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Question: Wye switches thrown/closed

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Question: Wye switches thrown/closed
Posted by DigitalGriffin on Thursday, April 11, 2024 3:56 AM

With normal switches, the straight route is closed.  Thrown is the diverging route.

 

With Wye turnouts which direction is closed?

 

Don - Specializing in layout DC->DCC conversions

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Posted by ATLANTIC CENTRAL on Thursday, April 11, 2024 6:47 AM

Whichever route the railroad decides.

Actually, same is true of any turnout. Railroads don't care about the geometry, it is route priority that decides.

Same with curved turnouts.

Now, we know that when railroads need the curved route thru a turnout to be high speed, they have lots of technology for that, closing frogs, very large turnout size, special guardrails, etc.

Do they prefer the primary route to be straight? Yes, but just like our model layouts, that is not always practical or possible. 

Sheldon 

    

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Posted by richhotrain on Thursday, April 11, 2024 7:02 AM

ATLANTIC CENTRAL

Whichever route the railroad decides.

Actually, same is true of any turnout. Railroads don't care about the geometry, it is route priority that decides.

Same with curved turnouts.

Now, we know that when railroads need the curved route thru a turnout to be high speed, they have lots of technolgy for that, closing frogs, very large turnout size, special guardrails, etc.

Do they prefer the primary route to be straight? Yes, but just like our model layouts, that is not always practical or possible. 

 

Sheldon 

 

Good answer. +1

Rich

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Posted by gregc on Thursday, April 11, 2024 7:22 AM

ATLANTIC CENTRAL
Whichever route the railroad decides.

CTC panels identify the turnout positions as N and R, presumably normal and reversed.

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Posted by ATLANTIC CENTRAL on Thursday, April 11, 2024 8:37 AM

gregc

 

 
ATLANTIC CENTRAL
Whichever route the railroad decides.

 

CTC panels identify the turnout positions as N and R, presumably normal and reversed.

 

Yes, "Normal" is the primary route and the position the turnout should be returned to after taking the "Reversed" route.

But Normal and Reversed has nothing to do with the geometry, the "normal" position can be the "curved" route.

Sheldon

    

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Posted by dehusman on Thursday, April 11, 2024 12:11 PM

DigitalGriffin
With normal switches, the straight route is closed.  Thrown is the diverging route.   With Wye turnouts which direction is closed?

None of the above.

Railroads don't use those terms.

Switches are normal or reverse.  Typically normal is the straight route and reverse is the diverging route.

With an equilateral switch (wye) they will designate one route or the other as normal.  Depends on where it is used.  For example if it's a high speed switch at the end of two main tracks, typically "normal" will be for whatever hand running is on the two main tracks.  If it's right hand running then they may have "normal" as single track to the right main track.  Otherwise they will have normal be the most used or through route.  If the main track is on the ledt route, then left is normal.  If the main track is on the right route, then right is normal.

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Posted by gmpullman on Thursday, April 11, 2024 2:11 PM

Some railroads physically designated the points in the field:

 Points by Edmund, on Flickr

I have some 3" tall N and R cast iron letters that came off an abandoned New York Central turnout.

I still despise the nomenclature that Digitrax likes to use 'thrown or closed' for customizing their products. To me it is quite arbritary. On my layout I use normal/reverse and have never had any problems with orientation.

Good Luck, Ed

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Posted by DigitalGriffin on Thursday, April 11, 2024 3:40 PM

This will make flag type switches, and dawrf signals confusing.   Red is Reverse/
Thrown, while Green is normal/Closed.

I guess you cant use color type semaphors for Wyes

Don - Specializing in layout DC->DCC conversions

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Posted by ATLANTIC CENTRAL on Thursday, April 11, 2024 4:03 PM

DigitalGriffin

This will make flag type switches, and dawrf signals confusing.   Red is Reverse/
Thrown, while Green is normal/Closed.

I guess you cant use color type semaphors for Wyes

 

Not sure I understand

Sheldon

    

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Posted by DigitalGriffin on Thursday, April 11, 2024 4:27 PM

ATLANTIC CENTRAL

DigitalGriffin

This will make flag type switches, and dawrf signals confusing.   Red is Reverse/
Thrown, while Green is normal/Closed.

