Rescue teams searching for the missing Titan submersible saw reason for optimism when they reported hearing underwater noises in the Atlantic.
While stressing that the sounds were “inconclusive” and not confirmation the crew was still alive, the news did raise the question of what happens if the sub is located – and what equipment will be necessary to retrieve it.
Surface vessels
The US Coast Guard said multiple ships were involved in the search for Titan.
The Polar Prince, the research vessel that the Titan was launched from, remained near the Titanic wreck site in the Atlantic Ocean. It is operated by OceanGate – the sub’s owner – and was reportedly being used as the “unified command” by the US Coast Guard.
It was quickly joined by Deep Energy, a vessel that is used to lay pipes at great depths along the ocean floor, and another commercial vessel, Skandi Vinland.
By Wednesday morning, Canadian coast guard vessels John Cabot – equipped with sonar capabilities – and Atlantic Merlin had also joined the search.
The final five vessels were expected to arrive on Thursday. French research vessel L’Atalante was expected to be the first to join the search.
Two further Canadian Coast Guard ships – the Anne Harvey and the Terry Fox – were also expected as well as another commercial vessel, the Horizon Arctic.
Finally, Canadian naval ship Glace Bay was en route to provide medical assistance. It is equipped with a medical team and a mobile hyperbaric recompression chamber. Hyperbaric chambers are used to treat people affected by a sudden and rapid change in pressure.
Sean Leet, co-founder and chairman of Horizon Maritime Services, which owns the Polar Prince, has praised how quickly specialist marine craft have been scrambled to help in the search.
“I’ve been in the marine industry since a very young age and I’ve never seen equipment of that nature move that quickly,” he said.
ROVs
If the Titan did reach the wreck of the Titanic, it could be trapped as deep as 3,800 metres below the surface of the ocean, so key to the search are camera-equipped remote-controlled vehicles known as ROVs, which are designed to scan the seafloor at depths other vessels can’t reach.
Two of the first vessels to join the rescue effort – Deep Energy and Skandi Vinland – both carry ROVs and have deployed them in the search.
US Coast Guard vessel Atlantic Merlin is also equipped with an ROV.
It is not clear, however, whether any of the ROVs operating in the early part of search could reach the extreme depths that might be required. David Marquet, a former US navy submarine commander, told CBC that only a “tiny percentage of the world’s submarines operate that deeply”.
Fortunately, the French research vessel L’Atalante carries an ROV that can reportedly descend to 6,000 metres. The Victor 6000 is connected to its parent ship by an 8km long cable that provides it with electrical power, meaning that in theory there is no limit to the duration for which it can dive. It is also equipped with arms that can cut cables or conduct manipulations to help release a stranded vessel.
Guernsey-based Magellan is also deploying its ROV which can operate at depths of up to 6,000 metres. The company specialises in deep sea rescue and said it was first approached by OceanGate to help.
Fadoss
If the search vessels are able to locate the Titan, retrieving it presents a number of challenges. While some ROVs are able to manipulate things, they would be unable to lift it to the surface.
The Flyaway Deep Ocean Salvage System (Fadoss) is a lift system designed to provide reliable deep ocean lifting capacity of up to 27,200kg. It has been deployed in the hope it could be used to hoist the Titan up to the service.
Fadoss can be used to recover “large, bulky, and heavy sunken objects such as aircraft or small vessels” and has in the past operated at a depth of almost 6,000 metres.
The system is essentially a huge winch with a cable, one end of which is attached to an ROV, which attaches it to the lost vessel.
Commercial vessel the Horizon Arctic, which is en route to the search site, is believed to have a Fadoss system on board.
The US navy has also sent a Fadoss to St John’s in Newfoundland. However, before it can be deployed, it needs to be welded to the deck of a ship, a process that can take a full day, according to a navy official speaking to CNN. “We have a vessel of opportunity that we are looking to put under charter, but it is not currently under charter.”
