Long Y Turnout on a Mainline Track

[beiland]

I think I know the answer to this question, but I just want to confirm my thoughts


I'm putting a long 'Y' turnout at this point on one of the two mainlines that are entering my external helix structure. The 'Y' turnout is allowing the train to 'recirculate' around the bottom of the room, rather than going up the helix. The trains might be entering this 'Y' either from the points end OR the frog end at particular times.

Since the bottom loop of track is not a reversing one, there should be no need for a reverser? And since the helix track it connects too is the same polarity, again no need for a reverser??


The Y turnout will be a Peco that will be solenoid operated since it is a little difficult to reach, and will be utilized quite often. I have both an electrofrog one and an insulafrog one. In either case I'm thinking I will install it with track insulators on those frog exiting rails,...thus no frog shorting. And the turnout (both types) become 'power routing' turnouts in this type of installation?


Okay with these assumptions?

 

[beiland]

Incorrectly thrown 'Y'

If we are in agreement with the aforementioned posting, then how about my next proposal. When insulating those frog rails of the Y turnout I would chose to go several feet away from the ends of the turnout,...why?

This would provide a dead track zone in front of the Y turnout for any train approaching the Y from the frog end,....IF the turnout was thrown incorrectly??

 

[beiland]

from another forum,...

I see two things needing comment. You have a potential reversing scenario with the track arcing above your turntable and joining the mainline. Follow the other two legs up to the helix and this is a wye. I would treat it as an isolated reversing section and wire it according to the needs of such a section. An AR is the easy way to go. As for extending the rail gap of the turnout to provide "crash protection"; eh?, You must have some wild operators. HA!

The other thing I noticed is the use of the Y turnout to fascilitate the geometry of the track. I have them in use on my layout in a couple of spots for that very reason and they perform very well. You don't show it, but have you considered using them in your helix for the turnouts to the rest of your wye. They would prevent or ease a kink in the track work of your helix.

That layout drawing above can be confusing,..as many helix drawings are,....it makes it look like numerous turnouts inside the helix area. Actually there is only one (that branches off of the bottom 'loop track' (not the helix track) to feed the peninsula area).


Here is a sketch on how the helix area is divided up into layers,..

You can see here that the actual main helix connecting the upper and lower decks has no other turnouts on it. It is strictly a double track helix. Those 2 tracks I showed going into that tunnel are basically 2 side-by-side mainlines going up to the top deck. And all of those tracks are wired such as to have their outer circumference rails of the same polarity.


So all of helix tracks AND that inner loop of track going around the bottom deck (the one the Y is installed on) are the same polarity,...thus no reverser needed here??





My concern about running into a switch thrown against me comes from my possible inattentiveness, and what I believe to be a potential big problem I've heard mentioned with big shorting of DCC by a wayward locomotive,...fire potential, or melting, or burned out decoders??

 

[MHinLA]

If you have a wye in a track, any track, anywhere, you will run into a polarity reverse/clash/short and will need to have a way to ameliorate the situ via a manually thrown SPDT toggle wired and mounted a particular way, or you'll need a HexFrog Juicer (or equivalent) to handle it, helix, or no helix...

 

[beiland]

Lets suppose I have a plain old loop of track. Then I place a Y turnout in it, and connect that into another loop of track surrounding that inner loop. I then have 2 concentric loops of track that have only one crossover between themselves,...and thus trains can NOT 'reverse direction' on those loops while running straight ahead. In fact the train on the inner loop would not be able to return to the inner loop once it made that transition to the outer loop.

In this particular situation I do NOT think I need any type of reverser??

What if I were to put another crossover between the 2 loops that would allow the train to return to the inner loop. Again I don't think I would need a reverser??

The train would just continue to run around either inner or outer loop in the same circular direction with the track polarities always looking the same to the locomotive?

 

[santafewillie]

Lets suppose I have a plain old loop of track. Then I place a Y turnout in it, and connect that into another loop of track surrounding that inner loop. I then have 2 concentric loops of track that have only one crossover between themselves,...and thus trains can NOT 'reverse direction' on those loops while running straight ahead. In fact the train on the inner loop would not be able to return to the inner loop once it made that transition to the outer loop.

In this particular situation I do NOT think I need any type of reverser??

What if I were to put another crossover between the 2 loops that would allow the train to return to the inner loop. Again I don't think I would need a reverser??

The train would just continue to run around either inner or outer loop in the same circular direction with the track polarities always looking the same to the locomotive?

Bryan - You are correct. I believe that Mark is confusing a Y turnout with a Wye track configuration.

 

[GeeTee]

from another forum,...



That layout drawing above can be confusing,..as many helix drawings are,....it makes it look like numerous turnouts inside the helix area. Actually there is only one (that branches off of the bottom 'loop track' (not the helix track) to feed the peninsula area).


Here is a sketch on how the helix area is divided up into layers,..
View attachment 116257


You can see here that the actual main helix connecting the upper and lower decks has no other turnouts on it. It is strictly a double track helix. Those 2 tracks I showed going into that tunnel are basically 2 side-by-side mainlines going up to the top deck. And all of those tracks are wired such as to have their outer circumference rails of the same polarity.


So all of helix tracks AND that inner loop of track going around the bottom deck (the one the Y is installed on) are the same polarity,...thus no reverser needed here??





My concern about running into a switch thrown against me comes from my possible inattentiveness, and what I believe to be a potential big problem I've heard mentioned with big shorting of DCC by a wayward locomotive,...fire potential, or melting, or burned out decoders??

Helix tracks ok.

Top and Bottom Loops need reversers or reversing section, otherwise they will short out when the locomotive , or other powered car (tenders , lighted passenger cars , caboose...metal wheel set, metal trucks) crosses the insulators.

A locomotive or powered car or even a metal wheel, like a Kadee 520 or a metal truck with metal wheels and axels , can short out the insulators as the train crosses ,and if it happens at both ends of the reversing track at the same time,You have potential catastrophe for the power supply if it is not well designed or protected. Distance between the insulators has to be longer than the longest train (the loco can short out one set of insulators , while a powered car on the tail could short out the other pair) .

It doesn't really matter if its DC or DCC the shorting hazards are the same .

 

[beiland]

Top and Bottom Loops need reversers or reversing section, otherwise they will short out when the locomotive , or other powered car (tenders , lighted passenger cars , caboose...metal wheel set, metal trucks) crosses the insulators.

That's what I thought. I just need to be careful about my wiring as I am electrically challenged.