Very nice to see someone looking at a diesel/Electric submarine concept for use in the Littoral role for the USN. But I do agree with TimothyCs comment about that it would look allot different then using Barbels hull design. Remember Barbel was a 50s design built submarine and was well ahead of its time in hull design, propulsion, electronics/sensors and weaponery for SSKs at the time. But times have changed allot since then and with the age of sub launched guided missile, fuel cell/AIP and computer designing software it could look anywhere from a scaled down version of the current Virginia Class SSN or possibly similar to the latest German, Japanese and Swedish Diesel/Electric designs and yes with the UGMs and Fuel cell/AIP technology added to the hull as you mentioned earlier.
It's a cute concept, but the USN already has a "littoral submarine," it's called SSN-774 Virginia.
Very true in all aspects! But when it comes to price per unit cost both in construction and operating it as well as potential export sales to other American aligned/friendly countries this could become a different ball game though you have to add in the cost of reintroducing as some would call past technology back into service as the USN hasn't operated a frontline SSK since 1989/1990. This will be a interesting thread!
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"The British Air Farce have droopped their bums on the water works..They have scored a direct hot on the pimps"- British agent/gendarme Officer Crabtree, "Allo,Allo."