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!

Uncoupling Magnet Placement

6462 views
31 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    November 2002
  • From: Colorado
  • 4,075 posts
Posted by fwright on Thursday, January 12, 2023 10:07 PM

Given that successful delayed uncoupling is VERY sensitive to very smooth operation of the locomotive and how free rolling given cars are, I am sticking with skewers for the present.  I have seen and been the victim of (not just on my layout):

  • Having the car surge or the locomotive pause just enough that the couplers disengage and re-center when doing a delayed uncoupling move.  Then the couplers recouple as soon as the no longer delayed couplers touch.  Rinse, lather, repeat.  Also known as the "Kadee Do-si-do".
  • Having to push a very free rolling light weight car into a bumper or other obstruction (often a finger across the track behind the car) to make it couple onto my train instead of bouncing away.  Also known as the "Bar that Car!"

Seriously, prototypical speed switching and delayed uncoupling requires a big step improvement in consistent weighting, equalizing rolling ability, track cleaning, and smooth running locomotives above the stock standard to be consistently successful.

Until I get my rolling stock to that level, deftly handled skewers and finger bars solve most of the issues.  Don't ask me how I know this.

Fred W

....modeling foggy coastal Oregon in HO and HOn3, where it's always 1900....

  • Member since
    November 2013
  • 2,775 posts
Posted by snjroy on Friday, January 6, 2023 2:23 PM

Before placing my uncouplers, I looked at my paper layout plan, and simulated, with my finger, a few operations to see where I would need to uncouple cars, including shuffling operations. My objective was to NOT use the five finger crane for that. I ended up with a few electromagnetic uncouplers on the mainline (to avoid unwanted uncoupling), and magnetic uncouplers for every track in my yard, right after the switch, where track is nice an straight. After two years of operation, I realize that I could have added an extra uncoupler on the mainline, but I can live without it. The five finger crane is only used to remove cars from the layout, including those with sticky couplers that need maintenance Embarrassed.

Simon

  • Member since
    May 2021
  • From: Northern Colorado
  • 86 posts
Posted by CharlieM on Friday, January 6, 2023 9:28 AM

I place the Kadee uncoupling magnets on the track using a strip of scrapbook double sided tape. This allows testing the location and moving if necessary. The tape is thin enough that the couplers work well in code 83 or 100 track. I've found the tape holds well enough that there is no need to glue down more permanently unless you're ballasting.

I also recommend the Rapido remote uncouplers for mainline locations. They work very well and will be available again later this winter. Check the Rapido site.

Charlie - Northern Colorado

  • Member since
    May 2008
  • From: Miles City, Montana
  • 2,289 posts
Posted by FRRYKid on Friday, January 6, 2023 3:30 AM

Shouldn't be a problem if you use delayed uncoupling magnets and back into the sidings. You can drop the cars off and as long as there is tension on the coupolers from pulling they won't uncouple.

"The only stupid question is the unasked question."
Brain waves can power an electric train. RealFact #832 from Snapple.
  • Member since
    February 2017
  • From: Harrisburg, PA
  • 660 posts
Posted by hbgatsf on Thursday, January 5, 2023 7:21 PM

Trainguy1988

I have a similar quandary. My HO scale layout will have six industry sidings from which trains can drop off and pick up cars. I figure an uncoupler would aid in the dropping off of cars, but am wondering if this would complicate matters regarding picking up cars from the sidings.

 

Just be careful if there are curves involved.  Uncoupling can be done if the magnet is placed properly, but hooking back up can be difficult if not impossible depending on the radius and car length. 

Rick

  • Member since
    January 2004
  • From: Canada, eh?
  • 13,375 posts
Posted by doctorwayne on Wednesday, January 4, 2023 12:00 AM

Trainguy1988
I figure an uncoupler would aid in the dropping off of cars, but am wondering if this would complicate matters regarding picking up cars from the sidings.

It shouldn't, as the cars can easily be re-coupled and shouldn't uncouple when passing over the uncoupling magnet, unless you stop or pass over it very slowly.

As long as there's drag on the couplers, they shouldn't uncouple....not like the Kadee couplers that I had on my first layout...

Here's one of them...

