On a HO left and right turnouts - how do you keep the cars from derailing in rev

[bktrains]

I am having trouble with reversing my HO cars on the left and right turnouts. They keep derailing.   Any suggestions?

[ACY]

Your problem could be that you have horn-hook couplers, the fix would be to replace with knuckle couplers like Kadde #5's or #148's, it would entail new trucks and body mounting the couplers.

[rogertra]

Poorly laid track, truck mounted couplers, out of gauge wheels and possibly horn hook couplers.  The four major reasons for derailing while pushing cars.

[jward]

are those the "standard" left & right switches? if so, the curved portion is 18" radius. that is far too sharp to be backing cars through them reliably, especially if you have two of them together in a crossover formation. the resulting s curve is sure to derail your cars, especially of they are 50 foot or longer.  changing wheelsets and couplers will not help you if that is the case. the best solution would be to replace the switches with numbered ones like the #5 or #6. you will have far fewer problems trying to back through the gentler curves that result.

[Doneldon]

bk-

You are inquiring about one of the most common problems with HO trains. The reason is that backing a train manages to bring all of the common tracking problems together at one time. These include faulty track work, coupler problems, truck problems, incorrectly weighted cars, and injudicious speed. I assume from your post that you haven't noted a pattern to your problems, e.g., a particular car which derails or a specific turnout (switch). Let's look at each of the possible culprits in turn. But remember, backing through turnouts can allow marginal problems to work together to create an issue though they might not be a problem by themselves under less challenging circumstances. So check each possible problem even if you find a given problem before checking all of them.

Faulty track work: There are several things to check, including the gauge of all parts of the turnout and the track the train will move on to after the turnout. You need to look carefully at gauge and make sure that all rails are in gauge. An NMRA standards plate will be very useful for this. Sometimes the gauge is wide which allows the wheels to fall off of the rails. Or, they can be too close so they squeeze the wheels up and off of the rails. So check the gauge at several points, including at the rail joiners which connect to the adjacent rails. Make sure that they are correctly on both pieces of rail so there isn't a bump at the transition point. Next, check any guard rails in your turnout. These are the short, bent rails which serve to guide the wheel flanges. Depending on what kind of turnout you have, these might be separate pieces of rail which are incorrectly placed or are loose and getting in the way. Then look at the turnout's points. These are the two pices of rail which move back and forth. They should move from contact with one rail to contact with the other. The top of the rails which move should taper to a fairly sharp point and nestle into the rail they are moved to. And they should stay where they are put. The frog is the wedge shaped piece of rail where the two tracks diverge. This should be lined up perfectly with the rails which lead into it. Last, and your problem is likely to be either here or with the points, make certain that your turnout is level. Non-level turnouts can cause binding or misalignment which can be deadly, especially when backing up.

Couplers: I don't know what kind of couplers you use. Many set trains come with the so-called NMRA, X2f or horn-hook couplers. These are all names for the same cruddy coupler which really doesn't look much like a coupler. If you have couplers which don't look like the real thing, you probably have these. They look from the top like an egret with a very long top knot on the back of its head. Lose them. Their odd appearance is their best feature; their function is even worse. There are several brands of knuckle couplers out there. All are at least pretty good and all will work together pretty well except when trying to couple on a curve. The Kadee brand is the oldest and the best. But even knuckle couplers can have problems. The first thing to check is that the couplers are mounted on the car bodies, not on the trucks (wheels). Then check to ensure that the couplers themselves are at the proper height and that the curved wire hanging below the coupler just barely clears the railheads. The NMRA gauge will help with this, too. Then make sure that the couplers center themselves but are able to move back and forth as needed.

