Project 651 was a series of Soviet diesel-electric submarines fitted with cruise missiles; in the West, it was referred to by its NATO reporting name, Juliett class. The class was designed in the late 1950s primarily to oppose enemy warships like aircraft carriers and to give the Soviet Navy a nuclear strike capability against locations on the U.S. East Coast. Abram Samuilovich Kassatsier was in charge of the design group.
With a range of about 300 nautical miles (560 km), these submarines were equipped with four nuclear-capable cruise missiles. Interestingly, these missiles could be fired when the submarine was going faster than four knots (7.4 km/h) on the surface. It was possible to fire the first missile in about five minutes, and successive missiles could be launched in about ten seconds each, demonstrating how quickly the procedure worked. The P-5 inertial-guided missiles, designated SS-N-3c Shaddock by NATO, were first mounted on the submarines. Though it was a quite different missile meant to target aircraft carriers, the P-6, also known by the NATO reporting designation SS-N-3a Shaddock, replaced the P-5s when they became obsolete due to submarine-launched ballistic missiles.
The Juliett class was distinguished by the unique 10 m2 target guidance radar that was built into the sail structure’s forward edge. The ability to precisely target the cruise missiles was greatly aided by this spinning radar. A Kasatka satellite downlink system was also installed on one of the submarines, which made it easier to receive targeting data for the P-500 4K-80 “Bazalt” anti-ship cruise missiles.
Due to their double hull made of austenitic steel, the submarines of the Juliett class had a minimal magnetic signature. These fearsome naval warships were made even more stealthy by the application of two-inch (51 mm) thick black tiles made of sound-absorbing hard rubber to the exterior hull.
With a displacement of 3,174 tonnes when above and 3,750 tonnes while submerged, the Juliett-class submarine is a powerful undersea vehicle. The submarine is a formidable presence in the naval realm, measuring 85.9 metres in length, 9.7 metres in beam, and 3.29 metres in draft.
With two propeller shafts powered by two 4,000 PS (2,900 kW) diesel engines, the Juliett-class submarine is propelled by two sources. It also has two electric motors that can produce 3,000 PS (2,200 kW) each, in addition to two additional electric motors that can produce 200 PS (150 kW). With the help of this extensive propulsion system, the submarine can reach a top speed of 16 knots when surfaced and an astounding 18 knots when submerged.
This submarine can snorkel up to 18,000 nautical miles at 7 knots, which is an impressive operational range. Underwater, its maximum speed is 18 knots or 27.8 nautical miles. A test depth of 240 metres is reached by the Juliett-class submarine, demonstrating its capacity to function well at significant depths.
There are seventy-eight people on board the Juliett-class submarine to ensure its smooth operation. Feniks-M (MG-10) and MG-13 hydrophones, Albatros (RLK-50) search radar, Argument missile guidance radar, and Artika-M (MG-200) and Herkules (MG-15) sonars are among the sophisticated sensor and processing systems aboard the submarine. The Nakat-M ESM system is in charge of decoys and electronic warfare.
The Juliett-class submarine is well-armed, with six 533 mm (21 in) bow torpedo tubes, four 406 mm (16 in) stern torpedo tubes, and two twin SS-N-3 Shaddock (P-5 or P-6) cruise missiles.