So they want to create a multi-story structure anchored at "60 feet"? Is that 60 to the bottom? 60 feet to the top of the structure? 60 feet to the moonpool? That thing looks 80 feet tall.
Fyi, moonpools are cool. They create all sorts of interesting practical physics problems. Take the one in the artist rendering. Say it is at 60 feet. What is the pressure depth of the rooms on the second floor, say 15 feet above the moon pool? What about the rooms below? If I poke a hole in a room below the moonpool room, does water come in or air leak out?
By having a moonpool, the entire structure has to be kept at the pressure/depth of the water at the moonpool. So rooms above are at higher pressure than the water immediately outside, while rooms below are at lower pressure. The simple act of having that open pool creates very interesting structural design issues.
My first thought was there could be an airlock separating the moonpool room from the rest of the structure. But putting the people through compression/decompression cycles would seem to defeat one of the benefits of having a habitat down there to begin with. Also, if the internal pressure was kept down to one atmosphere, how strong would the structure need to be to avoid being crushed like a soda can?
Airlocks are actually rather dangerous. Things can go wrong very quickly. An accidental rapid/unplanned decompression, even only across a few feet of pressure, can do real damage. Then there are the issues building the doors, which hold enough force that should they pop open they could kill. The biggest advantage of the moonpool approach is having the entire complex at the same pressure, with the pool acting as a passive safety valve against wild pressure fluctuations.
Yeah, pressure differentials are no joke. Look at the Byford Dolhin incident [1]:
> Hellevik, being exposed to the highest pressure gradient and in the process of moving to secure the inner door, was forced through the crescent-shaped opening measuring 60 centimetres (24 in) long created by the jammed interior trunk door. With the escaping air and pressure, it included bisection of his thoracoabdominal cavity, which resulted in expulsion of all of the internal organs of his chest and abdomen, except the trachea and a section of small intestine, and of the thoracic spine. These were projected some distance, one section being found 10 metres (30 ft) vertically above the exterior pressure door.
> The blood of the three divers left intact inside the chambers likely boiled instantly, stopping their circulation
Fyi, moonpools are cool. They create all sorts of interesting practical physics problems. Take the one in the artist rendering. Say it is at 60 feet. What is the pressure depth of the rooms on the second floor, say 15 feet above the moon pool? What about the rooms below? If I poke a hole in a room below the moonpool room, does water come in or air leak out?
By having a moonpool, the entire structure has to be kept at the pressure/depth of the water at the moonpool. So rooms above are at higher pressure than the water immediately outside, while rooms below are at lower pressure. The simple act of having that open pool creates very interesting structural design issues.