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Turnout numbers

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Turnout numbers
Posted by Steffen1601 on Friday, July 31, 2020 9:55 AM

I read a lot about turnouts and their numbers, for example PECO # 6 right hand turnout. My question is: Does a PECO # 6 turnout have the same characteristics (radius, length, etc.) as an Atlas # 6 turnout?

 

Thank you very much!!

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Posted by davidmurray on Friday, July 31, 2020 3:00 PM

In theory they should, unfortunately they do not.  Atlas #4 are closer to #4.5.  

The tail length, and diverging track length are also different.  I only know about Code  100.  Code 83 or Code 70 may differ, from my knowledge.

 

 

David Murray from Oshawa, Ontario Canada
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Posted by cuyama on Friday, July 31, 2020 3:28 PM

Steffen1601
Does a PECO # 6 turnout have the same characteristics (radius, length, etc.) as an Atlas # 6 turnout?

Mostly not. The frog number is the same, beyond that there are significant differences in overall length, etc.

Byron

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Posted by gregc on Friday, July 31, 2020 4:10 PM

greg - Philadelphia & Reading / Reading

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Posted by doctorwayne on Friday, July 31, 2020 5:02 PM

Actually, I'd consider the variations to be a positive thing, as they might allow you to use a choice better suited to the amount of room available, or a more appropriate angle of departure for some situations.
As discussed in another current thread, different brands of track and turnouts are either compatible as-is or pretty easily made-compatible.

Wayne

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Posted by Lastspikemike on Friday, July 31, 2020 5:12 PM

The Peco number is not really a "frog" number. Peco has very useful complete printable full sized templates complete with dimensions for all their turnouts and crossings. Search their website. 

Technically, Atlas turnout numbers aren't real frog numbers either. Snap track turnouts even have curved diverging routes that are a substitute radius, handy but not prototypical.   Their current Customline are quite good except for the large double curved turnouts that all seem to have incorrectly moulded frogs and very flimsy point rails. Left hand are worse than right hand. All the left hand Atlas Customline curved turnouts I bought needed the frogs and guard rails filed down to the point where the flangeways also needed deepening,  pretty bad QC. 

Atlas did make a line of really good turnouts branded as custom turnouts that were patterned after prototypes but they discontinued those. Pity because they were really quite nice. I have one and it is notable for having a straight diverging track as do prototypes. Silver grey packaging instead of red and grey.

No model railroad turnout can actually match a prototype. 

Alyth Yard

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Posted by cuyama on Friday, July 31, 2020 5:17 PM

Lastspikemike
The Peco number is not really a "frog" number. Peco has complete printable templates for all their turnouts and crossings. Search their website.  Technically, Atlas turnout numbers aren't real frog numbers either. 

Totally, abjectly false.

PECO Code 83 frog numbers are just what they say. The Atlas "#4" is actually a #4½, but it's still a frog with a measurable number. 

PECO Code 75 and Code 100 are defined by their diverging radius, but still have a measurable frog number (about #4½).

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Posted by Lastspikemike on Friday, July 31, 2020 5:23 PM

cuyama

 

 
Lastspikemike
The Peco number is not really a "frog" number. Peco has complete printable templates for all their turnouts and crossings. Search their website.  Technically, Atlas turnout numbers aren't real frog numbers either. 

 

Totally, abjectly false.

PECO Code 83 frog numbers are just what they say. The Atlas "#4" is actually a #4½, but it's still a frog with a measurable number. 

PECO Code 75 and Code 100 are defined by their diverging radius, but still have a measurable frog number (about #4½).

 

"Abjectly". Really?

So, please feel free to show your calculations from an actual model railroad Atlas or Peco turnout. 

Interested to see how you do that for a curved diverging track but go for it. 

Alyth Yard

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Posted by cuyama on Friday, July 31, 2020 5:29 PM

Lastspikemike
Interested to see how you do that for a curved diverging track but go for it. 

The frog comes before the curved diverging track. Easy.

You can do the measurements yourself, and I encourage you to do so – since you claim that the manufacturers are lying, you have the burden of proof. I don't have time to school you on it.

... you do know how to measure a frog, right? 

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Posted by ATLANTIC CENTRAL on Friday, July 31, 2020 5:50 PM

Lastspikemike

The Peco number is not really a "frog" number. Peco has very useful complete printable full sized templates complete with dimensions for all their turnouts and crossings. Search their website. 

Technically, Atlas turnout numbers aren't real frog numbers either. Snap track turnouts even have curved diverging routes that are a substitute radius, handy but not prototypical.   Their current Customline are quite good except for the large double curved turnouts that all seem to have incorrectly moulded frogs and very flimsy point rails. Left hand are worse than right hand. All the left hand Atlas Customline curved turnouts I bought needed the frogs and guard rails filed down to the point where the flangeways also needed deepening,  pretty bad QC. 

