The search continues to search for the Titanic sub as the occupants are running out of air.

Back in 2018 employees and others signed a letter voicing their concerns on this whole idea….

As search and rescue teams raced against time Tuesday to find the missing Titan submersible, news emerged on the long history of concerns about OceanGate Expeditions’ experimental vessel. In 2018, leaders of a submersible craft trade group wrote to OceanGate CEO Stockton Rush—who is one of the five people in the Titan—warning that there were potentially “catastrophic” problems with the vessel’s development, the New York Times reports. The Manned Underwater Vehicles committee of the Marine Technology Society noted that despite “misleading” marketing, the company had no plans to have the Titan examined by a risk assessment agency before it launched tours to the wreckage of the Titanic.

The letter was signed by three dozen people, including deep-sea explorers and oceanographers as well as company execs. “The submersible industry had significant concerns over the strategy of building a deep sea expedition submersible without following existing classification safety guidelines,” committee chairman Will Kohnen tells the Times. He says Rush later called him and complained that regulations were stifling innovation in the sector. Also in 2018, an OceanGate employee was fired after refusing to sign off on manned tests of the vessel over safety concerns, according to court documents seen by the New Republic.

According to the documents, OceanGate sued submersible pilot David Lochridge after he voiced his concerns and then sued him for disclosing confidential information about the vessel. In a counterclaim alleging wrongful termination, Lochridge said the company fired him to silence him and “avoid addressing the safety and quality control issue” he had highlighted. Lochridge had called for non-destructive testing of the vessel’s hull and “stressed the potential danger to passengers of the Titan as the submersible reached extreme depths,” court documents state. “The constant pressure cycling weakens existing flaws resulting in large tears of the carbon.”

As the search continues it is reported that tapping sounds have been detected….

“Banging sounds” were detected “every 30 minutes” in the area that a Canadian aircraft was searching for the missing Titanic submersible, according to internal email updates sent to the Department of Homeland Security and obtained by Rolling Stone. The aircraft involved “has underwater detection capabilities from the air,” the email says, and four hours after the sounds were initially detected Tuesday, “additional sonar was deployed and banging was still heard.” A retired US submarine commander previously told Sky News the sub’s crew might use rhythmic banging on the walls in an effort to transmit sound to search vessels using sonar. The email to DHS did not specify a time, nor did it speculate on a cause of the banging, and none of the official agencies contacted by Rolling Stone returned a comment.

A DHS official did, however, anonymously (and confusingly, given the timeline that has been reported) tell the publication that no noise has been detected since Monday. In its own email, the Explorers Society, a travel and research group that says two of its members were aboard the Titan submersible when it went missing Sunday, said Tuesday afternoon that, “It is being reported that at 2am local time on site that sonar detected potential ‘tapping sounds’ at the location, implying crew may be alive and signaling.” CNN also later reported on the internal government memo reporting the banging that was heard at two different times four hours apart, and the outlet notes that a separate memo from later Tuesday night indicated “additional acoustic feedback was heard and will assist in vectoring surface assets and also indicating continued hope of survivors.”

Further confusing matters, a US Coast Guard statement from early Wednesday says that “Canadian P-3 aircraft detected underwater noises in the search area. As a result, ROV operations were relocated in an attempt to explore the origin of the noises. Those ROV searches have yielded negative results but continue.” It’s not clear whether those “noises” are the same as those previously mentioned by the various media outlets. The Coast Guard earlier said at a Tuesday afternoon press conference that the search has so far “not yielded any results.” The DHS official who spoke to Rolling Stone said the “situation looks bleak.” The sub’s 96-hour oxygen supply is estimated to run out Thursday morning local time, CBS 8 reports. The retired sub captain who spoke to Sky News says the crew is likely trying to remain as calm as possible, possibly even meditating, to conserve oxygen.

Some have asked why this operation is not more successful…..here is what we know…..

A big issue in the search for the submersible that went missing during an expedition to the wreckage of the Titanic is just how deep that wreckage sits. It’s around 13,000 feet below sea level, and a retired Navy captain with three decades of experience including salvage operations tells CNN, “There’s very few assets in the world that can go down that deep.” Even sophisticated naval craft can only dive about 1,000 feet per hour, meaning if the sub is close to the wreckage, getting to it and surfacing again could take an entire day. On such a journey, a remote craft wouldn’t be able to search along the ocean floor once it got there: “When you’re going deep, you usually go up and down like an elevator,” the expert says. Adding to the difficulty: The sub is white, making it difficult to spot from the air, an expert tells Reuters, and rescuers aren’t sure whether they should be focusing on the surface or the sea floor, he adds.

Similarly, a US Coast Guard rear admiral tells the BBC, “There are very few vessels that can get that deep, and certainly not divers.” The Navy’s manned rescue craft only go to a depth of around 2,000 feet, Rolling Stone reports, and US military remote-operated vehicles wouldn’t be able to lift the sub. Because of that, according to internal emails obtained by Rolling Stone, “the Joint Rescue Coordination Centre is working to find an underwater remote-operated vehicle through partner organizations to possibly assist.” And, as Axios also notes, locating the sub in a search area the size of Connecticut is one thing, but far from the only thing—it must then also be recovered, no small feat. Last but not least, the occupants of the sub can’t let themselves out: Someone must undo the bolts from outside the vessel, and experts say there will be no way to transfer them to a rescue vehicle underwater.

A remote-operated craft about the size of a cargo van, tethered to a ship at the surface, might be an option to attempt to locate the sub, the expert who spoke to CNN says, but another even more specialized vehicle—the Flyaway Deep Ocean Salvage System or FADOSS, one of which was expected to arrive in the search area by Tuesday night—would be required to bring the sub up, since it can lift as much as 60,000 pounds. For more, the Wall Street Journal takes a look at the sophisticated equipment and vehicles assisting with the search, complete with illustrations, and NPR looks into one deep-sea rescue that was successful—among a number of others that weren’t

And the search continues but every hour is a step closer to a change in operation from rescue to recovery.

I Read, I Write, You Know

“lego ergo scribo”