3 ms·
I don't see how the limit of friction is relevant here. Trains don't drag their wheels along the rail; the whole point of a wheel is that it rolls. A useful cal
by flyingfences 5y ago
I don't see how the limit of friction is relevant here. Trains don't drag their wheels along the rail; the whole point of a wheel is that it rolls. A useful calculation would be based on rolling resistance.
- skulk 5y agototally forgot about that part. Rolling resistance seems to be at least an order of magnitude lower than friction so that does bring the numbers into a reasonable range.
- credit_guy 5y agowikipedia indeed says the rolling resistance for rail cars is indeed 0.002, so you are off by a factor of a round 100. 3.24 kg/mile is not that bad. Actually even 10kg/mile sounds very acceptable to me, so they may end up being able to use cheaper batteries like NiMH.
- sudosysgen 5y agoRolling resistance, for trains, is just a small part of the equation. Air resistance and changes in altitude are also quite significant.