switches/turnouts.

Fred2179G

Registered
20 Apr 2017
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133
USA
Why do they call them frogs?
(A dual gauge turnout on the D&RGW had 2 frogs and a toad.) I think they call them that so you can introduce 'thread drift' to confuse Igor.
 

Greg Elmassian

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8 Mar 2014
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So a #10 switch from Switchcrafters is 247" long, about 1.2 meter.... and the diverging angle is 5.7 degrees....


Your #15 switch should have about a 3 degree diverging angle... I don't think you could do a crossover in just twice the distance of the switch, with such a small diverging angle. I think you need more distance to get the track to track separation. Where else could you use a #15 and not eat up a lot of space to another track other than a crossover to a parallel track?

One thing I know you have not figured is how difficult it is to make a frog to model railroad standards (G1MRA for example) without having the wheels drop into the throat, since it is so long. One (awful) way is to use wheels of huge tread width. The other way is to make it a flange bearing frog, which I recommend in your case.

Please keep us abreast of your efforts to incorporate such a nice switch into your layout and the issues you encounter to make it work well.

Greg
 

Gavin Sowry

Garden Railroader and Raconteur
27 Oct 2009
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Gavin, please explain how a 1:9 frog in the UK is different from a #9 frog in the USA, here the number is determined by the ratio of run to spread, and a #9 frog is 1:9 here in the US.

Igor, your post says you can do 80 kmh turnouts, from your post this says 1:15... you can do 1:15 in your garden? Or just a few turnouts. I've seen a German made switch in #10 and it is VERY long. What is your calculated length of the turnout in 1:15?

Greg
Greg, there are different ways of measuring. I'll try to explain, put your triangle hat on.....
How we do it, is called the tangent method, where you simply measure your, say, 1 foot spread, at a right angle, then measure back along the rail to the point of frog, A true right angle triangle. Applying the 'solutions' for triangles, 1 divided by 9 gives you a number that is the tan (tangent) of the angle of the frog. Simple, that's why we use it.
Now, the AREA (Americn Railway Engineering Assn.) method involves measuring with two right angles, thus ending up with two triangles.... and in short the tan of two times the half angle, is not the same as the tan of one angle, because tan is not a linear scale. Worth a read up if you are interested, but NEVER trust Wiki.
 

Gavin Sowry

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27 Oct 2009
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Why do they call them frogs?
Next time after you've squashed a frog (the real reddit variety, not Kermit, or a turnout one), send up your drone, and take a piccy of it. If you have a nice symmetrical shape, with four legs pointing in the right directions, then score 10 out of ten. If it ain't so pretty, try again.
 

Gavin Sowry

Garden Railroader and Raconteur
27 Oct 2009
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(A dual gauge turnout on the D&RGW had 2 frogs and a toad.) I think they call them that so you can introduce 'thread drift' to confuse Igor.
The toad you mention is, in some circles, called a crotch frog. Such is the anatomy of a turnout.
 

Greg Elmassian

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Gavin you said:
"How we do it, is called the tangent method, where you simply measure your, say, 1 foot spread, at a right angle, then measure back along the rail to the point of frog, A true right angle triangle. Applying the 'solutions' for triangles, 1 divided by 9 gives you a number that is the tan (tangent) of the angle of the frog. Simple, that's why we use it."

That is the way we do it too... so your 1:9 frog is the same as our #9 frog... this is what I said, and you disagreed in post #12:
"Now, Greg mentioned 'Frog number'. This is usually just an American trait, as there are different recognised ways of measuring the frog angle. A #9 frog is NOT the same angle as a 1 in 9 frog in all cases."

But from your recent post you seem to agree that your 1:9 frog is the same as our #9 frog. That's all I was saying. If you want to talk about frog angle, I find it causes confusion, some people think of the angle from straight through, some people think half of the total angle. (Wye switch causes confusion). Also the frog angle may not be the same as the angle of divergence of the switch overall

Also speaking of angles or degrees in switches leads to the main confusion that all switches are curved past the point of frog, and that all switches have an "equivalent" constant curvature to a simple piece of curved track, which is where Igor was going, and this is even more complicated, since there is no "standard" for the amount of rail before the points or the length of the rails after the point of frog.