Atlas did make a line of really good turnouts branded as custom turnouts that were patterned after prototypes but they discontinued those. Pity because they were really quite nice. I have one and it is notable for having a straight diverging track as do prototypes. Silver grey packaging instead of red and grey.

No model railroad turnout can actually match a prototype. 

 

Atlas Custom line turnouts, both code 100 and code 83, currently in their product line, and made for some 60 years now in one version or another, are actual straight numbered frogs like the prototype, and always have been. Yes, the one lableled #4 is actually a #4-1/2.

ONLY their snap switch has a curved diverging frog.

The #6 turnouts in the silver packaging were/are the same geometry as the current Custom Line, the only difference was they had an extended diverging route - which had to be cut off to make crossovers and sidings or to continue curving the diverging route - useless in my view.

I have no comments on the new Atlas curved turnouts, I have never purchased or used them, they are too sharp for my radius requirements.

The PECO 83 line is also a correct straight frog design, older PECO products are curved frogs. I have never liked or used them.

I have been using the Atlas code 83 line since its inception.

Sheldon

 

    

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Posted by rrinker on Friday, July 31, 2020 6:08 PM

 Not to mention the Atkas CUstom Line and the Peco Code 83 turnouts don;t have a curved diverging track, it comes off straight. The closure rails curve, but so do the real ones. The Atlas Snap switches and the Peco 100 and 75 have curved diverging legs, but indeed the frog piece has some angle - it certainly isn;t variable. What they did witht he diverging track beyond the frog is meaningless when it comes to figuring the frog angle. If the diverging rails are curved, if you try to measure by how far apart the straight and diverging routes are relative tot he distance, you will get a changing answer, but that's not how you calculate the frog angle. It's just convenient when the diverging rails are stright.

                                             --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 selector on Friday, July 31, 2020 6:37 PM

Lastspikemike

...

No model railroad turnout can actually match a prototype. 

 

I would be more cautious about stating absolutes, at least insofar as hobby trains are concerned.  I think I tend to think like you do, generally, but I had to learn late in life that absolutes have few places in pragmatic living, working, loving, and play.

Just as a fr'instance, the Fast Tracks turnouts are so close to how prototypical turnouts of any description work, including electrically, that Tim Warris is justifiably proud of his enterprise and engineering that supports it.  Further, because the prototype makes customized turnouts to suit an often unique geometry in many instances, and so does the Fast Tracks template offer similar customization, your absolute appears once again to be incautious.

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Posted by ATLANTIC CENTRAL on Friday, July 31, 2020 6:47 PM

selector

 

 
Lastspikemike

...

No model railroad turnout can actually match a prototype. 

 

 

 

I would be more cautious about stating absolutes, at least insofar as hobby trains are concerned.  I think I tend to think like you do, generally, but I had to learn late in life that absolutes have few places in pragmatic living, working, loving, and play.

Just as a fr'instance, the Fast Tracks turnouts are so close to how prototypical turnouts of any description work, including electrically, that Tim Warris is justifiably proud of his enterprise and engineering that supports it.  Further, because the prototype makes customized turnouts to suit an often unique geometry in many instances, and so does the Fast Tracks template offer similar customization, your absolute appears once again to be incautious.

 

Fast Tracks is a great product, but it is pricey depending on your situation.

I was taught at a young age, 15, how to scratch build turnouts and hand lay track. My first layout was all TruScale milled roadbed track, some was ReadyTrack, some was from their "kits".

My next two layouts were hand laid on Campbell ties with scratch built turnouts. 

Today I use mostly Atlas for a number of reasons, but I build any customs that need, without any expensive fixtures or jigs.

Sheldon

    

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Posted by Doughless on Friday, July 31, 2020 7:15 PM

Steffen1601

I read a lot about turnouts and their numbers, for example PECO # 6 right hand turnout. My question is: Does a PECO # 6 turnout have the same characteristics (radius, length, etc.) as an Atlas # 6 turnout?

 

Thank you very much!!

 

No, while the angle of the frogs are the same from brand to brand (with the exception of the Atlas #4), the geometry leading up to and beyond the frog can vary from brand to brand, even product to product.

Pecos are more compact than Atlas.  What I've noticed with building my current layout, is that in order to achieve this compactness, the angle with which the point rails diverge from the tangent rail is more severe on the Peco than the longer Atlas turnout.  This results in an observable jerk or shift in the loco when it travels on the point rails where as the more gentler ange of the Atlas lets the loco glide more smoothly.  This is especially noticeable in some of my longer locos that I will be using more frequently on the new more contemporary themed layout.  I assume it would tend to give fixed drivered locos like a 2-10-0 more of a jerky shift than the Atlas too.

