the big guys would do, it should work fine the way you have it. To answer your original question, since track speed has to be limited, I don't think that there will be much difference between a 22" radius and a 24" radius, but again, obviously bigger is better.

Have you considered building a custom curved turnout?

Dave

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Posted by railandsail on Monday, February 11, 2019 6:37 AM

hon30critter

Have you considered building a custom curved turnout?

Dave

 
I do realize that would be a solution, but I just have resisted such a project. I have a few other places where this would help, but I have tried to get by with 'stock' turnouts.

My custom needs would not be solved with stock templates/assembly fixtures.
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Posted by Doughless on Monday, February 11, 2019 8:09 AM

Radius is radius, it doesn't matter if the curve is made from flex track or sectional track. 

I've built switching layouts with nests of curved turnouts, and what matters in your photos is the angle of the exit point of the curved turnout in question.  The part that heads off to the rest of the layout. If that angle has to be relatively fixed (and I assume it does given your plan to fit lots of track into tight places), then the position of the turnout relative to the crossing is going to dictate the radius of that small curve in between.  The only way you can make it broader is by trimming the curved turnout back to give a few more fractions of inches between the turnout and the crossing.  That will allow for a slightly broader radius made from flex track.  If you trim the short piece only, that will cause you to shove and rotate the turnout towards that piece, which will change the angle of the exit points of the turnout.

Keep in mind that if you don't trim the curved track (or any piece of track) precisely, kinks at the joints can be created if one rail is slightly longer than the other.  That can throw off your radius in that short space by quite a bit.  When I trimmed curved pieces, I would use a straight edge along a tie for a guide, then scored the tops of the rails with a razor saw before cutting the rails with a Xuron rail nipper.  You want a nice even cut on both rails.

- Douglas

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Posted by carl425 on Monday, February 11, 2019 8:31 AM

That curved leg will actually operate more smoothly than the other one since you have eliminated the S-curve.

This type of track arrangement is one I would build at the bench, solder all the pieces together and then install on the layout.  Install this first, then match the connecting tracks to it.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by ATLANTIC CENTRAL on Monday, February 11, 2019 8:31 AM

railandsail

 

 
hon30critter

Have you considered building a custom curved turnout?

Dave

 

 

 
I do realize that would be a solution, but I just have resisted such a project. I have a few other places where this would help, but I have tried to get by with 'stock' turnouts.

My custom needs would not be solved with stock templates/assembly fixtures.
 

You don't need stock templates or assembly fixtures to build a custom turnout.

Just get a smooth pine board, or a piece of homasote, draw the trackage you need, start by making the frog, cutting, bending and filing the rail as needed, spike it the board using three point track gauges, and solder the frog and guard rails, fit the points, etc.

To install on the layout, draw it again on the roadbed (hopefully homasote), glue individual ties in place to suit, move the various rail sections to the ties and spike. Again, using three point track gauges and the NMRA gauge to check everything.

Modelers did it this way for decades before fast tracks and circuit board ties.

Here is a new twist, I have found that you can make curved turnouts with large radii by simply cutting the tie webs under the rail and gently bending an Atlas Custom Line turnout.

I have also hand layed curved turnouts using the points, throw bar and frog from an Altas Custom Line turnout.

Sheldon   

    

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Posted by railandsail on Monday, February 11, 2019 8:43 AM

When I look at the photos again this morning I don't seem to detect any 'kink' at either end of that short, fixed curve portion of track?

But rather what I see is a rather smooth run of track, its just a bit tighter radius in that short section of track. I believe this might only be a problem when I try to run a multiple driver steam engine (like over 4 drivers in a row) over it. If I were to make that short curve piece at least 24"r, then I might even get a 5 driver wheel loco thru it, particularly since it is such a short section?

Most of my articulates should make it thru there?

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Posted by railandsail on Monday, February 11, 2019 8:49 AM

ATLANTIC CENTRAL

Here is a new twist, I have found that you can make curved turnouts with large radii by simply cutting the tie webs under the rail and gently bending an Atlas Custom Line turnout.

I have also hand layed curved turnouts using the points, throw bar and frog from an Altas Custom Line turnout.

Sheldon   

 

I forgot about those options of cutting some of the ties to change one of the radii. I'll have to take a look at that possiblity with that Peco dbl-curve from its outer 60"r to something a bit less.

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Posted by railandsail on Monday, February 11, 2019 8:51 AM

carl425

That curved leg will actually operate more smoothly than the other one since you have eliminated the S-curve.

This type of track arrangement is one I would build at the bench, solder all the pieces together and then install on the layout.  Install this first, then match the connecting tracks to it.

 

That's true isn't it!

