Deep-submergence vehicle

Deep Submergence Vehicles are deep diving manned submarines that are self-propelled. The term "DSV" is generally one used by the United States Navy, though several navies operate vehicles that can be accurately described as DSVs. DSVs are commonly divided into two types: research DSVs, which are used for exploration and surveying, and DSRVs (Deep Submergence Rescue Vehicle), which can be used for rescuing the crew of a sunken submarine and/or clandestine (espionage) missions. DSRV type vessels are equipped with docking chambers to allow personnel ingress/egress via a manhole.

The real-life feasibility of any DSRV-based rescue attempt is hotly debated, because the few available docking chambers of a stricken submarine may be flooded, trapping the sailors still alive in other dry compartments. Because of these difficulties, the use of integrated crew escape capsules and/or detachable conning tower has gained favour in military submarine design during the last two decades and most DSRV are now primarily relegated to clandestine missions and undersea military equipment maintenance, if at all. The rapid development of safe, cost-saving ROV technology has also rendered some DSV vessels obsolete.

Strictly speaking bathyscaphes are not submarines because they have minimal mobility and are built like a balloon, using a habitable spherical pressure vessel hung under a liquid hydrocarbon filled float drum. In a DSV/DSRV type vehicle the passenger compartment and the ballast tank functionality is incorporated into a single structure to afford more habitable space (up to 24 people in the case of a DSRV rescue vehicle).

Most DSV/DSRV vehicles are powered by traditional electric battery propulsion and have very limited endurance. Plans have been made to equip DSVs with closed circuit internal combustion powerplants (LOX Stirling engines) but none have been realized so far, due to cost and maintenance considerations. All DSV vehicles are dependent upon a surface support ship or a mother submarine, that can piggyback or tow them (in case of the NR-1) to the scene of operations. Some DSRV vessels are air transportable in very large military cargo planes to speed up deployment in case of emergency rescue missions.

List of Deep Submergence Vehicles

Trieste class bathyscaphe

* FNRS-2 - the predecessor to Trieste
* DSV-0 Trieste — the "X-1 Trieste" bathyscaphe has reached Challenger Deep, the world's deepest seabed. It was retired in 1966 [http://www.history.navy.mil/danfs/t8/trieste.htm]
* DSV-1 X-2 Trieste II — an updated bathyscathe (or bathyscaph) design, participated in clandestine missions, it was retired in 1984 [http://www.history.navy.mil/danfs/t8/trieste_ii.htm] [http://www.nvr.navy.mil/nvrservicecraft/details/DSV1.htm]
* Bathyscaphe Archimede — French-made bathyscaphe, operated around the time of the Trieste.

Alvin class submarine

"Alvin", owned by the Office of Naval Research (ONR) is operated under agreement by the National Deep Submergence Facility at the Woods Hole Oceanographic Institution (WHOI), where it conducts science oriented missions funded by the National Science Foundation (NSF), National Oceanic and Atmospheric Administration (NOAA) and ONR. "Alvin" has a maximum depth capability of 4500 meters and operates from R/V "Atlantas", an AGOR-23 class vessel owned by the ONR and operated by WHOI under a charter party agreement. The NSF has committed to the construction of a replacement sub with enhanced capabilities and 6500 meter depth capability to replace "Alvin", which will be retired upon its completion.

* DSV-2 Alvin — a deep diving sub, has 4500 meter depth capability, WHOI [http://www.nvr.navy.mil/nvrservicecraft/details/DSV2.htm]
* DSV-3 Turtle — Alvin's identical sibling, retired 1998, USN [http://www.nvr.navy.mil/nvrservicecraft/details/DSV3.htm]
* DSV-4 Sea Cliff — another Alvin class DSV sub, retired 1998, returned to active service on September 30, 2002, Sea Cliff has 6000 meter depth capability, USN [http://www.nvr.navy.mil/nvrservicecraft/details/DSV4.htm]
* DSV-5 Nemo — another Alvin class DSV sub, retired 1998, USN [http://www.nvr.navy.mil/nvrservicecraft/details/DSV5.htm]

Nerwin class DSVN

* NR-1 Nerwin — US Navy nuclear powered research and clandestine DSV submarine, which can roll on the seabed using large balloon wheels [http://www.chinfo.navy.mil/navpalib/factfile/ships/ship-nr1.html]

Aluminaut

* Aluminaut — a DSV made completely of aluminum by the Reynolds Metals Aluminum Company, for the US Navy, once held the submarine deep diving record [http://www.smv.org/info/aluminautEX.htm] . It is no longer operational.

Priz

* Priz — a DSRV class of five ships built by the USSR and Russia. The titanium-hulled Priz class are capable of diving to 1000 meters. These mini-submarines can ferry up to 20 people for very brief periods of time (in case of a rescue mission) or operate submerged for two to three days with a regular crew of three to four specialists. In early 2005, the Russian AS-28 Priz vessel was trapped undersea and subsequently freed by a British ROV in a successful international rescue effort.

Mir

* Mir — a strictly civilian (research) class of two DSVs which were manufactured in Finland for the USSR. These bathyschape-derived vessels can carry three people down to depths of 6000 meters. After visiting and filming the RMS Titanic's wreck, two Mir submersibles and their support ship were loaned to a US Pacific trench surveying mission in the late 1990s and made important discoveries concerning sulphuric based life in "black smokers".

hinkai

*Shinkai — JAMSTEC (Japan Agency for Marine-Earth Science and Technology) operates a DSV-series called Shinkai ("Deep Sea"). The latest DSV is Shinkai6500 which can submerge to 6500 m with three crew members. JAMSTEC was operating a ROV called Kaiko, which was able to submerge to 11 000 m, but was lost at sea in May 2003.

External links

* http://users.skynet.be/RonSubCovers/DSRV/USA%20DSRV%20Index.htm
* http://ussubvetsofworldwarii.org/ss_submarines/submarinelist.html
* http://www.nvr.navy.mil/nvrservicecraft/c_DSV.htm
* http://www.nvr.navy.mil/nvrservicecraft/c_DSRV.htm
* http://www.chinfo.navy.mil/navpalib/factfile/ships/ship-dsrv.html
* http://www.jamstec.go.jp/jamstec-e/ships/index.html