The Admiralty Shipyards built two Project 865 Piranha special-purpose midget submarines (SSW) (Losos class under the NATO classification) developed by the St. Petersburg-based MalaТhite Marine Engineering Bureau for the Soviet Navy in the late 1980s. These subs boasting a full submerged displacement of 319 t and a crew of three turned out to be extremely efficient. They featured low physical fields, good maneuverability, considerable diving depths (200 m), and easy handling. The subs were armed with two torpedoes and mines in containers and were capable of carrying up to six frogmen. Unfortunately, these submarines were not in demand in the post-Soviet Russia, which plunged into economic and political turmoil. At first they were mothballed and later on scrapped (in 1999).
However, Malachite designers have kept on working on midget submarines and developed a whole range of small-size subs with a displacement of 130 to 1,000 t.
While boasting small dimensions, SSWs can carry various weapons including torpedoes and mines, while larger subs, such as P-550s, P-650s and P-750s, can be armed with Club-S or BRAHMOS submarine-launched «submarine-to-ship» and «submarine-to-surface» cruise missiles. In other words, under certain circumstances they can perform strategic missions. State-of-the-art electronics enable SSWs to promptly detect targets and attack the enemy well in advance. Low noise and electromagnetic levels ensure their extraordinary stealth.
The high maneuverability is provided by the low-noise steerable shrouded propeller and the backup propulsion plant comprising two outboard steering columns, which enable the subs to literally spin on the same spot.
Another crucial feature, inherent in midget submarines, consists in their highly automated battle management and operation. It is not just a random capability. Malachite is the world leader in integrated automation of submarines. SSWs are manned by combat crews of only four to nine people who operate in quite comfortable conditions. In addition to the organic crew, a midget submarine can carry up to six fully equipped frogmen.
Piranha-family SSWs can be equipped with Air-Independent Propulsion (AIP) fuel cell modules that significantly boost their submerged range. This system deserves a special mention. It was for Piranha-family submarines that the St. Petersburg-based Special Boiler Design Bureau developed the 130-kW Kristall-20 AIP fuel cell power plant in the late 1980s. The Kristall-20 AIP power plant, incorporating electrochemical generators, produces energy from hydrogen and oxygen. The efficiency factor of an AIP system with electrochemical generators amounts to 70-75 percent. Following extensive tests the Kristall-20 AIP system was fielded by the Russian Defense Ministry in 1991. However, the USSR broke up soon afterwards and neither innovative power plants nor submarines powered by such systems turned out to be in demand.
Meanwhile, according to experts from the Krylov Central Research Institute, submarines fitted with electrochemical generators possess a 450-percent greater submerged endurance than ordinary diesel-electric subs. AIP-equipped submarines are even superior to nuclear-powered subs in littoral areas as far as their cost-efficiency ratio is concerned. The latter fact is of paramount significance since modern naval strategies envision deployment of submarines in friendly or hostile offshore areas rather than in ocean lanes.
However, let’s get back to midget submarines developed by the Malachite Marine Engineering Bureau. They are primarily designed to operate in littoral areas, shallow waters, and off islands. However, they also boast quite good diving capabilities with their submergence depths ranging from 200 to 300 m. Their operational range varies from 2,000 to 3,000 nautical miles, and their endurance totals 20 to 30 days. For instance, the largest Piranha-family submarine, designated P-750, features the following basic specifications: a normal displacement of 960 t (1,060 t with the AIP fuel cell module), a length of 66.8 m (70.4 m), a hull diameter of 6.4 m, a full submerged speed of 17 knots, an operational range of 3,000 nautical miles, a submerged range of 280 (1,200) nautical miles, a diving depth of 300 m, an endurance of 30 days, and a crew of nine men plus six frogmen.
The P-750’s armament is of special interest. The sub is fitted with four 533mm torpedo tubes, which can launch both torpedoes and cruise missiles. The torpedo tubes cannot be reloaded at sea, but they are always ready for immediate single or salvo fire. The SSW is also armed with eight 400mm torpedo tubes firing ASW torpedoes. The P-750 is capable of carrying up to 24 seabed mines in outboard mine containers. Finally, the submarine can be equipped with up to four vertical launchers with cruise missiles, including Club-S 3M-14E missiles, designed to hit coast-based targets out to a range of up to 300 km. In other words, such subs can both repulse attacks from the sea and deliver strikes against the enemy territory. On the whole, the armament of the P-750 is superior to that of many larger submarines, which can hardly be included in the subcategory of «small-size» subs. For instance, the WWII-vintage Shchuka class Series III medium submarine had a submerged displacement of 705 t, a maximum diving depth of 90 m, a submerged speed of 2.8 knots, and a weapon load of ten torpedoes and a 45mm gun.
These submarines (SSWs – editor’s note) can enter service with the Baltic Fleet, the Black Sea Fleet, and the Caspian Flotilla in the next two or three years. Four to six midget submarines of this kind can completely cut off such closed or semi-closed water areas as the Black, the Baltic, and the Caspian seas. Indeed, SSWs can discharge a wide range of tasks. They can covertly escort nuclear-powered submarines to their combat patrol areas and carry out reconnaissance missions in the Pacific Ocean and the Barents Sea. Such subs are virtually indispensable for setting up ASW defenses in littoral areas,» Vice Admiral Victor Patrushev emphasized.
Russian SSWs are superior to similar foreign rivals. The French DCNS shipbuilder displayed a model of the advanced Andrasta coastal submarine for littoral operations, named after the Celtic goddess of war whose name means victorious or invincible, at the Euronaval 2008 international naval show. The sub has a surface displacement of 855 t, a length of 49 m, a submerged speed of over 15 knots, a maximum diving depth of 200 m, an operational range of about 3,000 nautical miles, and a crew of 19 men. It is armed with torpedoes, antiship missiles, and mines. The project did not impress participants in the show. Actually, the project proper is not new. It is a slightly revised version of the SMX-23 submarine demonstrated at Euronaval 2006, which also failed to generate the interest of potential customers. As far as its characteristics and combat capabilities are concerned, the Andrasta submarine is considerably inferior to Malachite’s SSWs.
Russian midget submarines, on the contrary, attract attention of various navies from the Middle East and Southeast Asia. This trend was pointed out by head of Rosoboronexport’s Navy Department Oleg Azizov in an interview with National Defense. And it is quite justified. Russian submarines feature a great striking power and a low noise level, and are easy to operate. Last but not least, they are relatively cheap, which is an important factor given the global financial crunch.