Titan submersible implosion

On 18 June 2023, Titan, a submersible operated by the American tourism and expeditions company OceanGate, imploded during an expedition to view the wreck of the Titanic in the North Atlantic Ocean off the coast of Newfoundland, Canada. Aboard the submersible were Stockton Rush, the American chief executive officer of OceanGate; Paul-Henri Nargeolet, a French deep-sea explorer and Titanic expert; Hamish Harding, a British businessman; Shahzada Dawood, a Pakistani-British businessman; and Dawood's son, Suleman.

Communication between Titan and its mother ship, MV Polar Prince, was lost 1 hour and 33 minutes into the dive. Authorities were alerted when it failed to resurface at the scheduled time later that day. After the submersible had been missing for four days, a remotely operated underwater vehicle (ROV) discovered a debris field containing parts of Titan, about 500 metres (1,600 ft) from the bow of the Titanic. The search area was informed by the United States Navy's (USN) sonar detection of an acoustic signature consistent with an implosion around the time communications with the submersible ceased, suggesting the pressure hull had imploded while Titan was descending, resulting in the instantaneous deaths of all five occupants.

The search and rescue operation was performed by an international team organized by the United States Coast Guard (USCG), USN, and Canadian Coast Guard. Support was provided by aircraft from the Royal Canadian Air Force and United States Air National Guard, a Royal Canadian Navy ship, as well as several commercial and research vessels and ROVs.

Industry experts, friends of Rush, and OceanGate employees had previously stated concerns about the safety of the vessel.

Background

OceanGate

OceanGate was a private company, initiated in 2009 by Stockton Rush and Guillermo Söhnlein. From 2010 until the loss of the Titan submersible, OceanGate had transported paying customers in leased commercial submersibles off the coast of California, in the Gulf of Mexico, and in the Atlantic Ocean. The company was based in Everett, Washington, US.

Rush realized that visiting shipwreck sites was a method of getting media attention. OceanGate had previously conducted voyages to other shipwrecks, including its 2016 dive to the wreck of Andrea Doria aboard their other submersible Cyclops 1. (A near disaster on that expedition was recounted in Vanity Fair in 2023.) In 2019, Rush told Smithsonian magazine: "There's only one wreck that everyone knows ... If you ask people to name something underwater, it's going to be sharks, whales, Titanic".

Titanic

The Titanic was a British ocean liner that sank in the North Atlantic Ocean on 15 April 1912, after colliding with an iceberg. More than 1,500 people died, making it the deadliest sinking of a single ship at the time. In 1985, Robert Ballard located the wreck of the Titanic 320 nautical miles (590 km; 370 mi) from the coast of Newfoundland. The wreck lies at a depth of about 3,810 metres (12,500 feet; 2,080 fathoms). Since its discovery, it has been a destination for research expeditions and tourism. By 2012, 140 people had visited the wreck site.

The Titan submersible

Formerly known as Cyclops 2, Titan was a five-person submersible vessel operated by OceanGate Inc. The 6.7-metre-long (22 ft), 10,432 kg (23,000 lb) vessel was constructed from carbon fibre and titanium. The entire pressure vessel consisted of two titanium hemispheres (domes) with matching titanium interface rings bonded to the 142 cm (56 in) internal diameter, 2.4-metre-long (7.9 ft) carbon fibre-wound cylinder. One of the titanium hemispherical end caps was detachable to provide the hatch and was fitted with a 380 mm-diameter (15 in) acrylic window. In 2020, Rush said that the hull, originally designed to reach 4,000 m (13,000 ft) below sea level, had been downgraded to a depth rating of 3,000 m (9,800 ft) after demonstrating signs of cyclic fatigue. In 2020 and 2021, the hull was repaired or rebuilt. Rush told the Travel Weekly editor-in-chief that the carbon fibre had been sourced at a discount from Boeing because it was too old for use in the company's airplanes. Boeing stated they have no records of any sale to Rush or to OceanGate. OceanGate had initially not sought certification for Titan, arguing that excessive safety protocols hindered innovation. Lloyd's Register, a ship classification society, refused OceanGate's request to class the vessel in 2019.

