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Does Auto Reverser Work in This Diagram?

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Does Auto Reverser Work in This Diagram?
Posted by KisNap on Wednesday, December 10, 2014 2:12 PM

My next layout will have a station that allows trains to leave it going in either direction in the layout.  From everything I read, it seems necessary to have the auto reversing section larger than your largest train, but those were always geared towards loops.

In the diagram below, my trains will be longer than the reversing section which is illustrated by the green lines representing the isolation connectors.  The train will pass straight through, however the train will be entering the switching area as new cars are still coming in.  Some of my passenger cars are lighted which I heard could be an issue.

I imagine I'd need 4 auto reversers, one for each rail going to/from the station.  The switching area and station rails would then be powered in the same polarity as the main line.  If this setup won't work, are their any suggestions as to modifications of where to isolate the tracks?

I thought of isolating everything up until the station and having the whole switching area reverse, but then I figured that would mess up other trains who are traveling through the switching area at the same time.

Any advice is very welcome!  Thank you!!!

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Posted by skagitrailbird on Wednesday, December 10, 2014 2:27 PM

Some of questions:

  1. Where will the station be located?
  2. Does each brown line represent one rail or a track (two rails)?
  3. Which brown lines represent the main line(s)?

I don't guarantee I can come up with the answer to your question but this info should help.

Roger Johnson
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Posted by KisNap on Wednesday, December 10, 2014 2:47 PM

Sorry for the lack of information. 

1) The station is the green rectangle in the upper right hand corner. 

2) Eack line represents 1 line of track so there are a total of 4 tracks leading to wards the switching area that then goes to the station.

3) The two paralell tracks on the left hand side that go to the left and lower edges of the picture are the main lines.

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Posted by Mark R. on Wednesday, December 10, 2014 3:19 PM

You can eliminate the two isolated sections on the lower right two tracks and just leave the two tracks across the top isolated and install an auto reverser on each of the two tracks.

Based on your grid work, any train that will fit within the station tracks would fully fit within either of the two upper tracks to which the auto-reversers are connected .... very important, especially if you are running lighted cars.

Mark.

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Posted by skagitrailbird on Wednesday, December 10, 2014 3:36 PM

I agree with Mark. Two auto reversers should do the trick. But if I understand your initial post, the gridwork in the diagram may not be to scale since you indicated your lighted trains will be longer than your drawn reversing section. That would be a problem.

How far do the Y's tail tracks (those going off the bottom of your drawing) go? Far enough for your longest lighted train? If so, I would make the Y your reversing section, removing all of the gaps on the two horizontal main lines and on the tail tracks near the lower turnouts and adding gaps to the two Y tracks at the left hand turnouts. One auto reverser on each of the two Y tracks should then do the trick.

You might want to take a look at this link: http://www.wiringfordcc.com/track_2.htm#a19

About half way through the article there is a section dealing with wiring reversing sections.

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Posted by KisNap on Wednesday, December 10, 2014 3:50 PM

I've actually looked at that site already and while it was helpful, I didn't know what difference there may be since it's not a reversing loop.  The diagram is to scale (1 square is 1 square feet), but I was hoping to expand the station tracks an extra foot.  What would happen with the train being longer than the isolated track when there are lighted cars?  I'm more interested in why it would happen so I can get a better understanding of the problem.

I'm assuming that if the wheels are plastic that the length of the train is irrelevant.  Is that correct?

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Posted by skagitrailbird on Wednesday, December 10, 2014 4:02 PM

Here is the part of the article pertaining to wyes to which I referred earlier.

Other Wye Configurations:

Here are some sample wye configurations. There is nothing magic about them. I am providing these to give you some ideas. A reason to use a particular one is to minimize the need to trigger the reversing circuit. Some systems hesitate briefly while the switching takes place.


" B"


" C"


" D"


" E"

 

I have shown these wyes drawn with a straight side. I only did that because it was easy to draw. Please realize the orientation of the wye can be any way you need it to be. In fact, look at "B" and "D" carefully. Turn "D" on its side. "D" and "B" are essentially the same!

