Project 641B submarines are a series of Soviet diesel-electric submarines (Tango according to NATO classification). It is a modernization project 641. According to the design of the boat electronic two-hull, has seven compartments: the first - (nasal) torpedo; The second and fourth - bow and stern rechargeable; The third is the central post; The fifth is diesel; The sixth - electromotive; The seventh - the aggregate and residential. The first, third and seventh compartments are adapted to evacuate the crew. -link removed-