Not sure if when the knowledge about it's design was made public, but name Losharik gave everyone a hint. It is a cartoon character that's made from spheres/balls connected with a wire. This is a logical way to create a submarine that's intended to go very deep, spheres are the best shape to handle high pressures. So logical conclusion based on the name was that internally it's based around connected spheres.

Submarine itself looks cigar shape, but that is just her outer shell, it's pretty certain that outer shell is not pressure sealed but rather that internal spheres withstand the pressure while the just the shell around it.

I believe the name is from a cartoon character, who is made out of balls:

https://www.youtube.com/watch?v=1F_hX-QjDQw

A better diagram of the sub here: https://cdn.arstechnica.net/wp-content/uploads/2019/07/Ru_Lo...

basically a series of interconnected bathyspheres with a hydrodynamic shell over them.

So basically personnel can't access the reactor and engine compartments from the life support units, the sub has to surface. Here's a bigger version of the same diagram with readable text:

http://www.hisutton.com/images/Ru_Losharik_Cutaway.jpg

Skegs, hydraulic manipulator, no weapons. It's clearly ment to tamper with undersea cables.

Are any of these details more than speculation? I had the impression that the best information was some not-so-clear pictures which happened to catch it on the surface, plus the admission a few days ago that it is in fact nuclear powered, and had a suspiciously high-ranking crew.

I agree that tampering with cables seems like the obvious reason for the military to go super-deep. With recovering sunken things made by your adversary a close second. And in the mid-1980s, they were much better at titanium than at video cameras.