# Help with derailments



## Massey (Apr 16, 2011)

Hey everyone. So my little layout was in storage for a few months and I just brought it out to finish it and of course run trains. Before it was stored (inside my house) my Kato ONP trains ran flawlessly for hours at a time. Now the cars walk over the rails in the corners. No debris inside the rails, no hitches in the joiners, and I have cleaned the rails with both a bright boy and alcohol. The derailments are only the coaches and usually in the entrance or exit of the turn where the truck needs to twist. 

Now in HO this usually meant too heavy of a train or too light of a car, I imagine N scale has similar issues, but these cars never did this before. Any ideas? 

Ps trucks seem to twist freely and the wheels turn easy.


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## sid (Mar 26, 2018)

take a small piece of wood an press down firmly on the track while running it around the track. . track may have twisted or sumtin like that. check all the track connections as well. . if its kato track press down firmly at every track connection. those connection tend to come up a lil bit ive found out.


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## Massey (Apr 16, 2011)

Thanks Sid, I have done something very similar to what you desribe. Problem is the wheels walk over the rails an inch or two away from the joiners.


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## MichaelE (Mar 7, 2018)

Then your rails are out of gauge. Do you have an NMRA gauge?


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## DonR (Oct 18, 2012)

As Sid noted, derails usually happen when there is
a vertical track misalignment. The tracks could have expanded
or contracted while in storage.

In N scale a tiny difference can amount to a huge
problem.

Use a very light plastic glass or small med vial with a
small amount of water. (It should be light enough that
it doesn't press the track down) Draw a circle around the
water line when it is sitting on a very level surface. Then place it on your tracks in the area where there are derails. Make
tiny moves and note 
if the water is not level with the vial circle. That would
tell you of vertical misalignment. 

If you don't see anything amiss then do the old SLO MO
trick to find the problem.

Have the loco move the derailing cars as slow as it can
go. Have a bright light on their wheels. Get down close.
When you see a wheel START to lift, STOP. That is where there is a problem with the track.

A thought, you could easily try a coin on the derailing coach to
see if added weight helps.

And another thought, do the cars have 4 or 6 wheel
trucks?

Don


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## VegasN (Mar 14, 2016)

Oh the pains I feel for your situation. I have instances where a train will go around the layout 4 or 5 times, then suddenly derail....

But, with your situation, my guess is the tracks have "changed" shape over its storage time. I would recommend an NMRA gauge......it is exceptionally inexpensive, and does A LOT! Checks track gauge, rail heights, coupler heights.....all kinds of things.


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## Massey (Apr 16, 2011)

Thanks Don, Michael and Vegas for replying. I don’t have a gauge at this time for N, it should arrive soon. The trucks are 4 wheeled trucks on Kato Metra bi-level cars from my ONP 2016 set. 

I’m beginning to lean towards the cars being the issue and here is why. 
Same 2 cars at random spots its always just entering or exiting a curve (when the truck needs to pivot) 
The train does this on the upper or lower level (not connected) but the 2015 set doesn’t on either location. 
And it doesn’t matter which position the 2 cars are in it still happens. 

On HO we would use a light bearing or sewing machine oil on the trucks to help them pivot, but those cars are heavier and can handle dirt and lint better than the smaller cars. Would using something like that help here too?


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## traction fan (Oct 5, 2014)

*Derailing cars*



Massey said:


> Thanks Don, Michael and Vegas for replying. I don’t have a gauge at this time for N, it should arrive soon. The trucks are 4 wheeled trucks on Kato Metra bi-level cars from my ONP 2016 set.
> 
> I’m beginning to lean towards the cars being the issue and here is why.
> Same 2 cars at random spots its always just entering or exiting a curve (when the truck needs to pivot)
> ...


