'ash tree', NATO reporting name: Severodvinsk), also referred to as the Graney class, are a series of nuclear-powered cruise missile submarines designed by the Malakhit Marine Engineering Bureau and built by Sevmash for the Russian Navy.

[18] However, the project was delayed due to financial problems and it appeared during 1996 that work on the submarine had stopped completely.

[citation needed] In 2003 the project received additional funding and the work of finishing the submarine restarted.

In 2004 it was reported that the work on the submarine was moving forward, but, due to the priority given to the new Borei-class SSBNs, the lead unit of the class (Severodvinsk) would not be ready before 2010.

In July 2006 the deputy chairman of the Military-Industrial Commission, Vladislav Putilin, stated that two Yasen-class submarines were to join the Russian Navy before 2015.

On 26 July, the Russian navy command announced that starting in 2011, one multipurpose submarine would be laid down every year, although not necessarily of this class.

[25] According to 60 Minutes, unnamed Pentagon officials claimed that Severodvinsk on her maiden deployment[26] "slipped into the Atlantic Ocean and for weeks evaded all of the attempts to find her" in the summer 2018.

[29] On 4 October 2021, Severodvinsk performed two test launches of Zircon missile, from surfaced and underwater position.

[17] In other words, the torpedo tube outer doors are not located in the immediate bow as in the previous Akula class[39] but moved aft.

[48] The inclusion of new generation KTP-6 reactor on the Yasen-M boats is thought to significantly reduce their noise level: the reactor's primary cooling loop facilitates natural circulation of water and thus doesn't require continuous operation of the main circulation pumps, which are the key noise factor on a nuclear submarine.

[1] In 2011, then Defense Minister Anatoliy Serdyukov criticized the ever increasing cost of the Borei and Yasen classes.

Officials from the United Shipbuilding Corporation replied that work done in Sevmash accounts for only 30% of the submarine's completion cost, the remaining 70% being linked to suppliers/contractors.

[55] Due to the high cost of each Yasen class submarine, some sources believe that a next generation of SSNs would be of smaller dimensions[56][57] with a reduced armament/payload could be built.