The New Zealander who tried to stop the OceanGate Titan disaster

The New Zealander who warned about the Titan OceanGate disaster where five people died aboard a submersible en route to the wreck of the Titanic in 2023 says it was something he had long predicted.

On June 18, 2023, five people died aboard a submersible that was en route to the wreck of the Titanic — 3800m beneath the waves in the North Atlantic Ocean.

The Titan submersible, operated by the American tourism company OceanGate, imploded 90 minutes into the journey — killing all passengers.

New Zealander Rob McCallum himself runs expeditions to remote places through his company EYOS Expeditions.

Five years prior to the disaster, McCallum raised concerns with OceanGate about the risks of the vessel's carbon fibre and titanium construction.

In March 2018, he emailed OceanGate founder Stockton Rush to warn him about the dangers of their submersible and that he was risking lives.

Rush died in the implosion along with four others.

McCallum has a company that has run about 1800 expeditions across all oceans and all continents.

"I personally specialise in surface expeditions, that is, expeditions from the surface all the way down to 11,000 metres."

The Titanic site is very exposed and not sheltered by any land because it is in the North Atlantic and is about 563km offshore, he said.

McCallum said he felt sick when he first heard that something had gone wrong with the Titan submersible, but it was something they had long predicted.

"As soon as I heard that the sub had gone, I knew straight away what had happened. I had a call on the day of the implosion to say it imploded and you know, the next three days about the media reports about the oxygen countdown were a bit of a mystery to me — but, in a way, I'm glad that the end was an implosion and not an oxygen starvation scenario."

The Titan submersible was made of carbon fibre which was a composite material and was never usually used in manufacturing submersibles, he said.

"All of the subs we use are made of steel or titanium and the reason for that is that metals are a consistent material and because they're consistent, it means that from an engineering perspective, you can with great accuracy calculate out stresses and pressures and failure points."

It was not possible to do that with carbon fibre because it was a composite material, he said.

McCallum said all the submersibles that his company used were classed or independently certified but "the OceanGate submersible Titan was an unclassed vehicle".

He said he first became involved with OceanGate which developed the Titan in 2009 when his company owned three submersibles.

"When OceanGate started the two founding partners used to come down to see our work and to look at our subs and to ask us lots of questions about how you manage a submersible business, where you source staff, how you go about maintenance and that sort of thing."

In about 2015, OceanGate's chief executive decided that he would like to go to the Titanic and build his own craft, he said.

McCallum said they stopped having contact the following year.

"By 2016 when he announced that he wasn't going to build a classed vehicle, it was going to be an experimental craft that had no sort of independent oversight, no third party sign-off — that's when we part ways."

There are six main certifying or classing agencies throughout the world which get involved at the planning stage of building a submersible and are involved in making rigorous checks through the entire process including all the trials assessing the vehicle, he said.

The Titan was one of only two unclassed submersibles in the world that were doing commercial service, he said.

To get a vehicle classed or certified is expensive, he said, and costs about 25% to 30% of its total build cost.

OceanGate could not decide to get the vehicle classed when it was part-way through building it. Instead, to get it classed, they would have had to start again and get the assessors involved right from the outset which would have financially crippled the company, he said.

McCallum believed Rush's character also meant he was not able to admit that he was wrong.

The company designed the process to work around the legislation, he said.

The sub was built in the United States, he said, but the company was registered in the Bahamas where the sub was mainly tested.

"There seems to have been a miscommunication between the US and the Bahamas about who was keeping an eye on this vehicle."

OceanGate had the ridiculous idea that it would assess the hull to ensure it could deal with the depths it was being taken to by using a series of sensors around the vehicle to listen to the noises the hull made under pressure, he said.

"When they got to a certain point the idea was to relieve the pressure by ascending again.

"It's as ridiculous as it sounds, quite frankly if you're listening to the sounds of your hull degrading, you're standing way too close to the edge. I mean, this is not the right vehicle to be in this place."

McCallum said he sent a series of emails to Rush in 2017 and 2018 in which he tried to maintain a "professional coolness" on the basis he did not want to cut off communication since as long as they were talking there was a chance that Stockton would listen and change tack.

"The letters are polite but they become increasingly more pointed as I sort of lay out all the things that are going wrong and why he's on the wrong path."

But "every offer of support was firmly rejected", probably because Stockton was on a path that he could not get off, McCallum said.

McCallum said Rush should take the lion's share of the blame for the disaster as the company's chief executive and the founder and funder of the company, but there were others who enabled him to act the way he did who should be held to account.

"By enabled I mean the engineers who are prepared to sign off on something they're not comfortable with, or in a position where you know what their skill set, their experience, their qualifications shouldn't be signing off stuff anyway."

A board of directors also seemed to be absent and no one seemed to have the power to say stop, he said.

McCallum said there were many ticking clocks prior to the disaster.

The first was the decision to build a submersible from carbon fibre using end caps that were made of titanium, he said.

"You've got a material that is not suitable for this purpose being mated to two other components that are of a different material."

He added that every test model that they made failed and before they predicted it would, he said.

"Their operational model failed in a way they weren't expecting."

In the final model, there was a loud cracking sound which occurred on its 80th dive, about a year before the implosion, he said.

rnz.co.nz