The Titan submersible making a descent. Photo: AFP / OceanGate Expeditions
Rescuers searching for a missing submersible near the wreck of the Titanic have concentrated their efforts on a remote area of the North Atlantic where a series of undersea noises have been detected, though officials cautioned the sounds may not have originated from the vessel.
With estimates suggesting the air supply on board the submersible could run out by Thursday morning (Thursday evening NZ time), an international coalition of rescue teams has swept a vast expanse of the ocean for the Titan, which disappeared on Sunday while taking five people deep into the ocean to visit the century-old wreck as part of a tourist expedition.
The US Coast Guard said remotely operated vehicle (ROV) searches were deployed in the area where Canadian aircraft recorded the noises using sonar buoys on Tuesday and Wednesday, but have not found any sign of the Titan yet.
Coast Guard Captain Jamie Frederick said at a press conference that analysis of the noises has been "inconclusive."
"When you're in the middle of a search-and-rescue case, you always have hope," he said. "With respect to the noises specifically, we don't know what they are, to be frank with you."
Even if the submersible is located, retrieving it presents huge logistical challenges, given the extreme conditions miles below the surface.
Teams from the United States, Canada and France using airplanes and ships have searched more than 25,900 square kilometres of open sea, roughly the size of Lebanon or the US state of Massachusetts.
The 6.7-metre submersible Titan, operated by US-based OceanGate Expeditions, began its descent at 8am on Sunday (local time). It lost contact with its parent surface vessel during what should have been a two-hour dive to the Titanic.
The submersible had 96 hours of air, according to the company's specifications, which would mean the oxygen could run out by Thursday morning. But experts say the air supply depends on a range of factors, including whether the submersible remains intact and still has power.
The wreck of the British ocean liner, which sank when it hit an iceberg on its maiden voyage in 1912, lies on the seabed at a depth of about 3810m. It is about 1450 east of Cape Cod, Massachusetts, and 400 miles south of St. John's, Newfoundland.
Those aboard the submersible, the highlight of a tourist adventure that costs US$250,000 (NZ$400,000) per person, included British billionaire and adventurer Hamish Harding, 58, and Pakistani-born businessman Shahzada Dawood, 48, with his 19-year-old son Suleman, who are both British citizens.
French explorer Paul-Henri Nargeolet, 77, and Stockton Rush, founder and chief executive of OceanGate Expeditions, were also reported to be on board.
A friend of Harding, Jannicke Mikkelsen, who has accompanied the British entrepreneur on other expeditions, told Reuters on Tuesday she was hoping for good news but was not optimistic. "It would be a miracle if they are recovered alive," she said.
Safety concerns
Questions about the safety of the Titan were raised in a 2018 lawsuit filed by OceanGate's former director of marine operations, David Lochridge, who claimed he was fired for voicing concerns that the hull could not withstand extreme depths.
In its own court claim against Lochridge, OceanGate said he refused to accept the lead engineer's assurances and accused him of improperly sharing confidential information. The two sides settled their court case in November 2018.
Neither the company nor Lochridge's attorney have commented on the details of the dispute.
Months prior to the suit, a group of submersible industry leaders wrote to OceanGate warning that the "experimental" approach" to the sub's development could result in "minor to catastrophic" problems, the New York Times reported.
Aaron Newman, a former Titan passenger who knows some of the missing people, told NBC on Wednesday that he felt safe during his dive.
"Obviously, this is the type of exploration that's doing things - this is not a Disney ride," he said. "We're going places that very few people have been."
If the Titan managed to return to the surface, it could still be difficult to spot it in the open water, experts said. The submersible is sealed shut with bolts from the outside, making it impossible for those inside to escape without assistance.
If the Titan is on the ocean floor, a rescue effort would be even more challenging because of the massive pressures and total darkness at a depth of more than 3.2km. Titanic expert Tim Maltin said it would be "almost impossible to effect a sub-to-sub rescue" on the seabed.
A French research ship carrying a deep-sea diving robot submersible was expected to arrive later on Wednesday.
The unmanned robot is capable of diving as deep as the Titanic wreck and could help free the submersible if it is stuck, though the robot cannot lift the 9525kg Titan on its own. The robot could also help hook the sub to a ship on the surface that is able to lift it up, the operator said.
The sinking of the Titanic, which killed more than 1500 people, has long been immortalised in books and films. Popular interest was renewed by the 1997 blockbuster movie Titanic.
- Reuters