The R-27 was an intermediate-range, submarine-launched, liquid propellant ballistic missile. It represented a considerable leap forward for Soviet Submarine-Launched Ballistic Missiles (SLBM), incorporating a second-stage engine, superior range, accuracy, and Multiple Re-entry Vehicles (MRV). It used storable liquid propellants with a pre-launch time of roughly 10 minutes and an interval of 8 seconds between launches. It used an inertial guidance system.
There were three main versions of the R-27, with a fourth version designed for attacking ship surveillance radars that was cancelled during the design phase. Like all SLBMs, the purpose of the R-27 was to place hidden nuclear missiles within close range of their targets while maintaining secrecy. The R-27 was designed to destroy strategic land targets, but with its relatively limited (but still greatly improved) accuracy it could only really engage cities and other soft targets. The longer range enabled the submarine to strike US targets from well outside the range of anti-submarine defenses, even as far as some Russian territorial waters. It provided an effective preemptive and reprisal nuclear force.
The R-27 had a launch weight of 14,200 and carried a payload of 650 kg. It was 9.0 m long and 1.5 m wide. The Mod 1 and 2 were equipped with single nuclear warheads with 1 MT yields. The Mod 3 could deploy three 200 kT MRV warheads against a target area. The Mod 1 had a range of 2,500 km and an accuracy limitation of 1,900 m CEP. The Mod 2 and 3 used a superior design that increased the range to 3,000 km and the accuracy to 1,300 m CEP. The R-27 used a two-stage liquid propellant engine according to some accounts, a single stage by others.
Development on the R-27 began in 1962 with flight tests beginning in 1966. The R-27 Mod 1 entered service in the Soviet Union in 1968, with the Mod 2 and 3 entering in 1974. A total of 600 missiles were built and at their peak R-27 missiles were carried on 34 boats. The R-27 missiles were deployed on ‘Yankee 1’ submarines. This had been reduced to 12 boats and 192 missiles by 1991, and two boats and 32 missiles by December 1994. The last R-27 compatible submarine was decommissioned in 1996. 1
Update October 19, 2012
- Lennox, Duncan. “R-27 (SS-N-6 ‘Serb’ and RSM-25 Zyb/4K10).” Jane’s Strategic Weapon Systems (Obsolete systems). October 13, 2011. (accessed October 13, 2012). ↩