No matter.  The Peco #8 is about as compact as an Altas #6, a tad longer, but the entire diverging rail system is more forgiving than the Atlas #6 so I'm using the Peco 8s instead of #6 turnouts.  The Atlas #8 is a really long piece of track with an exceptionally long dead frog apparatus that would probably require powering to avoid having shorter locos stall. 

- Douglas

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Posted by gregc on Friday, July 31, 2020 8:25 PM

Doughless
Steffen1601

I read a lot about turnouts and their numbers, for example PECO # 6 right hand turnout. My question is: Does a PECO # 6 turnout have the same characteristics (radius, length, etc.) as an Atlas # 6 turnout?

No, while the angle of the frogs are the same from brand to brand (with the exception of the Atlas #4), the geometry leading up to and beyond the frog can vary from brand to brand, even product to product.

radius of closure rail (blue) on left, lead length, straight section (red) and frog number

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Friday, July 31, 2020 9:43 PM

gregc

 

 
Doughless
Steffen1601

I read a lot about turnouts and their numbers, for example PECO # 6 right hand turnout. My question is: Does a PECO # 6 turnout have the same characteristics (radius, length, etc.) as an Atlas # 6 turnout?

No, while the angle of the frogs are the same from brand to brand (with the exception of the Atlas #4), the geometry leading up to and beyond the frog can vary from brand to brand, even product to product.

 

radius of closure rail (blue) on left, lead length, straight section (red) and frog number

 

Greg,

Interesting data.

In actual application many turnouts also have straight points, making the closure rail radius even smaller, and requiring longer points, and longer leads to get desirable smoothness as the equipment enters the diverging route at the points.

As you drawings show, decreasing the lead length increases the straight portion of the closure rail as it sharpens the radius, so there is a practical limit to shortening the lead length even if the closure radius is not a concern.

And, turnouts with straight points locate all of the closure rail radius between the heel of the points and the frog, so longer points provide less angle of diversion and more of an easement effect.

It is, in theroy, desirable to have some straight near the frog to help center the wheel set, but too much is of no advantage.

Your example 2nd from the top is pretty close to the Atlas #6, which is actually longer than NMRA recommended practice.

If one builds their own turnouts, they have a number of options reguarding the construction and operation of the points and possible curvature of the diverging point rail.

I have actually found I can create very large radius curved turnouts by simply cutting tie webs and bending Atlas Custom Line turnouts.

Sheldon

    

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Posted by hon30critter on Saturday, August 1, 2020 2:17 AM

selector
I would be more cautious about stating absolutes, at least insofar as hobby trains are concerned.  I think I tend to think like you do, generally, but I had to learn late in life that absolutes have few places in pragmatic living, working, loving, and play.

I agree.

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 gregc on Saturday, August 1, 2020 5:31 AM

ATLANTIC CENTRAL
In actual application many turnouts also have straight points, making the closure rail radius even smaller, and requiring longer points, and longer leads to get desirable smoothness as the equipment enters the diverging route at the points

the geometry and equations are from the Catskill Archive - Frogs and Switches resulting in the values for prototype turnouts below

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Saturday, August 1, 2020 6:49 AM

Greg, I understand, great info.

At the end of the day, fact remains that the Atlas Custom Line, designed some 6 decades ago, remains one the closest to prototype geometry turnouts on the market.

People can complain all they want about the lack of "precision" or lack of fine detailed appearence, but they work, their wiring approach is straight forward, and they are affordable.

Otherwise build your own.

Sheldon

    

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Posted by Lastspikemike on Saturday, August 1, 2020 9:05 AM

cuyama

 

 
Lastspikemike
Interested to see how you do that for a curved diverging track but go for it. 

 

The frog comes before the curved diverging track. Easy.

You can do the measurements yourself, and I encourage you to do so – since you claim that the manufacturers are lying, you have the burden of proof. I don't have time to school you on it.

... you do know how to measure a frog, right? 

 

Yes, just did so for both Atlas and Peco code 83 on my layout. Turnout numbers are not their respective frog numbers. The frogs are longer for higher numbered turnouts (duh) but you cannot say the divergent angle corresponds accurately to the specific frog number they list on the package (but not on the actual turnout). I didn't check the double curved turnouts but I recall they use curved frogs so three are no frog numbers. Peco curved turnouts are labelled #7 which clearly they are not frog-wise. Atlas doesn't give a frog number for their curved turnouts.

Mind you at 1/87 it is tricky to measure with sufficient accuracy. I did not measure the actual frog angle in degrees which could be accurately done I suppose.

