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Off
Egg Island, Bahamas, Day 2, 1999
A good omen
it was to find slitsnails on the first two dives. Once the team had search images
for Midas, they found and collected another 14 animals. Jerry rode in the rear
chamber and Robert sat in the bubble on the first dive to 2,600 feet. On the second
dive, José was up front and Pat had the rear. During the collecting phase, the
sub creeps along, hovering a few feet off the wall, while the team concentrates
on the small patches of wall illuminated by the search lights.
The
pressure is so great that the 5.5 " Plexiglas sphere contracts under
the weight of the sea. In other words, the already small quarters get
a little bit smaller. To allow for the shrinking sub, the floor is not
attached to the bubble, that way the floor can pop up as the diameter
of the sphere decreases . . . which means our knees come ever so closer
to our chests. The bubble has two seats, one for the pilot and one for
the passenger. The rear chamber of the sub holds two
more people, another crew and team member each. The chamber is shaped
like a short sausage and the two people have to lie down or fold themselves
into a ball. The rest of the team remaining aboard ship enjoys seeing
those two emerge after three hours. They move slowly, they appear to
be shorter, and they stretch to loosen joints. We greet them smiling,
shake their hands, and say "welcome back," or "so nice to see you, again."
The submarine
is an extraordinary vehicle fitted with gauges, devices, and safety
and life support systems. It weighs in at 13 tons, a small percentage
of the 288 ton ship, the R/V Edwin Link. Each dive lasts for three hours,
a concession to battery life. Should the sub get stuck, there is life
support for five days. Inside each chamber a CO2
scrubber removes the carbon dioxide that would otherwise build up from
the natural process of respiration. Without the scrubbers, the team
would suffer the effects of carbon dioxide poisoning, become drowsy,
. . .
From
the sub, there is radio contact with the ship, and the two separate
chambers on the sub have intercom and headset communications. One video
and one still camera are mounted to the front and are controlled by
the pilot and passenger. The video feeds two monitors on board, one
in each chamber. Each camera is aimed by an array of lasers, four on
the video and two on the still. External sensors give continuous readings
of water temperature, depth, conductivity, and salinity. Internal ones
monitor oxygen and carbon dioxide levels, and pressure. Chamber pressure
is maintained at one atmosphere.
A
mechanical arm and a number of collecting buckets are the essential
tools of collecting specimens. These very rare specimens provide scientists
with invaluable information, especially since they cannot be studied
to any extent at such great depths. The arm has three ways to pick up
specimens. There is a grasping claw, a suction tube, and a closing scoop,
each mounted to the mechanical arm. Which one is chosen to pick up a
specimen depends on the size, shape, behavior and location of the object.
Deploying a
23'-7.5", thirteen ton, submersible takes a sizable ship and crew.
The R/V Edwin Link is an impressive ship run efficiently by the Harbor
Branch crew. At 168 feet in length, she is capable of carrying 30 people
for 7,000 nautical miles without replenishing supplies, which means
the ship can reach just about any location on Earth. By cruising at
11 knots, the team made their way back from Grand Bahama Island to Ft.
Pierce, Florida overnight, nearly 100 miles, and across the Gulf Stream.
On her stern
is an 18 ton hydraulic A-frame that safely lifts the sub from the deck
to the water and back. Once the sub is in position to be picked out
of the water, a large hydraulic rope is lowered to the swimmer who locks
it into place. The sub is then lifted from the water, and guided by
a tow rope, set down onto the deck where it is secured to a platform.
Together, the ship and submersible are marvels of engineering and technology,
combining old fashioned design principles with high tech materials.
Without
question, the most outstanding feature of the sub is the Plexiglas sphere.
This small bubble puts the scientist and pilot in the water. Two-dimensional
photographs cannot really capture the visual effect of being "in
the water" at 2,500, or 500, or even 100 feet. In this watery world
light is filtered and the effect is a loss of colors. Deeper down everything
is cast in blues and grays. The view is nothing short of spectacular,
full 3-D immersion into another world from the best seat anywhere.
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