Hello,
I'm from Germany, and I'm new here. I'm mainly European model railroader, but at the moment I'm building a small H0 layout located somewhere in the Southwest USA (Utah/Arizona). It contains three oval-shaped loops with 18", 22" and 24" radius. On the inner loop I have a problem: If a train runs clockwise (only curves to the right), everything works without issues. If the train runs counter-clockwise, and behind a larger engine (like SD70, AC4400) the first car is shorter than 60', the car derails.
At the moment, I solve this problem by running the trains only clockwise on this track.
Another possibility is paying attention that the first car is longer than 60' if the train goes counter-clockwise. Then, even a 89' Autorack runs without issues through the 18" radius.
I have read in the internet that a "long shank" coupler like this - CLICK - solves this problem. Is this true?
Perhaps anybody can help me.... Andreas Weise
For one thing the engines you mentioned are big enough that even 22"R is pushing it for minimum raduius. (For reference the biggest thing I have is an SD40-2 so I'm guessing just a bit here but from everything I've read with those big engines they don't like small radius.) Mostly try to keep that inner circle to smaller 4 wheel diesels (GPs, SWs) will help a bit.
With the cars you might double check that the cars have sufficent weight. A light car in the middle of heavy ones will tend to cause the light car to derail. (Hence why even the prototype puts light cars on the end of trains.
Those are a bit generic and always a good thing to check. Derailing going only the one direction is a bit of a challenge. Is there something on the engines or cars that is only on that side that could be causing a problem? If it derails at the same spot all the time, double check your track and make sure there isn't a problem there. (Should derail going both but stranger things have happened.)
Other than that, you have an intersting conundrum.
FRRYKidMostly try to keep that inner circle to smaller 4 wheeldiesels (GPs, SWs) will help a bit.
Because I started with this layout less than a year ago, I have not any 4-axle engines yet (only 3 six-axle engines), but presumably they also will come.
FRRYKidWith the cars you might double check that the cars have sufficent weight.
Yes, the cars are heavy enough.
FRRYKidDerailing going only the one direction is a bit of a challenge. Is there something on the engines or cars that is only on that side that could be causing a problem?
The cars are (of course) fitted with Kadee couplers. These couplers are asymmetrical built. This is the reason for the derailment in only one direction. The derailment itself is, because the coupler of the engine can't swing very wide. Because of that, I asked if longer or shorter coupler shanks would solve this problem, or are there other possibilities?
To add to that. Make sure the screw holding the boogie on is not to tight. So there is enough play. Some manufactures cars, like locomotives, can only take certain radio us curves. The wheels might not have enough room to clear and move in that direction forcing it to derail. Where the other way it has the clearance to move. Maybe the same car of the same size and type from another manufacturer will work better.
shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
Look for a tight spot, when you use 18" with larger engines the smallest tight area can cause proublems.
NVSRRTo add to that. Make sure the screw holding the boogie on is not to tight. So there is enough play. Some manufactures cars, like locomotives, can only take certain radio us curves. The wheels might not have enough room to clear and move in that direction forcing it to derail. Where the other way it has the clearance to move. Maybe the same car of the same size and type from another manufacturer will work better.
Please read correctly ... The wheels are NOT the problem, but the swinging of the couplers.
A SD70, AC4400 etc. is about 70' long. If I put 50' cars behind it, and the train takes only right-hand 18" curves, it works without issues. When the train runs counter-clockwise (only left-hand curves) and 50' cars are behind the engine, the first car derails in the curve. As soon as I put e.g. a 68' Gondola or 72' Centerbeam Flatcar between the engine and the 50' cars, the train also goes through the tight left-hand curves without derailing.
Andreaas WeiseIf a train runs clockwise (only curves to the right), everything works without issues. If the train runs counter-clockwise, and behind a larger engine (like SD70, AC4400) the first car is shorter than 60', the car derails.
That would tend to indicate a problem with the track rather than the engine, cars, or couplers. Make sure there isn't something like a misconnected track joiner - that could create a rise where the train would be fine going one direction, but cause a 'jump' that derails it in the other direction.
