Rolling stock and 18 inch curves

[mikec069]

I was wondering what the longest car (non-passenger) car that can manage an 18 inch turn.  I have one car do, not know length, that has a consistent problems moving from straight to 18 turn.   

Thank you.. you guys (and gals??) rock..   

[Nigel]

There are many factors other than length that govern out tight a radius curve a given car can take.  For a car by itself, truck swing is the main concern.  For a coupled car, additional items are coupler swing, and the coupler swing of the car or locomotive that it is coupled to. 

In addition, type of coupler makes a difference.  The now common knuckle coupler (Kadee original or copy) does not put side loading on the car, but the formerly common X2f coupler does put side loading on the car, and if truck mounted, will cause the trucks to be at a slight angle to the direction of travel, resulting in the wheels "picking" any imperfection.

That said, 50' cars generally have no problem.

[SteamGene]

Anything above a 40 foot car that has body mounted couplers will probably be a problem.  Talgo will go out to the Athearn passenger cars and maybe the IHC.
Another thing to consider is the car hitting something along the track.  I've been testing 30" plus curves with Walthers heasvyweight passenger cars.  Even with 2 1/8 inch between the tracks on the curve, passengers would be scared to death if they looked out the window at the other train!
Gene

[Hunt]

This is one of those… it depends.

Only rule of thumb is the longer the car over 40 to 50 scale feet; the larger the curve radius. A guide - If you can see the outside rail looking down on the car when in a curve, it likely needs to be run on a larger curve radius.

As already covered, two key things affecting derailments is the range of movement of the couplers and wheelsets.  Coupler placement and design will allow for some long rolling stock  to run on 18" curves.

Here are links to some general info
http://www.trains.com/mrr/default.aspx?c=a&id=911
http://www.trains.com/mrr/default.aspx?c=a&id=607

[RAM]

I have found that Talgo and body mounted couplers don't work well together.   The longer the car the greater the problem.

[HOplasserem80c]

i have a 90 foot pug door works fine but i cut those things really close