Trucks: It's not the trucks themselves which may be a problem. Rather, it could be that the couplers are mounted on them or that the wheels on the trucks are out of gauge. I already mentioned the coupler-on-truck matter (these are called Talgo trucks). You can use the NMRA gauge to check the spacing (gauge) of the wheels. This is very important. If the wheels are out of gauge, you can almost always correct the problem by twisting the wheels while exerting some force to push them closer together or farther apart. The odds are that your wheels aren't crazy out of scale but, if they are, try to keep the wheels an equal distance from each end of the axle. You probably don't have to worry about that but you don't want the situation where the wheels on one axle are closer to one end and the wheels on the other axle are closer to the other end of their axle. That can cause the truck to twist and get off of the rails. The last things to check with your trucks are that the wheels spin smoothly and easily, and that the trucks themselves pivot easily around their mounting screws. Most model railroaders find that one truck which turns readily but doesn't rock much and a second truck which both pivots and rocks works best. Tighten both trucks  until they only pivot easily and then back one screw out a quarter to half a turn.

Weight: Cars which are incorrectly weighted can have trouble staying on the rails. It's far more likely that your cars are light rather than heavy. Heavy cars at the leading end of a backing train can increase the chances of a derailment but, again, you are much more likely to have underweighted cars. The NMRA standards say that HO rolling stock should weigh one ounce plus one-half ounce for every inch of length. For a 40-foot boxcar (pretty much the rule until recent years when cars began to grow longer and longer) that means about 3.5 to 4.0 ounces. Cars which are too light can be pushed up and off of the rails, especially if there is resistance to a train which is backing. Look closely at the way your trains' wheels meet the rails. You'll see that the wheel faces are not flat and completely on the rails. Rather, they are tapered just a little. That's great for reducing rolling resistance, but that taper can work to increase derailments when the car is being backed against a resistance, like the tail end of a train.

Overweight cars can cause problems, too. Specifically, they can push down on the rails hard enough that they don't want to move easily. If they are behind a string of underweight cars on a curve there is a good chance that the underweight cars will "clothesline," i.e., be pulled off of the rails to the inside of the curve. Similarly, overweight cars at the end of a backing train can cause increased resistance to motion, causing light cars to bunch up and jump off of the rails. So check your cars' weights. Let us know if you need to add weight and somebody or several people will tell you how to do that.


Speed: Most model railroaders learn quickly that "seeing how fast it will go" pretty much guaranties  a derailment. This is really true when backing. Speeding backwards through a turnout is the single best way I can think of to have a train wreck. While that can occassionally be fun, it's awfully hard on the models so we don't speed with our trains, at least not very often. Please note: I'm not accusing you of running your trains too fast; I'm just pointing out the potential problem.

Well, I've written way too much but I have covered the possible problem areas. Hopefully, this will correct your derailment problem, or at least help you diagnose it. Don't hesitate to seek more information here if you need more help. Good luck, and have fun with your trains.
                                                                                -- D

[ACY]

I think you have enough information there to publish an article in Model Railroader.

[bktrains]

bk-

You are inquiring about one of the most common problems with HO trains. The reason is that backing a train manages to bring all of the common tracking problems together at one time. These include faulty track work, coupler problems, truck problems, incorrectly weighted cars, and injudicious speed. I assume from your post that you haven't noted a pattern to your problems, e.g., a particular car which derails or a specific turnout (switch). Let's look at each of the possible culprits in turn. But remember, backing through turnouts can allow marginal problems to work together to create an issue though they might not be a problem by themselves under less challenging circumstances. So check each possible problem even if you find a given problem before checking all of them.

Faulty track work: There are several things to check, including the gauge of all parts of the turnout and the track the train will move on to after the turnout. You need to look carefully at gauge and make sure that all rails are in gauge. An NMRA standards plate will be very useful for this. Sometimes the gauge is wide which allows the wheels to fall off of the rails. Or, they can be too close so they squeeze the wheels up and off of the rails. So check the gauge at several points, including at the rail joiners which connect to the adjacent rails. Make sure that they are correctly on both pieces of rail so there isn't a bump at the transition point. Next, check any guard rails in your turnout. These are the short, bent rails which serve to guide the wheel flanges. Depending on what kind of turnout you have, these might be separate pieces of rail which are incorrectly placed or are loose and getting in the way. Then look at the turnout's points. These are the two pices of rail which move back and forth. They should move from contact with one rail to contact with the other. The top of the rails which move should taper to a fairly sharp point and nestle into the rail they are moved to. And they should stay where they are put. The frog is the wedge shaped piece of rail where the two tracks diverge. This should be lined up perfectly with the rails which lead into it. Last, and your problem is likely to be either here or with the points, make certain that your turnout is level. Non-level turnouts can cause binding or misalignment which can be deadly, especially when backing up.

