Reversing Loops, Crossovers, and Yards

[starman]

I'm setting up my first layout.  I will be using DIgitrax.  I want to have two main lines with an auto reversing loop on each end of each main line.  I also want to have an auto crossover where I can take a train from one main line to the other.  Is what I want possible and where can I find the best directions on how to wire such a layout?  After getting the two main lines wired, I want to add a very large yard where engines will be entering from both directions.  Is this possible and where can I find the best directions for wiring such a yard?  To me, this sounds a little ambitious, but I am going to try. Thanks.

[rrinker]

 If possible, post a track diagram of what you are planning to build. It sounds like you are describing a dogbone shape layout with some extra crossovers on the main. There are a couple of ways to block out a revese section on such a layout,

                         --Randy

 

[starman]

I knew the general layout I wanted to put in my 12' by 19' foot room.  I built the benchwork and then covered it with white craft paper.  I have drawn most of my layout on that paper in actual size.  The yard is not yet complete.  I will draw out my design as soon as I can, hopefully in a day or two, and send it along.

[peahrens]

The following thread in the General section will advise how to post a photo from a hosting site such as Photobucket.  If you have a scanner just scan your diagram as a jpg file.

http://cs.trains.com/mrr/f/88/t/249194.aspx

You should be able to wire any track plan you desire.  Folks here can advise on ways to set it up.  For learning along the way, the following site See Track Wiring: Reversing) is one useful one on DCC reversing sections.  Note there can be options on how to set them up.

http://www.wiringfordcc.com/track_2.htm#c4

 

 

[richhotrain]

starman

I want to have two main lines with an auto reversing loop on each end of each main line.  I also want to have an auto crossover where I can take a train from one main line to the other.  Is what I want possible and where can I find the best directions on how to wire such a layout?  After getting the two main lines wired, I want to add a very large yard where engines will be entering from both directions.  Is this possible and where can I find the best directions for wiring such a yard?  To me, this sounds a little ambitious, but I am going to try. Thanks.

rrinker

It sounds like you are describing a dogbone shape layout with some extra crossovers on the main. 

From your description, I would have to agree with Randy that you are wanting to build a so-called dogbone layout.  You would have two parallel main lines with a pair of crossovers, or one double crosssover, with a loop at each end.

The simplest way to wire such a layout is to keep the outer rails one polarity and the inner rails the opposite polarity.  Maintain this wiring protocol throughout the layout.  The result will be mismatched polarities at one end of each loop where the loop rejoins the mainline.

If you draw a simple track diagram using a different colored pencil for the outer rail and the inner rail, you will see the two points of reverse polarity. To resolve these polarity conflicts, simply place insulated gaps on the rails as they enter and exit the loops.  That will require a total of 8 gaps.  You will need two auto-reversers, one to control each loop. The purpose of these insulated gaps is to complete isolate the reverse loops from the double mainline.

When you eventually build the yard, it can be wired in parallel to the mainlines. I assume that the yard will not be inside either loop.  No special wiring or separate auto-reverser will be required for the yard. If you do decide to build the yard inside one of the loops, you may or may not require special wiring, depending upon the track configuration and placement.

Rich

[starman]

I have uploaded 3 photos to Photobucket.  I hope I have done so correctly.

Picture 1 - My Layout - is a crude drawing of what I want to do.  The bench work is complete and I am ready to lay and wire the track.  As stated earlier, I have a Digitrax Super Chief Xtra (5 amp) that I will be using. The RED track represents Main Line A and the BLUE track represents Main Line B.  There is a 3% incline along the south wall and an additional 3% incline along the west wall.  The overall idea is to have coal trains leave the mountains (west wall), travel through the piedmont area (south wall) and through Norfolk, VA (east wall) into the Lambert’s Point Yard where coal is loaded onto ships for export. Main Line A is mostly for coal trains and Main Line B is mostly for passenger service.  I want to be able to switch trains between the A and B lines.

Picture 2 - Lambert’s Point Coal Yard – is for you to see the size of this yard.  It is gigantic! I barely remember occasionally riding around the maintenance area of this yard, on steam engines, with my uncle who was a hostler.  I will model as much of this yard as my space will allow.

