Will the "Titan" Repeat the Fate of the "Titanic"?

These days, the attention of the world's media is focused on the situation with the deep-sea maned submersible "Titan", on which a group of tourists went to the remains of the famous "Titanic". Communication with the mini-submarine was interrupted on Sunday, and the search for it is currently underway. Specialists at the Underwater Research Center of the Russian Geographical Society are also following the tragedy in the North Atlantic. Its executive director, underwater vessel pilot and diver-explorer Sergey FOKIN talks about what the problem with the “Titan” might be, what the chances are of finding its passengers alive, and whether a flight into space or a dive into the ocean depths is more extreme.

— Sergey, how structurally suitable is the “Titan” for such dives?

— The watercraft, so to speak, is not of optimal shape in terms of pressure resistance. It has a cigar-shaped hull, which is good for submarines, but for maneuvering around underwater objects, this is not the best shape. The hull of the “Titan” consists of three parts: two hemispherical titanium endcaps in the front and in the back and a cylindrical part in the middle that is made of composite material. And here lies, in my opinion, the weakness of the design. The hemisphere and the cylinder react differently to compression. At a depth of 3.5 km, the pressure is 350 atmospheres. That's a lot. The hemisphere is compressed less than the cylinder. As a result, the parts begin to move relative to each other. In addition, the materials have different degrees of resistance to static load. And on top of that, as far as I know, composite materials have not been tested for cyclic stress. It's one thing to lower it to the bottom once and raise it, but if you do it many times, the material begins to slowly collapse due to accumulated stress.

The combination of these factors has led, as the experts from the URC RGS tend to believe, to the vessel losing structural integrity. This means that the "Titan" is now actually flooded and, alas, there is no one left to save there. This is the most likely outcome, but I will be very happy to be mistaken.

— Do the knocks that were allegedly detected in the area of the emergency indicate that people are still alive inside the vessel?

— To be honest, I have reason to doubt that their source could be the passengers of the “Titan”.

— Are there any options in deep-sea vessels in case of unforeseen accidents?

— In general, watercraft of this kind should have rescue systems. By the way, I myself have been in emergency situations and I know from the experience of others that all successful rescues happened when the crew of a vessel could fix the situation using their own systems. And on the contrary, finding a vessel when its autonomous – in other words, as long as there is oxygen inside and people have not suffocated – is very, very difficult.

— And what are these rescue systems?

— For example, ballast that can be jettisoned, like on balloons. Anything that sticks out – say, manipulators – should be able to be jettisoned. Finally, there are the rules of design and the rules of operation, which are written with lives of those who did things "their own way".

— How well-developed is the technology of building habitable deep-sea vessels?

— In our country, the technology has been well-developed since Soviet times. It is, figuratively speaking, "crude", but it is resilient. Designers of modern, primarily foreign, vessels, especially those used for tourism, often strive to make them more innovative and attractive from the point of view of design. And here there is a task to maintain a balance that would ensure maximum security for the vessel. As far as I can tell, including from classified sources, Western colleagues who developed the “Titan” (formerly known as the “Cyclops-2”) violated this balance in favor of technical aesthetics, finding opportunities to use new materials, reducing weight and dimensions etc. But why haven’t people been building simpler, lighter, more accessible vessels before? Exactly because they break.

— How often do emergencies occur in such vessels?

— Specifically in inhabited vessels – infrequently. More precisely, we do not have complete statistics, since many such watercraft have departmental affiliation. The closest and more well-known analogues are incidents on submarines. This is a different type of watercraft, but they are essentially close when it comes to problems. The specificity of modern deep-sea vessels consists, in addition to the materials used, of the fact that the engines are activated by batteries, therefore, the energy reserve is limited.

— How can a deep-sea vessel in distress be saved?

— The golden rule of operation of such vessels is the availability of search and rescue means. Generally speaking, all this should have been on board the support vessel. And when, after 1 hour and 45 minutes, the connection with the “Titan” disappeared, two minutes later it all had to have been involved – they should have dived and started searching.

— And what can be done now?

— First you need to find it, which is what the relevant services are doing now. If the vessel still has unfilled volume and the crew is still alive, then its buoyancy is close to zero. It can be dead in the water, for example, because the propellers do not work, something has happened to the batteries, or the “Titan” has caught on something underwater. Therefore, it is necessary to untangle the vessel and then lift it to the surface as quickly as possible. It is not necessary to undergo decompression procedures, as with divers, in this case, since the human body is not directly exposed to pressure. Speed of action is obviously crucial. The habitability of the vessel is limited, since the oxygen supply and the capacity of the carbon dioxide absorber are limited. It should be taken into account that just the actual lifting of the vessel will alone take three to four hours – this is best case scenario. But if the vessel is already filled with water, it will be heavier, it will be much more difficult to lift it, and it will take longer. But in this case there will be no one to save there.

— To descend to a depth of 3.8 km, you need another deep-sea vessel. Are there many of them in general?

— I think there are about seven inhabited ones in the world, and the same number of uninhabited ones, if they are in service – assembled, not under repair or maintenance. Half of the inhabited deep-sea vessels are in Russia. And the remote-controlled ones are almost all foreign.

— Which underwater vessels are used in the work of the Underwater Research Center of the RGS?

— We have a three-seat spherical vessel in service with the possibility of diving to 300 m. Its advantage is that the hull is completely transparent. We have the opportunity to observe the situation from all sides, which increases maneuvering and reduces the risk of getting caught on something or colliding with an obstacle. We also have a "hundred-meter" vessel, which has a hemispherical body. It is used for educational purposes. Currently, the URC RGS is involved in the development of a domestic habitable underwater vessel with a diving depth of 2,250 m, also with a fully transparent hull, with a capacity of two people. This vessel is as innovative and promising as possible.

— In general, what is more extreme: a flight into space or a dive into the depths of the sea? Are astronauts safer than people trapped in mini-submarines?

— This is a long-standing dispute. One group believes that the most complex invention is a spaceship, the other – an underwater vessel. So far, none of the great scientific minds has won this dispute. A flight into space produces an exorbitant dynamic load to escape beyond the atmosphere. In this case, the difference in static loads will be 1 atmosphere. Meanwhile, when diving, every 10 m of water column give the same 1 atmosphere. And if the depth is 3.8 km, then the difference will be 380 atmospheres, that is, 380 times more than when flying into space. So judge for yourself…

Aivar Valeyev