Couplers: I don't know what kind of couplers you use. Many set trains come with the so-called NMRA, X2f or horn-hook couplers. These are all names for the same cruddy coupler which really doesn't look much like a coupler. If you have couplers which don't look like the real thing, you probably have these. They look from the top like an egret with a very long top knot on the back of its head. Lose them. Their odd appearance is their best feature; their function is even worse. There are several brands of knuckle couplers out there. All are at least pretty good and all will work together pretty well except when trying to couple on a curve. The Kadee brand is the oldest and the best. But even knuckle couplers can have problems. The first thing to check is that the couplers are mounted on the car bodies, not on the trucks (wheels). Then check to ensure that the couplers themselves are at the proper height and that the curved wire hanging below the coupler just barely clears the railheads. The NMRA gauge will help with this, too. Then make sure that the couplers center themselves but are able to move back and forth as needed.

Trucks: It's not the trucks themselves which may be a problem. Rather, it could be that the couplers are mounted on them or that the wheels on the trucks are out of gauge. I already mentioned the coupler-on-truck matter (these are called Talgo trucks). You can use the NMRA gauge to check the spacing (gauge) of the wheels. This is very important. If the wheels are out of gauge, you can almost always correct the problem by twisting the wheels while exerting some force to push them closer together or farther apart. The odds are that your wheels aren't crazy out of scale but, if they are, try to keep the wheels an equal distance from each end of the axle. You probably don't have to worry about that but you don't want the situation where the wheels on one axle are closer to one end and the wheels on the other axle are closer to the other end of their axle. That can cause the truck to twist and get off of the rails. The last things to check with your trucks are that the wheels spin smoothly and easily, and that the trucks themselves pivot easily around their mounting screws. Most model railroaders find that one truck which turns readily but doesn't rock much and a second truck which both pivots and rocks works best. Tighten both trucks  until they only pivot easily and then back one screw out a quarter to half a turn.

Weight: Cars which are incorrectly weighted can have trouble staying on the rails. It's far more likely that your cars are light rather than heavy. Heavy cars at the leading end of a backing train can increase the chances of a derailment but, again, you are much more likely to have underweighted cars. The NMRA standards say that HO rolling stock should weigh one ounce plus one-half ounce for every inch of length. For a 40-foot boxcar (pretty much the rule until recent years when cars began to grow longer and longer) that means about 3.5 to 4.0 ounces. Cars which are too light can be pushed up and off of the rails, especially if there is resistance to a train which is backing. Look closely at the way your trains' wheels meet the rails. You'll see that the wheel faces are not flat and completely on the rails. Rather, they are tapered just a little. That's great for reducing rolling resistance, but that taper can work to increase derailments when the car is being backed against a resistance, like the tail end of a train.

Overweight cars can cause problems, too. Specifically, they can push down on the rails hard enough that they don't want to move easily. If they are behind a string of underweight cars on a curve there is a good chance that the underweight cars will "clothesline," i.e., be pulled off of the rails to the inside of the curve. Similarly, overweight cars at the end of a backing train can cause increased resistance to motion, causing light cars to bunch up and jump off of the rails. So check your cars' weights. Let us know if you need to add weight and somebody or several people will tell you how to do that.


Speed: Most model railroaders learn quickly that "seeing how fast it will go" pretty much guaranties  a derailment. This is really true when backing. Speeding backwards through a turnout is the single best way I can think of to have a train wreck. While that can occassionally be fun, it's awfully hard on the models so we don't speed with our trains, at least not very often. Please note: I'm not accusing you of running your trains too fast; I'm just pointing out the potential problem.

