Technology at Work

Off Egg Island, Bahamas, Day 2, 1999

Deep sea fish

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.

Submersible reaching the surface after a diveThe 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 Sub rear chamber with side windowtwo 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, . . .

Robert Costello talking to scientist in rear chamberFrom 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.

Mechanical collecting armA 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.




Smithsonian, National Museum of Natural History