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I didn't want to hijack the thread with the raidus poll in it so I've started this one. What is the consensus on min radius for running the bigger longer six axle locos and rolling stock?
I remember years ago even my four axle daylighter passenger cars liked to derail on the "standard" curve track I had.
I'm sure you'll get as many different numbers as there are replies to this thread
I've heard people say that their HO scale SD40-2's will handle 22" radius curves - but with a lot of overhang - IOW, it looks weird and the coupler on a longer car will swing out and yank a shorter-wheelbase car off the track.
Here's the NMRA's RP-11 Standard for curvature & rolling stock: http://www.nmra.org/standards/rp-11.html
Scroll down and look closely at class keys "O" and "P", then at the bottom of the page is a matrix that shows the minimum recommended* turnout number and curve radius. It works out to something like: 3 times the length of the longest engine or car that will go on it. So in other words, an 89' auto rack [in HO scale] is just over 12 inches long - so the minimum recommended radius would be ~36 inches.
* My minimum radius is 31 inches and the auto racks handle it OK, so there is a bit of "wiggle room" built into the numbers!
