Science / Medicine : Fishing the Deep, Deep Sea Bottom : They’re treasure hunters and the CIA, adventurers and scientists, all sharing the same problem--how to get sunken material off the sea bottom and up to the surface.
When the Pac Baroness sank off the Santa Barbara coast after colliding with another vessel in a thick morning fog three weeks ago today, environmental concerns immediately arose. The freighter had taken with her 23,000 tons of finely powdered copper, iron and sulfur concentrates.
Would they pose a major threat to the marine environment? At 1,480 feet, how quickly would the copper oxidize and enter the food chain?
Not long ago, answers to such questions might never have been attainable. The fate of the cargo, like the condition of the wreck itself, would remain among the mysteries of the deep.
But no more. Only days after the Pac Baroness went down, scientists at UC Santa Barbara’s Marine Science Institute drafted a proposal to dispatch a remotely operated submersible to the bottom to find the answers.
Recent technological developments have paved the way for the location and exploration of wrecks that for centuries eluded all but the storyteller’s imagination.
The advances have all but overcome the considerable risks to humans of descending to great depths, such as powerful currents, tremendous pressure and uneven topography.
First came underwater listening devices such as hydrophones and sonar. Until their development, finding objects submerged in the oceans were limited to visual inspections in relatively shallow waters or dragging the bottom with nets.
More recently, both manned and unmanned submersibles were developed that can dive to the darkest regions of the ocean and not only to inspect but to actually recover objects--such as dishes from the wreckage of the luxury liner Titanic, which sank in 12,500 feet of water in 1912 after striking an iceberg on her maiden voyage.
Hydrophones were first used during World War I to detect enemy submarines.
But it wasn’t until the British invention of sonar in 1921 that objects such as sunken ships could be detected and the ocean floor accurately mapped.
In sonar systems, a transducer sends out a supersonic sound wave, which bounces off the ocean floor or anything in its path. The returning echo is then amplified and converted into electrical pulses, which are translated into “blips” on a cathode-ray screen, lines on a chart, or sounds from a loudspeaker. But such sonars had short ranges and had to be rotated by hand to search all directions.
After World War II, sonar technology was improved, and the new generation of sonars could automatically search in all directions, and their range increased to 10 miles or more.
During the 1970s more sophisticated sonars were developed, in large part as a result of advances in microelectronics and computers.
Known as side-scanning sonar, these instruments could cover a wide swath on either side of the search pattern.
The side-scanning sonars are towed beneath the surface by a ship or helicopter and look like a torpedo. They work by sending out one sonic beam to the left and another to the right simultaneously. Side-scan sonars are often used to make highly accurate maps of the ocean floor and to find sunken objects.
In the last few years, technological advances--particularly the advent of microchips--have extended the several hundred-foot swath of the early side-scanning sonars to 15,000 feet and greater today.
Computer processors also have made it possible to assure accurate images by compensating for the natural distortions that sound waves produce.
The ability to locate an object, in turn, has paved the way for the increasingly effective use of deep-diving submersibles--both manned and remote-operated vehicles--which are exploring wrecks whose very names speak of history, including the Civil War ironclad, the Monitor.
And in 1974, large sections of a sunken Russian submarine are believed to have been literally grabbed from the bottom of the Pacific by the Glomar Explorer, a salvage vessel especially built for the CIA with three-mile-long grappling arms.
Such feats are little short of spectacular, considering the humble beginnings of underwater ventures.
Back in 360 BC, Aristotle was writing about humans experimenting with breathing tubes to extend their stay under water.
The earliest diving bells were rather primitive. They were often nothing more than an open barrel turned upside down to capture air and then lowered into the water to salvage wrecks.
But diving bells offered little or no mobility and the need to maneuver led to diving suits.
The next great obstacle to deep diving was water pressure. Pressurized diving suits were designed and, over the decades, improved upon. Today, such suits allow virtually free movement by divers at depths of 1,500 feet and more, with no need to decompress upon returning to the surface.
Humans then extended their descent into the deep with pressurized capsules lowered by cable to as deep as a half mile. Later designs freed the capsules from such tethers by making them capable of diving and surfacing through the use of ballast and buoyance chambers.
It was in such a modern-day diving bell, called a bathyscaph, that a deep-diving record was set in 1960 by Jacques Piccard and U.S. Navy Lt. Don Walsh who descended to 35,800 feet in the Marianas Trench.
Still, it wasn’t until the development of submersibles--both manned and unmanned miniature submarines--that exploration leaped forward. Submersibles are capable of maneuvering and performing such tasks as recovering objects and repairing pipelines.
“The advances in the last decade in deep diving and therefore deep salvaging are far greater than everything that came before it,” remarked Phil Nuytten, the inventor of a new pressurized diving suit that is said to allow nearly as much flexibility at depths as great as 1,500 feet as free swimming scuba divers enjoy in the shallows.
Among the most fascinating deep sea adventures in recent years was the 1985 discovery of the Titanic, 450 miles southeast of Newfoundland, by a joint U.S.-French expedition that used an unmanned deep-diving sled called Argo, which was equipped with side-scanning sonar, lights and television cameras.
Later, the expedition, led by Robert D. Ballard of the Woods Hole Oceanographic Institution of Massachusetts, descended to the Titanic 2 1/2 miles below in the three-person Alvin.
