Titan sub implosion: What we know about catastrophic event

AMY

US authorities say a debris field located in the North Atlantic leads to a conclusion that OceanGate's Titan submersible suffered a "catastrophic implosion" (a violent collapse inwards), instantly killing all five passengers on board.

The US Navy says it detected sounds "consistent with an implosion" shortly after the sub lost contact on Sunday during a descent to the Titanic wreck at 3,800m (12,467ft) below sea level - but this information was only made public on Thursday.

The loss of the deep-water vessel was finally confirmed after a huge search mission in the area off Canada's Newfoundland province.

Fear of reprisals from the army and the pressure of having to provide for his family proved too much.

"It was a difficult decision. I love my country, my village, and I want to work for my people, but I chose to leave because our lives are valuable," he said.

Thang now takes on ad-hoc jobs in construction.

"I wanted to become director of my [former] department and to focus on child and youth development. Now I do not have regular work. I help friends and they share their earnings with me. This is not satisfying," he said.

"[Mizoram] is not our home, but I don't have a choice."

Among the things Thang misses most about Myanmar is "being able to live peacefully, to fish at sea, and have fresh fish". But he remains hopeful that his country will "regain democracy" one day with the support of international organisations like the UN.

Any investigation is sure to focus on the carbon fibre mid-section of the Titan sub.

The pressure vessels of deep vehicles like this are normally constructed from a robust metal such as titanium and are shaped in a sphere, to spread the immense pressure equally around the passenger compartment.

But to fit more people inside, the OceanGate sub adopted a cylindrical shape, with a carbon fibre tube inserted between to titanium end caps. Carbon fibre is very tough - they use it to build aeroplane wings and racing cars.

But did that immense pressure at depth - more than 300 times the atmosphere at the sea surface - play on the material to expose flaws in the original fabrication or to introduce and then worsen instabilities over repeated dives?3A娛樂城

Any investigation would want to know about the practice non-destructive testing.

Aircraft are subjected to regular, very fine-scale inspections to ensure their materials are not developing cracks or that their layers are not starting to separate.

Photographing the Titan debris found on the ocean floor and bringing them back to the surface for study in a forensic lab may allow engineers to identify where on the sub structural integrity was lost, initiating the catastrophic implosion.