Russia’s Khabarovsk nuclear submarine, the first purpose-built carrier of the multipurpose Poseidon system, has begun factory sea trials. The Project 09851 vessel left the Sevmash outfitting quay and headed to sea, Voennoye Obozreniye wrote, citing Russian resources.

Khabarovsk is the only Project 09851 submarine built under a contract signed in 2012. The design was developed by the Rubin Central Design Bureau. Construction began on July 27, 2014, and the submarine was rolled out of the construction hall on November 1, 2025.

The vessel was initially expected to enter service with the Russian Navy in 2020, but its construction schedule was pushed back significantly.

Khabarovsk’s defining feature is its role as the first standard carrier of the nuclear-powered Poseidon torpedoes. According to unofficial information, the submarine is equipped with six launchers for the systems. Its stern section, meanwhile, is almost identical in design to that used on Project 955A Borei-A strategic ballistic missile submarines.

Once the full testing program is complete, Khabarovsk is expected to join the Pacific Fleet and be based in Kamchatka. This could happen as early as next year.

The Russian fleet already operates one Poseidon carrier, the Belgorod special-purpose nuclear submarine. It was converted from an unfinished Project 949A submarine cruiser and carries four Poseidon launchers.

Earlier reports also pointed to Russian Defense Ministry plans to order four Poseidon carriers in total, with two intended for the Northern Fleet and two for the Pacific Fleet. Serial-production submarines were expected to be built under the modernized Project 09853 design.