Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Politics : Politics of Energy -- Ignore unavailable to you. Want to Upgrade?

To: Bilow who wrote (32937)	7/3/2012 6:58:14 AM
From: Maurice Winn	1 Recommendation Read Replies (1) \| Respond to of 86352

Coal dust is not going to "attract water" but what it would do is hold water and could act as a wet lubricant when the interstices of the stones are full, so that when a train goes over, the stones would be squeezed sideways and up, causing destruction of the ballast and therefore undermining sleepers. If the stones are free-draining, water would run through and out so the stones would all rest on each other forming a solid base, spreading the load down to the subgrade. Over time, the coal dust would act as a collector of other dust so that weeds could also grow, with moisture being held nicely. So okay, coal dust in ballast in quantity is a bad thing to happen. By "floats on top of the ballast" of course the dust would fall down the holes, but it wouldn't cause the stones to displace upwards because coal is lighter and would in fact stay on top. Even wet it's still less dense so would not float the stones upwards or displace them. It would only be under load that the stones would be displaced. That would happen with any fine medium such as garden variety dust gradually filling the ballast, as that would hold water too and result in high pore water pressures as trains go rumbling through. Mqurice