The deep sea submersible Alvin celebrates fifty years of operation this summer. After several major renovations, is it really still the same sub?
For us humans, birthdays and dates of death are clear-cut. A joint replacement or organ transplant may be necessary, cosmetic surgery may be opted for. But none of that fundamentally changes a person's identity.
Now consider the complicated life story of Alvin, the only American human-occupied deep sea submersible. On June 5th, 2014, Woods Hole Oceanographic Institution marked the fiftieth anniversary of Alvin's commissioning. But that's really more equivalent to a christening or bris than a birthday. The closest Alvin has to a human date of birth is probably the day construction was completed in spring of 1964. It's first free dive, on August 4th of that year, might equate to a baby's first steps.
Since that first foray to a modest depth of 35 feet, the sub has completed more than 4,600 dives, spending some than 33,000 hours underwater (not counting an unplanned ten month stay on the sea floor after a cable failed during launch) and carrying over 2,500 researchers to the sea floor. Alvin - with a little help from its crew, it should be said - has recovered a lost hydrogen bomb, explored the wreck of the Titanic, and discovered life at deep sea hydrothermal vents. It's also been speared by a swordfish, lost its mechanical arm, and been overhauled more times than any Hollywood actress, except maybe Cindy Jackson.
And therein lies the rub. Alvin has been completely disassembled and reassembled, complete with upgrades and modifications, every handful of years. You might say Alvin has been reborn six times. With the most recent renovation, completed earlier this year, Alvin now has a new hull - its third - that should last another 30-50 years.
With the demonstrated ability to repeatedly reinvent itself (or be reinvented), Alvin's lifespan is less dictated by physical parts, more by the availability of funding and the will to continue human exploration of the deep sea.
"We want to keep it going forever. Seriously," says Alvin group manager Bruce Strickrott. "I want to make sure that we keep this going and give it to other people."
Could Alvin be immortal? And, if every piece has been replaced multiple times over, is it even still the same vehicle?