Re: Single vs Trwin
At 06:49 PM 4/26/99 -0400, Al Pilvinis wrote:
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The question is so difficult that I can't imagine two weak links breaking
at exactly the same time. In fact I think it is a physical impossibility.
Back in my cave diving days, I used to hang out with a bunch of folks who
liked to nothing better than to evaluate the probability of a critical
failure in their equipment and to work out plans for minimizing the
probability of that happening. After all, the last thing you need to do is
be 3000 feet into an underwater cave and have a critical equipment failure
that will prevent you from exiting the cave alive. I've seen some very
spectacular failures, and some very unlikely ones, too.
One cave diving certification agency taught that every diver should carry at
least three lights, and the other one taught four. I carried five, and so
did Cindy. I know of one group of four divers that did a cave dive together
with 16 lights between them, and they had 15 light failures on that same
dive. All four exited the cave on the one and only working light remaining.
On another dive, I had two watch failures, a depth gauge failure, and my
pressure gauge blew out. That also took out one first stage regulator,
together with the one second stage regulator attached to it. That
eliminated my ability to control buoyancy in my dry suit. I guessed at my
decompression time, and exited the water with only 200 psi remaining.
Now part of my regular job is helping a Reliability Engineer analyze
complicated mechanical systems for critical single points of failure. We do
what is called a Failure Effects and Modes Analysis (FEMA). It is very
similar to the analysis that we used to do on our cave diving
equipment--except far more detailed.
With this background, it is very easy for me to see simultaneous failures in
both engines. Granted, it will be far less likely than a single failure of
a single engine; but it will happen eventually if you spend enough time
operating your boat. It is also a whole lot more likely than you would
think. The things that will get you is causes that can act simultaneously
on both engines, like four divers all stopping to buy batteries at the same
place and getting bad ones.
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::
Paul and Cindy Kruse :: KJV Joh 14:27 Peace I leave with you,
165 South Kenneth Court :: my peace I give unto you:
Merritt Island, FL 32952 :: not as the world giveth, give I unto you.
E-mail: plkruse@iu.net :: Let not your heart be troubled,
407-453-6206 :: neither let it be afraid.
::
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At 04:53 PM 4/27/99 -0400, you wrote:
With this background, it is very easy for me to see simultaneous failures in
both engines. Granted, it will be far less likely than a single failure of
a single engine; but it will happen eventually if you spend enough time
operating your boat.
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Paul I guess what you are saying is anythig is possible.
Maybe that statment will close the conversation.
AL
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Captain Al Pilvinis "M/V Driftwood"--Prairie 47
2630 N.E. 41st Street
Lighthouse Point, Fl 33064-8064
Voice 954-941-2556 Fax 954 788-2666
Email - CaptainAl@Juno.com
Website http://home.earthlink.net/~yourcaptain