# Frequent derailment on a sloped curve



## roykirk (Jul 20, 2012)

I'm building my first outdoor G Scale set up. I'll try my best to describe the layout. Long narrow flower bed with a slope (maybe 6" higher in back than front). I have 40' of brass track laid out, with 4' diameter curves on each end. The front section of track is level and the back section of track is level. All the track is just laying down on packed dirt right now because I don't want to deal with ballast until I make sure everything is going to work right. So if you're looking at the layout from the yard, I've got an uphill curve on the left, a downhill curve on the right, and two long level sections in between in the front and back. Train is running clockwise.

So the problem I'm running in to is frequent derailment when the train is coming downhill on the right side curve. It handles the straights and the uphill curve on the left just fine. I can only avoid it running off if I slow it to a crawl. I'm thinking what I'm going to need to do is dig out both curves until they're mostly level with the front section, then allow the train to climb to the straight section in the back. Digging out the entire flowerbed to level isn't really an option as there is too much mature vegetation and trees in between. Any advice from the experts?


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## DKRickman (Mar 25, 2008)

Is the derailment at a track joint, or where there is a vertical or horizontal transition? Is it always the same piece of equipment at the same location? 

If it is a joint, carefully realign the joint. If it is at a horizontal transition (straight to curve), check that there is not also a hump there. If it is at a vertical transition (level to down hill) check that it is not so sharp that it allows a long truck to ride up over the hump. If it is a specific piece of equipment, check that the model is properly tuned, not binding, properly weighted, etc. If it's always at exactly the same location, go get as close to that spot as possible and watch VERY CLOSELY to see if you can tell what is going on. Sometimes you can see the problem in action. 

Finally, have you tried running counterclockwise?


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## roykirk (Jul 20, 2012)

Thanks for the quick reply. It doesn't appear to be related to a joint, but it does happen at nearly the same spot. It occurs right where the train is coming down the right side curve and is pulling out of the curve on to the lower straight section. Like right at the last curved section before it hits the straight. The loco by itself usually does okay if I take it slow. If I'm pulling my three cars it will derail every time. I have tried running counter clock wise, but it also wants to derail when it's climbing the right curve (but a little farther in to the curve). It derails somewhat less often on the right curve when running clockwise, so I've been sticking with that for now.


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## mgilger (Feb 22, 2008)

Get your head down at ground level and see if the wheels are being lifted off the rail as it comes around the curve? You might need to put a bit of elevation on the drive then gradually come back to level once it hits the strait section. Nothing real quick, just nice and gradual over a couple of feet. If you see the wheel starting to rise and come up over the rail, put your finger under the rail and lift. If it works, then elevation is your ticket. 

Mark
*http://mmg-garden-rr.webs.com/*


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## Greg Elmassian (Jan 3, 2008)

Put a short level across the rails, check every 6 inches or so. If you find it out of level, this "warp" can be a problem, also called "cross level". Check the suspensions on the cars, but it sounds like too steep of a grade or no transistions to the grade (abrupt change from level to grade), or warp. 

Greg


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## roykirk (Jul 20, 2012)

Thanks for the great advice, everyone. I watched it this morning and it's the left front wheel coming off each time. I'll play around with some elevation changes on that corner and go get myself a small level to make sure there's no warp.


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## chuck n (Jan 2, 2008)

What kind of engine and cars are you using? If you are dropping 6 inches over the distance of 1/2 the circumference of 4' diameter curves that is a very steep grade. My calculations suggest that you are dropping 6 inches over a distance of about 75 inches. That workes out to an 8% grade. Way too steep. Does the train speed up significantly on the down grade? 

As others have suggested transition the straight down so that the grade difference on the curve is less than 3 inches. The 8% uphill grade will shorten the life of the gears in your engine significantly.

Chuck


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## s-4 (Jan 2, 2008)

I know you have some limitations due to your gardens, but I would highly recommend that you equalize the gradiants. In other words, slightly angle the straight track approaching the curve on each side such that any peaks or valleys occur only on straight track joints. In your case the track would peak in the front of the layout where the two straight sections mate. If this is not possible, I would consider using a wider radius curve.


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## Paul Burch (Jan 2, 2008)

Are there any straight sections on the curves or just the curved track? What I'm getting at is that you said the curves are 4' diameter and you have about 6" of elevation difference. If there are no straights then you are dropping or rising roughly 6" in 4' of track. That would be a very steep grade and could be the root of the problem. Maybe a picture would help.


