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Old 05-13-2010, 04:15 PM   #12 (permalink)
wyatt
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Quote:
Originally Posted by Big Dave View Post
The coefficient of friction for steel wheels to dry steel rails is the same as rubber tires on polished glare ice.
According to Wikipedia, railroad steel wheel on steel rail has a Crr from 0.0002 to 0.0010, compare that to ordinary car tires on concrete between 0.010 and 0.015. During coast down testing, I have found my car tires to be around 0.012.

I have also found quite a bit of good information in Mark's Standard Handbook for Mechanical Engineers, Seventh Edition. I don't have time to post now on that, but I will try to post up the "summary" section which is most relevant.
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