Structural issues with Titan sub hull could have caused implosion: expert

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Structural issues with the doomed Titan sub’s hull could be among the causes of the “catastrophic implosion” that destroyed the vessel and killed all five people on board in the depths of the Atlantic, an expert told The Post.

Investigators were hunting for clues on Friday as to how and why the OceanGate-owned submersible suddenly fell apart as it was descending toward the wreck of the Titanic this week.

While authorities say it is too early to tell the cause of the deep-sea disaster, one expert pointed to possible failures of the sub’s hull — its main body — as a likely explanation.

Virginia Tech ocean engineering professor Stefano Brizzolara suggested the sub’s pressure hull could have had a defect that may have fractured under the pressure and sparked an implosion.

“It is difficult to say what caused the structural failure in this case, but any small material and geometric imperfection, misalignment of connection flanges, tightening torque of bolted connection may have started the structural collapse,” Brizzolara said.

The Titan’s hull was constructed from two different materials: carbon fiber-reinforced plastic and titanium.

Brizzolara said the carbon fiber element is “very prone to possible defects” and that it “exhibits a more fragile behavior” than other materials — meaning that when it fails, it can break into small fragments.

The expert said the Titan’s repeated voyages down to the wreckage of the ocean liner may have also caused the hull to “deform and shrink.”

“These repeated deformation cycles may have started some material defects in the [carbon reinforced plastic] or some permanent deformations or misalignment between the two parts of the hull that were built with two different materials, which deform in a different way,” he said.

Brizzolara said he is certain those onboard would have been killed immediately when the implosion occurred because any small leak at that depth would have sent water rushing in at a speed of about 1,000 km (621 miles) per hour.

“Implosion is an explosion in reverse,” he said. “Imagine a cylinder: During an explosion, the charge placed in the center ignites and causes the pressure at the center to increase instantaneously.”

Such intense pressure would cause the ejection of mass to move the center axis of the cylinder to the outside “at incredible speed.”

“An implosion is the reverse,” Brizzolara said. “The inside of the cylinder can practically be considered void while the pressure of the wave that breaches the hull is 400 times larger.”

He said this would cause a violent flow of water from the outside of the cylinder to the inside.

“You can imagine how this impulsive flow of water can crush things inside the hull — human bodies included,” Brizzolara said.

Prior to this ordeal, questions about the submersible’s safety had already been raised by a former company employee.

David Lochridge, OceanGate’s former director of marine operations, argued in 2018 that the method the company devised for ensuring the soundness of the hull — relying on acoustic monitoring that could detect cracks and pops as the hull strained under pressure — was inadequate and could “subject passengers to potential extreme danger in an experimental submersible.”

OceanGate, at the time, disagreed.

Meanwhile, “Titanic” director James Cameron — who is a submersible pioneer — suggested Thursday that critics were correct in warning that a carbon fiber and titanium hull would enable delamination and microscopic water ingress — leading to progressive failure over time.

Cameron said carbon-fiber composites have “no strength in compression” in an interview with the New York Times.

“It’s not what it’s designed for,” he said, referring to deep-diving explorations.

With Post wires