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Quality turnout terminology and good prices

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Quality turnout terminology and good prices
Posted by BNSF UP and others modeler on Thursday, May 24, 2018 8:10 PM

I have always been confused by this: I know that turnouts are labled #4, #6, #8, etc. based on the length of the turnout, but how do you know what radius the diverging curve is? Is there a chart e.g. #4 turnouts=18 inch radius diverging routes, or something like that? Also, what is a good price for wider radius, good quality, used turnouts in ho scale?

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Posted by mbinsewi on Thursday, May 24, 2018 9:33 PM

Check this out, scroll down and read.  I'm sure this is not the only source of information, but a search had this at the top of the list, see if it answers your questions.

http://www.pcrnmra.org/pcr/clinics/Kolm-TurnoutsWhatYouNeedtoKnow-PCR2008-handout.pdf

Mike.

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Posted by BNSF UP and others modeler on Thursday, May 24, 2018 10:23 PM

Yes, that was exteremely helpful. Just one question: The closure radius is the radius of the diverging route curve, right? Thanks so much for the PDF!

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Posted by wp8thsub on Thursday, May 24, 2018 10:47 PM

BNSF UP and others modeler
Just one question: The closure radius is the radius of the diverging route curve, right?

What the pdf calls the closure radius is the radius through the closure rail, between the points and the frog.  On a standard turnout, much of the diverging route is straight through and past the frog, so the quoted figure isn't necessarily a substitution radius (i.e. a smooth or constant curve that could be substituted for the whole turnout).

The approximate closure radius and substitution radius for typical HO turnouts is listed below.

#4 15"/29"

#5 26"/36"

#6 43"/56"

#8 67"/110"

The first number (closure radius) is from the pdf linked in the earlier post, while the second number (substitution radius) is from a list I found posted on another forum.  There seem to be varying opinions on the actual numbers, so these are a rough guide only.

Rob Spangler

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Posted by gregc on Friday, May 25, 2018 6:41 AM

BNSF UP and others modeler
I know that turnouts are labled #4, #6, #8, etc. based on the length of the turnout, but how do you know what radius the diverging curve is?

that's not true.  The turnout number describes the angle of the frog, not the length.   

The lead-length, the distance between the switch points and the frog can vary.   The diagram below illustrates how the lead and closure rail radius can vary while the frog number remains the same.

greg - Philadelphia & Reading / Reading

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Posted by BNSF UP and others modeler on Friday, May 25, 2018 11:27 AM

Ok, so say I was using 30 inch radius on my layout. Which turnout would I use for diverging routes off the mainline?

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Posted by selector on Friday, May 25, 2018 11:32 AM

BNSF UP and others modeler

I have always been confused by this: I know that turnouts are labled #4, #6, #8, etc. based on the length of the turnout...

 

And here-in lies your confusion; you have assumed incorrect 'information.'

The number of a turnout is an expression of the RATIO of diversion at the frog, or through it (...and beyond in the typical N. American turnout geometry where the route through the frog and beyond is essentially tangential to the curvature of the closure rails.)

Again, it's a ratio.  For every four units of movement along the 'through route', a #4 frog diverges one unit of length.  A #6 turnout diverges one unit laterally for every six (6) units of travel down the turnout through the frog.  What this amounts to is a wider divergence, or angle of divergence, for a #4 than on a #6.

It has virtually nothing to do with the length of the whole appliance, from points all the way through the frog and beyond, either route.  On the whole, the higher the frog number, the longer the entire appliance will tend to be simply because the rolling stock must travel farther to exit beyond the frog, but that's because the closure rails are longer.

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Posted by riogrande5761 on Friday, May 25, 2018 11:40 AM

BNSF UP and others modeler

Ok, so say I was using 30 inch radius on my layout. Which turnout would I use for diverging routes off the mainline?

Based on Rob's list, the #4 has a substitution radius of 29 inches.  That appears to be the closest turnout size you could slip into the 30 inch radius curve and diverge out from there.

