در مورد sierra در ویکی تابناک بیشتر بخوانید

The Sierra-class nuclear fast-attack submarines were some of the deadliest subs that no one’s ever heard of. A successor to the much more numerous Victors, and the faster Alfas, the Sierras were vastly overshadowed by the much more numerous Akulas that still form the backbone of the Russian submarine fleet.