The R-29RMU2.1 Layner^[2] (Russian: Р-29РМУ2.1 "Лайнер" meaning Liner) is a Russian liquid-fuelled submarine-launched ballistic missile (SLBM) and the newest member of the R-29 missile family, developed by the Makeyev Rocket Design Bureau and produced by the Krasnoyarsk Machine-Building Plant.^[3] Derived from the R-29RMU2 Sineva SLBM, the Layner can carry twelve nuclear warheads, three times as many as Sineva. It was expected to enter service with the Russian Navy's Delta IV-class submarines after a successful test programme that spanned from May to September 2011. The Russian Navy confirmed in 2014 that the system was now in use.^[4]

History and design

On 9 August 2011, the Russian Ministry of Defense disclosed the details of the Layner SLBM, whose first launch occurred on 20 May earlier that year.^[3][5] The authorities originally claimed the launch to be of a Sineva missile, but on 23 May 2011 it was revealed that the missile fired was actually the Layner.^[6][7] The successful firing, aimed at the Kura Test Range, was conducted from the submarine K-84 Ekaterinburg.^[3][8]

K-114 Tula, one of the seven Delta IV-class submarines of the Russian Navy, launched the second Layner in September 2011.

The second launch of the Layner missile took place on 29 September 2011 from the submarine K-114 Tula in the Barents Sea aimed at the Kura Test Range.^[9][10] Following the second successful Layner test, the Russian Navy decided to accept the missile into active service to augment the RSM-56 Bulava missile and improve the future viability of the Delta IV-class submarines until at least 2030.^[11][12] Development work on the missile was completed by late February 2012.^[13] Missile was recommended by the State Commission for adoption as of December 2012.^[14] Missile weapons complex D-29RMU2.1 with missile R-29RMU2.1 accepted for service by decree of the President of the Russian Federation in January 2014.^[15]

The Layner missile is a highly advanced derivative of the three-stage liquid-propelled R-29RMU2 Sineva SLBM, which was accepted into service in 2007.^[3] While many technical details are not disclosed, it is known that the missile is capable of carrying up to twelve low-yield nuclear warheads called MIRVs capable of striking several targets individually.^{[citation needed]} This is twice the number of warheads the solid-propellant RSM-56 Bulava SLBM can carry, and, unlike those of the Sineva SLBM, these warheads can be of a mixed set with various yields.^[12] While it shares flight characteristics with the Sineva, the Layner is equipped with improved systems to overcome anti-ballistic missile shields.^[16] The missile can carry twelve low-yield warheads without penetration aids, ten low-yield warheads with penetration aids, eight low-yield warheads with enhanced penetration aids, or four medium-yield warheads with penetration aids.^[1]

Operators

 Russia

• Russian Navy