Many questions surround the tragedy of the Titan Subversive and its crew of five off the coast of Cape Cod.
Seattle-based Stockton Rush piloted the fateful voyage. Rush was the face of OceanGate which built Titan. Rush also bragged he built the Titan by cutting corners and with materials he shouldn’t have.
The Titan lost contact about two hours into its dive to the wrecked Titanic. A four-day, multinational search and rescue effort ended when pieces of the Titan were found on the ocean floor about 1600 feet from the ship. The U.S. Navy also picked up an underwater explosion Sunday, around the time the vessel went missing.
Rush said he used carbon fiber and titanium to make the Titan safe for the 13,000 ft dive; but many, including renowned explorer James Cameron, said the very design was fundamentally flawed. One major problem is carbon fiber has very high tensile strength, but not compression strength.
“That’s something I teach my students in the first class,” said UW Assistant Professor Dr. Aniruddh Vashisth.
Dr. Vashisth specializes in the mechanics of materials at the University of Washington. He said the materials used to make OceanGate’s Titan - carbon fiber and titanium - are pretty common.
“Most of the airplanes that we sit in today are more than 50% by volume made up of carbon fiber composites because they’re light and can take off in the air,” said Dr. Vashisth.
He said carbon fiber is a lightweight material, which is why it’s good for planes. He also said the material needs something stronger, a metal to make it more stable. That’s where titanium comes into play.
In a 2021 interview with YouTuber Alan Estrata, Rush admitted he broke the rules in using both.
“I’ve broken some rules to make this, I think I’ve broken them with good logic and good engineering behind me. The carbon fiber and titanium, there’s a rule you don’t do that – well I did,” Rush said in the video.
A co-founder of OceanGate, who left the company after four years in 2013, said the Stockton he knew emphasized safety.
“In the four years I was involved with the company and - I knew and I got to work with Stockton - safety was always number 1 priority for us and for Stockton in particular,” said Guillermo Sonhnlein. He continued, “Both to expand the capabilities of humanity exploring the oceans while also improving the safety of those doing it.”
Dr. Vashisth said carbon fiber is great in the air, but it doesn’t hold up well under pressure.
“How carbon fibers composites are made, let’s say my fingers are the carbon fibers, the fibers are really strong in tension but if you start compressing them they buckle really easily,” he explained. Dr. Vashisth added, “You can have basically a compressive failure. You can have a buckling failure here various ways materials fail.”
The Titan dove to the Titanic and surfaced successfully before. Each added square inch of pressure chipped away at the structure. It’s called fatigue damage.
“There is like this cyclical loading on this composite back and forth, back and forth, and after a certain while a composite starts accumulating a little bit of damage. My scientific guess would be when the Titan going down and up again and again, it would have some fatigue attached to it,” said Dr. Vashisth.
Officials haven’t said what caused the Titan’s implosion. KIRO 7 reached out to everyone currently on OceanGate’s team for a comment but didn’t hear back.