I haven't written anything about this idea for almost 11 months but I think about it occasionally. Then this week I saw an article in Defense News.
"A classified Pentagon maritime drone program is about to get its moment in the sun" 14 March 2019.
"WASHINGTON – A project birthed in the Pentagon’s Strategic Capabilities Office is getting some serious buy-in from the U.S. Navy, and could yield the world’s first large-scale armed unmanned warship. The Navy raised eyebrows in its budget rollout Tuesday when it requested $400 million for two large unmanned surface vessels to be purchased in 2020, with 10 total to be purchased across the five-year projection known as the future year defense program. But it was not immediately clear what exactly the Navy was buying two of, since no program of record exists for a large unmanned surface vessel (or LUSV).
Navy officials now say the request is an outgrowth of SCO’s Project Overlord, which first surfaced in 2017 with a draft solicitation outlining a program that would take existing autonomy technologies and integrate them into large and medium unmanned surface vessels with some heady ambitions: an autonomous ship capable of carrying up to 40 tons of payloads, and operate in up to sea-state five independently for 90 days without a crew for maintenance, while following all rules of navigation and obstacle avoidance.
... The draft lays out a two-phase plan that starts with a 12-month phase I, which asks industry to demonstrate a vehicle that could meet the requirements laid out in the draft, including a range of 4,500 nautical miles, “capable of operating in at least Sea State 5, with at least 80,000 lbs. of payload capacity and 75 kW of 450V, 60 Hz, three-phase AC power reserved for payloads.
... They are 200 to 300-foot, 2,000 ton [hulls],” said Rear Adm. Randy Crites. “I’m not sure what the final hull form will be, that’s what we’re using today in terms of what the ‘ghost fleet’ buy is. But I don’t think we know yet exactly what the hull form will be.”
https://www.defensenews.com/naval/2019/03/14/a-classified-pentagon-maritime-drone-program-is-about-to-get-its-moment-in-the-sun/This sounds like a couple prototypes to experiment with the technology and develop a concept of operations. So the production autonomous frigates would be larger. Perhaps it's time to start sketching some ideas for a model. I'm thinking of the old concept of a razee, where a wooden warship was cut down, e.g., a 3-decker cut down to a 2-decker, or a 2-decker cut down to a large frigate. By eliminating the accomodation spaces, a Frigate could have a deck eliminated from the superstructure, and perhaps the remaining superstructure integrated into the hull to limit the radar cross section. I need to maintain a useful height above the waterline for the radar arrays. That's about 50 feet to the center of the forward SPY-1 array on the Arleigh Burke DDGs, according to images found online.
A reasonable weapons load would be 48 VLS cells plus a light gun mount or two.
No need for the outrageous hull/power compromises of the LCS since the speed would be consistent with other frigates/destroyers and a conventional displacement hull will do.