Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

reverse loop complicated

6444 views
82 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2002
  • From: Westchester NY
  • 1,747 posts
Posted by retsignalmtr on Tuesday, March 4, 2014 7:07 PM

As I said you do not need to have the yard tracks in the reversing section. Try putting the AR in that single track at the top of your diagram between the switches. I did something similar for a friend and it worked perfectly. You won't be able to have two trains in the reversing section at the same time. But you will be able to use the yard tracks while another train is traversing the loop.

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 6:51 PM
The plan was to have one train exiting the loop and be able to head back up the helix , while another enters the loop fromthe helix, this causes the possibility of a short based on 2 trains hitting the gaps at the same time. Becomes an issue.
  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 6:48 PM
Rich, thanks for drawing that up, makes sense, but what happens if two trains enter the loop at different ends? Is there a way to avoid this? The reason i tried to put the gaps where i did was to avoid a short based on the fact that only one train can go through a turnout at a time. If this is the only way than ill have to try and see how to avoid this or modify the track to avoid this all together.
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, March 4, 2014 6:13 PM

OK, if the upper track dead ends, then here is a simplified track diagram with the gaps correctly place to avoid any shorts.

Rich

Alton Junction

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 5:59 PM

Yes i am using dcc system with the psx ar, this is a lower level area , the lower track before the gaps goes to a helix and up to other areas. This lower area is just a reverse loop with staging tracks inside, at least that was the purpose. The upper track is a dead end siding, it goes No where.  I was thinking my gaps should be fine also, but if you follow the track around from the lower area to the top once the track hits that trouble turnout, the polarity  crosses with the dead end sidings, i guess o should draw this all. Out with both rails.

 

thank you all for your input. I trily appreciate It!

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, March 4, 2014 5:56 PM

WardR

Yes i thought that i was using a dcc system was obvious using the psx ar. Sorry left that out.

 

On this forum, you can never be sure.   Hmm

Rich

Alton Junction

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 5:53 PM

Yes i thought that i was using a dcc system was obvious using the psx ar. Sorry left that out.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, March 4, 2014 5:03 PM

This thread is too long.  I just came across it and I am exhausted from trying to read through it.

OK, so you have a PSX-AR hooked up.  

Are you running in DCC?  

Is the track diagram only part of your layout?  Where does that upper track go?  What is beyond what you show to the left?

If that upper track is just a dead end siding and if you wired the PSX-AR correctly, then the two sets of gaps you show should be sufficient and no short should occur.  Just move that upper set of gaps to the divergent end of that LH turnout where the short is occurring.

How is this all different from yesterday's thread.  I am confused.

Rich

 

 

Alton Junction

  • Member since
    February 2002
  • From: Westchester NY
  • 1,747 posts
Posted by retsignalmtr on Tuesday, March 4, 2014 4:26 PM

In your first question you say you are using a PSX-ar reversing unit. Are you using a DCC system to power your track? Nowhere in your postings do you mention that. You do mention that your track is + and -. The PSX-ar's are for DCC only. I think the best place to put the AR is at the top single track on your diagram If you are using DCC. You do not need to reverse all the stub ended tracks to traverse the loop.

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 2:54 PM

this is the case if i have an auto reversing unit, I have the psx-ar?

  • Member since
    July 2006
  • From: North Dakota
  • 9,592 posts
Posted by BroadwayLion on Tuesday, March 4, 2014 1:57 PM

WardR
if the switch is thrown open for the rain to leave the loop, it will just run through no?

No. In the case of this loop you have a single switch which will select enter (say counter clockwise). The train then stops, (put a home signal there if you like),

When you through the switch the train will be able to continue, but if you throw the switch while the train is moving it will suddenly start moving backwards.

Think of that lower lead as and east west track. The train is moving east bound into the loop. when you align the switch for the train to leave the loop it is now heading westbound. You will have to move the reversing switch from eastbound to westbound.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    January 2007
  • From: Eastern Shore Virginia
  • 3,290 posts
Posted by gandydancer19 on Tuesday, March 4, 2014 1:54 PM

 

From an electrical standpoint, if you re-draw the diagram and leave out all tracks that dead end, it looks to me like everything is OK with the green gaps as they are.

The possible problem that I see with the turnout that is shorting out is that it may be an electro-frog type or a shinohara type with a live frog. If that is the case, gaps need to be cut on both rails coming from the frog. This would be true if the turnout shorts all the time when thrown in one direction.  OR, there could be a wiring problem on either side of the turnout.

If the short occurs only when a train (locomotive) is crossing it, then the problem could be that the rails coming from the frog are too close together and the locomotive wheels are making the short because it is touching both frog rails at the same time. This occurs most on Peco insul-frog turnouts that have plastic frogs. To correct it, you can apply some paint to both rails as they go in to, or are at, the frog.

