On 12/15/2010 5:34 AM, Larry Jaques wrote:

What percentage of that force is due to the truck rim flange and how
much is due to the jet force of a puncture? That's more of a
high-speed mechanical disconnect with mass vs a puncture.

And where does the energy come from? All the energy released in the
failure originates with the air pressure, the explosive nature of the
failure is due to the strength of the materials being exceeded.

I dunno, but it feels like an apple/orange comparison here.

Well in a sense it is, but it does demonstrate the power of compressed
air, or gas. There is a reason things like gas bottles are tested with
water under pressure (hydrostatic) instead of compressed gas. Spring a
leak with water, and pressure drops at once.

I can see that 400psi would blow out a lot of earth, but it doesn't
seem strong enough to lift a long, heavy, rigid pipe + earth unless it
had found a flame and exploded.

As for the explosion theory, where did the oxygen come from that would
be needed for an actual explosion? I could see gas seeping through the
earth catching fire and burning at the surface. But I can't see there
being any significant oxygen, let alone an ignition source, around a
buried pipe.
Don't forget, there was a hell of a lot of volume of gas in that
pipeline. It wasn't like the pressure suddenly dropped the instant the
pipe began to fail. And, the earth is a lot heavier than the pipe. If
the failure was at the bottom and there was enough force to move all
that earth, moving the pipe as well is rather trivial.

Just my seat of the pants thoughts, worth half what ya paid for them... G


Jon