Remember the basic rule of reversing sections: the reversing section must be at least as long as your longest powered train. Configuration "C" appears that it may be hard to implement if you have a lighted passenger train. It could also be a problem if you have a lighted caboose. If the only powered unit is your locomotives, than the reversing section in "C" may be able to be short. If you are lashing up locomotives, be sure it is at least as long as your longest lashup.

My reading of this would say if your lighted cars have plastic wheels it may not matter. I emphasize may because it depends upon how your car lights are powered. If by batteries then I do not believe the "excess" length matters. But if by some sort of wiper getting power from the track I think it does matter.

PS: You may have to copy the article segment and pasteit into a word processing application to be able to see all of it.

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Posted by Mark R. on Wednesday, December 10, 2014 5:13 PM

The problem with the train being longer than the reversing section is that a powered engine may be crossing one end, and a lighted (powered) passenger car may still be crossing the gap at the other end causing the auto reverser to try and align the power to BOTH ends - which it can't do, and thus a short would occur.

If, under no circumstances, engines or cars that would be picking up power from the rails should NOT be bridging the gaps at both ends at the same time. If the cars in your train do not reply on rail power pick-up, then you would have no problems.

Mark.

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Posted by richhotrain on Wednesday, December 10, 2014 5:28 PM

KisNap

I imagine I'd need 4 auto reversers, one for each rail going to/from the station.  

You do not need an auto reverser for each rail.  An auto reverser is used to match polarities between two sections of track.  So, in your case, you need 2 auto reversers, not 4.  

Any time that a section of track has the reverse polarity of an adjoining section, it is a "reversing section".  A reverse loop is just another reversing section.

A reverse loop presents a unique problem in that it not only requires an auto reverser, but it also has to be long enough to hold the entire train to prevent the loco from striking the trailing cars.

A passenger car or freight car with metal wheels, even without any lighting, can set off an auto reverser.  It has happened to me.  For that reason, the reversing section should be longer than your longest train. The only exception is that a car with plastic wheels will not set off an auto reverser.

I agree with Roger that you should consider making the tails of the wyes as your two reversing sections.  This would leave the entire upper section of track, and most of the mainline loop, as the non-reversing section.

Rich 

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Posted by Mark R. on Wednesday, December 10, 2014 8:13 PM

Making the entire "Y" section the reverse, it could pose problems depending on how it it operated. Potentially, one train could be arriving from the top left into the station while another could be leaving the station towards the bottom. If the entire "Y" was the reversing section, the two trains could be crossing the gaps at the same time.

With the two tracks at the top isolated as per the diagram (each with their own reverser), trains could be entering and / or leaving from all points with no interference of the reversers having two trains in the block at the same time.

Mark.

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Posted by richhotrain on Thursday, December 11, 2014 6:16 AM

What I would be most concerned with is the needed length of the reversing section.  As we have already discussed, the proper design is to have the reversing section be longer than the longest train.  Where on the layout can that be best accomplished?

The next most important consideration is traffic congestion.  Where will most of the train movements take place?  It is always advisable to keep the reversing sections away from high traffic areas if that is possible.

Once it has been established that a reversing section is long enough to hold the longest train, the remaining issue is the possibility of one train entering the reversing section while another train is simultaneously entering or exiting the same reversing section.  Whenever multiple trains are running on the same track, that is always a concern. 

All things considered, I don't see the locations of the reversing sections on this layout such that one location is superior to the other.

Rich

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Posted by richhotrain on Thursday, December 11, 2014 6:38 AM

Maybe this has already been covered and I missed it, but why are there gaps on those two horizontal sections of track at the top of the track diagram?

Those sections of track should match the polarity of the adjacent sections of track.

Rich

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Posted by Mark R. on Thursday, December 11, 2014 9:08 AM

richhotrain

Maybe this has already been covered and I missed it, but why are there gaps on those two horizontal sections of track at the top of the track diagram?

Those sections of track should match the polarity of the adjacent sections of track.