Picture 3 - My Version of the Lambert’s Yard – shows my idea of how I can make the yard.

 

Except for the bench work, nothing major has been done.  I need help with how to wire this layout.  Will I need boosters?  What do I need for automatic control of the reversing loops?  Where is the best location for the Digitrax Train Controller?  What else do I need?  Any suggestions on what crosssoveers and turnouts to use?  Any good references I can read?

 

If there is something you can’t read on my drawing, please let me know.  Thanks of any and all comments!  

[peahrens]

I don't see your photos but rather the links.  You want to copy (click on) the IMG link on the right when looking at your photo and paste it in your reply, then hit "return" to the next line.  Your post will then show the photo itself after you post it. 

It seems I can do so also, so here are your photos:

 

 

[starman]

peahrens

I don't see your photos but rather the links.  You want to copy (click on) the IMG link on the right when looking at your photo and paste it in your reply, then hit "return" to the next line.  Your post will then show the photo itself after you post it.  It seems I can do so also, so here are your photos:

 

Thanks, Paul, for showing my photos.  I see what you are talking about to make a photos seem.  I will be sure to do that in the future.

 

Jack

[richhotrain]

peahrens

so here are your photos:

  

Those two loops are reverse loops. Each loop should be controlled by its own auto-reverser. To isolate each reverse loop, gap both non-tail ends of the turnout that controls the entry and exit points of the reverse loop.  Wire the entire layout so that the "outer" rail is one polarity and the "inner" rail is the opposite polarity.  The auto-reversers will prevent any dead shorts as a train enters or exits one of the reverse loops.

Rich

[MisterBeasley]

For the main lines, you should have a total of 4 auto-reversers, one for each of the obvious loops at the ends.  I'm assuming that the red and blue lines do not interact where they cross, but are connected by straight crossing tracks (not double slips)  or even better as over-under crossings.

The yard, though, contains at least one reverse loop of its own.  You will have to be careful with how you isolate that.  You don't want to "daisy chain" reversing sections, since that can lead to ping-ponging as both reversers try to "fix" polarity differences at the same time.

Also, be careful of which turntable you choose.  Some come with built-in polarity reversal through split rings and such, but others do not and would require yet another auto-reverser.

[BigDaddy]

MisterBeasley

Also, be careful of which turntable you choose. Some come with built-in polarity reversal through split rings and such, but others do not and would require yet another auto-reverser.

There is an active thread right now on the Wathers TT and a shorting problem because of the split rings.  If that is your choice of TT's you best read that thread

[rrinker]

 Based on that last picture which shows the turntable, if he uses the Walthers one and puts the dead zone pointing almost directly up, at that top ladder, the issue from the other thread will not affect him.

                                --Randy

[richhotrain]

rrinker

 Based on that last picture which shows the turntable, if he uses the Walthers one and puts the dead zone pointing almost directly up, at that top ladder, the issue from the other thread will not affect him.

                                --Randy

Randy, what you say is true, but I think that some of this discussion may confuse the casual reader.

[BigDaddy]

I'm sorry I mentioned it in this thread, because it is still confused in the other thread.

[richhotrain]

BigDaddy

I'm sorry I mentioned it in this thread, because it is still confused in the other thread.

 

Henry, take a look at the other thread.  I tried to add some clarity. See if it helps.

Rich

[rrinker]

 I don;t think what  siad was confusing at all. Based on the diagram posted by this thread's OP, the issue from the other thread (which I took to be referring to the CURRENT Walther's turntable thread where THAT OP put some tracks on either side of the no track zone) would not occur here if the turntable were aligned as I said. No need to make it more complicated than that, the alignment I suggested keeps all the tracks on the same side of the no track zone (per the plan provided), and nothing else needs to be done, nothing to worry about.

 That's assuming the OP is even going to use a Walthers turntable.

                --Randy

 

[richhotrain]

rrinker

 Based on that last picture which shows the turntable, if he uses the Walthers one and puts the dead zone pointing almost directly up, at that top ladder, the issue from the other thread will not affect him.

