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Upgraded Alvin submersible sets sail

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May 28, 2013

After almost half a century in service, the revamped Alvin submersible is once again headi...

After almost half a century in service, the revamped Alvin submersible is once again heading for deep water

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You would think that a little sub built almost 50 years ago would be sitting in a museum somewhere, but Deep Submergence Vehicle (DSV) Alvin, which launched in 1964, is still going strong. Owned by the US Navy and operated by the Woods Hole Oceanographic Institution (WHOI), Alvin has completed a major US$41 million redesign and refit. The revamped submersible set sail on Saturday aboard its mothership R/V Atlantis for certification testing off the coast of Oregon and California.

Alvin’s certification tests are the end of its “Phase One” upgrade, which began with a redesign back in 2005. The little submersible, capable of carrying a crew of three, is hardly recognizable as the same craft that was built by General Mills in the 1960s. The refit has increased Alvin’s weight from 35,200 pounds (15,966 kg) to 45,000 pounds (20,411 kg) – more than 40,000 pounds of which is a brand new titanium personnel sphere designed and forged by the Southwest Research Institute. Its three-inch thick walls were forged and then welded together with an electron beam, allowing it to make descents to depths of 21,000 ft (6,500 meters) and has been tested to the equivalent of 26,000 ft.

In addition, the new sphere is 4.6 inches wider, which may not seem like much, but it increases its volume from 144 to 171 cubic feet (4 to 4.8 m³). This not only makes it more comfortable, but it also makes it possible to increase the number of viewports from three to five with overlapping fields of view.

The evolution of Alvin

The evolution of Alvin

Other improvements to Alvin include increasing the science payload from 200 to 400 pounds (91 to 181 kg), the installation of better exterior lighting, a high-definition imaging systems and an improved command and control system.

One example of the challenges faced in refitting Alvin is the new syntactic foam fitted to the submersible’s interior. Like many watercraft, it uses plastic foam to give it buoyancy, but conventional foams, such as Styrofoam, are buoyant because they’re full of air bubbles. At a depth of four miles, the water pressure would squash air-bubble foam into a hard mass of plastic. The syntactic foam used by Alvin replaces the air bubbles with microspheres made of glass or some other material, so it takes a lot more pressure to compromise the foam.

Alvin is regularly disassembled every three or four years and has undergone a number of refits over the decades. In 1973, its original steel sphere was replaced by titanium, manipulator arms have been added or replaced on a number of occasions and, in the 1980s, its rear propeller was replaced by a set of thrusters and new batteries installed. Because Alvin is much heavier after this latest refit, R/V Atlantis also had to undergo a refit with a strengthened A-frame to handle the heavier craft and a larger hanger for it.

Alvin on a deep diving mission

Named for WHOI scientist Allyn Vine, Alvin is the world’s longest-operating deep-sea submersible and has completed 4,664 dives. During its almost half a century in service, it has been involved in a number of historic events, such as the recovery of a US Air Force hydrogen bomb in the Mediterranean Sea off the coast of Spain in 1966, exploring the first known hydrothermal vents in the 1970s, surveying the wreck of the Titanic and studying the aftermath of the Deepwater Horizon oil spill.

Even Alvin’s accidents have been serendipitous. In 1968, the submersible was dropped into the ocean when a cable snapped. The sea rushed into the open hatch and, though the crew escaped, Alvin sank in 5,000 feet (1,500 m) of water. Recovered a year later, the craft not only showed very little damage, but the lunch packed for the crew was soggy, but still edible. According to WHOI, this sparked new research into the environment and biology of the deep ocean.

Alvin will undergo US Navy certification in September with a series of progressively deeper dives off Monterey, California. It will then carry out a science verification cruise in November to test its scientific equipment and, if everything checks out, will return to service in December. Though its new sphere allows Alvin to dive to 21,000 ft, it will only operate at a maximum of 15,000 ft until its Phase Two refit is carried out. This will see the addition of new lithium ion batteries that will increase its operating time to up to twelve hours.

Alvin is scheduled to reach Astoria, Oregon on June 20.