Titan could move at as much as 3 knots (5.6 km/h; 3.5 mph) using four electric thrusters, arrayed two horizontal and two vertical. Its steering controls consisted of a Logitech F710 wireless game controller with modified longer analogue sticks resembling traditional joysticks. The University of Washington's Applied Physics Laboratory assisted with the control design on the Cyclops 1 using a DualShock 3 video game controller, which was carried over to Titan, substituting with the Logitech controller. The use of commercial off-the-shelf game controllers is common for remote-controlled vehicles such as unmanned aerial vehicles or bomb disposal robots, while the United States Navy uses Xbox 360 controllers to control periscopes in Virginia-class submarines.

OceanGate claimed on its website as of 2023 that Titan was "designed and engineered by OceanGate Inc. in collaboration [with] experts from NASA, Boeing, and the University of Washington" (UW). A 1⁄3-scale model of the Cyclops 2 pressure vessel was built and tested at the Applied Physics Laboratory (APL) at UW; the model was able to sustain a pressure of 4,285 psi (29.54 MPa; 291.6 atm), corresponding to a depth of about 3,000 m (9,800 ft). After the disappearance of Titan in 2023, these earlier associates disclaimed involvement with the Titan project. UW claimed the APL had no involvement in the "design, engineering, or testing of the Titan submersible". A Boeing spokesperson also claimed Boeing "was not a partner on Titan and did not design or build it". A NASA spokesperson said that NASA's Marshall Space Flight Center had a Space Act Agreement with OceanGate, but "did not conduct testing and manufacturing via its workforce or facilities". It was designed and developed originally in partnership with UW and Boeing, both of which put forth numerous design recommendations and rigorous testing requirements, which Rush ignored, despite prior tests at lower depths resulting in implosions at UW's lab. The partnerships dissolved as Rush refused to work within quality standards.

According to OceanGate, the vessel contained monitoring systems to continuously monitor the strength of the hull. The vessel had life support for five people for 96 hours. GPS signals cannot be received underwater; instead, the support ship and Titan used an ultra-short baseline (USBL) acoustic positioning system to determine their relative distance and bearing. The same system could be used to send very short text messages between the two craft.

According to OceanGate, Titan had several backup systems intended to return the vessel to the surface in case of emergency, including ballasts that could be dropped, a balloon, thrusters, and sandbags held by hooks that dissolved after a certain number of hours in saltwater. Ideally, this would release the sandbags, allowing the vessel to float to the surface. An OceanGate investor explained that if the vessel did not ascend automatically after the elapsed time, those inside could help release the ballast either by tilting the ship back and forth to dislodge it or by using a pneumatic pump to loosen the weights.

Dives to wreck of Titanic

Dives by Titan to the wreck of Titanic occurred as part of multi-day excursions organized by OceanGate, which the company referred to as "missions". Five missions per year occurred in the middle of 2021 and 2022. Titan imploded during the fifth mission of 2023; none of the four earlier that year got close to Titanic, largely because of rough weather. YouTuber Jake Koehler was invited to vlog the submersible's Mission III, which did not dive due to poor weather, a ghost net wrapping around and destroying some of the submersible's parts, and the motor controllers malfunctioning. Following the submersible's implosion, Koehler uploaded a YouTube video documenting his experience.

Passengers would sail to and from the wreckage site aboard a support ship and spend approximately five days on the ocean above the Titanic wreckage site. Two dives were usually attempted during each excursion, though dives were often cancelled or aborted due to weather or technical malfunctions.

Each dive typically had a pilot, a guide, and three paying passengers aboard. Once they were inside the submersible, the hatch would be bolted shut and could only be reopened from the outside. The descent from the surface to the Titanic wreck typically took two hours, with the full dive taking about eight hours. Throughout the journey, the submersible's acoustic positioning system sent automated location updates ("pings") to the surface team's tracking equipment every 5 to 10 seconds; the two vessels were also expected to send "comms check" text messages every 15 minutes.