American style coupler problem

American style coupler problem

Postby ConducTTor » Sun Jan 01, 2012 10:09 pm

I can't imagine that I'm the first to come across this. On a left - right direction change on 310mm radii, the couplers are way out of alignment resulting in the locomotive "swinging" the car around and derailing it. I know that direction changes like that should be avoided and that 310mm is pretty sharp - but, if we expect to place such restrictions we can expect to have an even harder time attracting new people to the hobby. Not to mention that some of us with smaller areas for trains probably have to have reail geometries like that. BTW, the difference with the European couplers is that they have more side to side swing-ability so they can handle this. Any thoughts?

ub 003.jpg
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Re: American style coupler problem

Postby areibel » Sun Jan 01, 2012 11:49 pm

It is a problem, especially with longer rolling stock. The old time solution was mounting the coupler on a brass plate that could move independently of the car body- when it came into a tight radius, the plate could swing and keep the coupler aligned. Not 100% prototypical, but it's the only thing I've seen. A piece of .020 brass the width of the coupler pocket that is mounted to the chassis with the same screw the truck mounts? HO used truck mounted couplers that did the same thing, or an extended shank coupler but we don't have that option!
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Re: American style coupler problem

Postby areibel » Sun Jan 01, 2012 11:56 pm

P.S.- I checked out the video of that big bad U boat- NICE!
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Re: American style coupler problem

Postby ConducTTor » Sun Jan 01, 2012 11:59 pm

Thx :)

Regarding the couplers, there needs to be an easy to implement solution. I'll be thinking about it.
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Re: American style coupler problem

Postby Arseny » Mon Jan 02, 2012 5:59 am

The S-type curve, especially with 310-mm radiuses, will cause derailing for a lot of European cars too, especially long wagons.
I think it's obligatory to put a small straight section between the curves.
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Re: American style coupler problem

Postby CSD » Mon Jan 02, 2012 12:43 pm

There is nothing wrong with your couplers. The tracks are built wrong (sorry Boss). This is not a problem unique to this type of coupler and one has to accept that mechanisms work a certain way, room or no room. Tight S curves will derail the most well coupled train due to the opposing forces and weight issues anyway. The strait section that Arseny mentioned is actually applied on the real thing. A railroad engineer told me once that the rule of thumb between opposing points was a car length of strait track so that the wheels do not engage both curvatures at the same time. I have found this to be true on the models too. By the way if you install the opposing part of the switch as part of your curve you get a longer siding, more reliable operation and this problem is solved. I've pulled up the rails on my eastern approach 4 times to fix these kinds of operational problems. All part of the fun.
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Re: American style coupler problem

Postby ConducTTor » Mon Jan 02, 2012 2:56 pm

Actually I've had zero problems with long cars or anything else derailing there - although that bit of track does annoy me and I'll change it.


CSD wrote:if you install the opposing part of the switch as part of your curve you get a longer siding, more reliable operation and this problem is solved


Not sure I understand exactly what you mean - can you add a drawing or something.
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Re: American style coupler problem

Postby CSD » Mon Jan 02, 2012 3:59 pm

ConducTTor wrote:Not sure I understand exactly what you mean - can you add a drawing or something.


Yes. Like so...
Example.jpg


For me it really hasn't been the length of the car or coupler position so much as car weight. The light ones like to get pulled up. My philosophy (now) is anything will run on well planned and laid track.
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Re: American style coupler problem

Postby ConducTTor » Mon Jan 02, 2012 4:11 pm

Aha, gotcha. And yeah - it's all about well laid track - that in my opinion is an even higher order of importance than the plan.
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Re: American style coupler problem

Postby dileTTante » Mon Jan 02, 2012 9:28 pm

Attached is photo I took today showing the yard along downtown Vancouver. The arrow points to a track arrangement which has always caught my attention because it goes against better rail practice according to CSD's post. The photo is misleading because the perspective doesn't show that the curves are long, not sharp. There's no other access to get a better photo. The equipment generally found in this yard are long container trains which serve the ship loading docks, and grain cars for wheat. The long units of the container trains have very little overhang beyond the trucks at the end, so the couplers are close to the wheels. Still, it doesn't look right -it's definitely an S-curve without a straight section. Probably anyone with a very small layout should avoid using long cars and locos. That's from a guy who likes passenger trains and has almost no room for a layout.
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