EnglishRussia has a fantastic photo set showing the inards of a Russian sub. I burned a good amount of time pursuing the set. The sub is a B-413 that once was part of the Soviet Northern Fleet, but is now hosting tourists at the Museum of World Ocean in Kalinigrad. Supposably, the interior is just as it was when the sub was commissioned in 1969. Amazing.
As an added bonus, every visitor gets a massive dose of radiation – just like all the Soviet Sub crews!
Subs are one of the most complex machine ever made. It’s amazingly complex and dangerous.