What is Borei-class submarine?

The Borei class, alternate transliteration Borey, Russian designation Project 955 Borei and Project 955A Borei-A , are series of nuclear-powered ballistic missile submarines being constructed by Sevmash for the Russian Navy. The class is projected to replace the Soviet-era Delta III, Delta IV and Typhoon classes in the Russian Navy service.

Despite being a replacement for many types of SSBNs, Borei-class submarines are much smaller than those of the Typhoon class in both volume and crew. In terms of class, they are more accurately a follow-on for the Delta IV-class SSBNs.