I guess you cant use color type semaphors for Wyes

 

 

 

Not sure I understand

Sheldon

 



Let's say an Engineer is on the track and he's approaching a Wye switch.  He's gotta look at some signal apsect to determine if the switch is right or left.

 

 

Don - Specializing in layout DC->DCC conversions

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Posted by ATLANTIC CENTRAL on Thursday, April 11, 2024 6:08 PM

DigitalGriffin

 

 
ATLANTIC CENTRAL

DigitalGriffin

This will make flag type switches, and dawrf signals confusing.   Red is Reverse/
Thrown, while Green is normal/Closed.

I guess you cant use color type semaphors for Wyes

 

 

 

Not sure I understand

Sheldon

 

 

 



 

Let's say an Engineer is on the track and he's approaching a Wye switch.  He's gotta look at some signal apsect to determine if the switch is right or left.

 

 

 

OK, but real railroading does not work that way. If there is a dwarf signal as the Engineer approaches a facing point turnout, the engineer already knows which route is "Normal", the signal simply confirms the position, it does not define the position.

I take from your question and comment that you want an operator who does not know the railroad/layout to know from a signal (switchstand) which route is indicated?

If the turnout is too far away for visual observation, then I don't have an answer for you. And if the operator does not know the layout, how does he know where he is headed anyway?

My "view" of model railroading includes control panels with track diagrams which help with this sort of thing. On my layout, assuming this is signaled mainline trackage, a nearby tower panel will have a track diagram and a lighted pushbutton will indicate which "route" on the "map" is selected. And signals will indicate other information - speed, detection of other trains, permission from dispatch.

Signals are repeated on "cab signal" panels when the actual signal is hard to view.

Sheldon

    

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Posted by OldEngineman on Thursday, April 11, 2024 9:30 PM

If the wye is on a main track governed by interlocking signals and switches, I believe that generally the switches will remain in the position last used until the operator or dispatcher sets up for a specific movement. Then the switches will be thrown and signals displayed.

If the wye is on a non-main track (as many are), part of a yard, then there may be no "normal position of switches", or, there may be a timetable special instruction specifying which route the switches should be restored to after use.

I can remember a couple of wyes (from the old days, now gone) at Putnam Junction (Brewster NY) and in Croton-Harmon yard that had a spring switch on "the tail". If you were turning an engine, you generally entered from one leg, backed over the spring switch, and then pulled ahead on the other leg.

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Posted by gregc on Friday, April 12, 2024 6:38 AM

dehusman
Switches are normal or reverse.  Typically normal is the straight route and reverse is the diverging route.

i've wondered why the track board below (for Sand Patch, PA) are not drawn straight, why they have the diagnonal "kinks".  For example, the 3rd switch from the left, the one after the crossover for what i believe is a pocket for a pusher coming from the right to back into to return to the right.

 

it seems to me that drawn that way makes clear that the diverging (Reverse) route is into the pocket

however, it's not clear how the lower right switch is aligned.  Does it mean that the Reverse route is to the upper hoirzontal track because the points are aligned with a diagonal line, that the Normal route is always in-line with the points

also, are tracks for a crossover alway spaced closely together?  why couldn't the lower track on the left have been aligned with the lower track below the loco pocket and the crossover have been made longer?

is the track board trying to precisely depict the actual geometry around the turnouts

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Friday, April 12, 2024 9:49 AM

Greg, my understanding is that some effort is made to make the primary route thru the turnout appear as the straight route on the CTC panel. But obviously the CTC diagram is "straight line" representation of the whole section in question.

I think there is/was an effort to keep parallel tracks the same distance apart on the diagram.

In drafting we are taught all sorts of "rules", then we are told that if breaking a rule makes the drawing easier to understand, break the rule.

I think CTC panel track plans are the same way, no hard rules, just guidlines of design that have worked and are clear to the users.

Even though I don't use the traditional CTC controls, I set my tower and CTC panels up like a prototype panel. But I put my lighted pushbuttons and my indicator lights right in the track diagram.

So the turnout controls actually create a lighted "map" of the route that is set.

