Need Help Installing a Wye Section of Track.

[Dusten Barefoot]

I am installing a wye section of track for my engine to turn around on, but there is one problem. There is an electrical problem with the tracks; I do know what it is, but can't seem to work my way around it. Rail one eventually turn into rail 2 over one of the switches and causes the wires to short.

I know I have discribed this vaugly but can't seem to but the words in a proper order lol. If you know what I am talking about, and can help me, I will appreciate it.

Rock On!
Dusten

[Hamish K]

Are you running DC or DCC? What type of track and turnouts are you using? How are you connecting it and are how you using the isolating section/s?. A wye is like a return loop and will short without special wiring arrangements. There are several methods,  so without knowing the method you are using it is difficult to advise.

The NMRA guide might heip http://www.nmra.org/beginner/wiring.html
or there are many books on railroad wiring that cover this in detail.

Hamish

[railtwister]

I am installing a wye section of track for my engine to turn around on, but there is one problem. There is an electrical problem with the tracks; I do know what it is, but can't seem to work my way around it. Rail one eventually turn into rail 2 over one of the switches and causes the wires to short.

I know I have described this vaguely, but can't seem to but the words in a proper order lol. If you know what I am talking about, and can help me, I will appreciate it.

Rock On!
Dusten

Dusten,
This is the same problem a reverse loop has. The solution is to electrically isolate one leg of your wye. Hopefully, one of the wye's legs will go to a dead ended stub siding, as this is usually the easiest leg to isolate, by putting insulated railjoiners on the four rails connected to the frog end of that leg's turnout. This will make the section beyond the insulators totally dead. Then, if you are using straight DC, just wire a separate reversing toggle switch to provide power to this section. Then to operate it, you will have to manually match the polarity of the entry & exit rails using the reversing toggle, as the train enters and leaves that leg. If you are using DCC, then this can be done with an auto-reversing module instead of the toggle switch, and the DCC system will switch the polarity manually in a matter of milliseconds when  a train bridges the insulators. Just be sure to wire the layout in such a way that you can reverse the polarity of the main line or the leg of the way independently. This usually requires that you also have a reversing toggle for the main, and that you not ever use the reverse switch that may be built into your power pack. Atlas makes a special controller for doing this or a reverse loop, and it should also be explained in any of the how to books on layout wiring.

Good luck,
Bill

[Joe Satnik]

Dear Dusten,

With track powered 2 rail operation (any control method) you would need to isolate your Wye turnout and tail track from the main with 2 gapped pairs:

M = main track (wiring), L = left turnout, R = right turnout, G = gap pair (both rails), Y = Wye turnout, T= tail track (wiring)

L, R connected to main track wiring, Y connected to tail track wiring.

Gapping methods vary. 

Non-roadbed track you would just replace metal rail conectors with insulated connectors.

With roadbed style track, some just cut through the rails in the middle of a section with a fine tooth hack saw or hobby saw, fill the gap with plastic and then epoxy around it, then trim the excess with an exacto knife blade.     


M
M
L
LL
M  M
M    G
M       Y
M          YTTTTT
M       Y
M    G
M  M
RR
R
M
M

Wiring depends on type of control system. 

Hope this helps.

Sincerely

Joe Satnik

[Dusten Barefoot]

Thank you all for your help.

But now since I can conjur up the right sentences, i hope I can make things more clear .

I have done most of what ya'll said, but the wye section of track is connected to another loop, this helps turn the trains around with out switch backs, and sends the train to the other loop on the other table. I don't have the money for DCC at the moment, so I run DC.

I appreciate all of your help.
Rock On!
Dusten

[Hamish K]

Dusten

I couple of things to check.

Is the isolated section (gaps across both rails at each end, separate power feed though a double pole double throw reversing switch) in the right place?

If I have understood your layout correctly the isolating section shoud be as follows

('m' is any track recieving power from the main feed)
('lt' and 'rt' left and are right turmouts respectively, yt is a wye turnout)
('g' is a gapped rail)
('i' is part of the isolating section)


m
m
lt
mg
m  i
m   i
m    i
m      g
m        yt m
m      m     m
m     m        m
m   m           m
m m              m
mm              m     
rt                m       
m              m
m           m
m        m   
m m
     


The method shown by Joe above won't work where the tail of the wye joins up with other track to form a loop.

Are your trains longer than the isolating section? If they are that can cause shorting across the gap.

I hope this helps rather than confuses
Hamish

[Dusten Barefoot]

Thanks Hamish; you hit the nail on the head.

Thanks to all, for your help.
Rock On!
Dusten

[Joe Satnik]

Where's Jim Banner when you need him?

I'm not sure if there's a name or prototype for what Hammish drew, but it reminds me of an upside down ice cream cone, drawn by Salvidor Dali. 

A normal (single turnout) turn around loop is apparently called a balloon track, as seen at the WP RR museum in Portola, CA:

http://maps.yahoo.com/#mvt=s&lat=39.802241&lon=-120.475415&zoom=18&q1=Ponderosa%20Cir,%20Portola,%20CA

A balloon with a wye built in the middle of it (3 turnouts total) -<o forms a loop with 2 escape routes to a single track.  I'm not sure what else to call it.   