This is also quite useless information for a model railroad which is possibly why Peco doesn't use frog numbers at all for their UK market. Model railroaders want to know radius substitution for the whole turnout and track separation for crossovers and yards. Atlas prints radius substitution the back of their line of  snap switches. They do not print the frog number on the back of their Custom line.

Alyth Yard

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Posted by Lastspikemike on Saturday, August 1, 2020 9:13 AM

selector

 

 
Lastspikemike

...

No model railroad turnout can actually match a prototype. 

 

 

 

I would be more cautious about stating absolutes, at least insofar as hobby trains are concerned.  I think I tend to think like you do, generally, but I had to learn late in life that absolutes have few places in pragmatic living, working, loving, and play.

Just as a fr'instance, the Fast Tracks turnouts are so close to how prototypical turnouts of any description work, including electrically, that Tim Warris is justifiably proud of his enterprise and engineering that supports it.  Further, because the prototype makes customized turnouts to suit an often unique geometry in many instances, and so does the Fast Tracks template offer similar customization, your absolute appears once again to be incautious.

 

Point taken. I was aiming at reminding all that our 1/87 world cannot be completely accurate to prototype no matter how hard you may work. Nor is that very important. 

I think the original poster wanted practical advice to which the useful answer was, in essence, don't assume the model turnout number is equivalent to the prototypical number. If it were then turnouts from different manufacturers but bearing the same frog number would be interchangeable. They are not because the frog angle of the model is not actually the frog or any other real number relating to the prototype. 

This information is relative and not absolute. This is why I referred to Peco's very handy templates on their website. 

Alyth Yard

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Posted by ATLANTIC CENTRAL on Saturday, August 1, 2020 9:34 AM

Lastspikemike

 

 
Model railroaders want to know radius substitution for the whole turnout and track separation for crossovers and yards. Atlas prints radius substitution the back of their line of  snap switches. They do not print the frog number on the back of their Custom line.
 

Maybe they do, maybe some have a better understanding of track engineering to understand that turnouts do not "fit into curves".

Is the Atlas Custom Line #6 9.32 degrees? No. It is 9.5 degrees - close enough.

Does it have a straight frog and straight points? YES, that's why they don't put a subsitution radius on the package. It's approximate subsitution radius is about 40".

Is it straight after the frog to make the best crossovers? Yes. Is it set up to make crossovers at 2" track centers without cutting? Yes.

The "#4" was purposely mislabled 60 years ago to keep things simple - it is now well known that it is really a #4.5, give or take.

You may think the detail is crude or the quality low, but they work fine and are easy to use for crossovers, yard ladders, parallel passing sidings, etc, etc.

The best track is still hand layed by someone with suitable skill and experiance.

The next best track is Atlas 83 or PECO 83 installed by someone with suitable skills.

Beginners need to learn a few basics of railroad civil engineering and they will do much better. Itis not just circles and straight lines......... 

Sheldon

    

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Posted by Doughless on Saturday, August 1, 2020 11:20 AM

North American hobbyists tend to want to know the frog#, not the substitution radius, which is why producers label the product with frog#s.

The Atlas Snap Switch, labeled such, does NOT identify a frog # or frog angle because the purpose of the switch is to fit into a curve...in the code 83 version I believe its a 22" radius curve.  The frog angle is not particularly relevant for someone who is looking for a switch to fit into a curve.  They would want to know the substitution radius. That switch is one of the few that has curved rails up to the frog, and beyond the frog:  (And I think the PECO code 100 and/or its europeon-based switch has the same geometry, and IIRC, they are not labeled by the frog number either.  They are called small radius, medium radius, and large radius).

Atlas - Code 83 Snap-Switch(R) Manual Turnout - 18" Radius, Right ...

The Peco small "radius" switch.  Seems to be not curved as much post-frog as the Atlas:

Toys & Hobbies HO Scale PECO STREAMLINE SL-91 INSULFROG Code 100 ...

The more popular switch is labled by the frog#, not the degrees nor the substituion radius.  While it can be used in a curve, that's not really what its designed for, so the labeling identifies the frog# and not the radius.  It has more normal geometry with the track straightening sooner before the frog and extending beyond.

Atlas HO Scale Code 83 Custom-Line #4 Turnout Manual Right

 

- Douglas

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Posted by SeeYou190 on Sunday, August 2, 2020 1:00 AM

Steffen1601
My question is: Does a PECO # 6 turnout have the same characteristics (radius, length, etc.) as an Atlas # 6 turnout?

I will try to answer your question directly.

No, the turnouts are different, but the frog angle is the same, or close enough.

If you are working with a track plan designed for one of them, you should be able to substitute one for the other with little-to-no problems unless a very tight situation is in the design.

I use Walthers/Shinohara #6 turnouts, and they are very close to both the Peco and Atlas #6 turnouts. Close enough for any of my concerns.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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