Re: HO Tank Car Lid
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Now if you were to have a tank car built to the minimum required standards, you
might be tempted to fill it full of some heavy but free flowing liquid. Something with a
suitably low viscosity, like clipper oil.
And then, if you were to open a drain valve at the bottom of the tank, some of that
liquid would drain out. BUT! What if in doing so, it sucked in some bubbles of air,
like my ketchup bottle sometimes does? Then more such liquid could pour out the
bottom. And you would have a mess between the rails that your track cleaning
car probably wouldn't be able to clean up.
BUT! If you put a hose on that drain, and ran a long hose down into a deep hole,
like maybe the Grand Canyon, and put a check valve on it so the bubbles couldn't
get back up the hose, then you could maybe get yourself a mess of scrap iron out of it.
Better, if you used a sharp file to create some stress points in vulnerable places,
you could maybe use less hose.
Presto! You have demonstrated why most model RR tank cars are plastic and not steel.
Chuck Peck (enjoying some wine and a few laughs)
On Mon, Nov 23, 2020 at 8:00 PM mopacfirst <ron.merrick@...> wrote:
There are formulas in ASME Section VIII of the Boiler and Pressure Vessel Code that will allow you to calculate, or at least read off a set of curves, the expected maximum external pressure a steel fabricated vessel (say, a tank car) can withstand without collapsing. Suffice it to say that the maximum possible external pressure a vessel in free air can see is 14.7 psi absolute (psia). This would be less, say, if you assume this tank car is on Tennessee Pass or somewhere like that.