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## roykirk (Jul 20, 2012)

No straight sections in the curve. I may be overestimating the 6" difference, but I'll admit it appears to be a steep section. I'm at work right now so I can't post a photo, but I'm thinking what I'll likely end up needing to do is elevate that corner so that it's mostly level through the turn and then transition to the lower straight away.


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## aceinspp (Jan 2, 2008)

Buy your self a string line bubble it fits just perfect across the rails. There is a difference between warp and cross level they are not the same as stated above. Warp is when one rail on a side is out of level then you move down a bit and then the level goes the other way. Cross level is just one rail out of level for a given distance. I would just check every 6inches or so and just put the rail to level. I would do this over the entire RR. Later RJD


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## chuck n (Jan 2, 2008)

Another test would be to slow the engine down as it approaches the down grade and see if it stays on the track. If slowing it down keeps it on the track you could add a resistor at the top and bottom of the grade. This would work if you are always going to run the train in one direction, as it would really slow the engine when going up hill.

Chuck


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## rdamurphy (Jan 3, 2008)

If you have a video camera/cell phone or smartphone that takes video, just video a derailment at normal speed. 

Then, upload it to your computer, or even youtube if you want assistance from others, then you can slo-mo, pause, reverse, and look at it repeatedly and see the remotest details. I've even done this to help out a buddy with a troublesome N-scale derailment problem. Sometimes the problem is glaringly obvious, other times more subtle, but you'll see it. 

So, three things to NEVER do when building a layout. 

Change grade at the intersection of a curve and straight. 

Attach a bridge with straight track directly to a curve. 

Never lead out of a curve directly into a turnout. 

And related, NEVER build an "S" curve without a straight section the length of your longest car - this includes crossovers. Always use turnouts that are straight through the frogs. 

Robert


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## DKRickman (Mar 25, 2008)

Something to think about.. 

A curve on a grade (or a grade in a curve, if you prefer) means that the rails are not co-planar. In other words, they do not form a flat surface, and a car or locomotive on the track must twist to accommodate the change. The tighter the curve and the steeper the grade, the worse the problem becomes. Think about it like this - take a section of a curve, and elevate one end so that the lower portion is at a 4% grade. Aside from any vertical transition issues (which we'll ignore for the moment) you could connect a level straight section there and no problem. however, at the upper end of that curved piece, the rails are not at the same height, with the outer rail higher than the inner one. In order to get them level, you have to twist the section of track. It's that twisting that could be causing some problems. 

As has been said, it sounds like you need to double check the track work, and reduce the grades as much as possible. The derailments are not the problems - they are the symptoms of a more fundamental problem in the track.


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## rdamurphy (Jan 3, 2008)

chuck n has a valid suggestion, however, adding a pair of diodes would make the "slow down" circuit directional. 

Also, the reason that the prototype superelevates (banks) the track. Not so the trains don't fall over at speed, but it lengthens the effective radii of the curves, Pretty hard to reproduce in model form, though. Anyone have any thoughts on that?

Robert


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## JackM (Jul 29, 2008)

Scanning the responses above, I couldn't find any reference to track gauge. Have you checked the track in the area of the derailment for gauge? The flange gotta so somewhere when the rails get too tight. 

JackM


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## cape cod Todd (Jan 3, 2008)

This morning while showing off the RR to a visitor I had the same car derailing in the same spot over and over again. I had 2 trains running one with 5 cars the other with 4 and they all made it except one. Apon closer inspection the spot in question had a slight bend/curve to it and even though the car looked and rolled fine I bet the wheels are out of gauge. So your derailing issue could be a combination of just one out of gauge wheel and a slight twist to your track. 
It doesn't take much sometimes. 
Unless you have some really old track or it is handlaid or someone stepped on a piece I doubt it is out of gauge. 
Do watch out for too steep a grade and tight curves don't help at all they put alot of stess on longer equipment with truck mounted couplers. If you layout is smaller why not pick a high spot and make that your goal and then bring the track up to that point with either a small retaining wall or bridges and trestles. That way your layout will be level but look otherwise. 
Good luck 
Todd


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## roykirk (Jul 20, 2012)

Thanks, Todd. It's brand new brass track that's just out of the box so I also doubt that it's out of gauge. It's driving me nuts being stuck at work because I'm thinking of all sorts of stuff to try when I get home. The two main things I'm focusing on are either digging out those turns so they're closer to level or simply raising the entire front section with a retaining wall and connecting to the turns with trestles, as you suggested. That might actually look a little nicer than simply digging out the corners. Because even if I do that then there's going to be a climb on the back section and a sharp descent before the turn.