Uncoupling was achieved by pressing a button on the control panel, which was connected by choke wires to the uncoupler, which was a slim, diamond-shaped metal device between the rails...upon pushing and holding the button, the uncoupler rose high enough to contact those pins in the knuckles, speading them and thereby opening the knuckles.
Uncoupling on industrial sidings was somewhat similar to nowadays, but with some skill and good timing (along with a fairly fast locomotive on the mainline) you could do a flying drop, and if you were quick enough, flip the points on the turnout so that the uncoupled car could roll into the siding on it's own.


I was never quick enough to accomplish that.

I have in-track magnets in my staging yards, but am installing small rare-earth magnets in my industrial sidings. 

There's one here, beneath the rails, indicated by the striped post...

...and, as you can see, the knuckle is open, which will allow a locomotive to push the car to the door where it will be loaded or unloaded.

Wayne

  • Member since
    August 2019
  • 25 posts
Posted by Trainguy1988 on Tuesday, January 3, 2023 9:47 PM

I have a similar quandary. My HO scale layout will have six industry sidings from which trains can drop off and pick up cars. I figure an uncoupler would aid in the dropping off of cars, but am wondering if this would complicate matters regarding picking up cars from the sidings.

  • Member since
    January 2004
  • From: Canada, eh?
  • 13,375 posts
Posted by doctorwayne on Monday, January 21, 2019 10:44 PM

FRRYKid
....I am also using delayed uncouplers. So that should avoid unintended uncouplings.

Delayed uncoupling doesn't prevent false (unwanted) uncouplings.  The "delayed" part refers to the ability to uncouple over the magnet, then back away slightly from the uncoupled car, with the car or locomotive from which it was uncoupled still with that coupler over the magnet.  The force of the magnet will then deflect the couplers, each to the opposite side.
The train can then push the uncoupled car (it won't re-couple due to the formerly coupled couplers being misaligned by the magnet) to a spot farther down the track.  When the car is spotted at its destination, the train can then back away, leaving the car. 
This delayed uncoupling is what allows you to spot several cars at different locations on a siding, using only a single magnet placed on the siding, just clear of the turnout.

Wayne

  • Member since
    November 2013
  • 2,775 posts
Posted by snjroy on Monday, January 21, 2019 6:23 PM

The Rapido uncoupler works very well and prevents unwanted uncoupling. I would recommend it for higher traffic track.

Simon

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Monday, January 21, 2019 1:16 PM

I have a few electromagnets on my main lines to let me uncouple but not have issues when I don't want to.

I've been getting rid of all my old plastic wheelsets, which causes two new problems.  First, the lower rolling resistance means that my sidings must be flat or the cars will roll away.  I fix this by gluing some tufts of field grass between the ties on sidings so the cars will stay put.  The second problem is that the stronger magnets attract the metal wheels and axles, making use of the delayed uncoupling to spot cars difficult.  Grass tuft can help with this, too.

After years of struggling with magnets, though, I went to the supermarket and bought a bunch of wood bamboo skewers.  The magnets are now only for hard to reach places.

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

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Wednesday, January 16, 2019 12:53 PM

FRRYKid

As for the grumble about unintended uncoupling, this is an industrial main.  

Grumble?  Laugh

Rich

Alton Junction

  • Member since
    May 2008
  • From: Miles City, Montana
  • 2,289 posts
Posted by FRRYKid on Wednesday, January 16, 2019 12:45 PM

mbinsewi

OK, yes a simple run around move.  The switcher is coming from the yard on the right, facing forward, pulling a line of cars that need to be spotted on the 3 spur tracks on the left.

The switcher stops, and parks the cars on the main, making sure the cars are clear of each turnout.  The switcher uncouples from the cars, pulls forward past the turnout on the left,  then backs into the siding, goes through the siding, and comes back out on the main, behind the string of cars.  The switcher pulls forward, couples to the cars, and then pushes the cars to their respective spots on the 3 spur tracks on the left.

Just put your magnet on the main, making sure than when the switcher uncouples, the cars are clear of both turnouts, so the switcher has room to run around.

Is that what your looking for?

Mike.

 

Exactly.

As for the grumble about unintended uncoupling, this is an industrial main. It only serves the three tracks on that yard. I am also using delayed uncouplers. So that should avoid unintended uncouplings.

"The only stupid question is the unasked question."
Brain waves can power an electric train. RealFact #832 from Snapple.
  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Wednesday, January 16, 2019 8:48 AM

richhotrain
Don't like magnets on the main. A bad place for unintended uncouplings to occur.

