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(Photo by Tom Kleindinst, Woods Hole Oceanographic Institution) [ Hide caption ]
Rebuilding Alvin: Ben PietroA series on the people reassembling the iconic subBy Cherie Winner :: Originally published online March 19, 2013 : In print Vol. 51, No. 1, Summer 2014TOPICS:Underwater VehiclesSHARE THIS: TOOLS: Since the beginning of 2011, Alvin, the U.S. science community's only human-occupied submersible dedicated to deep-sea research, has been undergoing a thorough overhaul and upgrade that will enhance its capabilities. The improvements include a new personnel sphere, updated command-and-control systems, enhanced lighting and high-definition imaging systems, new syntactic foam to provide buoyancy, and more and larger viewports, or windows.
The centerpiece is a larger personnel sphere with improved interior design to enhance the comfort of pilots and researchers who will occupy it. The titanium sphere is also designed to withstand pressure at depths of 6.5 kilometers (4 miles), with the eventual goal of allowing Alvin to dive beyond its current 4.5-kilometer (2.8-mile) diving capacity.
Now in the final stages of the first phase of the upgrade, the iconic sub is being painstakingly reassembled, piece by piece, by a one-of-a-kind team of engineers, technicians, and pilots at Woods Hole Oceanographic Institution (WHOI). They also carefully inspect and test each component to ensure its reliability and the safety of those who will use to sub to explore the depths.
Here, engineering assistant Ben Pietro describes what it takes to give Alvin's sail its gleaming, colorful coat:
That piece is what they call the sail. It extends the height of the dry area around the hatch while the sub is on the surface, to protect the hatch from waves. It's also a good high spot for mounting navigation equipment.
The sail is made of carbon fiber, which is very strong and light so it doesn't add a lot to the vehicle's weight. In previous overhauls, they've used a red. They wanted to go with international orange this year to make it as visible as possible on the surface of the ocean.
We're inside the paint booth up in Clark South. We try to keep all the dust down as much as possible. There's air that comes in through the intake and pushes out through the vents at the back. We bring the garden hose in and spray down the floor and the lower part of the wall to keep the dust down. With a showcase piece like the Alvin sail, we wanted to eliminate all possibilities of anything coming in and disrupting the paint. If there's dust flying around, some of it would stick on the wet paint and the sail wouldn't shine like it shines right now.
The paint is called AwlGrip. It's a two-part epoxy paint. It's nasty - it's not stuff that you want to be inhaling a lot. You wear a full-face respiratory mask, your gloves, your paint suit.
We did three coats on this. The first one you put on is kind of spotty. The second coat, you fill everything in and make sure it's uniform. Then the third coat is the one that you gotta make sure it goes on perfect. You want to put it on sort of robotic-like, and paint every area with the same amount of paint. If you put too much paint on something, it'll open up and it'll become a big, round 'fish eye.'
We actually had to paint this twice because the first time we did it, it didn't come out perfect. So we had to sand it all back down again and then re-do it.
I work for UOP [the Upper Ocean Processes group]. I do mostly mechanical work - build, fabricate, design moorings. I've just always been able to work with my hands, and my father taught me at an early age that 'we've got to fix cars, so get out there and help me do it.' It never left me. I always enjoyed it.
I've been doing a lot of painting since I started here, but I'm learning as I go - I don't have a degree in painting or anything like that. [WHOI mechanic] Victor Miller helped me a great deal with this. He taught me how to control the paint through different series of thinning it and testing the material, so you don't get drips. He taught me more in a week when I worked with him doing this than I have in four years that I've worked here.
It was a great experience and a privilege to do this for Alvin. I was honored to be asked to do it, and I'm really proud of the piece.
Alvin is owned by the U.S. Navy and operated by WHOI. The current upgrade has been funded largely by the National Science Foundation, with support from private donations to WHOI.
From the Series REBUILDING ALVIN
Ben Pietro
ALVIN upgrade, Applied Ocean Physics & Engineering Dept., HOV ALVIN, paint, sail Woods Hole Oceanographic Institution is the world's leading non-profit oceanographic research organization. Our mission is to explore and understand the ocean and to educate scientists, students, decision-makers, and the public. About