Massey;

If you have isolated the problem to two particular cars, then I agree those cars are the problem, or at least part of it. Since this happens only when entering a curve, the track, or at least the transition from straight track to curved track, is likely to be contributing to the problem also.
There are several possibilities. One of which you have touched on, "the trucks need to pivot." Before you reach for that oil can, I'd like to know a few details.

1) Have you checked how easily, or reluctantly, each truck on the whole train (not just the suspect cars) pivots?

2) Do the trucks on your suspect cars pivot as easily as those on the other cars?

I'm guessing that these are long cars 85' ? and high, since they are bi-levels. They are likely also a bit too light just because they're models. However adding weight can only mask the underlying cause of the derailments, not find it. Find and fix the real problem first, then add weight as low and centered as possible, if you wish. Doing so will help the cars track better.

3) What radius is the curve they are attempting to enter?

4) Are you using an "easement" (a curve of larger radius) at the entrance, and exit, of the main curves? Are any of the bi-level cars, (again not necessarily just the two problem cars) leaning over at all when they enter the curve? 

5) Are the couplers body-mounted or truck-mounted?

I certainly agree with the advice to get an N-scale NMRA gage and use it to check both the gage of all the track, and the gage of all the wheels. You will probably find that the wheels are too close to each other to fit the gage. Kato equipment is made to that Japanese company's own standards, and often Kato rolling stock has the gage set narrower than NMRA standards. While its quite wise to check the gage of the track and wheels, unless you find a bit of out of gage track near the curve entrance, or a major difference in the wheel gage of the suspect cars from the gage of the others; I don't think gage fits the scenario of your problem.
I think you may have put your finger on it, the trucks on those two cars are not pivoting as easily, or as far around, as they should be. If you find that to be true, try dismounting the trucks, one at a time and very slightly drilling/filing out the hole that they pivot in. Oil is not necessary here, and will attract dust. Also, unless the oils you mentioned are plastic compatible oils, they may damage the plastic over time.

Though I like and respect DonR, and agree with nearly all his posts, I disagree with his notion that N-scale equipment will derail at the slightest imperfection of rail height. True, we all want smooth track, but that's equally true in any scale. You don't need to use a microscope to check N-scale track anymore than you do for HO-scale track.
Unless the track is badly laid, out of gage, or has some other major defect, like a rail not seated in a joiner; the trains should be able to traverse it safely. This is equally true for any of the modeling scales. My old N-scale club had some roadbed that was so bumpy that the trains bobbed up and down like boats in choppy water, but they didn't derail.

Lastly, I know that part of troubleshooting (I've spent much of my life troubleshooting for a living) any problem is trying to find out, What changed?
You may well wonder why something that worked perfectly before doesn't do so now. Well, if you think about it, that's exactly why we have repairmen, technicians, and doctors; things fail.
You have established that something is causing derailments NOW. Don't fall into the mental trap of arbitrarily disregarding any possibility that doesn't neatly fit all the parameters of the current scenario. Sometimes they just don't, but if you keep plugging away, you will find the cause.

Enjoy "the thrill of the hunt!"  
, 
Traction Fan:smilie_daumenpos:


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## Massey (Apr 16, 2011)

Thank you Traction Fan. I love to troubleshoot problems which is why I have been an auto mechanic for almost 30 years now. While finding the problem isn't a problem here, I was not sure of the correct solution to it. 

The couplers are truck mounted, the cars are bone stock Kato as delivered. No lighting no modifications, nutin. The thing that changed was time. The cars were put back into their book case and stored on a book shelf, the layout was placed in a bathroom under a window that we usually leave open in the summer. While my part of Washington doesn't get crazy humidity, we tend to be a bit damp in the mornings and dry once the sun comes up. I imagine this has made some effect to the wood of the layout's frame. This was evident with the facia having pulled away from the mountain in an area that didnt get glued. It's now glued. 

