The submarine was laid down on July 24, 1992 at the
Severodvinsk Shipyard as pennant number 664 of the
Oscar II class cruise missile submarines. In April 1993, submarine 664 received the name
Belgorod after
the Russian city with that name and the tactical designation K-139. In 1995, crew training began at the
Obninsk-based 510th Naval Training Center, named after L. G. Osipenko of the
Russian Navy (
510-й учебный центр Военно-Морского Флота имени Л.Г. Осипенко). In 1997, construction was put on hold due to the severe economic crisis after the collapse of the Soviet Union, with the submarine three-quarters finished, mainly for financial reasons. In January 1998, the crew was disbanded and the unfinished hull was mothballed. The
loss of
Belgorods
sister ship, the
Kursk, in 2000 led to the decision to resume construction of
Belgorod to replace
Kursk, upgraded to Project 949AM specifications. By December 31, 2004 the hull was mostly complete, missing its powerplant, equipment and missile silos. In 2009, re-designing the submarine and arming it with the cruise missiles originally developed for the Project 885
Yasen-class submarines was considered. In early 2012, the Commander-in-Chief of the Russian Navy, Admiral
Vladimir Sergeyevich Vysotsky, stated that
Belgorod would be completed as a "special projects" vessel. In December 2012, this specification received the official designation Project 09852. The Project 09852 Belgorod refit began in 2012 in order to transport
Losharik for
GUGI operations from the 29th submarine division Military Unit 13090 base at
Olenya Bay. The refit included both removing the cruise missile launch tube bay to make room for a new bay about 18 meters long that is capable of accommodating special operations submarines such as the
Losharik or
Paltus (Project 18510), and lengthening the bow bay to 38 meters to accommodate the new Poseidon nuclear-powered torpedoes. Belgorod may have a revolving launcher capable of accommodating six Poseidons. The submarine was planned for commissioning in the Navy in 2018. A crew was formed again in November 2018. In April 2019, the
Belgorod was taken out of the covered dry dock and put afloat. The commander of the ship at that time was
Captain 1st rank Anton Alyokhin. In 2019, the sub was to complete its fitting out, nuclear reactor testing and sea worthiness trials. By June 2020, one source reported it "in service", though this appears to have been inaccurate. Others suggested it was still fitting out, possibly including sea trials. In January 2021, the director-general of the Russian Shipbuilder Sevmash, Mikhail Budnichenko, stated that tests on Belgorod were proceeding. The plans to commission the submarine in the Russian Navy in 2020 and to introduce the Poseidon system in 2021 did not materialize. A press report by the official Russia state-owned TASS agency from April 2021 indicates a new objective from the Russian Defense Ministry to send the K-329 into service in the Pacific zone. This information could confirm the problems encountered with the
Losharik submarine and the shift to the background of the operations envisaged on the
Arctic continental shelf. In April 2021, military analyst H. I. Sutton reported that the
Belgorod was out of the water and had returned to the construction hall. On June 25, 2021, the
Belgorod left the Severodvinsk shipyard for the first time on a trial regime by the builder Sevmash. The submarine was delivered to the Russian Navy on 8 July 2022. ==Characteristics==