Well, I've written way too much but I have covered the possible problem areas. Hopefully, this will correct your derailment problem, or at least help you diagnose it. Don't hesitate to seek more information here if you need more help. Good luck, and have fun with your trains.
                                                                                -- D

--D, yes I have horn hook couplers on my freight cars; most are hooked to the trucks; any suggestions on changing them to kd couplers?  Thanks for all the info.  as a new railroader, I need all the help I can get.  I wanted a hobby that my 9 year old daughter and I could do together.  We both love the trains! bk

[Doneldon]

bk-

You say you have horn-hook couplers on Talgo trucks. You may have other problems, too, but absolutely you need to change these two circumstances or you'll continue to have derailments even if your trackwork and weights are perfect.

View this as two distinct problems which require separate fixes. First, get rid of the X2f couplers. The easiest way to do that is to cut the arms of your trucks which hold the couplers. You can still operate your trains with these trucks although you may want to upgrade at some point. In any case, service your trucks at this point. Check the gauge of your wheels and the tightness of the pins or screws which hold your trucks to the car bottom. If you have plastic wheels, give serious thought to upgrading them to metel wheels. That will save you a lot of track maintenance as time goes by as well as looking better, sounding better and tracking better. But your plastic wheels are okay for now.

Let's move on to the couplers, which your cars no longer have. I urge you to make Kadees your choice. There are a couple of other brands out there but I think just about all model railroaders would agree that Kadees are the best. And they only cost a little more than the others. Kadees come in little envelopes with two pairs of couplers per envelope. There are myriad configurations for mounting the couplers and as many different shank (the arm which holds the coupler) lengths and shapes.

In your case, you aren't trying to fit your couplers into an existing draft gear (the box which holds the coupler pivot point, also called a draft gear or coupler pocket by some) so you have the option of using the famous #5. These have a medium length shank (arm) and a centerset head (the fist-like working part of the coupler). These are available in quantity packages which will save you some money. However, the quantity packages don't include the draft gear so you'll need those, too. At one time Kadee sold #5 couplers assembled in draft gear boxes in quantity packages, but I don't think they do that any longer.

When you are shopping for couplers, be advised that you can also get a scale size Kadee #58 which mounts and works the same was as a #5, a #148 "whisker" which is the same size as a #5 but has a more convenient (IMHO) mounting, and a #158 "whisker" which is the scale version of the #148. You need to decide whether to go with scale or oversize couplers and the #5 style centering mechanism or the whiskers. I'd probably recommend scale with whiskers (#158).

You'll need a Kadee coupler gauge (the NMRA gauge will work but the Kadee gauge works better) to check for coupler and pin height. Check your cars to see if you have some which ride especially high or low as Kadee also makes couplers with the coupler head set as high as possible on the shank and as low as possible on the shank. The odds are that you'll need a few of each. For very minor adjustments, Kadee makes little washers which go between the top of your trucks and the car frame and little filler pieces which can be placed between the draft gear and the car body. The washers on the trucks will raise the car just a little (while also raising the coupler pocket) and the draft gear pieces will lower the coupler a little. So use washers for minor adjustments and offsets for larger adjustments. Remember that up and down reverse when you are working on a car that's on its back.

This should get you started so I won't go into more detail here. Kadee provides good instructions in its packages. There is also a wealth of information on Kadee's web site. Good luck.
                                                                                                                        -- D

[jward]

truck mounted horn hook couplers, probably wheels that don't conform to nmra specs, you are probably better off buying new cars with knuckle couplers and rp25 wheels. what you are trying to run is very primitive compared to the newer cars. they can be upgraded, but it will be time consuming and when you are done you will have at least as much invested in each car as you would buying new ones.

here are a few things involved in bringing those older cars up to spec:

body mounted couplers. if you are going to be backing them alot don't even think of trying to keep the truck mounted couplers. body mounted horn hooks back better than truck mounted kadees. to body mount the couplers you will have to build a pad to mount a coupler box to, then drill and tap it so the coupler box can be secured with a screw. if uing knuckle couplers, the height o the coupler nd box re criticl so you nee  coupler height guage.

