car weight

[Anonymous]

how much should a car weigh? i have mostly aristocraft cars w/k-dee couplers,
and i notice when i have alot of cars the first few want to pull off the track.

[cabbage]

The question should be "Where should the coach's Centre of Gravity be?'

Ideally this should be as low as possible. This can be lowered by metal wheels or metal wheels and bogies (which is what I use). This will stop the flanges riding up the rail side (AKA cold snatch).

regards

ralph

[markperr]

A number of things could be causing this. AS you say, you could have too much weight pulling against the couplers. How many cars are you pulling? It also depends on whether your Kadees are truck mounted or body mounted and the diameter of your curves. I't possible you may not have enought swing on your couplers. Have you tried changing cars to see if all cars do the same thing? Or is it just certain cars? If so, what's different about them. Does the derailment happen only on the same curve or does it happen on every curve? Does it only happen if you curve to the left or to the right? Do you have the same derailment happening no matter which locomotive is driving? All of these things can help you troubleshoot where the culprit lies. I had a devil of a time a while back trying to find out the cause of a derailment and it turned out that I didn't have enough swing on the coupler of my U25B. I found this only after checking it in situations like I've described above.

Good luck and hope this helps.

Mark

[Anonymous]

the couplers are body mount, min radi is 4' pulling about 12 to 14 cars, i did check the swing and its fine. i think the problem is the layout , i might have too much bank on the curves and incline about 3% at the curve. i thought that adding scale weight would help. thanks for your help.

[cacole]

What type of wheels are you using, and are they hard to pull individually? I put ball bearing adapters into all of my rolling stock and use body-mounted Kadee couplers, and I have no derailments with trains of the length you have, even pushing them up a 2 to 3 percent grade and around curves. The rolling resistance of some wheelsets is probably more of a contributing factor to derailments than car weight. Changing to metal wheelsets helps a little because that adds more weight down low, but ball bearing wheels are the biggest advantage to easy rolling.

[Anonymous]

I was having a problem with a car right behind the engine, the wheels came off of the track, i put a piece of lead in the car about 4 oz. , i used silocone to keep it from sliding in the box car., problem solved, it was in a 10 car train pulled by an R S 3 . Ben

[crackerpete]

[:)]
Good morning from the P & S Central from Central Florida. I spoke to a "real" engineer the other day... on long trains, the light cars are at the rear end of the train... the heavy stuff up at the headend.

The other day, I was pulling 12 cars with out problem, until I turned it around and had the 2 light cars at the headend. As I rounded the curve, the first 2 light cars peeled off...

Hope this helps
Cracker Pete

[Anonymous]

I agree center of gravity helps being lower, but someone must have a rule of thumb for car weight, probably related To length. I Know in N scale clubs, we had a preferred weight

Any one researched or implemented this?

Greg

[cacole]

crackerpete,

That "real engineer" you talked to should come out to Arizona some time and take a look at what UP does. He'd have a heart attack if he could see trains that run along the Sunset Route. I have a video I took just a couple of weeks ago near Benson, Arizona where the tracks climb a 20-mile long 2 percent grade, around numerous curves. One train had 6 engines and the first car in the train was an empty flatcar, followed by nearly 100 loaded boxcars, covered hoppers, autoracks, etc.

If we try putting an empty flatcar as the first in our model consists, that's a guaranteed derailment on the curves. I don't see how real trains can do this and stay on the track.