Going Deep with Alvin

Launch

Submerge

Alvin is a deep submergence vehicle, or ‘submersible’ owned by the Navy but operated and maintained by Woods Hole Oceanographic Institution in Massachusetts. Alvin is not a submarine. Its maximum speed is a little over 2 MPH and it cannot travel more than about three miles laterally. It is built for scientific research and exploration. Alvin can dive to 4500 meters (2.8 miles), much deeper than submarines can descend. Its six thrusters give it a high degree of maneuverability and its two robot arms can be used to perform many varied tasks in its abyssal work place. Alvin is battery powered. It carries four video cameras, sonar, an altimeter, an underwater “telephone” for talking to the ship above, and an array of sensors. It incorporates a sophisticated navigation system in which sonar, acoustic transponders (deployed underwater beacons) and a fiber optic gyrocompass are used. A basket on the front of the submersible can carry up to 250 pounds of scientific equipment, which can be operated or deployed using the robot arms.

A typical dive is eight hours, but life support onboard will last for three days. During diving operations a pilot and two scientists sit inside the 6.5-foot diameter titanium sphere in the forward part of the submersible, their noses close to each of three small thick round windows. When the ballast tanks are filled the submersible begins to descend. Darkness closes in as Alvin moves beyond the deepest level at which sunlight can penetrate. Inside, the only light comes from blinking LEDs on the sophisticated electronics packed inside the sphere. Outside a bazaar light show is sometimes seen: Strange greenish flashes or pulses emanate from small fluorescing marine animals disturbed by Alvin as it descends through their realm. On a 4500-meter dive it takes two hours to get to the bottom where the pressure is a tremendous 946,080 pounds per square foot. The pressure under a resting elephant is about 157 pounds per square foot. To attain the 4500-meter pressure, 6,000 full-grown elephants would have to stand on his back! *

Return

Many queer sights have been seen through Alvin’s portholes over the years since it’s first launching in 1964: A hydrogen bomb lost in the Mediterranean Sea; the famous Titanic in its underwater grave; and many dynamic and primal hydrothermal vent fields at the boundaries of tectonic plates where scalding hot fluids pour out of the Earth through chimney-like columns. In September of 2000, a new hydrothermal vent field dubbed “Sasquatch” was discovered during an Alvin dive 200 miles off the coast of Washington. Three months later, scientists aboard the research vessel Atlantis unexpectedly discovered what was later named “Lost City”. Alvin was immediately launched and the colossal carbonate towers of this extraordinary hydrothermal field were seen through the naked eye for the first time and sampled using the submersible’s robotics.

*No elephants were harmed or mistreated during the making or testing of Alvin.