# (Kato) Having constant derailing issues.



## Mithril_Maiden (Nov 28, 2020)

I'm using Kato Unitrack, superelevated with banked curves (Kato pack V13), and this issue is specific to lightweight Kato passenger cars. These cars include the 12 car El Capitan set and the 5 car Caltrain BiLevel set. I use 3 locomotives to pull El Capitan and one locomotive to pull Caltrain. Generally derailing happens coming out of a curve, and the derailing is constant. It's usually the front truck on the lead passenger car that derails, sometimes causing cascading derailments down the train, sometimes not.

I've checked that the track is fitting together properly, and it is. The derailment happens in either direction of operation, not at one specific spot, and if I run a trainset that doesn't have standard couplers, there are no derailment problems, no matter how fast or for how long I run the train. For example, the Kato TGV Reseau 10 car set doesn't use external couplers, in uses internal ones with a very tight grip, and it never derails on my track. I also have a Rapido Turbotrain, which also uses internal couplers with a tight grip, and it also never derails.

I'm hearing that the issue could be the banking of the tracks combined with the very light weight of the train cars? Like maybe the banking is tossing the cars? That could explain why the TGV and Turbotrain don't derail, since both have a locomotive at each end that evenly distribute weight across the train. If this is the issue, how could I address it? Kato double track is banked, so switching to non-banked curves will be a huge change.


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## Steve Rothstein (Jan 1, 2021)

A quick check if it is the light weight of the cars might be to temporarily put some weight on a couple of them and see if that helps. If it does work, putting permanent weights inside the cars should not be too hard. I have not had this problem, so I cannot say more than that.


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## CTValleyRR (Jul 26, 2014)

I think the most likely cause of your derailment is simply that your curves are tighter that those long cars can handle, and something is binding between the cars. You should probably check that first of all. The solution to that is to swap out the coupler for one with a longer shank, although this has the drawback of making the cars unrealistically far apart. Then make sure the trucks can swivel enough to actually follow the curve. If there are no issue there, then check the weight.

A couple of resources for you: 1) go to the NMRA (that's National Model Railroad Assn) website (www.nmra.org) and check their standards section. This will give you minimum curve radii, proper measurements for cars (including weight), and lots of other good info. 2) Buy an NMRA standards gauge, which will enable you to rapidly confirm that many of these measurements are within spec.


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## Old_Hobo (Feb 20, 2014)

I vote for the “add extra weight to the cars“ side.....after testing, of course.....


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## Mithril_Maiden (Nov 28, 2020)

CTValleyRR said:


> I think the most likely cause of your derailment is simply that your curves are tighter that those long cars can handle, and something is binding between the cars. You should probably check that first of all. The solution to that is to swap out the coupler for one with a longer shank, although this has the drawback of making the cars unrealistically far apart. Then make sure the trucks can swivel enough to actually follow the curve. If there are no issue there, then check the weight.
> 
> A couple of resources for you: 1) go to the NMRA (that's National Model Railroad Assn) website (www.nmra.org) and check their standards section. This will give you minimum curve radii, proper measurements for cars (including weight), and lots of other good info. 2) Buy an NMRA standards gauge, which will enable you to rapidly confirm that many of these measurements are within spec.


I believe I do own an NMRA gauge. Kato lists a minimum turning radius of 249mm for these, and my curves are 381mm, so it shouldn't be too tight. I do have a different set of rail with 447mm curves and no viaduct walls. I don't think I've seen anything hitting the viaduct walls, and I'd think I'd notice that, but Kato does list it as a potential issue. I can try these wider, unwalled tracks tomorrow and see if the derailment keeps happening. It is still banked curves, though, but if it still derails, that would isolate the issue at least.


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## Steve Rothstein (Jan 1, 2021)

I did think of one other thing, but I assumed you knew about this and checked it already. Kato makes adapter curves that change from super-elevated at one end to flat at the other to mate with the straight track. I don't know how big the difference is and I assume you can see it, but have you checked they are mounted in the right direction? So far, I've only used the Kato single tracks which are flat on the curves also, so I can't say much more about this possible problem.


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## Mithril_Maiden (Nov 28, 2020)

Steve Rothstein said:


> I did think of one other thing, but I assumed you knew about this and checked it already. Kato makes adapter curves that change from super-elevated at one end to flat at the other to mate with the straight track. I don't know how big the difference is and I assume you can see it, but have you checked they are mounted in the right direction? So far, I've only used the Kato single tracks which are flat on the curves also, so I can't say much more about this possible problem.


That would explain my derailment issues, yes. I took the loop apart, so I can't check, but when I build the next loop tomorrow, I will check to make sure. I haven't been checking, so it is possible this is the problem. I would wonder why this doesn't derail the TGV or Turbotrain sets, though.


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## Wooky_Choo_Bacca (Nov 13, 2020)

It's easy to see the correct connection of the shorter easement track to the super-elevated curve sections, between the connectors look for a little arrow, that will be the end to connect to the SE curve


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## Mithril_Maiden (Nov 28, 2020)

If I do need to add weight to the cars, how should I do it?


