It's an old design (ca. mid-'80s) so I am not surprised that Russia will move on to the next class. A class of 10-12 is rather large considering that its U.S. contemporary (and fellow victim of the post-Cold War reduction in defense spending), the Seawolf class, only had three units. Also consider that the Royal Navy will built seven Astutes.
Yasen is an underwater hunter for the USSR, Russia's potential is only 40%. We need a smaller submarine
Husky from above
Ash tree from below
Great drawing. Russia's double hull designs and preference for high reserve buoyancy and crew rescue spheres all necessitate larger hulls. Simply put, you have a different engineering heritage than we Westerners do. The rescue capsule concept, for instance, only made its way into the 4 IKL Type 209 1500 subs for India, and even then, there are rumors that this very expensive concept had been fully funded by the Shah of Iran in the 70s for an order that had been cancelled. My point is that much of what Russia does differently is rather expensive by Western standards.
It does occur to me that if the Amur/Lada class had been more successful, a scaled up design, akin to how Brazil's SN-BR scaled up the French export Scorpene, might have been possible. To this day, I still don't fully understand the sad saga of that first Lada class submarine. I'm not denigrating anyone, just pointing out that the Lada might have been any evolutionary way point to inherently smaller missile submarines.