Rich

 

As per my suggestion, I would use the top two tracks as the reverser sections as they are longer than the other two that are gapped in the diagram ....

Mark.

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Posted by richhotrain on Thursday, December 11, 2014 9:35 AM

Mark R.

 

 
richhotrain

Maybe this has already been covered and I missed it, but why are there gaps on those two horizontal sections of track at the top of the track diagram?

Those sections of track should match the polarity of the adjacent sections of track.

Rich

 

 

 

As per my suggestion, I would use the top two tracks as the reverser sections as they are longer than the other two that are gapped in the diagram ....

Mark.

 

Interesting.  How long would each of those two reversing sections be?

Rich

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Posted by MisterBeasley on Thursday, December 11, 2014 10:24 AM

As I recall, the part of the layout not shown is a double loop with some switching in the center and off-page on the lower right.  I would consider the option of gapping the tracks as each of the 4 station tracks meet the loops, and then using a pair of reversers to control the loop polarity rather than the station track polarity.

This is always going to be somewhat tricky.  I would gap it as you have shown, and keep your feeders separated.  Wire things through terminal blocks so that you have the option to re-configure the auto-reversers easily until you find the configuration that works best when you start running trains.

I'd definitely get solid-state autoreversers, not relays.  You may encounter situations where the ability of autoreversers to flip polarity back and forth several times per second is important.

It takes an iron man to play with a toy iron horse. 

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Posted by richhotrain on Thursday, December 11, 2014 11:41 AM

I don't recall the overall track plan either.   But, if this were my layout, I would have a scale drawing of the entire track plan so I knew the exact length of any proposed reversing section(s).  Otherwise, we are all submitting our best guesses, nothing more.

This is a complicated track plan, just from what is shown.  That station track configuration is complicated enough.  Then, you have two crossings that affect both mainlines.   Then, there is the double wye.  Lots to consider. 

Rich

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Posted by Mark R. on Thursday, December 11, 2014 3:07 PM

richhotrain

I don't recall the overall track plan either.   But, if this were my layout, I would have a scale drawing of the entire track plan so I knew the exact length of any proposed reversing section(s).  Otherwise, we are all submitting our best guesses, nothing more.

This is a complicated track plan, just from what is shown.  That station track configuration is complicated enough.  Then, you have two crossings that affect both mainlines.   Then, there is the double wye.  Lots to consider. 

Rich

 

I think YOU are reading way more into this than needed. This is a reversing wye - it doesn't matter at all whether the right leg is a single track or has 1400 switches, all he's dealing with is the reversing wye. The rest of the layout is not important what's going on either.

The track plan IS to scale (IF you read his posts). I don't understand why you are trying to make this sound way more difficult than it actually is. The solution is so simple ....

Mark.

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Posted by richhotrain on Thursday, December 11, 2014 3:25 PM

Mark R.

I think YOU are reading way more into this than needed. This is a reversing wye - it doesn't matter at all whether the right leg is a single track or has 1400 switches, all he's dealing with is the reversing wye. The rest of the layout is not important what's going on either.

The track plan IS to scale (IF you read his posts). I don't understand why you are trying to make this sound way more difficult than it actually is. The solution is so simple ....

Mark.

 

Mark, be nice to me.  I am very sensitive.   Laugh

Seriously, though, I think that the thread has grown complicated.

Where exactly are you suggesting gaps?

Incidentally, following up on Mr. B.'s comment, I was asking for a scale drawing of the entire track plan.

Rich

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Posted by Mark R. on Thursday, December 11, 2014 3:48 PM

richhotrain

 

 
Mark R.

I think YOU are reading way more into this than needed. This is a reversing wye - it doesn't matter at all whether the right leg is a single track or has 1400 switches, all he's dealing with is the reversing wye. The rest of the layout is not important what's going on either.

The track plan IS to scale (IF you read his posts). I don't understand why you are trying to make this sound way more difficult than it actually is. The solution is so simple ....

Mark.