Right now the tracks are not secured to the foam, but they are seated in place via the bridge and the wiring. These prevent the track from moving from the train, but can be moved by hand still if needed. I am using Kato Unitrack here btw. This is the same exact configuration that was in place before storage, I have not touched the scenery around the upper level of the layout yet (still need to build a few more buildings first). 

In my experience with HO scale I found that when the wheels were too narrow the cars wouldn't walk over the rails but fall into them. I am having issues with the wheels climbing the rail either entering or exiting the curve, push or pull, and not always at the same spot but usually near the area where the trucks need to start moving. When the wheels are too far apart you get what I am having right now. I am going to guess that a train is a train HO or N and the things I have experienced as an HO modeler are going to fit for N as well. 

The trucks snap into the frames, there is no pin or any way to shim them, or put in a washer to act as a pivot point. I took them off last night and checked for burrs or anything that may cause binding and didn't find any tattle tales. I will try putting a penny or 2 inside the cars are see if that helps. and I will get some calipers out to measure the gauge of the rails as well as the wheels. 9mm for the track and just under 9mm for the wheel sets.


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## sid (Mar 26, 2018)

also check them plastic dokickies that hold the rails in place on the ties, some times they stick up a bit. also with kato track a twist will do the same thing. i have removed and reinstalled my kato track a dozen times and ifound out real quick you got to go to each section and make sure there down and not twisted even a lil bit. some cars dont like kato track either. hope you get it worked out.
added weight does help too.


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## DonR (Oct 18, 2012)

Massey

You have truck mounted couplers. 
You have 85' long cars. Does the derailing
occur by the trucks coupled to the next car? One truck
pivoted entering curve, the other still on straight track. Stress
on the couplers transferred to the wheels. This
could be the coupler of one car pulling the other off.

Does the truck at the end of the train derail in the
same places?

You could try changing car position in the train. If
it doesn't derail when it's the truck at the end car, the truck mounted couplers may be the problem. It's why many of us go
to body mounted couplers. 

Don


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## Massey (Apr 16, 2011)

OK some experimenting has had some predictable results, and some not.

First it didn't seem to matter which position or which direction the trouble car was facing or placed. I did notice it was only one truck derailing ever. This leads back to my thinking the track is not the issue. The truck on the derailing car felt strange as I rotated it by hand. I checked the wheels and all was well there, they were about 8.8mm to the inside of the flanges. I took the truck off the chassis but couldn't see anything odd, or that would cause the strange rough feeling. I removed the other truck and all looked identical. For giggles I placed the trucks on opposite sides of the car and they both pivot free and smooth. I put the car back on the rails and all so far has been good. I have had about 15 minutes of running with no derails. Before this I could get maybe 2 or 3 minutes of running.

So we will see how it goes. Thank you all for your input


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## traction fan (Oct 5, 2014)

*Congrats*



Massey said:


> OK some experimenting has had some predictable results, and some not.
> 
> First it didn't seem to matter which position or which direction the trouble car was facing or placed. I did notice it was only one truck derailing ever. This leads back to my thinking the track is not the issue. The truck on the derailing car felt strange as I rotated it by hand. I checked the wheels and all was well there, they were about 8.8mm to the inside of the flanges. I took the truck off the chassis but couldn't see anything odd, or that would cause the strange rough feeling. I removed the other truck and all looked identical. For giggles I placed the trucks on opposite sides of the car and they both pivot free and smooth. I put the car back on the rails and all so far has been good. I have had about 15 minutes of running with no derails. Before this I could get maybe 2 or 3 minutes of running.
> 
> So we will see how it goes. Thank you all for your input


Massey;

Congratulations! It sounds like you may have fixed the problem.
You suspected that some trucks were not pivoting properly, and it looks like you were right.