And I agree Rich, thats why the first time I attemted to figure out what he's doing, I suggested that he pull the cars into the siding, and use the main as a run around.  But it a took awahile to figure out what he wanted to know.

I don't know if that's his actually main line or not.  He can figure that out.

Mike.

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Wednesday, January 16, 2019 8:45 AM

Thats a good idea, Ron.

Mike.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Wednesday, January 16, 2019 8:45 AM

mbinsewi

Just put your magnet on the main, making sure than when the switcher uncouples, the cars are clear of both turnouts, so the switcher has room to run around. 

Don't like magnets on the main. A bad place for unintended uncouplings to occur. Dead

Rich

Alton Junction

  • Member since
    November 2003
  • 266 posts
Posted by Ron High on Wednesday, January 16, 2019 8:44 AM

Why don't you try temporarily glueing the magnets in different locations to see which arrangement works best. I have used a couple of spots of contact cement or spikes on the ends of the Kadee in the track magnets . When you have done your testing you can do a more pemanent location.

Ron High

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Wednesday, January 16, 2019 7:51 AM

OK, yes a simple run around move.  The switcher is coming from the yard on the right, facing forward, pulling a line of cars that need to be spotted on the 3 spur tracks on the left.

The switcher stops, and parks the cars on the main, making sure the cars are clear of each turnout.  The switcher uncouples from the cars, pulls forward past the turnout on the left,  then backs into the siding, goes through the siding, and comes back out on the main, behind the string of cars.  The switcher pulls forward, couples to the cars, and then pushes the cars to their respective spots on the 3 spur tracks on the left.

Just put your magnet on the main, making sure than when the switcher uncouples, the cars are clear of both turnouts, so the switcher has room to run around.

Is that what your looking for?

Mike.

  • Member since
    May 2008
  • From: Miles City, Montana
  • 2,289 posts
Posted by FRRYKid on Tuesday, January 15, 2019 9:44 PM

Apologies for the confusion. Let's try this mockup. It is not an exact track plan, but it should give you an idea of what I am looking at:

The switcher would come from the main yard facing the left. As can be seen, the engine has to switch ends. Otherwise, the engine would be trapped. Hence why the need for the passing sidng.

"The only stupid question is the unasked question."
Brain waves can power an electric train. RealFact #832 from Snapple.
  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Tuesday, January 15, 2019 5:21 PM

I know Wayne.  He is hard to follow.  I'm probably not right either.  If we seen his track plan, maybe we could figure out what he's doing.

Mike.

  • Member since
    January 2004
  • From: Canada, eh?
  • 13,375 posts
Posted by doctorwayne on Tuesday, January 15, 2019 4:34 PM

I'm more confused now than when this started.

If the locomotive is pulling the cars out of the yard, which is to the left, then it's easiest to push them to the two industries from the right-hand turnout - the one on the left is not needed. 

The cars to be spotted should be "blocked" in a manner so that the ones for the far (left) end of the industrial track, will be first-in when pushed from the turnout at the right.  They'd be uncoupled and then pushed to their appropriate stop, as I outlined in my original post. 
The cars for the other industry would then be pulled back to the uncoupling magnet, and, once uncoupled, be pushed to their respective spot.

If you need the track as a run-around, then don't use it for industries, as your industries will soon start shipping by truck if you keep moving their cars while they're trying to load or unload them.

I have passing tracks in all of my small towns, and they allow another train to pass one which is stopped on the other track.  However, on my DC layout, only one train is allowed to move at a time....

 

When most trains come to these towns, they're there to "work" the industries, so the passing track can then serve as a run-around, allowing the locomotive to lift or drop cars at any industry, whether its turnout is a facing-point or trailing-point type. 
It does help if the train is blocked appropriately to minimise the number of moves needed, but it's possible to switch the entire train from either end because of the run-around.  

I don't know how much room you have available in the area under discussion, but if you need a run-around, can you put it on the other side of the main?
If so, use the turnout on the right end of your industrial track for the left end of your new run-around.  It's not needed where it is now.

Wayne

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Tuesday, January 15, 2019 12:43 PM

OK, well, I would use the siding track to park the cars and use the main track to run around to the other end.

I would think you'd want to put the magnet so when the cars uncoupled, they wouldn't be fouling the turn out, on either end.

Mike.