Rio Grande.  The Action Road

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Posted by BATMAN on Friday, May 25, 2018 12:00 PM

Just one more suggestion, take a look at curved turnouts, they can buy you some more length on sidings or other situations. I have used several to overcome the problem of difficult turnout placements.

Brent

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Posted by BNSF UP and others modeler on Friday, May 25, 2018 12:29 PM

So it is physically impossible to make a perfect curve with turnouts unless you are using flextrack? That would explian all of the problems I have been having with gaps in sectional track joints when there was a turnout forming part of a loop.

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Posted by cuyama on Friday, May 25, 2018 12:50 PM

riogrande5761
Based on Rob's list, the #4 has a substitution radius of 29 inches.  That appears to be the closest turnout size you could slip into the 30 inch radius curve and diverge out from there.

Substitution radius is very misleading as to performance. Since the tightest radius through the #4 turnout is much tighter than the substitution radius, that is the limiting factor in the size and type of equipment that can operate. Probably not a great fit for the Original Poster’s desired large modern locos and intermodal equipment. Note that the Atlas “#4” Customline is actually a #4½, so it’s slightly better, but still might be a bit too tight.

Curved turnouts may help, but even curved turnouts used with flextrack will be slightly off from a true circle owing to the points and frog. The PECO Code 83 curved turnout, though broadly curved, is very compact relative to Walthers and some others.

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Posted by gregc on Friday, May 25, 2018 1:04 PM

BNSF UP and others modeler
Ok, so say I was using 30 inch radius on my layout. Which turnout would I use for diverging routes off the mainline?

you're assuming that there is a smooth curve from end of the turnout near the switch points and at the end diverging route.   That you can replace a section of a curve with the divering route of a turnout.   This may be true for Atlas snap turnouts, but not for standard turnouts.

The turnout is straight between the switch point and the end of the turnout, and straight after the frog on both diverging and non diverging routes.

greg - Philadelphia & Reading / Reading

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Posted by cuyama on Friday, May 25, 2018 1:11 PM

gregc
This may be true for Atlas snap turnouts, but not for standard turnouts.

It's not even true for SnapSwitches, as there is a short straight section (1½") in front of the curve.

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Posted by rrinker on Friday, May 25, 2018 1:18 PM

 Conveniently though, Atlas makes short filler pieces of sectional track, so if you use the extra 1/3 curve section plus add one of those short straights on the opposite side, it will work without flex track.

                             --Randy


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

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Posted by rrebell on Saturday, May 26, 2018 8:58 AM

Trouble is there are really no exact standards in HO that manufactures follow, they cab be a little loose.

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Posted by dehusman on Saturday, May 26, 2018 9:50 AM

riogrande5761
Based on Rob's list, the #4 has a substitution radius of 29 inches. That appears to be the closest turnout size you could slip into the 30 inch radius curve and diverge out from there.

That wouldn't work well at all.  If the minimum radius of the layout is 30", putting a #4 in makes the minimum radius 15", that's the ACTUAL radius in the switch.  The cars and locomotives have to transit the actual closure radius.  If you want to preserve a 30" min radius you have to go with a #6 switch, a #5 has a radius of 26" which is less than 30, the first switch that preserves a 30" minimum radius is a #6.

Dave H. Painted side goes up.

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Posted by dante on Saturday, May 26, 2018 10:10 AM

My Walthers/Shinohara #4s have a radius of 25"≠ through the frog as measured with Ribbonrail 24" and 26" gauges. That explains why my 6-axle diesels can negotiate these turnouts.

Dante

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Posted by jjdamnit on Saturday, May 26, 2018 6:16 PM

Hello all,

BNSF UP and others modeler
...but how do you know what radius the diverging curve is?

Ahhh...I believe I now understand your question.

The diverging route is not a curve expressed in radius, it is an angle which can be best described in degrees.