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## Wooky_Choo_Bacca (Nov 13, 2020)

You could use small hex nuts and a dab of glue inside of cars where they can't be seen and gondolas (have the coal "load" to cover them) or fishing weights and glue. At the hobby stores they also have square weight bars for pinewood derby cars, won't need much. Tank cars usually come with weights inside


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## Steve Rothstein (Jan 1, 2021)

Mithril_Maiden said:


> If I do need to add weight to the cars, how should I do it?


Doing it as a test to see if that helps, I would just use masking tape to hold a small weight down, maybe a couple pennies. For permanent, if the test shows it helps, I would suggest taking the body off the frame for the passenger cars and gluing down the weight as Wooky_Choo_Bacca just suggested.


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## MichaelE (Mar 7, 2018)

How severe is the transition from super elevated to flat? That was my first thought. Super elevation is done on a lot of layouts in Europe and if the transition is too abrupt derailments are the norm.

One car is straightening out on the straight track while the one behind it is still at an angle on the elevated curve.


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## Wooky_Choo_Bacca (Nov 13, 2020)

MichaelE said:


> How severe is the transition from super elevated to flat?


This is on a 15" curve, N scale, right at 80 scale feet from whatever degree lean to flat


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## DonR (Oct 18, 2012)

I can imagine how a long passenger car truck would act when on a flat track then encountering the banked curve track...the truck is rigitd, it cannot
flex, so the front right wheel would follow
the rail, but the front left wheel would lift from it's rail...thus causing the truck to slip to the left...and this is further
affected by the truck mounted couplers.

As always, when there are derails, get down close with a good light. Run the train as slow as it will go...watch the
front truck wheels...when you see one lift...STOP...something right there is the cause.

Don


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## Mithril_Maiden (Nov 28, 2020)

Okay, so, different layout, ground level this time, and I'm getting the same results. Front passenger truck derails leaving the corner. I'll try weighting the cars down, I just need to find something to weight them with.


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## LJClark (Jun 26, 2017)

Mithril_Maiden said:


> If I do need to add weight to the cars, how should I do it?


I've used BBs mixed with a little silicone sealant/adhesive. (Back in the day some people used lead shot, but we don't do that any more.)


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## CTValleyRR (Jul 26, 2014)

Anything heavy, fixed in place. Steel washers, BBs, spare nuts and bolts, fishing stinkers, car wheel weights, or hobby weights (available from Woodland Scenics and others. Try to put the weight on the centerline or symmetrical about it.

You're fixated on the weight, though. Have you ruled out truck swing, mechanical interference, and insufficient space between cars as possible causes?


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## Mithril_Maiden (Nov 28, 2020)

If it is truck swing or short couplers, I don't know what the next step is. I really don't know anything about truck swing, and I hope I don't have to use longer couplers.

I've chosen motorcycle wheel weights. Smaller than car ones. Should get here tomorrow. I can tape them to the cars and see if that helps. I do hear that the weight needs to be low, though, and some of the Santa Fe cars have almost no clearance, so I can't go under the car. I'm thinking the sides down low, with even weight on each side, and if it works, I can do the labor of getting the passenger cars open to put them inside.


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## CTValleyRR (Jul 26, 2014)

Cars generally have a structural beam in the center underneath, and you can often place weights in pairs on either side of that, tucked into the web of the I beam.

You've identified one solution to couplers: longer ones. The trucks are the assemblies that hold the wheels. If they can't turn far enough to follow the curve of the track, that's a problem. Sometimes, it's details under the car that restrict the swing, and you can file these down, or remove them completely. Of course, the best fix for all of these is to use broader curves on your track.


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## Wooky_Choo_Bacca (Nov 13, 2020)

Someone correct me if I'm wrong on this. This applies to the actual trains as well as the models, there is suspension on the cars and can be seen with the cars rocking side to side. The trucks have to give a little even with the easements of the rails up and down as well as the curves. The longer cars need wider curve radius than the short ones or you risk derailments. I'd agree that if one wheel is lifting off the track and causes a derail the the truck is hanging up on something


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## CTValleyRR (Jul 26, 2014)

Correct.


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## Mithril_Maiden (Nov 28, 2020)

CTValleyRR said:


> Cars generally have a structural beam in the center underneath, and you can often place weights in pairs on either side of that, tucked into the web of the I beam.
> 
> You've identified one solution to couplers: longer ones. The trucks are the assemblies that hold the wheels. If they can't turn far enough to follow the curve of the track, that's a problem. Sometimes, it's details under the car that restrict the swing, and you can file these down, or remove them completely. Of course, the best fix for all of these is to use broader curves on your track.


