Which country built the world's deepest and most silent nuclear submarine nicknamed 'Losharik'?

Answer 1

The Soviet (later Russian) submarine "Losharik" (Project 210) design (multiple pressure-hull spheres with a submarine external superstructure) is believed to be able to approach depths approaching 20,000'. As far as being silent, reactors can only be quieted so much, and the sound profile characteristics at that depth mean that any sound she generates would be pushed back toward the surface by sea pressure (cold temperatures bend sound down in the ocean, until pressure forces it back up) with a vengeance. While she'd have an advantage in deep, cold water, she'd be vulnerable to detection within the 100 fathom curve of most continents (where the edge drops from shallow to deep depths) like any other boat.

While such a design might make it able to dive deeper and quieter, it also exacts strict limitations in equipment (weapons, sonar, etc.). While a unique design, it's more of a long-range independent DSRV / Research platform than a traditional submarine by naval warfare concepts.

The vessel was originally laid down in 1988, but over the years the lack of funding after the collapse of the Soviet Union led the Russians to actually seek outside investors to complete it (including Americans, who declined). This is likely due to Soviet-era submarine reactor technology, which had significant problems. Either way, the boat's design makes it essentially useful only as a rescue/special operations/research platform, not unlike the U.S. Navy's NR-1 and DSRV, though on a much larger scale and with its own power source, not requiring a tender to launch and recover.

It's most likely that the Soviets, having gained considerable intelligence knowledge from spy John Walker in the 80's, and release of the story concerning Project Azorian in the early 70's (erroneously called Project Jennifer by the press), could also have envisioned their own spy boat in the spirit of the U.S. Navy's USS Halibut (SSN-587) (Soviet submarine K-129 discovery/imaging), and USS Parche(SSN-683) ("Operation Ivy Bells"), but with much deeper depth capability, which was a limiting factor in the recovery effort of the K-129 by the CIA. Both the Halibut and Parche were used extensively in research, special operations, and rescue roles. Since the decommissioning of those boats, the Seawolf-class USS Jimmy Carter (SSN-23) has replaced them in those same spy roles.

With the intelligence-gathering aspect it's important to also note submarine concept design and implementation; it takes many years for the concept to go into actual production (even for the Soviets, who experimented with many design concepts). This means that the idea for Project 210 likely started in the late 70's or early 80's. As an example, we were first briefed on the initial Seawolf-class design in 1982, but 7 years before the first hull was laid down, and another 9 before commissioning.