As has been posted before, frog numbers are a ratio. A frog #1 would put the angle of the diverging track at 45º.

On the PECO website turnouts are described by Frog #, Nominal Radius and Angle.

If you notice the Nominal Radius of the #5 turnout does not directly match any sectional track manufactured.

BNSF UP and others modeler
So it is physically impossible to make a perfect curve with turnouts unless you are using flextrack?
That would explian all of the problems I have been having with gaps in sectional track joints when there was a turnout forming part of a loop.

Even when using sectional track it is necessary to modify the track beyond just cutting custom lengths.

Check out this thread...

http://cs.trains.com/mrr/f/11/t/256138.aspx

Now, that being said...

Curved turnouts are expressed in Nominal Radius and tend to match or approximate the common radi of sectional track.

Hope this helps.

Post Script:
As far as pricing on "previously owned" turnouts...
I was at a train show and made an offer to a vendor for used turnouts. I knew the price of the same units NIB at a local hobby store on my way home.

The vendor declined my offer. I thanked him for his time.
When I left the show went by the LHS and paid less than $5.00 difference for all the turnouts. New in box with all the little bits and a 30-day gurantee.

Caveat Emptor.
HTH- -JJ

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Posted by BMMECNYC on Saturday, May 26, 2018 7:28 PM

BNSF UP and others modeler
Also, what is a good price for wider radius, good quality, used turnouts in ho scale?

Free, because generally speaking, unless the previous owner was super careful about how they were attached/removed, they will probably not be in perfect condition and may or may not work right.  Buy in person where you can visually inspect the item (train show).  Everything else is pretty much at your own risk.  

Rule 108: In case of doubt or uncertainty, the safe course must be taken.
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Posted by BNSF UP and others modeler on Saturday, May 26, 2018 10:27 PM

I have 3 curved shinohara turnouts right now, plus 2 peco curved turnouts. Will try to post pics, unless someone already knows what radii they would be. Thanks for all the helpful comments!

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Posted by BMMECNYC on Sunday, May 27, 2018 7:28 AM

BNSF UP and others modeler
I have 3 curved shinohara turnouts right now, plus 2 peco curved turnouts. Will try to post pics, unless someone already knows what radii they would be. Thanks for all the helpful comments!

Do you have the part numbers from the packaging?  That will likely be most useful.  

If you have the approximate length and code of track for the Peco ones, that would be very useful.

If you have a piece of plywood that long enough and wide enough, you can use a piece of string tied to a nail and a pencil (the length of the string from nail to pencil is the radius) to draw arcs of different radius.  Then lay the curved turnout down on the plywood.  This will get you in the ballpark.

Rule 108: In case of doubt or uncertainty, the safe course must be taken.
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Posted by BMMECNYC on Sunday, May 27, 2018 9:28 AM

mbinsewi

Check this out, scroll down and read.  I'm sure this is not the only source of information, but a search had this at the top of the list, see if it answers your questions.

http://www.pcrnmra.org/pcr/clinics/Kolm-TurnoutsWhatYouNeedtoKnow-PCR2008-handout.pdf

Mike.

 

Fasttracks and Oak Hill Model Railroad Track supply would be good to add to the list of manufacturers.

 

Rule 108: In case of doubt or uncertainty, the safe course must be taken.
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Posted by jjdamnit on Sunday, May 27, 2018 12:26 PM

Hello all,

If you can find the PECO part number then just go to their website and look up the curved turnouts you have and that will give you the frog #, Nominal Radii; Outside and inside, and length. 

The Nominal Radii will help you match the turnout to radius of the curve.

PECO does provide downloadable, printable copies of their turnouts.

These are listed under the Technical Advice Bureau > PECO Turnout And Crossing Plans. Not every turnout is provided here but it helps.

Unfortunately I am not familiar with Shinohara.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by BNSF UP and others modeler on Sunday, May 27, 2018 4:30 PM

Ok, I will try to do that and then get back in a couple of days.

