[Podvodnaya Lodkae Spetsial'nogo Naznacheniya - PLSN]
As of 2009 the Russian Navy had at least seven "Special-Designation Submarines" [Podvodnaya Lodkae Spetsial'nogo Naznacheniya] designed for testing of new technologies and weaponry. The term "Spetsial'nogo Naznacheniya" [aka Spetsnaz] is also rendered as Special Purpose, Specialised Designation, Special Operations, or Special Forces. Some but not all of the Spetsial'nogo Naznacheniya submarines support special operations, others are deeper submergence "ocean engineering", a few are engineering test programs, while the exact purpose of some remains obscure.
The earliest referenced practice of diving occuring in the Iliad. Pearl and sponge diving and salvage operations have been engaged in since Greek and Roman times. Early divers were sometimes provided with devices for drawing air from above the water such as through a tube, one end of which would be carried in the mouth while the other end was made to float on the surface. In 17th century England, rudamentary diving bells were developed. When a container is immersed in water, with its opening pointing downward, the volume of air enclosed in it diminishes in proportion to its depth in the water, the air pressure being balanced by the pressure of the water at its own level. If, however, air is compressed in a container at a pressure slightly above the already existing pressure, the level of the water inside will drop until the air escapes from the lower rim of the vessel.
Greater mobility for the submerged diver has been provided in more recent times with the advent of the self-contained underwater breathing apparatus (scuba), wherein tanks of compressed air are worn on the diver's back and, when combined with a diving mask, a weighted belt and a means of propulsion, enabled men to swim and explore under water with greater freedom. Apparatus designed by J. Y. Costeau and E. A. Ghenan which provide a demand valve regulator for supplying air to the diver only on inhalation, have come into common usage. The scuba diver, however, has a limited diving time of approximately one hour, the duration of which depends on the average depth of his dive, and this limits the distances over which he can explore while submerged.
The bathyscaph first constructed by Piccard and Cosyns in 1948, was a sealed steel cabin equipped with Plexiglas observation protholes, and was a self-contained submarine vessel equipped with its own means of propulsion. The principal application of a bathyscaph is for relatively deep diving at depth in excess of 1,000 feet. The devices of the above-mentioned type however present some disadvantages involving either the need for embarking an operating and/or observation crew or of working in blind conditions. In the case of a manned device, said crew incurs great risks due, in particular, to the high compressive forces exerted by the hydrostatic pressure prevailing in the medium in which the device is being operated, and also to the explosion hazards when it is operated in the vicinity of explosive charges (mines or others). In the absence of a crew, the device maneuvers are not highly dependable and the work done is often of poor quality.
A submarine at shallow depths derive their buoyancy from the leaktight seal of the hull and which, for great depths, use buoyancy products resistant to very high pressures, to constitute a "wet submarine". This vehicle comprises, in addition to the resistant sealed capsule in which the passengers are housed if the vehicle is manned, a structure forming a tubular or other form of framework connecting the various weighty parts to one another. The buoyancy product in the form of blocks of small or moderate dimensions is generally fixed to this framework. These wet submarines may or may not comprise a hydrodynamic hull which, if provided, is in the form of a thin hull, but the hull does not, under any circumstances, coincide with the outer surface of the buoyancy product.
The Russian Navy does not seem to have a single standard designation for this diverse collection of submarines. Some designations include Large Test submarine [Bolshaya Opytovaya Podvodnaya Lodka] for the Project 20120 Sarov Experimental Submarine (Auxiliary submarine (SSA(N)) and Small nuclear-powered submarines [Malaya Atomnaya Podvodnaya Lodka] for the Project 1083 "Paltus" (Turbot).
The "Dronovskiye" Special Purpose Submarine Unit is one of the most classified units of the Defense Ministry. This unit is based in one of the bays along the coastline of one of the northern seas, not far from the home station of one of the Russian fleets. Actually, this unit is not subordinated to the fleet, but rather is subordinated directly to one of the main directorates of the General Staff. The name of this unit is not known to very many in the fleet. They know that it has special-purpose nuclear submarines.
There is fairly general confusion as to the allocation of the Project 09774 and Project 09780 numbers. Some sources report that Project 09780 is K-403 "Kazan", the Yankee Big Nose ("Akson-2") [deepstorm has never heard of Yankee Big Nose]. Wikipedia favors this theory assigning Project 09774 to both Yankee Pod and Yankee Stretch. This seems improbable, since both Yankee Pod ("Akson-1") Yankee Big Nose ("Akson-2") are the same sonar trials ship, K-403 "Kazan", wheras Yankee Stretch is K-411 "Orenburg", a mini-submarine mother ship. Different editions of Harpoon assign Yankee Stretch to both 09774 and 09780. The larger number of more authoritative sources support the 09774 Yankee Stretch and 09780 Yankee Pod nomenclature.
|09774||Delta IV Stretch||Podvig www /|
|09774||Yankee Stretch||deepstorm / Podvig / Harpoon / submarine.id.ru / wiki / CDP /|
|09774||Yankee Pod||wiki / hazegray /|
|09780||Yankee Stretch||warfare.ru / hazegray / Harpoon|
|09780||Yankee Pod||deepstorm / Podvig / Harpoon / CDP /|
|09786||Delta III Stretch||deepstorm / online / CDP /|
|09787||Delta IV Stretch||militaryrussia.ru|