Titan sub implosion as quick as ‘turning on the light switch.’ What happened?

Investigators are turning their attention to finding out how a submersible carrying five people to the Titanic wreckage suddenly imploded.

All hopes for a positive outcome vanished Thursday when the U.S. Coast Guard confirmed it found debris belonging to OceanGate Expedition’s Titan near the famous ocean liner at the bottom of the North Atlantic.

The submersible’s disappearance Sunday set off an international rescue mission that captivated the world’s attention given its link to the Titanic. As well, the five passengers aboard the Titan were reported to have 96 hours of breathable air – an added element that led to the frantic search.

With its unfortunate demise and the death of those on board, investigators are focusing on how the Titan suffered a “catastrophic implosion,” as it was described Thursday by the U.S. Coast Guard.

Here’s what we know so far.

First off, an implosion is a process in which objects are destroyed by collapsing on themselves.

It is the opposite of explosion, which is a rapid expansion in volume associated with an extreme outward release of energy.

“The implosion of the hull means the water pressure was greater than the strength of the material,” said Will Kohnen, president and CEO of submarine manufacturer Hydra Space Group, and chair of the Marine Technology Society’s manned underwater vehicles committee.

“When you reach the point where it doesn’t go anymore, all that stored energy goes into it and that’s what creates the inverse explosion, i.e., implosion, and it happens very fast.”

On Sunday, the Titan suddenly lost contact with Canadian research vessel Polar Prince roughly an hour and 45 minutes after it submerged to descend for a view of the Titanic. It takes more than two hours to get to the wreck.

The Titanic sits almost four kilometres below sea level. The U.S. Coast Guard said Thursday that the Titan’s debris had been found roughly 500 metres from the Titanic.

“The debris field is consistent with a catastrophic implosion of the vessel,” U.S. Coast Guard Rear-Adm. John Mauger told reporters in Boston.

Mauger initially described the Titan’s debris as “consistent with the catastrophic loss of the pressure chamber.”

Undersea expert Paul Hankin told reporters in Boston that searchers found five pieces of debris, including the nose cone, which was roughly 500 metres from the Titanic’s bow, and the front-end belt of the pressure hull.

The other end of the pressure hull was found in a second, smaller debris field nearby, Hankin added, which … “basically comprised the totality of that pressure vessel.”

Charles Beeker, a professor and director for Indiana University’s centre for underwater science and academic diving program, told Global News that at the Titanic’s depth, the pressure on the submersible would’ve been 400 times that compared with the surface.

“They weren’t to the depth of the Titanic, they were maybe two-thirds of the way down, which is estimated. That amount of pressure, 250-280 times the surface pressure, an implosion would have been very quick,” he said.

“Almost like turning on the light switch. It just happens.”

Questions about the Titan’s safety have been raised in the past week.

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 disagreed and noted Lochridge was fired after refusing to accept assurances from the company’s lead engineer that the acoustic monitoring and testing protocol was better suited to detect flaws than a method he proposed.

According to company files, at least 46 people successfully travelled on the Titan to the Titanic in 2021 and 2022. One of the company’s first customers likened a dive he made to a “kamikaze operation.”

“Imagine a metal tube a few metres long with a sheet of metal for a floor. You can’t stand. You can’t kneel. Everyone is sitting close to or on top of each other,” said Arthur Loibl, a retired businessman and adventurer from Germany.

“You can’t be claustrophobic.”

J. Kim Vandiver, a professor of mechanical and ocean engineering at the Massachusetts Institute of Technology, told Global News that deep-sea submersibles like the Titan are designed to withstand not only the pressure of certain depths, but also a finite number of dives to those levels.

As the Titan took more dives to the ocean floor, he said, the pressure hull likely began to grow “little tiny micro-cracks” from the fatigue brought on by multiple high-pressure descents.

Mauger didn’t give any timelines Thursday for when the investigation would be complete.

“I know there are also a lot of questions about how, why and when did this happen. Those are questions we will collect as much information as we can about now,” he said, adding that it was a “complex case” that happened in a remote part of the ocean and involved people from several different countries.

The five passengers aboard the submersible were identified as a British billionaire adventurer, a wealthy Pakistani businessman and his son, a French explorer and the CEO of OceanGate.

Mauger could not say if the bodies of the passengers could be recovered.

“This is an incredibly unforgiving environment down there on the seafloor,” he said.

“We’ll continue to work and continue to search the area down there, but I don’t have an answer for prospects (of finding human remains) at this time.”

Aileen Marty, a professor of translational medicine with Florida International University, told Global News the human body wouldn’t be able to handle that implosion.

“It’s a massive amount of force … incredibly fast crushing that would have dissolved skin and bones and muscle to almost nothing in an instant,” she said.

Beeker said the Titan’s demise is a reminder of the dangers of deep-sea explorations – but perhaps it’s time to enhance measures to make it safer.

“Without explorers, we’re not going to be able to go into the inner reaches of the oceans,” he said.

“I’m not condoning this type of activity but at the same time, they were inspecting, they were looking, they were not bringing up objects, and I think we need to continue this type of research but maybe some types of regulations and inspections would help us in the future to make these endeavours much safer.”

— with files from Global News’ Sean Boynton and The Associated Press