In the 1980 fleet table, SS denotes a conventional diesel submarine, while modern usage often makes that distinction with SSK. Adding N identifies nuclear propulsion, giving SSN for a nuclear-powered attack submarine. G identifies cruise-missile armament, producing SSG or SSGN according to propulsion. B identifies ballistic missiles, producing SSB or SSBN. The letters distinguish the submarine's propulsion from its weapon role.
Notable Point · 1:16:26-1:17:06
How to read Cold War submarine letter codes
SS, SSN, SSG, SSGN, SSB, and SSBN distinguish conventional or nuclear propulsion and cruise- or ballistic-missile armament.