Underwater habitat | wkpd
We saw in Breakaway Civ. 6, how big concrete spheres could become a thing, but the story was light on details, mostly about the location, ocean atolls. In this go, we take a closer look at big balls, and about colonizing lakes. In all cases, this idea is not about deep water (ambient air pressure is same as surface air). The idea is for tethered spheres held vertically in place near the surface by cable and buoyancy, and horizontally by being set within an array of like modules, perhaps miles across.
Mass production of habitats
Surface architecture takes various configurations (except for suburban housing, aka tiki-taki). If all cities had only one style of building, they would eventually be very boring from a scenery perspective. See Venus Project, a Marxist habitation utopia for a Technocratic Society.
However, the breakaway big-ball scenario would be invisible since it is unseen beneath the water. The interiors could be decorated in any style imaginable. The main structure element, the concrete sphere, can be mass-produced with a 2-axis centrifugal casting process (pioneered in clock design), in one location and easily transported to site by towboat. The entire system seems readily adaptable to factory-robotic assembly.
A feature not mentioned in Breakaway 6 was about how bbs could be adapted for energy storage (scroll down to Pumped Hydro). That idea considered the submerged ball as a singleton, but with computer-monitored control, an entire community of bbs could act together.
Most large lakes ("meandered waters") are "owned" by governments, thus considered public domain. I imagine that a well-funded organization could persuade a government to license construction rights for a submarine community, since (properly operated) it would have virtually zero effect on anything except maybe certain types of fishing, but could provide a new source of funds. No way for me to guess what kind of deals could be arranged, but possibly cost-effective compared to land purchases, especially near cities like Chicago, considered for underground expansion (warning, "underground" has several meanings.)
Going under water is easier than digging under ground
future of cities: underground development
A submerged array of big balls would have less natural security from attacks than any underground facility, but also would have much better access for escape (many points of egress), in case of some system malfunctions that threaten undergrounds, for examples fire, flood, collapse of vital passages, distance from surface, earthquakes, etc.
Repairs for bbs are not much of a problem, compared with underground. If something catastrophic ruins a bb, it can be replaced without much ado. That cannot be said for underground chambers, which can only be repaired in place, or sealed-off and abandoned.
lakes, homesteading surface of
lake, houseboat moored on surface of
floating community projects
submersible community projects
submarine habitations, patents of
submerged habitat patents
Investigating patents, a superficial websearch had poor results. I suspect the idea of big balls, iow habitable, submersed concrete spheres (assembled into array) has not been patented. So attention go-getter entrepreneurs looking for patent ideas. Here is one for you on a saidit platter.
same link, images only
Nuance on centrifugal casting of big balls: layers
Casting process is a sequence of spin sessions, each one introducing a different mix of concrete ingredients. Result is a layered hull, with outermost surface focused on chemical resistance and impermeability, then structural strength, and finally insulation, vapor barrier, and anti-fungal properties.
In accord with previous paragraph, we want a casting machine capable of inputting mix without stopping entirely. One of the axes rotation stops on the horizontal position, and a port opens at center of other axis.
Later afterthoughts, Oct.30
Alternative to a mechanical tourbillion, float the molding-shell, with restraining wheels, and drive wheels. This does-away with the heavy, above-deck framework, and simplifies the system. Also, there is the simulated weight-measuring device by shell-displacement. (Ships have this too, but for them it's not accurate because ships are so much bigger than big-balls. See hull markings for displacement.) Removal of a big-ball from the hydro-tourbillion could be a simple release from restraints, float the shell into a holding pen (which might be heated) for curing.
Artificial Reef Or Habitat Patents (Class 119/221)