That expedition dramatically proved the capabilities of a lawnmower-sized robot camera system called Jason Jr. that was deployed from the Alvin.
Jason Jr., attached to the Alvin by a 200-foot half-inch-thick tether and maneuvered with a joy stick, actually entered the Titanic to send back spectacular images of crystal chandeliers and other objects.
Jason Jr. is powered by small electric motors which run four propellers that permit it to move in any direction. Sensors measured both heading and pressure. Jason Jr. is neutrally buoyant, has three floodlights and a strobe light for high-resolution color video and still pictures from rotating cameras.
Jason Jr. is a prototype for a slightly larger propeller-driven system that the Navy hopes to use to find downed jets, sunken subs, missiles and other items of military interest. It has a titanium hull and is 20 inches high, 27 inches wide and 28 inches long.
Another submersible, the U.S. Navy’s Deep Drone, descended near Cape Hatteras, N.C., last May to photograph the USS Monitor.
Among Deep Drone’s equipment was an instrument that measured weak electrical currents created naturally by the combination of the Monitor’s iron and steel with salt water. The varying strength of the current at different locations along the sunken ship told researchers what areas were rusting fastest. The data has allowed scientists to set priorities as to which areas to preserve first.
While environmental concerns are involved in the Marine Sciences Institute’s proposal to survey the Pac Baroness wreckage, basic research is the primary objective. Researchers want to determine how quickly the copper powder might work its way into the food chain.
Much depends on the oxygen content of the ocean at those depths. The more oxygen, the more likelihood that marine ecosystems would be affected.
The institute is seeking a $43,000 grant from the National Science Foundation and hopes to begin work as early as Thursday.
An unmanned submersible known as Recon IV would play a key role in the proposed six-month survey.
The Recon IV is uniquely suited to make the initial inspection. “It just doesn’t seem productive to hop into a submersible and dive down there not knowing what we’re getting into,” Bruce H. Robison of the institute said.
The Recon IV has not only a mechanical arm, called a manipulator, that is common to many submersibles but also a stereo 35 mm camera and a color video system. It, like many submersibles used throughout the world, has been widely used for inspection and maintenance of underwater oil pipelines and offshore oil rigs.
After the successful combination of the Alvin and Jason Jr. last year in exploring the Titanic, John Steele, director of the Woods Hole Oceanographic Institution, told reporters of plans for a larger more versatile system.
The new system, to be called the Argo/Jason system, would be able to dive 5,000 feet deeper than the Alvin. Its unmanned robot, unlike Jason Jr., would be equipped with a manipulator to gather samples as well as take pictures.
The system is expected to open up a new world of exploration to scientists. “The real leap forward is still ahead, when we put it all together,” Steele said.
ALVIN
Alvin is a self-propelled, 33,500-pound, manned submersible capable of diving to 13,123 feet deep. Built by General Mills, Inc. in 1964, it can lift 1,000 pounds. It is 25 feet long, just under nine feet wide, and just over 12 feet high. It has four viewports, TV and still cameras and manipulator arms.
Alvin first became known when it helped recover an H-bomb in April, 1966 lost off Spain in 2,310 feet of water following a collision a B-52 bomber and its jet tanker during a refueling mission.
In September, 1985, Alvin played a key role in the discovery of the liner Titanic 13,000 feet deep, about 350 miles off Newfoundland. The Titanic sank on April 15, 1912 after hitting an iceberg.
GLOMAR EXPLORER
Built as a ocean mining vessel by the Global Marine Corp. of Los Angeles, the 618-foot Glomar Explorer was completed in May, 1974. It had a sophisticated system for recovering sunken wreckage. It was reportedly capable of hovering over one spot where it could use a huge grappling machine to retrieve objects over 1,500 tons from 17,000 feet.
In 1974, the Glomar Explorer, is believed to have recovered parts of a Soviet submarine for the CIA. It may also have retrieved missiles from a depth of 16,500 feet below the Pacific.
JIM SUIT
Invented by Joseph Peress in 1921, the Jim suit was first used to search the wreckage of the Lucitania. The first model was made of stainless steel with fluid-filled joints for use at a depth of up to 600 feet. Later, other metals were used. A pressurized suit allows divers to breathe air pumped from the surface, and time under water is not limited. There is no need to depressurize even after working at depths exceeding 250 feet.
Jim suits are most often used for repairs such as patches on ships. Divers climb into the Jim suit, which is then lowered by crane.
RECON 4
Recon 4, built by Perry Oceanographics, Inc. of Riveria Beach, Fla., is one of a class of unmanned submersibles or ROVs (remotely operated vehicle) designed chiefly for inspecting offshore oil rigs and pipelines. It has two manipulator arms, sonar, television camera and still camera and is connected by cable to its surface power source and command systems. It has a maximum operating depth of 5,000 feet.
Scientists at UC Santa Barbara want a grant from the National Science Foundation to use Recon 4 or a similar system to examine the freighter Pac Baroness, which sank Sept. 21 about 15 miles off Santa Barbara in about 1,800 feet.
TANKER
The 14,412-ton Pac Baroness, a Liberian registered freighter built in 1976, had six holds for the bulk carrying of cargo bound for Japan. The 561-foot ship carried 23,000 tons of powdered copper, iron and sulfur concentrates and 386,000 gallons of bunker fuel.
