Experts reveal what will happen when oxygen runs out of Titanic sub

The US Coast Guard, air force and the navy among other search and rescue groups, are now facing the ultimate pressure test as they race against time to locate the vessel.

The Titan went missing on Sunday morning, US time, after it lost connection with its mothership while voyaging to the wreckage of the Titanic, in the North Atlantic Ocean.

At the time of its descent it had 96 hours of life support installed, with estimates saying oxygen had expired as of 9.08pm (AEST).

With air levels dwindling rapidly, many questions have been raised about what will happen to those aboard the vessel once they no longer have clean air to breathe.

Dr Kenneth Ledez, hyperbaric medicine specialist at Memorial University in Newfoundland, says even if emergency air levels exhaust, those onboard may still survive if they’re rescued on time.

“Depending on how long and how low the oxygen has been, will determine what the long term outcome is,” he told BBC.

Humans can survive for a few minutes without oxygen, however permanent brain damage can begin after four minutes of not breathing, multiple medical sources said.

“Can people survive after exposure to those conditions? Yes, they could have damage to the nervous system and heart after an extended time, so really, it’s going to be a gradual deterioration,” Dr Ledez said.

“I don’t think (rescue teams) should give up, I think they should keep their efforts going to see if they can (find the passengers) in time, absolutely.”

Meanwhile, a retired US navy submarine captain believes the five-member crew onboard would be facing bleak, “freezing cold” conditions.

The CEO of Titan’s manufacturer OceanGate, Stockton Rush, is believed to be on the Titan alongside British billionaire Hamish Harding, 73-year-old veteran submarine pilot Paul-Henry Nargeolet, and Pakistani businessman Shahzada Dawood and his son Suleman.

Former navy Captain David Marquet said the group – who are likely four kilometres below the ocean surface – are probably thirsty and hungry, however it’s the oxygen supply that’s key to their survival.

“They’re freezing cold. The water entirely surrounding the ship is at freezing or slightly below. When they exhale, their breath condenses. There’s frost on the inside of the parts of the submarine,” he told CNN.

“They‘re all huddled together trying to conserve their body heat. They’re running low on oxygen and they’re exhaling carbon dioxide.”

He also said they’d be incredibly uncomfortable due to the size of the vessel which is no bigger than a van and isn’t fitted with seats.

“The oxygen and the carbon dioxide and the freezing are what they got to hold onto as long as possible to give the rescuers the time they need,” Mr Marquet added.

In addition to the uncomfortable physical conditions, Dr Justin D’Arienzo, who served six years of active duty as a clinical and forensic psychologist, told Fox News the crew is likely going through “significant mood swings” and “sheer panic” as their oxygen runs out.

“Certainly there is sheer panic where their heart is racing and they’re having trouble breathing … or they feel like they are going to lose their mind,” D’Arienzo told the news outlet.

“And certainly in a cramped space that is dark — like this situation — that can be exponentially worse.”

He continued: “I think they are probably moving in and out of phases of panic, to gallows humour, to fear, to feeling really bonded with the other passengers that are with them.

“There’s just lots of significant mood swings.”

Dr D’Arienzo also added the crew would be wise to not talk too much and remain calm so “they’re not using up any oxygen”.

Still a glimmer of hope

Richard Garriot de Cayeux, president of travel and research group The Explorers Club – where Hamish Harding and Paul-Henri Nargeolet are members – remains optimistic the submersible will be found on time in what will be a “positive outcome”.

On Wednesday, he released a social media statement listing four reasons why he was hopeful the vessel would be found.

“We have much greater confidence that 1) There is cause for hope, based on data from the field — we understand that likely signs of life have been detected at the site; 2) They precisely understand the experienced personnel and tech we can help deploy; 3) We believe they are doing everything possible with all resources they have; and 4) We now have direct lines to the highest levels of Congress, The Coast Guard, air force, navy and The White House thanks to your support,” he wrote.

Mr de Cayeux has since released another statement to Twitter, saying the “odds of a positive outcome” have improved due to the efforts of everyone partaking in the search.

“Explorers Club team, Thanks for all your support and hard work on the rescue operations for our friends aboard Titan,” he wrote.

“I believe we have importantly improved the odds of a positive outcome through our advice, volunteering of services and equipment, and even the political pressure we continue to bring to bear.

“All has been needed. All continues to be needed. Magellan is en route (should have been accepted sooner), we are still trying to get side scan sonar (should have been accepted sooner), and still working on ships to transport equipment and other details.

“We continue to come together for our friends, their families and the ideals of The Explorers Club, and the cause of safe scientific exploration of extreme environments.

“There is good cause for hope, and we are making it more hopeful. I thank you! Keep searching!”

Five specialist vessels backed by deep-sea robots and search-and-rescue aircraft were already combing a vast 40,000 square km up to a depth of 4km, but more are on their way, The Sun reports.

It comes after banging noises were heard multiple times in recent days, suggesting there’s potentially still signs of life.

“There were multiple reports of noises and every one of them is being analysed,” US Coast Guard captain Jamie Frederick said on Wednesday at a press conference.

“The noises have been described as banging noises.”

However, so far, Captain Frederick said the searches have yielded negative results.

“The noises were heard yesterday and this morning, experts are analysing the data but at the moment it is inconclusive,” he said.

“We need to have hope … what I can tell you is we are searching in the right area.

“We have to remain optimistic and hopeful when we are in a search-and-rescue case.”

– With New York Post and The Sun