Broader curves just isn't an option, and if it is the ultimate solution, I'd be pretty upset. I'm running a turn radius almost twice that of the minimum radius of all cars and locomotives that are derailing, and if that still isn't broad enough, I don't know what to say other than it would make Kato Unitrack functionally useless. I can't go any wider without flex track, and that'll quickly run into space issues. If Kato's passenger car sets can't operate on the widest Unitrack curves Kato makes, that would be a severe indictment of Kato as a company. I just don't think it's the case, though. Especially since I can chain together locomotives as much as I want without derailing.

I'm still leaning on weight as the cause, because from research, it seems that the lead car in a string of light cars being the one to derail in a curve isn't an unheard of issue. It's just a tedious job, and I've been a mix of busy and not really up to sitting down and weighting all the cars to see if it works. Eventually I will, and see it that helps.

If the solution is new couplers, it looks like those aren't really in stock right now? That would be bad, not to mention looking weird for passenger trains. I do have some cars and two locomotives where I need to switch out Micro Trains couplers for Kato couplers, but that's more a medium term issue for me, especially with stock issues on couplers. I want to get my Kato cars to stop derailing before handling the non-Kato stock. I know Micro Trains couplers are usually considered better, but my collection split is something like 90% Kato, 5% Micro Trains, 5% Con-Cor and Life-Like. I eventually want all of my collection to utilize one coupler design, and and I'd rather replace 10% of my couplers than 95% of my couplers.


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## Mithril_Maiden (Nov 28, 2020)

I think another reason I'm leaning towards weight as a solution is that I see that light cars derailing can be an issue on rougher track, and I can't really smooth out the track. My layouts are temporary, so I can't make everything 100% perfect all the time, and if just making the passenger cars heavier works, that may be more ideal. Especially with how much motive power I have available. My passenger train sets generally are around 12 passenger cars, give or take, but have multiple locomotives because they did in real like, and my B units are mostly powered. So I have 3 powered locomotives pulling 12 passenger cars for El Capitan, 4 powered locomotives and 12 passenger cars on the Super Chief, and 2 or 3 powered locomotives for long Amtrak trains or the 20th Century Limited. Only real outlier is the Southern Pacific Morning Daylight, at one locomotive for 8 cars. What I'm getting at is, with the possible exception of the Daylight, if I make these passenger cars heavier, I should have enough excess motive power to cope with the increased load, especially on layouts without inclines. IIRC, one locomotive for 15 cars in N scale is the normal max recommended load.

I did figure out where to weight the cars, at least for El Capitan. I can remove the shells, and slide the weights in between the passenger seats above the trucks. The motorcycle wheel weights I bought just about fit.


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## CTValleyRR (Jul 26, 2014)

Not saying that adding weight won't work, but it's unlikely to completely fix issues with rolling stock. Unfortunately, this is a hobby of compromises. Sometimes you have to sacrifice rigidly prototypical appearance to get better performance.

That said, Kato is quality product. But it is not a true statement to say that if Kato equipment doesn't run on Kato track, that's an indictment of the company. Far from it. This isn't a series of toys where every product is designed to work together. It's a hobby with scales and standards. Kato isn't building product for Unitrack users, but for the larger hobby. If a car built to their standards of fidelity doesn't perform well on Unitrack, it's because it wasn't intended to. Minimum turn radius means just that: the model in question can be coaxed through a turn of that dimension. Not necessarily that it will perform well in all possible track or equipment combinations using that radius. It's also possible that you have enough rolling resistance and motive power that your cars are "stringlining", that is, attempting to follow the straightest path through a curve rather than that set by the rails.

You should also go back and dispassionately assess all of your track. Scrupulously check it for conformance to standards (you need an NMRA standards gauge for that; most any hobby shop will have them). Make absolutely certain that it is free of kinks and torque, and every joint is dead smooth. It's a common assumption that because the track pieces snap together that it's impossible to lay them badly, but it's not true.


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## Mixed Freight (Aug 31, 2019)

Mithril_Maiden said:


> If I do need to add weight to the cars, how should I do it?


NMRA guidline for N-scale car weight is 1/2 oz. (.5 oz) initial weight plus .15 oz for every inch of length.

Example #1...............
40' box car (approx. 3" long in N-scale): .5 oz initial weight plus (.15 oz x 3" = .45 oz) adds up to .95 oz. Just shy of 1 oz. Check the weight of the car and add weight until the car weighs .95 oz. (or pretty close to it, doesn't have to be super exact).

Example #2..............
80' long passenger car (6" long): .5 oz initial plus (.15 oz x 6" = .9 oz) adds up to 1.4 oz. Almost 1-1/2 oz. Check the weight of the car and add enough weight until the car weighs 1.4 oz. (or pretty close).

You can maybe use a postal scale, a food portion diet scale, or maybe pick up an inexpensive little digital scale at Harbor Freight Tools if you have one close by.

Your cars will track much better if weighted to NMRA standards. Unfortunately, a fair amount of N-scale stuff is still being produced at less than ideal weight. Micro Trains (MTL) is one good exception - most of their stuff tends to be weighted pretty close to ideal, in my experience.

Good luck, hope this helps a little.
Paul.


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