DonR mentioned truck-mounted couplers and how stress can be passed from the couplers to the trucks. This can cause the wheels to try and climb the rails to relieve the stress between couplers. However for tight curves (for N-scale I'd say anything under 12" radius) truck-mounted couplers actually produce less of this sideways stress than body-mount couplers do. This is especially true of long cars, because of their greater overhang. This may not have anything to do with the current problem; I only mention it for future reference in case you plan to body-mount couplers. Body-mounts do have many advantages though, as long as you're not trying to run long cars through tight curves. That's really about the only case where truck-mounts are better than body-mounts. The worst possible scenario is mixing body and truck mounts. It's much better to pick one type and stick with it.
You didn't say what radius curve you have, or whether you were using easements at the ends of the curve. Again this is only for reference, I'm assuming that you have already fixed the current problem. Easements are very good at getting cars from straight track into a curve. If you build another track arrangement at some later time, it's a good idea to include easements at each end of a curve.

good luck, and have fun;

Traction Fan:smilie_daumenpos:


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## VegasN (Mar 14, 2016)

Massey said:


> OK some experimenting has had some predictable results, and some not.
> 
> First it didn't seem to matter which position or which direction the trouble car was facing or placed. I did notice it was only one truck derailing ever. This leads back to my thinking the track is not the issue. The truck on the derailing car felt strange as I rotated it by hand. I checked the wheels and all was well there, they were about 8.8mm to the inside of the flanges. I took the truck off the chassis but couldn't see anything odd, or that would cause the strange rough feeling. I removed the other truck and all looked identical. For giggles I placed the trucks on opposite sides of the car and they both pivot free and smooth. I put the car back on the rails and all so far has been good. I have had about 15 minutes of running with no derails. Before this I could get maybe 2 or 3 minutes of running.
> 
> So we will see how it goes. Thank you all for your input



Awesome!!:smilie_daumenpos:


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## Massey (Apr 16, 2011)

I dont have any easements on the layout. If you look at my Holiday ONP layout thread you will see the layout in question. With these cars and my radii I'm thinking that leaving the truck mounted couplers is best as the upper part is a bit tight. On these cars though are 2 that have body mounted couplers. They are the cab cars that are in the back of the train. the rear coupler under the control portion of the car is a body mount. They did this because there is a snow plow here. There are 2 of these cars in use on my 2016 train and only one gets coupled to another car. Ironically I don't have an issue here. 

When I get home from work tonight I will turn the layout on and see what happens. Hopefully the trains wont derail... or I will be right back were I started.


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## Massey (Apr 16, 2011)

Well....

So the cars that were derailing have given up the derailing issue but once again I have a new car doing the same thing. GRR I took the truck off the chassis and checked it over and again found nothing but installing back on the chassis seemed to make it work smoother. I don't know whats up with this train, it's brother isn't doing it and its even older. Looks like I'm going to get down and disassemble these cars and do some cleaning.


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## Massey (Apr 16, 2011)

This time I took my micrometer to all the wheels. Wow there were some variences. I'm guessing this is the cause of my issue. I set all the wheel sets to be around 8.7 to 8.8mm measured between the flanges and that seems to keep them on the tracks again. The trains ran for several hours with no issue after I did that.


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## CTValleyRR (Jul 26, 2014)

An NMRA standards gauge is a great tool for making sure wheels and track are properly aligned. If you don't have one, it should be your next purchase.


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## Massey (Apr 16, 2011)

CTValleyRR said:


> An NMRA standards gauge is a great tool for making sure wheels and track are properly aligned. If you don't have one, it should be your next purchase.


I have to order another. The one I ordered said N scale in the listing but I received a HO one. The guy had to refund my money as he didn’t have any N scale. I will order one here soon... my local train shop didn’t have one either.


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## VegasN (Mar 14, 2016)

Massey said:


> I have to order another. The one I ordered said N scale in the listing but I received a HO one. The guy had to refund my money as he didn’t have any N scale. I will order one here soon... my local train shop didn’t have one either.


Yeah, I was unable to locate one locally in Vegas too, had to order it online....I think I got mine from modeltrainstuff.com (MBKlein)


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