The R-13 missile (D-2 complex) is the first native ballistic missile to be arranged aboard a submarine. The R&D work was started in 1960 upon completion of the first phases of the R-11FM flight tests. The one-stage missile configuration was not modified. However, the obtained results were weighty in comparison with those of the R-11 FM, in particular: the transition from a nuclear to thermonuclear charge increased the yield by more than 50 fold at a 1.5-fold increase in weight; the firing range increased by 4 fold at a 2.5-fold increase in launch weight.
The unique development within the framework of the R-13 project was a warhead (nuclear weapon) created by SKB-385 and NII-1011 of the Ministry of Medium Machine Building), where bodies of the warhead and the combat charge were combined. The combat qualities of sea-based strategic weapon were convincingly demonstrated in the R-13 missile submarine launching and resulted in actual thermonuclear explosion of 1,450 tons of TNT in yield on October 20, 1961 at the Novaya Zemlya range.