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Posted by Doughless on Monday, February 11, 2019 9:05 AM

railandsail

 

 
ATLANTIC CENTRAL

Here is a new twist, I have found that you can make curved turnouts with large radii by simply cutting the tie webs under the rail and gently bending an Atlas Custom Line turnout.

I have also hand layed curved turnouts using the points, throw bar and frog from an Altas Custom Line turnout.

Sheldon   

 

 

 

I forgot about those options of cutting some of the ties to change one of the radii. I'll have to take a look at that possiblity with that Peco dbl-curve from its outer 60"r to something a bit less.

 

Yes, you can broaden the radius of any fixed piece of track by cutting the webbing and using force.  I would change the radius of any "filler" short pieces before I'd mess with the webbing of a curved turnout.  

A steam loco can bind on any short piece of sharp curve.  Rolling stock rolls better, but the big steamers require a minimum radius, so I would look to make that filler piece as broad as possible.  

I was assuming you just threw something together and photographed it to simply illustrate a problem, because I see kinks and misalignments all over the place.  

- Douglas

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Posted by ATLANTIC CENTRAL on Monday, February 11, 2019 9:12 AM

railandsail

 

 
ATLANTIC CENTRAL

Here is a new twist, I have found that you can make curved turnouts with large radii by simply cutting the tie webs under the rail and gently bending an Atlas Custom Line turnout.

I have also hand layed curved turnouts using the points, throw bar and frog from an Altas Custom Line turnout.

Sheldon   

 

 

 

I forgot about those options of cutting some of the ties to change one of the radii. I'll have to take a look at that possiblity with that Peco dbl-curve from its outer 60"r to something a bit less.

 

I actually made curved turnouts from regular turnouts this way. BUT, they are VERY large radius, with the inside divirging route being 36"R or 40"R.......I don't do tight curves.

Smallest mainline or passenger track radius on my old layout, and the new one, 36". Many are more in 40"/42" range.

Sheldon

 

    

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Posted by richhotrain on Monday, February 11, 2019 9:14 AM

This is all conjecture. No one can say for sure whether it will work or not, unless someone builds the exact track configuration. You already have it assembled. Add some 36" lengths of flex track to the ends of it and run some locomotives through it, forwards and backwards, at slow speeds and high speeds. Then report back with the results.

Rich

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Posted by Doughless on Monday, February 11, 2019 9:30 AM

richhotrain

This is all conjecture. No one can say for sure whether it will work or not, unless someone builds the exact track configuration. You already have it assembled. Add some 36" lengths of flex track to the ends of it and run some locomotives through it, forwards and backwards, at slow speeds and high speeds. Then report back with the results.

Rich

 

If I had to guess, I don't think there is a curve on the whole layout that will be broader than 24 inches.

- Douglas

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Posted by richhotrain on Monday, February 11, 2019 10:03 AM

In the first photo, the RH turnout at the lower left appears mangled at the point of the divergent track. What is that all about?

Rich

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Posted by riogrande5761 on Monday, February 11, 2019 10:05 AM

I don't see any visible kink.  What is mocked up looks good to me.  Go for it.

BTW, you can simply refer to that turnout as "curved turnout" since there are not that many Brit's hanging around; my wife won't mind Wink

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Posted by railandsail on Monday, February 11, 2019 10:34 AM

Doughless

I was assuming you just threw something together and photographed it to simply illustrate a problem, because I see kinks and misalignments all over the place.  

 

You are correct Doug, this was just a mock-up. The outer connecting tracks (1 curved, one straight) were just laid on top of the other rails,..not connected at all.  I was trying to get a feel/perspective on that one thru track that contained the crossover, the short radius piece and the dbl-curve,...the one that eliminated the S curve of a double crossover.

I also utilized MED radius Peco's that are basically 30"r diverging routes.

BTW, cutting the ties on this Peco is NOT a possiblity at all, just due to configuration.

BTW, I do have many of almost all of my major mainline tracks with curve radii greater 24",...mostly 30" and 28",..including my helix with 31" & 28"

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Posted by mbinsewi on Monday, February 11, 2019 10:35 AM

richhotrain
In the first photo, the RH turnout at the lower left appears mangled at the point of the divergent track. What is that all about?

Oh yea, I see it, just north of the frog, left rail.  ?

Mike.

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Posted by railandsail on Monday, February 11, 2019 10:42 AM

It is a shame I don't have any operating trackwork at this time that I could power a few locos thru.

But just now I was pushing a 3 axle pair tender back and forth over this NEW Peco crossover and discovered a problem with it !! A couple of the plastic track-joining sections were molded in too low, creating a dip. I need to look at my other 7 crossovers. This appears to be a manufacturer defect.

The tender was severely bumping over this crossover. I couldn't find the problem at first glance,...thought it was some gard rail or something with a high spot.