knuckle couplers: kadee are the standard but there are numerous plastic knuckle couplers. most are compatable with each other. knuckle coupler re more relibe thn horn hooks.

rp25 wheels. the ones on older train set cars like you described are usually cheaply produced, often out of guage, and have wheel langes tht resemble pizza cutters. all of this contributes to derailments. you can often reuse the truck frames from your old cars once you cut the coupler boxes off, but you will einitely wnt new rp25 wheels.

weight: i can almost guarantee that your cars are underweight. you will want to add weight, and pennies glued inside the car at each end are a cheap way of adding this weight.

like i said, you are probably better off buying new cars for around $10 each than trying to upgrade the ones you have. as an alternative, you can often find unbuilt car kits at train shows for about half that. these often have horn hook couplers, but you will at least have body mounted couplers nd rp25 wheels with these. an added advantage to these kits are that you can make a couple of "conversion" cars by only replcing the horn hook coupler on one end, so that the car has one coupler of each type. this will allow you to mix coupler types within a train until you hve the time and money to convert all your cars.

[Joe323]

One other tip:

If you ballasted your track make sure the turnouts including stock rail the frog and the guide that the frog rides back and forth on (and the manual lever hole) are free of stray ballast.  I amost pulled my hair out trying to stop derailments until I learned this.

[Doneldon]

Chug-

I'm not a big fan of transition cars with different couplers on each end unless it's a very temporary situation while conversion are underway. Keeping track of which cars can be coupled to which other cars is a major nuisance as far as I'm concerned.

What jward wrote about the cost of upgrading older cars is mostly true but does leave the fact that you already have a bunch of cars out of the equation. The conversions can be educational and make it easier to diagnose the inevitable future problems. So decide for yourself which way to go. If your cars are cool ones in good shape and you don't have to rebuild the whole thing, upgrade. But give yourself the freedom of acknowledging the hopeless cases and turn them into static displays like a roadside diner or a railroad shed.
                                                                                -- D

[rogertra]

With body mounted Kadees, wheels to NMRA standards, with the track in gauge, correctly weighted cars, carefully handlaid switches I could run a 16 car plus van freight, in reverse, through number six crossovers and into yard tracks at line speed without a single derailment.  I could do it with any random freight train.  That's how I backed my freight and passenger trains out of stub end hidden staging between operating sessions, so I could turn them around and take care of the waybills.  A good way to find cars that need servicing.   

If I could do that with hand laid track, it should also be possible for you to do the same thing with carefully laid commercial track and well maintained rolling stock.

It's a goal aim for and not settle for anything less.

Keep trying and best of luck.

[Doneldon]

Roger-

You bring up an important point: servicing. Even our rolling stock needs servicing from time to time, just to make sure everything is within specs. Lots of people keep an index card on each car, recording service done and every incident of derailing or uncoupling. If a pattern emerges they send it to the RIP track. I know one fellow who keeps similar records on every switch, bridge and length of track. (No, not every 9" piece, a stretch of track between two features like maybe switches or curves.) This allows him to keep track of cleaning and also reveals track issues which are causing operational problems.
                                                                                                                                                 -- D

[Terry Toenges]

Can a kid buy a Bachmann train set with EZ Track and a couple of turnouts for sidings and back his cars up without them derailing? Why would he want to buy it to begin with if he has to also buy new wheels, couplers, coupler boxes, weights, and a scale to add the weights to the cars?

[ACY]

Can a kid buy a Bachmann train set with EZ Track and a couple of turnouts for sidings and back his cars up without them derailing?

If the set has cars with truck mounted couplers or talgo trucks then he cannot.

Why would he want to buy it to begin with if he has to also buy new wheels, couplers, coupler boxes, weights, and a scale to add the weights to the cars?

Because kids are stupid and don't realize that what they are buying and that it would be problematic.