DSV Alvin

Alvin in 1978, a year after first exploring hydrothermal vents. The rack hanging at the bow holds sample containers.
History
United States
Name:	Alvin
Namesake:	Allyn Vine
Operator:	Woods Hole Oceanographic Institution
Builder:	Litton Systems
Acquired:	26 May 1964
In service:	5 June 1964
Status:	in active service, as of 2016[ref]
General characteristics
Type:	Deep-submergence vehicle
Tonnage:	17 t (17 long tons)
Length:	7.1 m (23 ft 4 in)
Beam:	2.6 m (8 ft 6 in)
Height:	3.7 m (12 ft 2 in)
Draft:	2.3 m (7 ft 7 in)
Speed:	2 knots (3.7 km/h; 2.3 mph)
Range:	5 km (3.1 mi)
Endurance:	72 hours with 3 crew
Test depth:	6,500 m (21,300 ft)
Capacity:	680 kg (1,500 lb) payload
Crew:	3 (1 pilot, 2 scientific observers)

Alvin (DSV-2) is a manned deep-ocean research submersible owned by the United States Navy and operated by the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, Massachusetts. The vehicle was built by General Mills' Electronics Group in Minneapolis, Minnesota. Named to honor the prime mover and creative inspiration for the vehicle, Allyn Vine, Alvin was commissioned on 5 June 1964. The submersible is launched from the deep submergence support vessel RV Atlantis (AGOR-25), which is also owned by the U.S. Navy and operated by WHOI. The submersible has made more than 4,400 dives, carrying two scientists and a pilot, to observe the lifeforms that must cope with super-pressures and move about in total darkness, as well as exploring the wreck of Titanic. Research conducted by Alvin has been featured in nearly 2,000 scientific papers.

Alvin was designed as a replacement for bathyscaphes and other less maneuverable oceanographic vehicles. Its more nimble design was made possible in part by the development of syntactic foam, which is buoyant and yet strong enough to serve as a structural material at great depths.

The vessel weighs 17 tons. It allows for two scientists and one pilot to dive for up to nine hours at 4,500 meters (14,800 ft). The submersible features two robotic arms and can be fitted with mission-specific sampling and experimental gear. The plug hatch of the vessel is 0.48 m (1 ft 7 in) in diameter and somewhat thicker than the 2-inch (51 mm) thick titanium sphere pressure hull; it is held in place by the pressure of the water above it.

In an emergency, if Alvin were stuck underwater with occupants inside, the outer body, or cladding, of the submersible could be released and discarded using controls inside the hull. The titanium sphere would then rise to the surface uncontrolled.