Research Vessels: Submersibles - ALVIN

Submersibles are a great scientific tool to help researchers explore the ocean depths. They are small submarines that can maneuver underwater easier than larger submarines. Submersibles are equiped with viewports (windows), searchlights, mechanical arms, cameras and scientific instruments that enable seeing and recording data from underwater vehicles.

Perhaps ONR's most famous submersible is ALVIN, a three-person deep submergence vessel (DSV). Among some of its most memorable missions are discovery of deep-sea hydrothermal vents and recovery of a missing H-bomb. ONR funded the development of ALVIN in 1962 for almost $10 million.

ALVIN was named for Allyn Vine, a Woods Hole Oceanographic Institution (WHOI) oceanographer. ALVIN was built with ONR money and is now used by WHOI scientists.

In 1966, the two-year-old ALVIN was presented with its first difficult task. A 20 mega-ton H-bomb was lost off the Spanish Coast in the Mediterranean Sea after two planes collided. Three other subs, including the U.S. Navy's Deep Jeep, newspaper publisher John H. Perry Jr.'s PC-3B and J. Louis Reynold's Aluminaut, also participated in the search for the missing bomb. Despite the competition, it was ALVIN that located the bomb resting below 2,500 feet of water.

Then, in August of 1968, tragedy struck. ALVIN was lost. As the DSV was being placed into the water a few hundred miles off Cape Cod, a cable holding it up broke. Luckily, the men inside were able to escape through the open hatch before ALVIN sank 5,500 feet to the bottom. After spending 11 months on the ocean floor, ALVIN was located by sonar. Aluminaut placed a hook inside ALVIN's open hatch and towed it to the surface. ALVIN was back in shape and diving again before the end of 1970.

When ALVIN was first built, its pressure hull was made with steel, and it could only dive 6,000 feet. In 1973, ALVIN was rebuilt with a titanium hull making it possible to reach depths of 13,124 feet (4,000 meters).

ALVIN has three video cameras, two still cameras, 12 lights and two hydraulic robot arms. A basket found on the front of the submersible carries scientific instruments.

Today, ALVIN makes between 150 and 200 dives each year and has more than 3,200 dives on record. Its support ship, required to tote it to study sites and provide support, is the catamaran R/V Atlantis II, which holds up to 27 crew members, 19 scientists and 9 ALVIN crew members.