By MARK GLASSMAN
Published: August 7, 2004
WASHINGTON, Aug. 6 - A manned deep-sea submarine that for 40 years has shed its lights on the likes of new life forms, superheated sea vents, a sunken hydrogen bomb and the Titanic is succumbing to the disease most lethal for technology: obsolescence.
Alvin, the small white transport that changed undersea science, will be replaced in four years by a $21.6 million vehicle designed to go deeper faster, the National Science Foundation said Friday. The old sub has made roughly 4,000 dives, spending a total of more than three years underwater.
Alvin was instrumental in confirming the theory that the sea floor was expanding along the Mid-Atlantic Ridge, and in uncovering the existence of hydrothermal vents in the Pacific. In 1966, it retrieved a hydrogen bomb that had fallen into the Mediterranean after the collision of a B-52 and a tanker plane. Dr. Robert D. Ballard later used it to explore the wreck of the Titanic, and other scientists have recorded more than 300 new species, including bacteria, clams and tube worms, from inside the sub's hull.
It is unclear whether Alvin will be laid to rest in a museum or left to explore relatively shallow waters, but the announcement of a successor, not yet named, all but ended its stint as the United States' primary deep-sea vehicle. (Other countries, including Russia and Japan, now have research submarines that can go deeper than Alvin's limit of 2.8 miles.)
"It's not like a worn-out shoe that we're going to be happy to get rid of," said the Alvin project director, Barrie B. Walden of the Woods Hole Oceanographic Institution, who has worked with the submarine since 1969. Alvin is still functional, Mr. Walden said. Indeed, as its replacement was being announced, Alvin was at work, trolling the Gulf of Alaska in fisheries research.
But a global interest in going deeper, an interest Alvin helped cultivate, has made a replacement necessary, the foundation said. Alvin's ability to withstand depths of nearly three miles makes 62 percent of the sea floor accessible; the new craft, to be financed largely by the science foundation and, as with Alvin, operated by Woods Hole, will reach four miles, giving the three-member crew access to 99 percent of the floor.
Six years ago, the Navy donated Sea Cliff, a newer sub whose hull could tolerate depths of 3.8 miles, to Woods Hole, the idea being to use it for spare parts for Alvin, somehow combining the best aspects of the two craft. But the useful parts proved incompatible, and Alvin remained just Alvin.
Then, last year, a report from the National Research Council recommended substantial changes to the sub, or a replacement.
"The scientific demand for deep diving vehicles is, at present, not being adequately met," the council's report said.
So with input from hundreds of scientists with a stake in deep-sea exploration, Woods Hole collaborated on a proposal for a new sub, which, in addition to its capacity for greater depth, will provide the crew 27 more cubic feet of space and will deploy an ultrathin fiber-optic cable to the surface, speeding transmission of data and images to the ship from which it is launched.
Faster descent and ascent will allow the new model to spend more time underwater, and portholes placed more closely together will allow the scientists on board to view the same swath of seabed together.
Alvin's name is derived from that of Allyn Vine, the Woods Hole scientist who largely inspired it.
"There's always a debate," Mr. Walden said. "Is it a 'he' or a 'she'? Our own people refer to it as 'the sub.' "
The new sub will evict Alvin from its support ship, Atlantis, which has the equipment to lower heavy craft into the sea and raise them again. Some minor adjustments will have to be made to Atlantis.
"It's sort of like buying a new Cadillac when you've had a Chevy in your garage," said Emma Dieter, the program director of ocean sciences at the science foundation.
But there will be some love lost, scientists said, with the replacement of the boxy sub that made so many discoveries.
"I think it's clear," Mr. Walden said, "that the new vehicle has its work cut out for it."