                                --Randy

 

starman

 

 

rrinker

Based on the diagram posted by this thread's OP, the issue from the other thread (which I took to be referring to the CURRENT Walther's turntable thread where THAT OP put some tracks on either side of the no track zone) would not occur here if the turntable were aligned as I said. No need to make it more complicated than that, the alignment I suggested keeps all the tracks on the same side of the no track zone (per the plan provided), and nothing else needs to be done, nothing to worry about.

When I installed my turntable, the Walthers 130' non-DCC version, I paid little attention to the position of the turntable. That was a mistake. You need to plan for the position of the NO TRACK dead zone.  

The NO TRACK dead zone is clearly marked on the underside of the turntable, but it is easy to find it topside. The "zero point", the optical sensor, runs perpendicular to the NO TRACK dead zone. On the underside of the turntable, the optical sensor runs from the center of the turntable to the pit. So, on the topside, the "eye" of the optical sensor can be clearly seen on the side of the pit.

In the OP's diagram, the zero point should be placed facing the approach track. That will set the NO TRACK dead zone perpendicular to the approach track. The three stub ended service tracks on either side of the approach track should be wired the same way as the approach track to maintain polarity. All of the other service tracks and the stall tracks are all stub ended and should be wired the same way to each other, but with the opposite polarity to the tracks on the other side of the NO TRACK dead zone.  Since all of the tracks other than the approach track are stub ended, no gapping is required and no auto-reverser or DPDT toggle switch is required.

That is the point that Randy is making.

Rich

[starman]

I am fairly new to model railroading.  I am the OP and had no idea wiring a turntable was so involved.  I do plan on using a Walthers 130' turntable as I will have several steam engines on my layout.  I appreciate the explination and believe I can follow the directions Rich gave in his post.  I am pleased this was discussed before I begain laying out my yard and turntable, which I will begin in the not to distant future.  Thanks!

[rrinker]

 It isn't. THe split ring design is supposed to make it EASIER. But it does mean you have to pay attention to the markings. I don't know that all split ring turntables are marked like Walthers ones are, so at least you aren't on your own to find the split position.

 Seems it would be far easier if it just had a constant pickup and you needed ot use an autoreverser on the bridge - then it wouldn;t matter where or how any stall or approach tracks were wired. Worst case, the reverser would flip the bridge polarity driving on to it, and then have to flip again when you drove off on a stall track. No one would even notice unless you were watching the LED on the autoreverser change. And your biggest worry would be cutting the right size hole for the pit to drop into. But, while easy for DCC, this would make it more complicated for DC, since you can't use an autoreverser with DC.

                             --Randy

 

[richhotrain]

rrinker

 It isn't. THe split ring design is supposed to make it EASIER. But it does mean you have to pay attention to the markings. I don't know that all split ring turntables are marked like Walthers ones are, so at least you aren't on your own to find the split position.

 Seems it would be far easier if it just had a constant pickup and you needed ot use an autoreverser on the bridge - then it wouldn;t matter where or how any stall or approach tracks were wired. Worst case, the reverser would flip the bridge polarity driving on to it, and then have to flip again when you drove off on a stall track. No one would even notice unless you were watching the LED on the autoreverser change. And your biggest worry would be cutting the right size hole for the pit to drop into. But, while easy for DCC, this would make it more complicated for DC, since you can't use an autoreverser with DC.

                             --Randy

 

 

Amen.   

Rich

[dehusman]

starman

I want to have two main lines with an auto reversing loop on each end of each main line. I also want to have an auto crossover where I can take a train from one main line to the other. Is what I want possible and where can I find the best directions on how to wire such a layout? After getting the two main lines wired, I want to add a very large yard where engines will be entering from both directions. Is this possible?

It's actually a very simple set up with DCC.  You have auto reversers on your reverse loops and then the ENTIRE rest of the railroad, all the rails on one side get connected to one bus wire and all the rails on the other side get connected to the other bus wire.

That's it.

Put in as many crossovers as you like, run as many trains in and out of the yard as you like.