 

 

 

Mark, be nice to me.  I am very sensitive.   Laugh

 

Seriously, though, I think that the thread has grown complicated.

Where exactly are you suggesting gaps?

Incidentally, following up on Mr. B.'s comment, I was asking for a scale drawing of the entire track plan.

Rich

 

C'mon Rich, read the posts. I've already posted twice how I think it should be done and why.

The top two tracks make the most sense as they are longer than the bottom/right two tracks and also longer than any of the storage tracks in the terminal (provided the diagram is correct). By have the reverser on the top two tracks, trains can enter and leave across the top through the reverses while two other trains could enter or leave towards the bottom requiring no reversing section.

I don't see what needing a diagram of the entire layout would have any bearing on this. That's be like asking for directions how to get to my house and you want a map of Canada !

Mark. 

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Posted by richhotrain on Thursday, December 11, 2014 3:57 PM

Mark, I am not trying to give you a hard time.  I was merely picking up on Mr. B.'s suggestion that it would be interesting to see the entire track plan.

If you make the top two sections of track the reversing sections, it appears that you only have a 3 foot length of track, hardly enough to accommodate long trains particularly passenger trains with lighted cars.

Incidentally, if the scale is 1 square equals 1 foot, that means that the station tracks are only 2 feet plus a few inches.  Not that it has anything directly to do with the reversing sections, but that seems like a pretty limiting track plan.

Rich

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Posted by Mark R. on Thursday, December 11, 2014 3:58 PM

richhotrain

Mark, I am not trying to give you a hard time.  I was merely picking up on Mr. B.'s suggestion that it would be interesting to see the entire track plan.

If you make the top two sections of track the reversing sections, it appears that you only have a 3 foot length of track, hardly enough to accommodate long trains particularly passenger trains with lighted cars.

Incidentally, if the scale is 1 square equals 1 foot, that means that the station tracks are only 2 feet plus a few inches.  Not that it has anything directly to do with the reversing sections, but that seems like a pretty limiting track plan.

Rich

 

Don't forget he's modelling in N scale.  Smile, Wink & Grin

Mark.

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Posted by richhotrain on Thursday, December 11, 2014 4:12 PM

Mark R.

Don't forget he's modelling in N scale.  Smile, Wink & Grin

N scale ???  

Hmm, and to think, I actually did read all of the posts.......just not completely.

OK, but can we agree then that he doesn't need any gaps on those wyes?

Rich

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Posted by Mark R. on Thursday, December 11, 2014 4:19 PM

He doesn't not need any gaps on the wye ? (wait ... what ?)

No gaps in the "Y" as per the diagram .... just gaps to isolate the two tracks across the top as he already has drawn. A reverser module on each of the two tracks.

Mark.

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Posted by richhotrain on Thursday, December 11, 2014 4:24 PM

Mark R.

He doesn't not need any gaps on the wye ? (wait ... what ?)

No gaps in the "Y" as per the diagram .... just gaps to isolate the two tracks across the top as he already has drawn. A reverser module on each of the two tracks.

Mark.

I said that he doesn't need any gaps on those wyes using your arrangement.
 
Four pairs of gaps on those top two tracks.
 
If wired correctly, no need for any insulated gaps on the wyes.
 
Rich
 
 

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Posted by MisterBeasley on Friday, December 12, 2014 9:52 AM

I went back and found the OP's track plan from a thread in November:

Another thing that would be good to know is how the operations will be split between the busy station at the top and the somewhat more relaxed main line.  My suggestion that the two main line loops be considered the reversing sections is based on the idea that the station area does not itself need internal auto-reversing, and keeping the whole thing on one circuit would reduce constant polarity flips and avoid some unreconcileable conflicts.

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Posted by richhotrain on Friday, December 12, 2014 10:56 AM

Good job, Detective Beasley.

I stick by my original suggestion to treat the two wyes as reversing sections.  I used green dots to mark the location of the gaps.

That gives you a lot more length than Mark's option of gapping the top two tracks.

