The lead engineer for an experimental submersible that imploded on its way to the Titanic wreck says he felt pressured to get the vessel ready to dive and refused to pilot it on a journey several years earlier.

“I’m not getting in it,” Tony Nissen said he told Stockton Rush, co-founder of the OceanGate company that owned the Titan submersible.

British adventurer Hamish Harding and father and son Shahzada and Suleman Dawood died alongside Rush and Frenchman Paul-Henri Nargeolet when the submersible imploded on June 18, 2023.

Nissen, OceanGate’s former engineering director, was the first witness to give evidence at what is expected to be a two-week US Coast Guard hearing in South Carolina.

Nissen said Rush could be difficult to work for and was often very concerned with costs and project schedules, among other issues.

He said Rush would fight for what he wanted, which often changed day to day. He added that he tried to keep the clashes between the two of them behind closed doors so others in the company would not be aware.

“Most people would eventually just back down to Stockton,” he said at the hearing in North Charleston.

Today, the Coast Guard’s Marine Board of Investigation heard testimonies from former OceanGate employees Tony Nissen, Bonnie Carl, and Tym Catterson to investigate the Titan submersible’s loss. Follow #TitanMBI here and view exhibits at the hearing website:https://t.co/h3ySH0PhiA pic.twitter.com/Y4yvI9JXbD

— USCG MaritimeCommons (@maritimecommons) September 16, 2024

Nissen also noted the Titan was struck by lightning during a test mission in 2018, and that might have compromised its hull.

When asked if there was pressure to get the Titan into the water, he responded, “100 per cent”.

He said he refused to pilot the Titan years ago because he did not trust the operations staff, and he stopped the submersible from going to the Titanic in 2019, telling Rush the Titan was “not working like we thought it would”.

He was fired that year. The Titan did undergo additional testing before it made later dives to the Titanic, Nissen added.

Asked if he felt the pressure from Rush compromised safety decisions and testing, Nissen paused, then replied, “No. And that’s a difficult question to answer, because given infinite time and infinite budget, you could do infinite testing.”

The submersible was left exposed to the elements while in storage for seven months in 2022 and 2023, and the hull was also never reviewed by any third parties, as is standard practice, Coast Guard representatives said in their initial remarks on Monday.

One of the last messages from the Titan’s crew to the support ship Polar Prince before the submersible imploded stated “all good here”, according to a visual re-creation the Coast Guard presented earlier in the hearing.

The crew lost contact after an exchange of texts about the submersible’s depth and weight as it descended. The Polar Prince then sent repeated messages asking if the Titan could still see the ship on its onboard display.