Sheldon

    

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Posted by cv_acr on Friday, April 12, 2024 10:13 AM

OldEngineman
If the wye is on a non-main track (as many are), part of a yard, then there may be no "normal position of switches"

 

Incorrect. There is always a "normal" position that will be indicated by the position of the switch stand.

However on yard and other non-main tracks it may be permissable by the rules to leave a switch in reverse position.

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Posted by cv_acr on Friday, April 12, 2024 10:18 AM

gregc
is the track board trying to precisely depict the actual geometry around the turnouts

Almost certainly it is trying to show the correct diverging positions of turnouts. However nothing will be drawn "to scale". Just to show the straight and diverging routes.

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Posted by dehusman on Friday, April 12, 2024 11:31 AM

gregc
is the track board trying to precisely depict the actual geometry around the turnouts

Short answer, no.  The CTC and interlocking diagrams are schematics.  They are drawn for operational clarity, but are not to scale and may not reflect the exact physical relationship in either alignment or proximity.

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Posted by gregc on Friday, April 12, 2024 12:36 PM

dehusman
may not reflect the exact physical relationship in either alignment or proximity.

how does the operator know which switch route is "Reverse"?

what does "proximity" mean?   that the switches on the diagram are not in the same order left-to-right order as the USS machine?

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Friday, April 12, 2024 3:30 PM

gregc

 

 
dehusman
may not reflect the exact physical relationship in either alignment or proximity.

 

how does the operator know which switch route is "Reverse"?

what does "proximity" mean?   that the switches on the diagram are not in the same order left-to-right order as the USS machine?

 

No, it means the distances between them are compressed and may not be proportional to real life.

It also means a turnout shown as a conventional "left hand" turnout with the straight route being "normal", may in fact be a curved turnout with the route to the right, or outer route, being "normal".

Sheldon

    

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Posted by dehusman on Friday, April 12, 2024 7:04 PM

gregc
how does the operator know which switch route is "Reverse"?

Typically the normal route is drawn as the straight route and the reverse route is drawn as the diverging route.

gregc
what does "proximity" mean? 

Proximity:  the state of being near someone or something in distance or time

The switches may be displayed in close sequence on the board but be miles apart in real life.

 

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Posted by gregc on Saturday, April 13, 2024 4:11 AM

perhaps it's not obvious enough that it needs to be pointed out, but did you notice the tunnel depicted in the diagram, on the other side of which was Manilla tower ?  thanks for your clarifications

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Posted by Jovet on Friday, April 19, 2024 8:45 AM

In the interest of being pedantic...

A wye is a meeting of three tracks, where approach on any track can be routed to any other track.  A "wye" is not a switch or turnout. 

Some wyes have one or more equilateral turnouts, but this is not a requirement of a wye's track design. An equilateral turnout is a turnout without a "straight" or tangent path—both routes "diverge" and by the same angle. 

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Posted by MidlandMike on Friday, April 19, 2024 8:30 PM

Jovet
Some wyes have one or more equilateral turnouts,...

If a switch has two diverging routes, it is not necessary that both routes take off at equal angles, so maybe it would be better to call it a double diverging switch.

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Posted by ATLANTIC CENTRAL on Friday, April 19, 2024 10:47 PM

Jovet

In the interest of being pedantic...

A wye is a meeting of three tracks, where approach on any track can be routed to any other track.  A "wye" is not a switch or turnout. 

Some wyes have one or more equilateral turnouts, but this is not a requirement of a wye's track design. An equilateral turnout is a turnout without a "straight" or tangent path—both routes "diverge" and by the same angle. 

 

Well, maybe so, or maybe not. There is a very long well established use of the term "wye turnout" or simply a "wye" to describe an equalateral turnout in the model railroading hobby. EVERY track manufacturer, current and past uses the term. NO track manufacturer uses the term "equalateral turnout".

Countless authors, manufacturers, and modelers understand and use the term to describe either, the single equalateral turnout, or the three track junction.

Merriam-Webster #1 definition :a Y shaped part or object

I think the single piece of track meets that definition rather perfectly.