As far as trains entering and exiting the wyes simultaneously, that should not be a concern from an auto reverser point of view because two trains would not be operating in such a fashion on the same track.  At least, I don't see a concern unless someone can show me differently. I see no problem with using the two wyes as the reversing sections, each using its own auto reverser.

Rich

 

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Posted by Mark R. on Friday, December 12, 2014 11:07 AM

richhotrain

Good job, Detective Beasley.

I stick by my original suggestion to treat the two wyes as reversing sections.  I used green dots to mark the location of the gaps.

That gives you a lot more length than Mark's option of gapping the top two tracks.

As far as trains entering and exiting the wyes simultaneously, that should not be a concern from an auto reverser point of view because two trains would not be operating in such a fashion on the same track.  At least, I don't see a concern unless someone can show me differently. I see no problem with using the two wyes as the reversing sections, each using its own auto reverser.

Rich

 

 

And where are you attaching the reverser modules ? If all you are using is the green dots (not the red lines), the wye at the bottom right is still going to cause a short. There are two cross-overs between the sections you have gapped that don't protect two different trains passing each other on the mains.

The track plan submitted at the opening of this thread has also been revised in comparison to this full plan.

Personally, I would not install auto reversers on the main in the middle of a closed loop - but that's just me.

 

Mark.

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Posted by richhotrain on Friday, December 12, 2014 11:25 AM

Well, you know what?   We should all stop commenting because we are doing all the leg work and the OP hasn't really helped us at all.

But, let me say this about the wyes as reversing sections.  Aside from the fact that the OP has changed the track diagram since he first posted about it in November, there is really only one crossover within the reversing sections and that could be moved outside the reversing sections.  The other piece of track work right below the beginning of the tail of each wye is a crossing, or at least it should be.  

As diagrammed, both in November and December, the track diagram seems flawed or, at least, not thoroughly thought out.  There are more efficient ways to design it.

Rich

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Posted by Mark R. on Friday, December 12, 2014 11:43 AM

But .... you could have two separate trains on each main line running in the same or opposite directions that would need to remain separated electrically should one divert off the main into the passenger terminal. If the inside train is running counter-clockwise and wants into the terminal, it has to cross over to the outside at the top of your reversing section. That cross over would need to be insulted between the inside loop and outside loop.

So now, you are moving from one auto-reverse section to an adjacent auto-reverse section, then finally into the terminal wye. 

 

Doesn't sound like the best of set-ups to me.

 

Based on the revised trackplan in the opening, the two tracks across the top still make the most sense. The auto-reversers are their own separate entity and not part of the main line. They would only be used when trains are entering / exiting the terminal at the top.

 

Rich, mentally run trains on the layout the way you have it configured. Run more than one train at a time. Use every possible combination of entrances / exits / cross overs .... you will quickly see its flaws.

 

Mark.

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Posted by KisNap on Friday, December 12, 2014 2:20 PM

Hi Everyone.  I have been reading all of the posts and revising parts of my layout.  I've removed the wye at the bottom of the layout and instead opted for a line dedicated to freight which will be at least 2 inches below the main commuter line.  I have connected it to the commuter line with two transition grades that will not act as a wye.

The station yard has increased in complexity appearance, but I will have a detailed switching board to help keep track of switch direction.  Most of the changes there are for storage purposes.  I know that it can be done easier, but I want the complex look to have the same idea as the prototype.

Train length will be between 2 1/2 and 3 feet long.  I still have some room to extend the station area so I can make the station tracks longer and add more length to the tracks leading to the switching area.

Your input has been INVALUABLE!!!  I have definately learned a lot and now know that only two reversers are needed.  There will still be some changes like sidings for local industries on the mainline, but I believe the station area is complete as far as tracks go.

Below are images of the updated layout diagram and a look at the protype in Hoboken NJ.

A look at the layout.

Note: The maintenance building siding will be used for locomotive housing or single car maintenance so I don't have to worry about the reversing section's length to that point.

 

The prototype

  

The N scale section of my website is now uploaded with a lot of various things.  Check it out: www.CarlettaTrains.com

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