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## Greg Elmassian (Jan 3, 2008)

The best advice I have is make the 2 end curves dead level, and add to the grade on the straights. That will cure all your problems. I missed the 4' diameter at the beginning. Way too tight for a grade. 

Greg


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## rdamurphy (Jan 3, 2008)

Design of Railway Location by Clemen C. Williams published in 1924 says this, in part, about this subject. 

"Where curves occur on the ruling gradient, or on grades nearly equal to the ruling gradient, the rate of grade must be reduced in order to permit the locomotive to pull its train with no more resistance than it encounters on a tangent on the same grade..." 

The book cites American Railway Engineering Association rules which call for compensating curves by between .03 and .05 percent for each degree of curve. Several factors, including the relationship of the train and curve length affect the choice of compensating factor."


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## chuck n (Jan 2, 2008)

It would help us help you if you mentioned what engine and cars you are running.

Chuck


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## roykirk (Jul 20, 2012)

Chuck - It's a Bachmann set with a Baldwin 4-6-0 loco & tender, box car, and caboose.


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## chuck n (Jan 2, 2008)

I'm sure that this is not what you want to hear, but 30+ years in the hobby has taught me some hard lessons.

That engine is designed to run on a flat track around a Christmas tree. It would love to run on wider diameter track, especially if there is a grade. 

The only engines, in my opinion, that will run well and not self destruct on that radius are 2-axle engines, like the LGB Stanz. Many engines are "rated" for R1 (4' diameter) curves, but most last longer and give better performance on larger diameter curves.

There are 5 or more versions of that engine out there. The latest are more robust than the earlier versions. If you say what set you have others may be able to tell you about what to expect with that engine. 

Any 4-6-0 pulling even a short train up a 8% grade on a 2' radius curve is going to have a short life.

You can add weight to the pilot truck, that will help it stay on the track.

Chuck


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## roykirk (Jul 20, 2012)

Posted By chuck n on 31 Jul 2012 04:33 PM 
I'm sure that this is not what you want to hear, but 30+ years in the hobby has taught me some hard lessons.

That engine is designed to run on a flat track around a Christmas tree. It would love to run on wider diameter track, especially if there is a grade. 

The only engines, in my opinion, that will run well and not self destruct on that radius are 2-axle engines, like the LGB Stanz. Many engines are "rated" for R1 (4' diameter) curves, but most last longer and give better performance on larger diameter curves.

There are 5 or more versions of that engine out there. The latest are more robust than the earlier versions. If you say what set you have others may be able to tell you about what to expect with that engine. 

Any 4-6-0 pulling even a short train up a 8% grade on a 2' radius curve is going to have a short life.

You can add weight to the pilot truck, that will help it stay on the track.

Chuck
Not a problem. It was my introduction in to the hobby and if it blows up after a few months or weeks, I'll go out and get another one. It's a good learning tool for me and so far it's been a lot of fun.


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## chuck n (Jan 2, 2008)

Welcome to the hobby and HAVE FUN!! There are a lot of great people in the hobby who are there to help. There are many potential solutions to a problem. It all depends upon where you live (local climate is very important), your skills and how much you want to invest in time an money. As a beginner you will be given advice from engineers, geologists, geophysicists, contractors, mathematicians, and many others who come from different skill sets. Sit back, listen, read, and ask. Only you can ultimately decide what is best for your train.

My last suggestion is to find and join a local club. They are a wonderful source for help and ideas.

Chuck


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## aceinspp (Jan 2, 2008)

Why would one want to stick a resistor in the the circuit. That is not the problem of the loco derailing. As we have said it is a surface condition or wheel gage problem that is causing your derailment problems. Later RJD


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## chuck n (Jan 2, 2008)

It was suggested that he check the speed going down hill. If slowing down the engine on the down hill grade and he liked the layout, a resistor at the top and bottom of the grade could slow the engine enough to keep it on the track. I realize that grade and diameter are working against him. This is a possible solution to keep the layout as it is and keep the engine on the track. Larger curves and shallower grades are a much better solution. But space may limit his options.

