How was the Titan submarine crushed?

With no black box, the investigation team needs to collect every possible piece of wreckage from the ship and examine the fracture structure in the carbon fiber material.

OceanGate Expeditions' Titan submersible. Photo: OceanGate Expeditions/AP — OceanGate Expeditions' Titan submersible. Photo: *OceanGate Expeditions/AP*

After discovering the wreckage of the Titan submersible on the seabed, rescue efforts will now turn to finding out the cause of the incident. Titan is a submersible carrying 5 people to visit the Titanic wreckage that lost contact in the Atlantic Ocean on June 18.

According to US Coast Guard Rear Admiral John Mauger, what they found was like a catastrophic crush event, BBC reported on June 23. The reason is that they discovered a piece of debris containing the stern of the Titan and the other piece containing the landing frame, indicating that the ship was crushed.

To answer the question of why the incident happened and what those involved could have done to prevent it, authorities will collect every piece of debris possible, according to Ryan Ramsey, a former submarine commander in the British Royal Navy.

“Without a black box, you wouldn’t be able to trace the final movements of the submersible,” Ramsey said. If there were a black box, the investigation would be similar to an airplane crash.

When the team brings the pieces to the surface, they will look for cracks in the carbon fiber structure. This is key to understanding what happened in the final moments. Each piece will be carefully examined under a microscope to examine the orientation of the carbon fibers, looking for tears that will reveal the exact location of the break.

The big question the investigation team will try to answer is whether structural failure was to blame. If so, the submersible was subjected to extremely high pressures, equivalent to the weight of the Eiffel Tower, according to Professor Blair Thornton of the University of Southampton. “We’re talking about a very powerful explosion of the main hull,” he said.

Another important question is whether, if this is indeed happening, it is due to a lack of comprehensive testing and inspection, as some experts have suggested.

“The carbon fibres fail due to internal structural faults,” said Professor Roderick A Smith of Imperial College London. He said the joints between the carbon fibres and titanium would need to be investigated very carefully. The violence of the explosion meant it could be difficult to determine the sequence of events, so careful salvage and examination would be needed if possible, he added.

It’s unclear which agency will lead the investigation, as there are no established protocols for such incidents involving submersibles. Mauger said the incident was particularly complex because it occurred in a remote area and involved people of many different nationalities. But the Coast Guard has played a key role so far, and it’s likely to continue to do so.

The Titan submersible is made from carbon fiber and titanium, according to OceanGate. Measuring 6.7 m x 2.8 m x 2.5 m, the Titan is designed to carry a pilot and four passengers. It weighs 10,432 kg, can travel at a top speed of 5,556 km/h and dive to a depth of 4,000 m.

The ship has no dedicated steering system, but is controlled by a PlayStation controller. To communicate with the mothership, Titan sends messages via a sonar system (USBL).

The Titan submersible went missing on June 18 while carrying five people on a tour of the Titanic wreck at the bottom of the Atlantic Ocean, about 600 km off Newfoundland, Canada. According to the company's website, the underwater expedition to the Titanic wreck is being conducted by OceanGate from 2021, at a cost of $250,000 per person.