Experts say the five men aboard the missing Titanic sub could still suffocate even if the vessel resurfaces because its hatch cannot be opened from the inside.
The submersible, named Titan, lost communication with tour operators on Sunday while about 435 miles south of St John’s, Newfoundland, during a voyage to the Titanic shipwreck off the coast of Canada. The 22ft craft made by US firm OceanGate is designed to resurface on its own after a specific amount of time underwater. Weights are supposed to be released from the vessel to increase buoyancy even if it has lost power.
But if the sub did float back to the water’s surface, it would need to be located by rescuers before the vessel’s limited oxygen supply runs out because the five passengers would not be able to open its hatch internally. The craft’s door is sealed shut by 17 bolts so it can withstand the immense water pressure at depth.
READ MORE: Difference between submersible and submarine is key in Titanic search
Rescuers are in a race against time to locate the missing sub, which experts say is due to run out of air at around midday on Thursday (UK time).
The submersible, a Cyclops-2 model named Titan, is the second Cyclops model built by OceanGate, after the Cyclops-1.
As there are no doors on the craft, passengers begin their journey by climbing in through an entry hatch which is then bolted shut from the outside before they descend 13,000ft (2.4 miles) beneath the ocean surface to the Titanic, Mail Online reported.
There are no seats on the 22ft long, 9.5ft wide and 9.2ft high cylindrical craft, meaning passengers must sit on the hard floor without shoes, which they are required to leave behind.
If they need the toilet, they must use a small black box separated by a curtain from the rest of the crew. Cut off from communication with the outside world, they have no idea whether they will ever be found.
There are no windows except a small porthole directly next to the toilet at the front of the craft, which is also the primary viewpoint to look out at the Titanic. When the craft was still operational, the pilot used a modified Logitech games controller to steer it.
The Titan’s dive on Sunday is one of many that have been made to the wreck, which is about 2.4 miles below the surface, by OceanGate Expeditions since 2021. With the temperature on the ocean floor near freezing and an estimated 40-hour oxygen supply remaining on the vessel, occupants are at increasing risk of hypothermia or suffocation.
The five-man vessel contains British billionaire Hamish Harding, UK-based businessman Shahzada Dawood and his son Suleman. They’re reportedly joined by French submersible pilot Paul-Henry Nargeolet. OceanGate confirmed on Tuesday that its chief executive and founder Stockton Rush “is aboard the submersible as a member of the crew”.