Engineers carefully lowered the Cyclops 2 model into the testing tank nose-first, like a bomb being loaded into a silo, and then screwed on the tank’s 3,600-pound lid. Then they began pumping in water, increasing the pressure to mimic a submersible’s dive. If you’re hanging out at sea level, the weight of the atmosphere above you exerts 14.7 pounds per square inch (psi). The deeper you go, the stronger that pressure; at the Titanic’s depth, the pressure is about 6,500 psi. Soon, the pressure gauge on UW’s test tank read 1,000 psi, and it kept ticking up—2,000 psi, 5,000 psi. At about the 73-minute mark, as the pressure in the tank reached 6,500 psi, there was a sudden roar and the tank shuddered violently.
“I felt it in my body,” an OceanGate employee wrote in an email later that night. “The building rocked, and my ears rang for a long time.” “Scared the shit out of everyone,” he added.