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Posted by Doughless on Monday, February 11, 2019 10:57 AM

railandsail

 

 
Doughless

I was assuming you just threw something together and photographed it to simply illustrate a problem, because I see kinks and misalignments all over the place.  

 

 

 

You are correct Doug, this was just a mock-up. The outer connecting tracks (1 curved, one straight) were just laid on top of the other rails,..not connected at all.  I was trying to get a feel/perspective on that one thru track that contained the crossover, the short radius piece and the dbl-curve,...the one that eliminated the S curve of a double crossover.

I also utilized MED radius Peco's that are basically 30"r diverging routes.

BTW, cutting the ties on this Peco is NOT a possiblity at all, just due to configuration.

BTW, I do have many of almost all of my major mainline tracks with curve radii greater 24",...mostly 30" and 28",..including my helix with 31" & 28"

 

Ok.  As I first noted, I don't think you'll have a problem with what you're trying to do, but it is important to note that adjusting the angle of one joint is going to impact how other tracks align, especially when using a curved turnout.  If you think the main problem is going to be that short piece, then I suggest building the crossover everywhere else first, precisely, then see if you need a 22 or 24 inch radius curve. 

Even that straight piece that's laying over the other outside turnout looks like it needs a little S bend in it to line up the two turnouts properly.  You'll need to shorten the diverging route on one of the turnouts to bring the tangent track in line with the other.  Or extend the diverging route of the other. Things like that matter, IMO. 

My apologies about the minimum radius.  I forgot you're using broad radii and was focusing on the notion you were using relatively sharp curved turnouts which effectively reduces your minimum radius to what ever they are, assuming all cars will have the freedom of traveling over all track.

Also, which is robably obvious, you're going to have to trim the tie ends at angles so they don't bump into each other in those close angles.  It looks like some are touching which can inhibit proper alignment.

- Douglas

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Posted by rrinker on Monday, February 11, 2019 1:23 PM

 Check the wheel gauge on that tender. Every single time I had a piece of equipment that bounced like that over Atlas turnouts, it was ALWAYS that the wheels were out of gauge, not a defect in the turnout.

 I don't see any defects in the turnouts, there's a whole extra piece of track taped down on top of it, that's what looks like a broken or bent rail near the frog. 

                                        --Randy

 


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Posted by richhotrain on Monday, February 11, 2019 2:06 PM

mbinsewi
 
richhotrain
In the first photo, the RH turnout at the lower left appears mangled at the point of the divergent track. What is that all about? 

Oh yea, I see it, just north of the frog, left rail.  ?

Mike. 

Yep, it would be sheer luck to get anything to roll over that section without derailing.

Rich

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Posted by richhotrain on Monday, February 11, 2019 2:10 PM

rrinker

I don't see any defects in the turnouts, there's a whole extra piece of track taped down on top of it, that's what looks like a broken or bent rail near the frog.           

ConfusedConfusedHuh?

If that's the case, he is off to a bad start trying to determine if this thing will fit and work properly.

Rich

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Posted by rrinker on Monday, February 11, 2019 4:16 PM

 Well maybe not a whole extra piece of track, but a piece that will need to be cut to fit, since it overlaps the turnout. On the right side too. No one's sectional track geometry has precut pieces to solve this puzzle.

                                    --Randy

 

 


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Posted by richhotrain on Monday, February 11, 2019 4:56 PM

rrinker

 Well maybe not a whole extra piece of track, but a piece that will need to be cut to fit, since it overlaps the turnout. On the right side too. No one's sectional track geometry has precut pieces to solve this puzzle.

                                    --Randy 

Yep, he just has to build it and see if trains run through it or derail. He is getting the same advice on the other forum.

Rich

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Posted by Doughless on Monday, February 11, 2019 6:56 PM

I'm going to say this again.  This entire project hinges on the what angle/position the exit points of the curved turnout need to be.  That needs to be determined first.  I don't see any markings on the white template indicating that it needs to be at a specific place and position, so if OP has plenty of leeway to angle it within reason, then he has many options for what the radius of the short curve can be, as well as the long piece of flex track on the outside.   

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Posted by railandsail on Monday, February 11, 2019 8:08 PM

My exit point for the curved turnout is NOT that crtical. I have a lot of leeway. I was just trying to not stretch the ladder turnouts into the container yard too far down that side of the layout.

I was having some concerns about those 2 tracks at the upper deck level,...because I wanted to locate a modified double-cross over arrangement there.

 

So I did a little mock up using 3 med radius Pecos and 1 dbl-curve Peco. Since I had not yet sliced the 3” box beams in half, I used some other slightly wider width alum channels I had for this image. But the basic idea is there.

The 2 box beams are on the left, ...and when cut down will provide 2 channels like those shown on the right. The upright 'web' between the two channels will be shaved down where needed for the 'crossover track piece'.

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