Delta III-class submarine

The Delta III-class submarine is the NATO reporting name for the Soviet Project 667BDR Kalmar, a nuclear-powered ballistic missile submarine built at Sevmash in Severodvinsk. FAS says the class carried 16 R-29R missiles, could fire any number of missiles in a single salvo, and introduced a MIRV-capable Soviet SSBN design that remains a reference point for Russia's aging strategic submarine force.

Various Conflicts🏳️ Unspecified

Delta III-class submarine, Ballistic missile submarine, Naval Systems

Image source: Submarine Delta III class.jpg - Wikimedia Commons

Profile

Origin: Soviet Union
Built by: Sevmash
Type: Ballistic missile submarine
Service note: 1976-present
Designer: Rubin Central Design Bureau for Marine Engineering
Designed: 1972
Produced: 1975-1981
Number built: 14

Also Known As

Project 667BDR
Project 667BDR Kalmar
Kalmar-class
NATO Delta III
Delta-III

naval submarine nuclear nuclear-powered ballistic missilestrategic

Specifications

Length: 155 m
Beam: 11.7 m
Displacement: 8,940 tons surfaced; 10,600 tons submerged
Speed: 13-14 knots surfaced; 22-24 knots submerged
Crew: 130
Armament: 16 R-29R ballistic missiles and 4 x 533 mm torpedo tubes
Propulsion: Two pressurized water reactors and two steam turbines

Service And Conflict Use

Service History

In service: Entered service in 1976. FAS describes 14 boats commissioned by 1982, and NTI says Russia retained aging Kalmar-class boats in service while Borei submarines replace them.
Used by: Soviet Navy, Russian Navy

Conflict Usage

Side: 🏳️Unspecified

Russian Strategic Nuclear Forces reported that K-44 Ryazan, a Project 667BDR / Delta III submarine, took part in a 2019 strategic forces exercise and launched its missile from the Sea of Okhotsk to the Chizha test site, but the open-source record does not tie the class to a specific named conflict.

Timeline

Delta III-class submarine Key Events

Jan 1, 1972
Development begins
FAS says development of the 667BDR Delta III began at the Rubin Central Design Bureau for Marine Engineering in 1972.
Sources: 667BDR DELTA III - Russian and Soviet Nuclear Forces
Jan 1, 1976
Enters service
FAS says the advanced Delta III SSBN entered service in 1976, and by 1982 a total of fourteen submarines had been commissioned.
Sources: 667BDR DELTA III - Russian and Soviet Nuclear Forces
Jan 1, 2018
Fleet shrinks to one boat
NTI says the Russian Navy retired two Delta III submarines in early 2018 and then possessed one Project 667BDR Kalmar-class SSBN.
Sources: Russia Submarine Capabilities

Delta III-class submarine Images

Delta III-class submarine, Ballistic missile submarine, Naval Systems - view 1 — Source: Aerial Delta III submarine image - Wikimedia Commons

Delta III-class submarine, Ballistic missile submarine, Naval Systems - view 2 — Source: Delta III class SSBN.svg - Wikimedia Commons

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Sources

667BDR DELTA III - Russian and Soviet Nuclear ForcesPublisher: Federation of American Scientists | Note: Supports the class's development history, designer, builder, service period, number built, and technical characteristics including dimensions, crew, propulsion, and missile armament. | Accessed: 2026-06-25 Russia Submarine CapabilitiesPublisher: Nuclear Threat Initiative | Note: Supports the Kalmar-class identifier, Russian service context, and technical background; NTI says Russia retained aging Kalmar-class boats in service while Borei submarines replace them. | Accessed: 2026-06-25 Ryazan, a Project 667BDR/Delta III submarine withdrawn from servicePublisher: Russian Strategic Nuclear Forces | Note: Supports Various Conflicts: the article reports that K-44 Ryazan, a Project 667BDR / Delta III submarine, took part in a 2019 strategic forces exercise and launched its missile from the Sea of Okhotsk to the Chizha test site; the report does not identify a named conflict. | Accessed: 2026-06-25 Submarine Delta III class.jpg - Wikimedia CommonsPublisher: Wikimedia Commons | Note: Supports image provenance and public-domain status for the Delta III class submarine photo used as the primary image. | Accessed: 2026-06-25 Aerial Delta III submarine image - Wikimedia CommonsPublisher: Wikimedia Commons | Note: Supports gallery image provenance and public-domain status for the aerial Delta III submarine photograph. | Accessed: 2026-06-25 Delta III class SSBN.svg - Wikimedia CommonsPublisher: Wikimedia Commons | Note: Supports gallery image provenance and licensing context for the Delta III class silhouette. | Accessed: 2026-06-25