Andreaas Weise Please read correctly ... The wheels are NOT the problem, but the swinging of the couplers.
Its worth a try. I have 18R curves and had to change a few 6 axle locos (SD 60/40s) to a longer shank coupler. They run great now and I can use any length car behind them. The Whisker type have more side to side movement so that is what I would use.
Let us know what you find out.
Jim
Andreeas to the forum. By now you have discovered your posts are delayed by moderation. Keep posting, that will go away in time.
I have no experience with the coupler you have asked about. In your part of the world space for a layout maybe less than here in the US. I model a freelance rail road in the transition era in a rural area so I don't have long engines nor rolling stock.
I think it is a mistake to model modern equipment with 18" curves but I understand, not everyone can have 30" curves.
Henry
COB Potomac & Northern
Shenandoah Valley
I think you can solve the problem by using a "first car" that is longer, with the trucks "set inward" a little (from the end of the car).
This will create more "overhang" (on the first car), which will "match up" more with the overhang of the engine (which is longer, thus the coupler ends up more toward the outer rail in curves).
And as also mentioned above, use a Kadee "long shank" coupler, which will give it a bit more "swing" in the curves (even if it doesn't look as well as a short coupler).
A friend gifted me with an Amtrak ACS64 (Siemens) engine. It has the trucks set considerably "inward" (away from the ends of the loco). My small layout is freight only, no passenger cars. Curve radius is 18.75" in places, 21.5" others (Kato track).
If I try to pull 40' freight cars, the outward "swing" of the engine on curves is so extreme that [even with extended shank couplers] it can pull the lead car right off the rails. I found that if I use a 50' express reefer (that has a modest amount of "overhang" due to trucks set inward), that will get around the curves ok.
Although it looks a little odd to be running a modern Amtrak electric with old wooden express reefers...!
Since it only happens turning one direction, it could be something is preventing the engine's coupler from turning all the way. Sometimes it does happen that a Kadee coupler (esp. with the bronze spring-gizmo) will move more easily one direction than the other. Sometimes just making the screw holding the coupler box a little too tight can restrict it's movement enough to cause problems. Of course, make sure all the car's couplers move easily too.
PLaying Devil's advocate here, but why not just have the layout without narrow curves? Boring right?! At least you avoid the inevitable issue.
Can we stick to advising him on what he says is the problem?
I do think part of what he is describing is that some of the couplers are not swinging freely or hanging up in the box, as noted. That would indicate filing, either at top/bottom of the box or, to give a little more swing, at the lateral edges.
It should be easy to check whether the coupler shank is hitting the side of the box at the point of greatest swing... or at the point where derailment is observed. Check whether pushing the cars through the curve by hand produces the same effect as locomotive-hauling through the couplers. I'd also make sure there is no flash in the coupler mating faces.
That he only sees the problem in one direction may be that he has a sharper radius in the approach in one direction that is pushing the car ends far enough apart that the swing 'bottoms'. This could probably be observed by watching the car ends as each one enters and then traverses the curve. Increasing the effective coupler swing ought to address the problem he's having without having to relay track with better gauges or transition. It might also be a 'cross-level' problem if the cars are mutually slightly twisting and perhaps binding -- check that the track is level side-to-side all the way through, with no warping or bumps.
To the extent that longer shanks reduce radial motion at the mouth of the box, they would help this issue.
You may need the longer shanks on both the locomotive and the first car. Does this happen as the loco is on the curve and the car is just entering, or elsewhere on the curve? Really, your problem is inherent to running long cars and long engines on tight curves, particularly 18" radius. I have one engine that won't negotiate 18 inch curves by itself.
You may be able to find "swing shaft" couplers that are body-mounted but contain a pocket within a pocket for greater lateral coupler motion.
I had a curve I'd put down with flex track years earlier. It was fine for years, until I got some new passenger cars that would supposedly run on 18 inch curves. I had a lot of derailments until I discovered that I had mismeasured and actually put down some 17 3/4 radius curves. Up they came, and after redoing them correctly, no more problems.
It takes an iron man to play with a toy iron horse.