The barrel is of similar size to the Oto Malera 127mm. The radar "patches" might be big but it´s not as big inside. The structure it self is based on the proposed APAR system. The arrays are bigger than the original arrays.
which makes the systems backing them bigger as well. cooling, power generating, computing, waveguides, all scale with the arrays.
and the barrel looks HUGE in length, the barrel being twice the length of the turret instead of just as long. you know they cut back RoF for the /64 mount, due to that longer barrel, right?
AIP subs are quiter. Normal Electro-Diesels are not. At least not when comparing them to the Seawolf and the Virginia wich are the best nukes in the world.
and that is why the dutch dieselelectric subs still beat the USN ones in exercises every now and then.
really, diesel subs are quieter then nukes, due to the nukes needing to cool their reactor constantly + the turbines vibrating while the electrical engines make next to no noise except for the propeller. nukes have the speed and range on their side, though.