Our friends across the pond at Oxford:

  1. 1.
    NORTH AMERICAN
    a triangle of railroad track used for turning locomotives or trains.

A rather short sited and incomplete description of North American useage.

I don't question how they use words in our shared language, maybe they need to check up on how the word has been used here for the last 70-100 years.

And yes, you do win the pedantic prize for the week.

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Posted by richhotrain on Friday, April 19, 2024 11:26 PM

They call it a wye because it is shaped like a Y.

Why? Why not? Smile, Wink & Grin 

Rich

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Posted by zugmann on Saturday, April 20, 2024 9:34 AM

ATLANTIC CENTRAL
I don't question how they use words in our shared language, maybe they need to check up on how the word has been used here for the last 70-100 years.

Maybe it's regional, but the only time I ever heard of "Wye" was when referring to an actual wye arrangements of tracks that allowed turning of equipment (or sometimes referring to tracks that once formed a wye, but now part of that wye is missing, but the rest of the remaining tracks are still called a wye - even though you can't wye anything on it).

 And yes, we do use wye as a verb.  "go and wye that power". 

An equliateral switch was always called that, and never a wye switch (as far as I can remember). 

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

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Posted by Overmod on Saturday, April 20, 2024 9:56 AM

It was pretty obvious to me from the beginning that he's discussing the 'wye switch' that is at the apex of a conventional 'wye' -- the one that is an equilateral switch between the two legs.  This is what Wikipedia suggests be called a 'turning wye' to distinguish it for would-be pedants.

And he's asking what the 'normal' position of a switch with no natural normal or reverse is.  In CTC that problem could be addressed via current-of-traffic concerns.  Here it would have to involve a railroad rules convention, something like "looking at the apex from the main, 'normal' is lined for the right approach curve, and 'reverse' for the left."

For a spring switch the issue is moot, because the locomotive or train can approach from either direction, and the switch would then have to be lined against spring pressure to exit the opposite way but then be simply released and locked.

I wonder what the terminology mavens would use to discuss the switches at the apices of a 'star' (which is like a folded wye with less required curvature for a tight fit).
From the Wikipedia introduction to wyes and their terminology (which happened to be easy to locate and paste):

 The "reversing star" (red) compared to the ordinary wye (blue)

Convoluted wyeturning star or reversing star (ItalianStella di inversione) is a special wye layout used in places where the space is tight. It has a pentagram-like form and consists of five turnouts (versus three for a wye) and three,[6] four[5] or five diamond crossings. Because of this, a reversing star is more expensive to build and service.

And that OED definition accords perfectly with my North American interpretation of what a wye normally is, and what it is normally used for.  (I do question what someone who can't spell 'sighted' correctly is doing criticizing English usage, though... Wink)

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Posted by zugmann on Saturday, April 20, 2024 10:09 AM

Overmod
And he's asking what the 'normal' position of a switch with no natural normal or reverse is.

If there's a target, then which ever side would make the target green or white?  (or whatever color scheme is in use.  Even yellow vs. purple?  Don't laugh - it's a thing). 

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

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Posted by Overmod on Saturday, April 20, 2024 10:19 AM

zugmann
 
Overmod
And he's asking what the 'normal' position of a switch with no natural normal or reverse is.

If there's a target, then which ever side would make the target green or white?  (or whatever color scheme is in use.  Even yellow vs. purple?  Don't laugh - it's a thing).

I'm actually thinking that if you have the 'red' and 'green' targets at an angle to each other, instead of at right angles, they could clearly and unambiguously indicate 'go' for a train moving on the leg the switch is lined for, and 'no go' for one on the opposite leg, which seems to me to be precisely what is wanted.

How you 'remote' this to a model railroader's console that only shows green and red for how the points are positioned ... or on a CTC board with similar control display 'modality' ... is a more difficult issue.

OK, I'll bite... what are yellow vs. purple used for?

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Posted by zugmann on Saturday, April 20, 2024 10:27 AM

Overmod
OK, I'll bite... what are yellow vs. purple used for?

Normal vs. diverging off a siding.  I believe yellow was normal?  Or was it for the derail right next to it?  It's been awhile.  One of the 2.  We don't target shoot - always look at your points. 

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any

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