Russian submarine Severodvinsk

K-329 Severodvinsk is a Yasen-class nuclear attack submarine of the Russian Navy. The construction of the submarine started in 1993 and was first planned to be launched in 1998. However budgetary problems delayed the construction for years, and she was only launched on 15 June 2010. Severodvinsk began sea trials on 12 September 2011. The submarine returned from her first voyage by 6 October 2011.

The submarine is expected to begin operational service with the Russian Navy by the end of 2011. The Russian Navy plans to have two Yasen-class submarines in service by 2015. Severodvinsk's torpedo-launching systems have been fitted behind the compartment of the central station.

Trials
On 7 November 2012, the boat (while submerged) successfully launched a Caliber cruise missile (anti-ship version) at a sea target in the White Sea. Later that same month the submarine successfully test fired two additional (land attack) cruise missiles. The first land attack SLCM was launched on 26 November 2012 from a surfaced position and a second two days later from a submerged position.

K-329 "Severodvinsk" spent some 100 days at sea from September 2011 to October 2012. During trials some 2000 defects were reportedly discovered with problems concerning the submarines acoustic performance, nuclear reactor output and some weapon systems (torpedoes) being highlighted by the media. The submarine will be at sea until 25 November 2012 and if she meets the navy's requirements, she will be put into active service. On 28 November 2012 it again launched caliber cruise but this time from submerged position. Later it was reported that an officer in the state acceptance board said that "First trial round was held in October 2011 which revealed hundreds of failures and defects, and manufacturing shipyard Sevmash promised to eliminate them in the shortest possible period. But the number of defects at present is even larger".As for naval mariners, main problem is cruise missiles Caliber, the sub's basic attack weapon. According to trials program, the submarine performed three test launches, including those from underwater position and at moving sea targets. One underwater launch failed.Now the Navy command and United Shipbuilding Corporation are facing the problem whether to redesign the sub and repeat state trials or deliver her to the Navy and eliminate defects while in service. Project 855 subs have been in batch production for 13 years now, and that's a good time to make a decision", said the naval officer.He added that the board was inclined to elimination of serious problems and fastest commission of the sub into the Navy. In this case, Severodvinsk would be put in service in the first half of 2013 or even by the coming New Year holidays. On the other hand, third state trials would shift the sub's commissioning to the second half of 2013 or even later.