Chuck


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## roykirk (Jul 20, 2012)

A few hours of work tonight and several hundred pounds of landscaping block seems to have fixed my problem. I put the landscaping block on the front section, essentially bringing it up to level with the back section. Still needs some fine tuning, but I ran it around about 20 times with all cars and no derailment this time. Here's a video: http://youtu.be/IF1yg-LjF1A I hope the purists will pardon some of the poor shoring in sections, but it's working for the time being. I ran it at a slow speed on purpose until I make sure I have all the kinks worked out. The last time I ran it up to speed (before the fix) the loco launched halfway across the yard.


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## DKRickman (Mar 25, 2008)

Much improved! Looking at that video, if the original track grade was at "ground" level under those blocks, I'm surprised you only had one derailment-prone spot! That's a good looking little garden, by the way. Nice job.


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## chuck n (Jan 2, 2008)

Looking good, glad that you solved your problem.

Chuck


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## Paul Burch (Jan 2, 2008)

Looks good. You have a good spot there to do a nice layout. Maybe aquire a little more real estate in the lawn area to make it a little wider.


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## roykirk (Jul 20, 2012)

Well, I appreciate all the advice from everyone. I would have been screwing around with it for days trying to figure it out on my own when all it took was $30 worth of concrete block and an hour and a half of work. The next project is solar panels, a car battery, and a 400W inverter, so I don't have to run AC all the way out there. I'll post some photos in a relevant forum when I get it done.


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## chuck n (Jan 2, 2008)

Roy:

I'm not an EE so this is probably a dumb question, but why do you need an inverter? I thought that solar cells put out DC. Doesn't an inverter convert DC to AC? Our trains run on DC and if you are going to charge batteries for power storage, they also charge on DC, don't they? 

Or, do you just need some AC for accessories, like switch motors?

Chuck


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## roykirk (Jul 20, 2012)

Hi Chuck - 

I've done a fair amount of research on this, but I'm no expert either. My understanding is that you certainly *can* power the train directly from the DC that comes from the panels, but then you have to build or buy a different rheostat to control the power the track does get. Plus, you're only going to be able to run the train when sun is directly on the panels. Overcast, rain, or darkness (of course), and you've got no train. If you're working off of the battery (which is charged by the panels), you still need to build or buy a new controller. The inverter hooked up to the battery still gives me AC power to plug in the regular transformer that powers my stock controller. Plus I gain an AC outlet in the back forty without having to trench in new wire. I already own an inverter that's not being used for anything, so at least I'm not out anything to try it. If I find in the future that it's easier to run directly off the panels or battery, I'll give it a shot.


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## chuck n (Jan 2, 2008)

Thanks, I understand the need for a battery. You need to store the power somehow, somewhere. Couldn't you just have a rheostat and a DPDT switch between the battery and the track. Aren't you going to loose power going from DC to AC and back to DC?

Many years ago I made a battery car for my LGB engines with a rheostat, DPDT and rechargeable batteries. The only problem was that I didn't isolate the engines electrical pickup, so car light lit and the battery charge didn't last very long.

Chuck


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## roykirk (Jul 20, 2012)

Yeah, I imagine there's going to be some loss in power in the setup. But using calculations I've found on a few other websites, I should be able to run the train for hours and hours on a single battery charge, even going through a 400W inverter. Right now I'm just trying to do it as cheaply as possible by buying the least amount of material and equipment. Already own the inverter, which means I don't need to go buy or build a new controller. The panels and battery need to be bought regardless. It's all a learning experience, I guess. If I find out it doesn't work as well as I anticipate, I'll throw the inverter back on the work bench and figure out how to run it directly off the battery


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## chuck n (Jan 2, 2008)

Thanks for your answers. 

Chuck


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## rdamurphy (Jan 3, 2008)

I have an inverter for 12VDC to 120VAC, that plugs into a cigarette ligher/power outlet on a car. Honestly, I've never really worried about the battery going dead when I've used it for power tools or even plugging in my NCE power supply. Even after a few hours, it doesn't seem to run the battery down to a point where the Jeep hesitates to start... 

Robert


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