When newly made blocks of syntactic foam for the upgraded Alvin submersible arrived from the manufacturer, WHOI research engineer Rod Catanach tested each to ensure they fit correctly. The "raw" blocks are yellow because they have not yet been painted white and given a fiberglass coating. Here, Catanach aligns a block with a clevis on the sub's titanium personnel sphere. A tie rod through the clevis and block will fasten the block to the sphere. "You can computer model it all you want, but when it's actually fit in place, if it's off by half a drill hole, it's a pain to correct," said Catanach.
(Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)