A Penetrating Task

Dexter Tan installed penetrators—the large metal lugs—to the hull of Alvin during the submersible’s recent overhaul and upgrade. The plastic tubes connected to the penetrators contain electrical and fiber-optic cables that transmit power and data through the spere from batteries and computers housed in pressure-resistant canisters attached to the sub’s frame. The tubing will eventually be filled with oil to keep the sensitive wires at ambient pressure, but safe from seawater.(Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)