About seven years ago rumors started going round ye old intertubes about a new catamaran Chinese aircraft carrier. Some high tech looking computer simulations were released, and nothing became of it as China seems wedded to the proven Russian design for the time being. Pretty good summary of the rumor, and the reality, here: https://www.truthorfiction.com/china-new-aircraft-carrier/
Now Russia is announcing that it is creating another medium size carrier, but with a catamaran like hull, or “semi-catamaran” as described in the puff piece. One of the many propaganda arms of the Russian government that targets english speaking audiences, in this case TASS dot com, released a photo of a proposed design and an appropriately vague description of the design, and some hard numbers about planned capabilities.
My bet is that the semi-catamaran design goes nowhere for at least quite a while. Russia doesn’t have the resources to waste on a large scale project that might fail such as a new hull design without some extensive smaller scale modeling to prove/disprove the concept.
What irks me, is how many western news outlets immediately parroted the Russian press release without bothering to talk to anyone in the boat building industry. You now, actual experts in marine engineering might have something to say about a “semi-catamaran hull” especially when the press release doesn’t show any pictures of the hull, only a picture of a model from the top down.
There are a lot of good things about catamaran and trimaran hulls. The Chinese have fielded at least two trimaran recovery ships, and are building a new class of Frigate based obviously on the Independence class Littoral Combat Ships that will have trimaran hulls. The shallower draft per displacement of a the multi hull design over mono-hull design makes sense for operating in the littorals, and the fact that China is making a warship a tri-hull design means they want the option to put some relatively serious firepower seriously close to the beach. More about the Chinese tri-hulls: https://www.popularmechanics.com/military/navy-ships/a25375/chian-three-hull-frigate/
Speaking of the Russia/Chinese connection working on multi-hull aircraft carriers, that rumor goes back at least a decade: https://www.navalofficer.com.au/well-well-what-have-we-got-here/
As far as the Littoral Combat Ships go, the Independence class hulls started out as “cost a lot for small performance.” But, as newer weapon systems are coming online, such as a long range surface to surface anti-ship missile, the “dogs” are growing some “teeth.” The fact that they can serve as impromptu floating airbases for Cobra and Apache attack helicopters, or possibly an F-35B if the deck plating can get replaced with cobalt steel alloy so it doesn’t melt…
Eventually someone will manufacture a catamaran aircraft carrier. The design advantages are too numerous to avoid forever, although the advantages in terms of top speed really only helps with “strategic mobility” rather than tactical mobility and shallower draft could mean more deck pitch for landing aircaft in rough seas (the deeper your draft and longer the ship, the more the ship “cuts” rather than “rides” the sea). Then again, if deck pitch is a serious concern, the weather is so bad planes should not be flying, in my opinion anyway.