  • Member since
    May 2008
  • From: Miles City, Montana
  • 2,289 posts
Posted by FRRYKid on Tuesday, January 15, 2019 12:33 PM

mbinsewi

Yea, that makes perfect sense, but to me, he seems like he wants to park the cars so he can run around them.

Maybe I got up too early. Sleep

Mike.

That's exactly what I've loosing at.

gregc

if you want to be able to spot the car from either end would you then need two uncouplers?

That is true as well.

I will only be spotting the cars on the left hand side. The area in question has an industrial area with two turnouts. The first turnout is for a woodchip loading area/team track. The second turnout controls access to a two track yard for storage of inbound and outbound cars,

The engine would need to be "flipped" before it enters the yard so that the cars can be parked and not bury the engine hence two magnets.

"The only stupid question is the unasked question."
Brain waves can power an electric train. RealFact #832 from Snapple.
  • Member since
    February 2008
  • 2,360 posts
Posted by kasskaboose on Tuesday, January 15, 2019 8:24 AM

This is a great discussion thread.  Two questions to help myself and others to consider:

1. Are the magnets only needed when there's a run-around track?

2. Would it make sense to put one at each area leading to a yard or just one?  Perhaps that depends on what you're trying to achieve.  I am just wondering for the future.

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Tuesday, January 15, 2019 6:42 AM

if you want to be able to spot the car from either end would you then need two uncouplers?

greg - Philadelphia & Reading / Reading

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Tuesday, January 15, 2019 6:21 AM

Yea, that makes perfect sense, but to me, he seems like he wants to park the cars so he can run around them.

Maybe I got up too early. Sleep

Mike.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, January 15, 2019 6:14 AM

doctorwayne

If your locomotive is pulling cars from the left, you don't really need the turnout at the left end of your industrial track.  Instead, pull past the turnout at the right, and then push the cars into the dead-end track.  

Place the magnet on the dead-end track, near the turnout, but far enough in that a car uncoupled there and left there will not foul the main line.  With Kadees, you can uncouple a car over the magnet, then back away from it slightly.  This will allow the magnet to force each coupler aside, so that when you push the cars back together, they don't re-couple.  This will allow you to push the uncoupled car to wherever it needs to be spotted.  You simply leave it there and back the rest of the train away - the couplers will spring back to their normal positions.

So: one magnet, and one turnout...unless there's other stuff you've not mentioned.

Wayne

 

Exactly. Yes

Rich

Alton Junction

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Tuesday, January 15, 2019 6:06 AM

FRRYKid
I have the "main" and a passing siding. Where do I put the magnets: on the siding or on the main?

i believe the uncoupler has to be on the main in front of the facing point (see diagram and link below).

in the typical case where there is a spur with just a single turnout, you need to uncouple the train behind the car you want to spot and push it back on the main clear of the turnout, then uncouple the the car and push it into the spur  (see the case in the top right corner of the diagram).

uncouplers on the main may car unintended uncoupling if a train is moving slowly past it.

in your specific case, as doctorwayne described, you can put the uncoupler on the siding.   The cars behind the car you want to spot can be uncoupled and pushed out onto the main using the turnout on the far end of the siding.  you can then uncouple and spot the car at the industry.   (i don't see anything similar in the diagram).

greg - Philadelphia & Reading / Reading

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Tuesday, January 15, 2019 5:46 AM

Just so I understand, your pulling cars from the left on the main, but you need to run around the cars so you can push them to the final destination.  So you want to park the cars on the main, and use the siding/run around track to reposition the loco, or use the siding to park the cars, and use the main as your run around, right?

Mike.

  • Member since
    January 2004
  • From: Canada, eh?
  • 13,375 posts
Posted by doctorwayne on Tuesday, January 15, 2019 1:28 AM

If your locomotive is pulling cars from the left, you don't really need the turnout at the left end of your industrial track.  Instead, pull past the turnout at the right, and then push the cars into the dead-end track.  

Place the magnet on the dead-end track, near the turnout, but far enough in that a car uncoupled there and left there will not foul the main line.  With Kadees, you can uncouple a car over the magnet, then back away from it slightly.  This will allow the magnet to force each coupler aside, so that when you push the cars back together, they don't re-couple.  This will allow you to push the uncoupled car to wherever it needs to be spotted.  You simply leave it there and back the rest of the train away - the couplers will spring back to their normal positions.

So: one magnet, and one turnout...unless there's other stuff you've not mentioned.

Wayne

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!