Source: Woods Hole Oceanographic Institution

About the Author
David Szondy David Szondy is a freelance writer based in Monroe, Washington. An award-winning playwright, he has contributed to Charged and iQ magazine and is the author of the website Tales of Future Past.   All articles by David Szondy
15 Comments

This is the same vehicle used to explore RMS Titanic.

Seth Miesters
28th May, 2013 @ 08:34 pm PDT

Wow nice sub and they have replaced a lot of gear including the sphere.... are we sure its the same sub !!!

chaalfontcrew
28th May, 2013 @ 11:39 pm PDT

For that kind of money, I hope it's not the same sub. Wish they would let public vote on whether to blow 41 million bucks on a minisub.

JimD
29th May, 2013 @ 12:06 am PDT

JimD, the science this little sub does is well worth the money. Even tho I am Swedish and my tax money don't pay for it. But I do wish there was a international oceanographic program that does lots of subs and science of the deep. By the world for the world.

Toffe Kaal
29th May, 2013 @ 05:36 am PDT

Toffe is right. The scientific return is HUGE compared to the investment. This particular vehicle pretty much proved the existence of life on other worlds. That was just one single discovery in a long list of discoveries during 50 years of exploration. As the article pointed out, there are practical reasons for funding this as well. If you lose something important at the bottom of the ocean, Alvin may be able to reach it 3 miles down. Trillions of dollars in mineral wealth are waiting to be discovered at depths only this submersible can reach.

Oh, never mind. We can let Honey Boo Boo decide.

Seth Miesters
29th May, 2013 @ 07:35 am PDT

another sub the alumnanaut that rescued alvin is on display in richmond virginia at the virginia science museum

hummer boy
29th May, 2013 @ 09:36 am PDT

Is it just me or does that sphere look flimsy. it needs bigger windows, ones that can slide open.

Jay Finke
29th May, 2013 @ 10:13 am PDT

Jay: Alvin already has one hatch and making the "windows" openable pretty much defeats the entire "submersible" concept. Also, JimD, the technology skills achieved in designing things like Alvin or the various space exploration tools, satellites, shuttle, & astronomical telescopes, etc., has paid off, spin off, benefits that are on the order of 10 times greater than the development costs, (this is an absolutely minimal estimate). Digital electronics alone has radically changed and improved everyone's life and is a direct outcome of hard science research that was first applied to research, defense, and aerospace objectives.

StWils
29th May, 2013 @ 12:42 pm PDT

re; chaalfontcrew

I had the same thoughts on the subject.

Slowburn
29th May, 2013 @ 07:00 pm PDT

reminds me of the joke my Dad used to tell about Paddy's axe:

'Nice new axe Paddy, when did you get rid of the old one?'

'Oh no' says Paddy, '3 new heads & four new handles now, but its still the same axe...'

Gearhead
29th May, 2013 @ 08:48 pm PDT

The Alvin provides the navy with a capability that every now and then they really need. The cost of keeping the capability available is defrayed by loaning (renting) it to academic and commercial interests. This benefits all involved.

Slowburn
29th May, 2013 @ 09:59 pm PDT

Since pretty much every part of the sub has been replaced, why not take all the best previous parts and build another sub (or two) to use for shallower dives?

Gregg Eshelman
29th May, 2013 @ 11:39 pm PDT

One thing I wonder is why not place some sealed cameras all along the outside of the sub, and stitch their views together into a massive panorama that can be viewed by the occupants? Then they wouldn't even need but a couple of portholes, and could probably dive deeper with the stronger containment sphere (windows are structural weaknesses). Toss a few thermal or IR cameras into the setup and then they could switch between normal & augmented vision for better identification of things down there.

Onihikage
30th May, 2013 @ 06:36 am PDT

Onihikage - that's what has happened on the most recent naval subs - the periscope no longer penetrates the pressure hull - all done with electronics.

Marc 1
31st May, 2013 @ 12:33 am PDT

re; Onihikage

Seeing some thing without it passing through a video system has value aside from the fact you know it is not a recording.

Slowburn
31st May, 2013 @ 09:36 pm PDT
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