 Both tracks at the green gaps should have both rails gapped.  (Four gaps total at this point.)  The output of the auto reverser should start feeding power at the right of these gaps before the turnout that shorts.  All other tracks inside the loop should also have feeders every three feet or so, also from the output of the auto reverser.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 11:11 AM
Gosh, sorry for the typos, im on a darn Ipad: thanks for your reply!!!! and help!! the gaps you did draw that will allow a train to enter and leave the loop, will that be automatic? you say i will have to stop? if the switch is thrown open for the rain to leave the loop, it will just run through no? I would say the other option where i gap the small area maybe the best option, trains cant occupy that together or they will collide.
  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 11:08 AM
does that mean that the reverse loop device would only be powering hat little section of track? all other track will be outside reverse loop? sorry if im not following this.
  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 11:05 AM

thanbsk for your reply!!!!  and help!!  the gaps you did draw that will allow a train to enter and leave the loop, will that be automatics, you say i will have to stop? if the switch is thrown open for the rain to leave the loop, it will just run through no? I would say the other option where i gap the small area maybe the best option, trains cant occupy that tohgether or they will collide.

  • Member since
    July 2006
  • From: North Dakota
  • 9,592 posts
Posted by BroadwayLion on Tuesday, March 4, 2014 11:00 AM

Yeah, I was trying to illustrate two things at once and so made a mud pie.

The track with the dot on it is gapped at each end of the segment, but I did not show the gaps.

The gaps I did draw will alow you to bring a train into and through the loop, where it must stop before re entering the main line. The position of the switch determines which way the power enters the loop.

 

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 10:00 AM

him, so what your saying is gap the track in that little section near the red dot, this way that little piece of straight track becomes my reverse loop section? i see you have one red gap in that area , but the other one is all the way down at the bottom, would that need to be down there?

 

thanks!!!!

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 9:58 AM

thats how I had the gaps at one point and it seemed to work the issue  ran into was that if a train hits the loop sections at the same time i short, That was not favorable as it happened a few times.

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 9:54 AM

Thanks for your help!! the onlyissue is that top north track is not my main line thats just a dead end siding, the only track coming inand out of the loo would be the bottom (left of the gaps) i though about bringing the upper loop all the way down to that first switch. i can gap things in certain areas , but that runs the risk of shorting out things if 2 trains are in the gapos at the same time. thats why i tried to put the gaps after a turnout, that would never happen as the trains would have to collide for a short to occur. crazy how I have over complicated this, I wish there was  a simple fix, i though of adding an addiitonal reversing unit to the inside yard area.

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Tuesday, March 4, 2014 9:35 AM

Hi Ward

If that top left track forms a loop and comes back to the bottom left track then it would have to be gapped. If i'm reading this right.  IMHO

Have fun.

Lee

  • Member since
    July 2006
  • From: North Dakota
  • 9,592 posts
Posted by BroadwayLion on Tuesday, March 4, 2014 9:32 AM

The problem is the track segment covered by the red dot...

Your gaps need to isolate this little section. You can get your power from the upper track or the lower track but not both. Gap both ends of this segment so that the sidings get their power always from the lower segment. The cutoff gets its power from either switch A or switch B but never both.

You have enough room to move an engine, or perhaps an engine with one car across the gap, but no more.

A better solution would be to re track things so that the outer loop would exit to the north main line, but that the inner loop would not, this way a whole train can tie up on the inner loop while the switches are re aligned for loop movement. Switches B and C are removed, and gaps placed as I show them here.  The whole train can arrive on the turning loop, and the switches are then aligned for the exit movement and for working the yard.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Tuesday, March 4, 2014 9:27 AM

If you have both rails gapped at both locations shown, your entire yard area is being reversed.  I'd move the upper gap to beyond the turnout that is causing the short, to a location beyond the next turnout where you show a single line at the top of your sketch.  There's no need to reverse all the yard tracks like you're presently doing, since they're not really part of the loop.

If you continue getting a short, you have your feeder wires crossed somewhere withiin the yard.

 

  • Member since
    March 2011
  • 152 posts
Posted by WardR on Tuesday, March 4, 2014 9:08 AM

just an fyi the top siding that looks cut off ends there, the lower track to the left of the gaps is where the mainline comes in.

  • Member since
    March 2011
  • 152 posts
reverse loop complicated
Posted by WardR on Tuesday, March 4, 2014 9:08 AM

Hello everyone,

I created this section over 2 years ago, it was my first section before i totally understood the reverse loop issues, i have had issue in the past and have tried certain gaps in different areas, the problem is I would like to keep the gaps close near each other , so that i don’t run the risk of 2 trains hitting the gaps at the same time, which was happening, so when i moved the gaps like they are now in the photo, I get short, I’m pretty sure it like a reverse loop within a reverse loop issue, following the + and - it looks like after it goes through the loop it comes back in on itself and shorts where that last turnout is converging with the sidings. i don’t know how I would fix this issue, add another reversing unit, or pull out the track in the back that comes back on the reverse loop return, either way i would like to not have to rip anything out, but i may have no choice. Any ideas would be greatly appreciated!!  The outside track  outside rail is  +.

Thanks!!

Image below:

the reverser is an psx-ar and the entire reverse loop and inside sidings are powered by the reverser, the power on the left side of gaps is the only area not in the loop.

reverse looploop

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!