Greg
 
Last edited:

justme igor

Registered
17 Apr 2020
260
19
Netherlands Westwoud
our #15 switch should have about a 3 degree diverging angle... I don't think you could do a crossover in just twice the distance of the switch, with such a small diverging angle. I think you need more distance to get the track to track separation. Where else could you use a #15 and not eat up a lot of space to another track other than a crossover to a parallel track?
I intend to use for the garden 150 mm centre to centre.

One thing I know you have not figured is how difficult it is to make a frog to model railroad standards (G1MRA for example) without having the wheels drop into the throat, since it is so long. One (awful) way is to use wheels of huge tread width. The other way is to make it a flange bearing frog, which I recommend in your case.
I made some things according with and to G1MRA and now i want to be prototypical.
In most of my replays in most of my topics I stated several times that my frogs will be flange baring, for two simple reasons:
1: freight
2: length

Your answers are apparently serious so i give you a serious replay, no negativity giving!
I made already one of 1 meter 80 for test, trail and error.
I must learn a lot according to the university's lessens that they give me...

Greg, there are different ways of measuring. I'll try to explain, put your triangle hat on.....
How we do it, is called the tangent method, where you simply measure your, say, 1 foot spread, at a right angle, then measure back along the rail to the point of frog, A true right angle triangle. Applying the 'solutions' for triangles, 1 divided by 9 gives you a number that is the tan (tangent) of the angle of the frog. Simple, that's why we use it.
Now, the AREA (Americn Railway Engineering Assn.) method involves measuring with two right angles, thus ending up with two triangles.... and in short the tan of two times the half angle, is not the same as the tan of one angle, because tan is not a linear scale. Worth a read up if you are interested, but NEVER trust Wiki.
Big thumb up, tell more if you want.
We are not up to that chapter...2 weeks from now.

Oke all of you...
About the frogs, you made me laugh out loud behind my laptop in the garden...some comments.....
But for real? now i am in doubt......
Toad?????HEU??

Please keep us abreast of your efforts to incorporate such a nice switch into your layout and the issues you encounter to make it work well.
Of course i will, incl a successful AA20 on them.

Thanks for all the replays and answers to come, it is also really helpfully for my study!
With best regards Igor
 

justme igor

Registered
17 Apr 2020
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Greg Elmassian

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The #15 frog will be a sight to behold, if I can make a suggestion, the frog will be the toughest part and hardest to make and hardest to modify. Keep to the G1MRA "standard" standards on flangeway widths. Also your point of frog will be very "sharp" and subject to wear, so perhaps your design could make this piece easily replaceable.

Looking forwards to it,

Greg
 

Paul M

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25 Oct 2016
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Royston
Next time after you've squashed a frog (the real reddit variety, not Kermit, or a turnout one), send up your drone, and take a piccy of it. If you have a nice symmetrical shape, with four legs pointing in the right directions, then score 10 out of ten. If it ain't so pretty, try again.
Yeah I'll give it a go. I'm surprised this didn't spawn more jokes
 

trammayo

Interested in vintage commercial vehicle, trams, t
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Yeah I'll give it a go. I'm surprised this didn't spawn more jokes
H'mm - I bet Galvani would have given it a leg-up in his day!
 

Gavin Sowry

Garden Railroader and Raconteur
27 Oct 2009
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Yeah I'll give it a go. I'm surprised this didn't spawn more jokes
A quote from Q. "I never joke about my work (007)".
 

Gavin Sowry

Garden Railroader and Raconteur
27 Oct 2009
6,961
2,236
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Hutt Valley, NZ

trammayo

Interested in vintage commercial vehicle, trams, t
24 Oct 2009
21,273
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Co. Mayo