NM,

Nice Drawing.  However......

The purpose of your cross wired DPDT switches is to swap polarity.  Correct?

You have 2 wire pairs (each red/black) feeding each of the three isolated sections of track.

Suppose the feeder pairs connected to an isolated section match each others polarity. 

What happens when you flip a (single) DPDT switch?

Answer:  Dead short.  Tripped circuit breakers.

Fix:  Only one distinct feed per isolated track section.   

Bus that feed out to the end of that (long) isolated track section (being careful to match polarity) if needed to reduce voltage drops.

Hope this helps.

Sincerely,

Joe Satnik

[NarrowMinded]

I thought I'd make it simpler knowing the track layout, I would use the ALT Gap shown which would give you plenty of track to move your constist onto before flipping the switch to change polarity. But thinking about it now if main power went to the "Circle" and the Polarity Switch was on the end of line section, then as soon as your last car crossed the "ALT" gap you could flip the polarity switch and your loco could merge back onto the track it came from with out stopping. once again feel free to comment.


Larger image http://i792.photobucket.com/albums/yy202/NarrowmindedRR/Untitled1.jpg

Joe, I'm not sure where dead shorts would occure on my other drawing (Removed) with each section being isolated. but I will study it like a puzzle til I see it.

[Joe Satnik]

Dear NM,

Oh, man, super drawings.  What program are you using?

There's beauty in symmetry. 

I think the gap pairs should be near the bottom of the ice cream cone:

Pull "C" back next to "A" and eliminate "B".

Now that we have the gaps in place, we need to focus on "control systems" and "reversing mechanisms".

If you were using DCC, replacing the DPDT switch in NM's drawing with a "DCC reversing module" would work perfectly.

For DC, I think you want to be able to change the polarity "on the fly".  To do that, you would want to be able to change the polarity of the track you are not on, without disturbing the polarity of the track you are on.

For this you would need a second cross-wired DPDT switch between the "single main line" and the power pack. 

The loop DPDT would be labeled "clockwise/counterclockwise" (or CW/CCW). 

The main line DPDT would be labeled "eastbound/westbound" (or EB/WB).

I think Jim Banner had a post once that showed how to wire lamps or LEDs across the gaps to show when the polarities of the two tracks matched, so it would be safe to proceed across the gap (DC control only).

Hope this helps.

Sincerely,

Joe Satnik     

   

[NarrowMinded]

Thanks Joe,
I just use the "paint" program that comes with windows and free hand the drawings. I agree with you on where the gaps should be, and I would move the reversing toggle leads there as well.

NM.

[renniks]

If Justen is prepared to stop the train on the loop, the following will work.  You can use a DPDT SLIDE switch, Drill a hole in the 'knob' and connect to turnout 'A' with an 'omega' wire. Operating the switch will then set the turnout in appropriate direction.Note that loop turnout B or C must also be set to the Y.
Note also that direction of travel round the loop depends which leg of the Y is used to enter loop. If normal direction of trains on the loop is clockwise then turnout A is normally set to the side (curved)leg or set to straight leg if normal circulation is ccw. Run the train onto the loop and stop it. Change switch and turnouts. Set Controller for opposite direction and exit loop. After train is clear of turnout A restore turnouts and switch to 'normal'. Switch can be marked 'IN' and 'OUT' as appropriate.



Eric UK

[NarrowMinded]

Eric,
In order for this to work you must be able to switch the polarity of the isolated part of the track from the main track. in your drawing it appears you can only turn the power to the loop on or off. however if you switch the wires around on one end of the switch your configuration would work. my only problem with your design then  would be more wires to run to accomplish what could be done with less.

Just my 2 cents

NM

[renniks]

NM

Can't understand your reply. Remember that this is for use with stopping trains not switching 'on the fly'. The turnout acts as a switch using the changing polarity of its frog rails.
With switch set to top and turnout A set to 'straight',the loop is set for CCW running.Setting switch to bottom and turnout to 'curve' sets the loop to CW running. Connecting the switch to the turnout keeps them 'in phase'.
I repeat---run train onto loop and stop,reverse switch and turnout, reverse controller and train will continue its direction and run back thru Wye.
Changing wires on one end of switch means that loop is connected at constant polarity and destroys method of operation.

Eric UK.

[Joe Satnik]

Dear Erik,

Let's number the terminals on the back of the DPDT switch 1 through 6 as follows:

1  4

2  5

3  6

In one paddle or slider position, 1 connects with 2, and 4 connects with 5:

1  4
l  l
2  5

3  6

In the other paddle or slider position, 2 connects with 3, and 5 connects with 6:

1  4

2  5
l  l
3  6

Trace your red wires backwards from your loop.  You will see that no matter what the paddle or slider position, the inside rail of your loop (red wire) always goes back to the red power pack output.

In order for polarity to change, you would need to swap the wires on 1 and 4, or 3 and 6, but not both. 

Hope this helps.

Sincerely,

Joe Satnik