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Posted by BNSF UP and others modeler on Sunday, May 27, 2018 6:20 PM

My peco turnouts say "peco- setrack reg- england" Hopefully that helps. It seems that every curved shinohara turnout on ebay looks like mine and claims to have an inside radius of 24" and an outside radius of 28". Two questions: first, how well will 24" work for long passenger cars and equipment? Second, I have some atlas #4 snap switches that I was going to get rid of. Now, after reading this, do you think I should keep them if I am planning to run longer equipment? What is the approximate raduis of their diverging routes?

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Posted by BMMECNYC on Sunday, May 27, 2018 8:47 PM

Does your Peco Turnout look similar to this:

https://www.peco-uk.com/product.asp?strParents=3309,3322&CAT_ID=3327&P_ID=17436

Im guessing yes because these are the only set-track curved turnouts.  Im pretty shure the radius is 21 outer (approx, its metric) and 19 or 17 inner (again, metric system isnt my strong point).

As for the Shinohara, recent production included frogs numbered 6.5, 7, 7.5, 8

Radius of turnouts discussed here:

http://cs.trains.com/mrr/f/11/t/196857.aspx

BNSF UP and others modeler
Two questions: first, how well will 24" work for long passenger cars and equipment?

Borderline not working.  I built a layout with 24" radius and had trouble keeping full length passenger cars on the track.  

BNSF UP and others modeler
Second, I have some atlas #4 snap switches that I was going to get rid of. Now, after reading this, do you think I should keep them if I am planning to run longer equipment?

Not sure who above gave you that impression. You can do what you want.  Those will probably not work well with your desired long equipment, which as was pointed out in your other currently running thread, you probably dont have the room for the radius you will need to run the trains you want to run in the scale you are wanting to build in.  

BNSF UP and others modeler
What is the approximate raduis of their diverging routes?

If memory serves correctly, 18" or less. 

They might be good for industrial tracks where you would be shoving a car a low speed into an industry spot.  

MR used them on their Virginian project railroad.

 

Rule 108: In case of doubt or uncertainty, the safe course must be taken.
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Posted by riogrande5761 on Sunday, May 27, 2018 8:47 PM

cuyama

 Substitution radius is very misleading as to performance. Since the tightest radius through the #4 turnout is much tighter than the substitution radius, that is the limiting factor in the size and type of equipment that can operate. Probably not a great fit for the Original Poster’s desired large modern locos and intermodal equipment. Note that the Atlas “#4” Customline is actually a #4½, so it’s slightly better, but still might be a bit too tight.

I agree.  Personally I wouldn't use anything less than #6 turnouts as a rule.

Rio Grande.  The Action Road

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Posted by BMMECNYC on Sunday, May 27, 2018 8:51 PM

To answer your original question, or what I think your actual question is:

You will want at a minimum a #6 turnout when running intermodal equipment or full length passenger cars.  

Rule 108: In case of doubt or uncertainty, the safe course must be taken.
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Posted by riogrande5761 on Sunday, May 27, 2018 8:54 PM

dehusman
  If you want to preserve a 30" min radius you have to go with a #6 switch, a #5 has a radius of 26" which is less than 30, the first switch that preserves a 30" minimum radius is a #6.

Yep.  I've designed and built 3 layouts so far and that is the reason I use #6 as a minimum turnout type.Wink

Rio Grande.  The Action Road

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Posted by BMMECNYC on Sunday, May 27, 2018 8:57 PM

riogrande5761

 

 
dehusman
  If you want to preserve a 30" min radius you have to go with a #6 switch, a #5 has a radius of 26" which is less than 30, the first switch that preserves a 30" minimum radius is a #6.

 

Yep.  I've designed and built 3 layouts so far and that is the reason I use #6 as a minimum turnout type.Wink

 

I know a guy who has an HOn3 layout and he used all #6's with a minimum radius of 24"

Rule 108: In case of doubt or uncertainty, the safe course must be taken.

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