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!!
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.
Mostly not. The frog number is the same, beyond that there are significant differences in overall length, etc.
Byron
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
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.
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.
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?
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
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
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
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.
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 adv
I agree.
Dave
the geometry and equations are from the Catskill Archive - Frogs and Switches resulting in the values for prototype turnouts below
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
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.