Doug Levin is the Associate Director for the Center for
Environment and Society at Washington College in Chestertown, Maryland,
and is an expert in underwater exploration technology, as well as
designing fun programs that teach complex engineering concepts.
The following is a dissection of the March 12th email from James Cameron
to Don Walsh–co-pilot of the bathyscaphe Trieste that went down to
Challenger Deep in 1960–following Cameron’s successful 8,000-meter dive
to the bottom of the New Britain Trench.
This email speaks
volumes to what goes on in and outside of the submarine. I’ve dissected
each paragraph and inserted my interpretation of what might be going on
behind the words. Of course, including my explanation has lengthened the
email by an order of magnitude. However, I was blown away by how much
was revealed within the short communication, and I wanted to share my
reactions with you. In the copy below I’ve kept Mr. Cameron’s type
normal. My responses are preceded by several dashes (—-) and are written in bold italics.
_______________________________________________________________________________
Once at the bottom of the ocean, James Cameron has the capability to
remain on the sea floor for up to six hours to conduct science
experiments.
Illustration Courtesy Acheron Project Pty Ltd.
Don,
The
8000m dive went very well. Not an unqualified success, since the
manip(ulator) was balky and my push core sediment sample washed out on
ascent because the sample door wouldn’t stow all the way, and because of
the speed of the flow over the vehicle on ascent (5 knots average).
—- At 8,000m, Mr. Cameron’s mechanical appendages would have been working
at pressures 800 times that experienced at the sea surface. The
manipulator may have been balky because the pressures caused the
fittings that normally give the arm its agility to tighten.
—- A push core does exactly what its name suggests: A tube is
shoved into the sediment at the trench bottom and pulled back out to
collect a sample. First, a “core catcher” is placed in the end of the
core tube that enters the sediment; inverted metal or plastic fingers
keep the sample from falling out. Once the core is pushed to its
refusal (i.e. the point at which it won’t go any deeper), the top is
capped to create air pressure. (If you’ve ever put your thumb over a
drinking straw, you know that you can remove the straw from a beverage
container without losing the liquid within. The liquid will then be
released when you remove your finger from the straw top. Putting the
cap on top of the core should keep the contents from spilling out in
much the same manner.)
Continue reading “Email From Mr. Cameron to Mr. Walsh–A Dissection”
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A very detailed cross-section of the ocean as seen through the eyes of elementary students, exposing the various depth-related layers encountered as one goes to the ocean floor.
