- Original Article
Submersible Alvin awaits major overhaul
FALMOUTH — Eventually, the submersible used to locate a missing hydrogen bomb and first view the Titanic will take scientists deeper into the ocean's impenetrable abyss than humans have ever gone.
But not without sinking a larger-than-anticipated chunk of money into this famed submarine.
Alvin by the numbers
- Built in 1964 for $500,000
- Named after WHOI scientist Allyn Vine and owned by the U.S. Navy
- 23 feet long, 12 feet tall, 8.5 feet wide
- Weighs 37,000 lbs.
- Travels at a speed of 2 knots
- Requires 3,500 pounds of batteries
- Moves using 6 reversible thrusters
- Allows scientists up to 11 hours in the water
- More than 13,000 researchers have gone on more than 4,500 dives
Alvin — the celebrated submersible — is 45 years old and plans to replace it have been in the works for 10 years. But the original $21.6 million price tag set in 2004 by the National Science Foundation could rise as high as $35 million, said Susan Humphris, acting vice president of Marine Facilities and Operations at the Woods Hole Oceanographic Institution.
Also, instead of a new submersible, Humphris said existing components of Alvin will be merged with new and improved materials.
But that means instead of being able to dive 4 miles under the ocean's surface as originally planned, scientists will initially be restricted to the same 2.8-mile limit they had with Alvin.
"The cost estimates to go straight to a 6,500-meter (21,300 feet) vehicle were prohibitively expensive," Humphris said, noting the price of titanium alone more than quadrupled in recent years.
To cope with the cost overruns, Humphris said project officials have decided on a two-phase approach.
The first phase uses existing federal funds to merge new materials on the body of the old Alvin, while the second phase consists of finding additional funds to upgrade all other components on the sub in order to get to depths of four miles.
Humphris said the modified Alvin will be ready to make dives by the end of 2011, but enabling the vehicle for greater dive depths may not happen until Alvin's next five-year scheduled overhaul in 2015.
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courtesy of WHOI
At that point scientists will have access to 98 percent of the ocean instead of the 63 percent Alvin currently allows them to explore.
Despite some setbacks, Humphris said "a lot of progress" has been made recently.
The brand new titanium personnel sphere, which will house a pilot and two scientists, has been forged using an electron beam, Humphris said. The titanium is 3 inches thick, compared with Alvin's 2-inch thick sphere, and weighs more than 11,000 pounds.
The sphere maintains sea level atmospheric pressure on the inside while resisting nearly 5 tons of pressure per square inch at maximum depths of 4 miles below the surface of the ocean.
And while the 7-foot inside diameter may not be luxurious, it is a foot wider than Alvin's current sphere and its volume is 18 percent larger, which gives scientists more room for themselves and their equipment.
The new design allows for five windows with overlapping views, as opposed to Alvin's three small windows with only one facing forward, Humphris said.
The lighting and video systems, battery capacity and maneuverability will also be improved.