Don is correct..The rule of thumb calls for #4s for yards,#6s for mains. As far as size 8's Well-if you have the room if not a crossover made of #6s will work for a medium speed crossover.
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Chip said:Bill, just because there's a prototype doesn't mean you want to do it. I have enough problems with getting my track to work.
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Chip,Us older and more experience industrial switching layout builders model track like you see in that picture with out any derailment problems.[:0]
If you are having derailment problems I suggest getting a NMRA gauge so you can check your track and wheels.Then check your cars trucks to ensure they are not to tight.[:D]
Maybe slow your trains down as well?[:0]
Of course it could be the track and switches..That's why I stick with Atlas track as I know its the best from my years of experience.