The Delta IV-class submarine is the Soviet Project 667BDRM Delfin nuclear-powered ballistic-missile submarine, built by Sevmash for the Northern Fleet and retained by Russia as an aging but still visible sea-based nuclear deterrent. The class carries a D-9RM missile system with 16 R-29RM-family SLBMs, four 533 mm torpedo tubes, and modernized Sineva/Layner-era missiles; public sources distinguish the seven boats built from smaller operational counts as individual hulls cycle through overhaul or replacement by Borei-class SSBNs.
Russian Delta IV / Project 667BDRM boats appeared in strategic nuclear signaling around the full-scale invasion: Karelia launched a Sineva missile during the February 2022 Grom exercise shortly before the invasion, and Tula fired a Sineva from the Barents Sea during October 2022 strategic-deterrence drills amid the war. This row documents deterrence and signaling activity, not a conventional battlefield strike in Ukraine.
Role detailsThe Delta IV design centers on underwater ballistic-missile launch from a strategic patrol submarine rather than tactical naval strike. FAS describes the class with the D-9RM launch system, 16 R-29RM missiles, and an ability to fire ballistic missiles from about 55 m depth while moving at 6-7 knots.
Sixteen R-29RM-family SLBMs in the D-9RM launch system.
Supported by FAS and CSIS missile-family references.
Four 533 mm torpedo tubes for torpedoes and antisubmarine missile-torpedoes.
FAS describes the torpedo and missile-torpedo capability without naming every munition carried.
Omnibus-BDRM battle management, Shlyuz navigation, and Skat-VDRM sonar.
These systems frame the class as a strategic missile platform with supporting undersea sensors and fire-control equipment.
Delta IV-class submarines are strategic missile carriers. The catalog link below points to the broad ballistic-missile class because a publishable R-29RM-family missile record is not yet available.
| Carried item | Item type | Carriage evidence |
|---|---|---|
 | Submarine-launched ballistic missile | FAS identifies the Delta IV's D-9RM system as carrying 16 R-29RM liquid-fueled missiles, and CSIS describes the SS-N-23 / R-29RM as developed for Delta IV SSBNs with 16 missiles per boat. Sources: 667BDRM DELTA IV, R-29RM Shtil (SS-N-23) | Missile Threat - CSIS |
FAS traces Project 667BDRM development to Rubin Central Design Bureau for Marine Engineering beginning on 10 September 1975.
Sources: 667BDRM DELTA IV
FAS lists construction and outfit for the class as beginning in 1981 at the Severodvinsk yard that later became Sevmash.
Sources: 667BDRM DELTA IV
FAS says the first Dolphin submarine was launched in January 1985 and introduced into the Northern Fleet in December 1985.
Sources: 667BDRM DELTA IV
CSIS Missile Threat says the SS-N-23 / R-29RM entered operational service aboard Delta IV SSBNs in 1986.
Sources: R-29RM Shtil (SS-N-23) | Missile Threat - CSIS
CSIS says 112 SS-N-23 missiles were deployed on seven Delta IV submarines by 1991, matching the class's completed seven-boat build run.
Sources: R-29RM Shtil (SS-N-23) | Missile Threat - CSIS
RussianSpaceWeb lists R-29RMU Sineva service beginning in 2007, while CSIS and NTI describe Sineva as the upgraded SS-N-23 family missile carried by Delta IV boats.
Sources: Submarine-Launched Ballistic Missiles, R-29RM Shtil (SS-N-23) | Missile Threat - CSIS, Russia Submarine Capabilities
Barents Observer reports that K-18 Karelia launched a Sineva from the Barents Sea during the Grom strategic exercise five days before Russia's full-scale invasion of Ukraine.
Sources: Karelia Arctic Nuclear Buildup
Al Jazeera reported Russian strategic nuclear drills amid the Ukraine war with state footage of a Sineva launch from the Barents Sea; RussianSpaceWeb identifies the missile as launched from the Project 667BDRM Tula.
Sources: Al Jazeera Strategic Nuclear Drills 2022, Submarine-Launched Ballistic Missiles
NTI's 2024 Russia submarine capabilities review says the Russian Navy possesses seven Project 667BDRM Delfin / Delta IV SSBNs in the Northern Fleet, with four to five operational at any given time.
Sources: Russia Submarine Capabilities
Barents Observer reported K-117 Bryansk conducting post-upgrade sea trials and described the boat as returning toward deterrence patrols with 16 Sineva missiles.
Sources: Bryansk Sea Trials
Public sources separate three related counts: seven boats were built, NTI still describes seven Delfin / Delta IV SSBNs as possessed by Russia, and operational counts are lower because refits and conversions affect individual hulls.
| Hull | Name | Service note |
|---|---|---|
| K-51 | Verkhoturye | One of the original seven Project 667BDRM boats listed by FAS; later public force counts treat the class as being replaced gradually by Borei SSBNs. |
| K-84 | Ekaterinburg | Listed by FAS in the seven-boat class roster and associated in open sources with later R-29RM/Sineva test-launch history. |
| K-64 | Vladimir / Podmoskovye | Part of the built class in the FAS roster; later specialist sources commonly treat it as converted away from the standard SSBN role. |
| K-114 | Tula | Identified by RussianSpaceWeb as the Project 667BDRM boat that fired Sineva during the October 2022 strategic exercise. |
| K-117 | Bryansk | Barents Observer reported post-upgrade trials in 2025 and described its return toward deterrence patrols with 16 Sineva missiles. |
| K-18 | Karelia | Barents Observer identifies Karelia as the Delta IV boat central to the February 2022 Grom exercise and later modernization reporting. |
| K-407 | Novomoskovsk | The final completed boat in the FAS class roster and the subject of the current gallery's 2016 onboard photographs. |
