 Alvin in 1978, a year after first exploringhydrothermal vents. The rack hanging at the bow holds sample containers. | |
| History | |
|---|---|
 United States | |
| Name | Alvin |
| Namesake | Allyn Vine |
| Operator | Woods Hole Oceanographic Institution |
| Builder | General Mills' Electronics Group[1] |
| Acquired | May 26, 1964 |
| In service | June 5, 1964 |
| Status | in active service, as of 2024[ref] |
| General characteristics[2] | |
| Type | Deep-submergence vehicle |
| Displacement | 17 t (17long 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 | 2knots (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 crewed deep-ocean researchsubmersible owned by theUnited States Navy and operated by theWoods Hole Oceanographic Institution (WHOI) ofWoods Hole, Massachusetts. The original vehicle was built byGeneral Mills' Electronics Group[1] inMinneapolis, Minnesota. Named to honor the prime mover and creative inspiration for the vehicle,Allyn Vine,Alvin was commissioned on June 5, 1964.
The submersible is launched from the deep submergence support vesselRV Atlantis (AGOR-25), which is also owned by the U.S. Navy and operated by WHOI. The submersible has made more than 5,200 dives, carrying two scientists and a pilot, observing the lifeforms that must cope with super-pressures and move about in total darkness, as well as exploring thewreck ofTitanic. Research conducted byAlvin has been featured in nearly 2,000 scientific papers.
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Alvin was designed as a replacement forbathyscaphes and other less maneuverableoceanographic vehicles. Its more nimble design was made possible in part by the development ofsyntactic 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 6,500 metres (21,300 ft). The submersible features two robotic arms and can be fitted with mission-specific sampling and experimental gear. Theplug 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;[2] it is held in place by the pressure of the water above it.
In an emergency, if previous versions ofAlvin were stuck underwater with occupants inside, an upper part of the submersible including the titanium sphere could be released using controls inside the hull. This would then rise to the surface uncontrolled.[3] The current version of the vehicle uses releasable weights and emergency releases on jettisonable equipment.
Harold E. Froehlich was one of the principal designers ofAlvin.[4]
Alvin, first of itsship class ofdeep submergence vehicle (DSV), was built to dive to 2,440 metres (8,010 ft). Each of theAlvin-class DSVs have different depth capabilities. However,Alvin is the only one seconded to theNational Oceanic and Atmospheric Administration (NOAA), with the others staying with theUnited States Navy.
Alvin's first deep sea tests took place offAndros Island, the Bahamas, where it made a successful 12-hour, uncrewed tethered 7,500-foot (2,300 m) test dive. On July 20, 1965Alvin made its first 6,000-foot (1,800 m) crewed dive for the Navy to obtain certification.[1] On March 17, 1966,Alvin was used to locate a submerged 1.45-megatonhydrogen bomb lost in aUnited States Air Forcemidair accident overPalomares, Spain. The bomb, found resting on a steep slope nearly 2,500 ft (760 m) deep, was located byAlvin but the submersible had difficulty raising it up, initially causing it to fall deeper to 2,800 ft (850 m). The bomb was eventually raised intact on April 7 by aNavy CURV-I and the experience gained by theAlvin crew's 34 dives with over 220 hours logged led to new improvements to the vehicle's navigations systems.[5]On July 6, 1967, theAlvin was attacked by aswordfish during dive 202. The swordfish became trapped in theAlvin's skin. The attack took place at 2,000 feet (610 m) below the surface. The fish was recovered at the surface and cooked for dinner.[1] During Dive 209, on September 24, 1968Alvin found anF6F Hellcat, #42782, 125 miles southeast ofNantucket.[6] The aircraft had ditched September 30, 1944 during carrier qualifications, with the pilot surviving.[1]
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Alvin, aboard the Navy tender shipLulu, was lost as it was being transported on October 26, 1968.Lulu, a vessel created from a pair of decommissioned U.S. Navypontoon boats with a support structure added on, was loweringAlvin over the side when two steel cables snapped. There were three crew members aboardAlvin at the time, and the hatch was open. Situated between the pontoons with no deck underneath,Alvin entered the water and rapidly began to sink. The three crew members managed to escape, butAlvin flooded and sank in 1,500 m (4,900 ft) of water in theAtlantic Ocean at approximately39°53′30″N069°15′30″W / 39.89167°N 69.25833°W /39.89167; -69.25833 ("DSVAlvin"), about 88nautical miles (101 mi; 163 km) south ofNantucket Island.[7]
Severe weather prevented the recovery ofAlvin throughout late 1968, but it was photographed at the bottom of the Atlantic Ocean in June 1969 by a sled towed byUSSMizar.Alvin was found to be upright and appeared intact except for damage to the stern. It was decided to attempt recovery; although no object ofAlvin's size had ever been recovered from a depth of 5,000 feet (1,500 m), recovery was "deemed to be within the state of the art". In August 1969, theAluminaut, a DSV built byReynolds Metals Company, descended toAlvin but had trouble attaching the required lines, and side effects fromHurricane Camille were producing worsening weather, causing the team to return to Woods Hole to regroup. The second attempt started on August 27, andAluminaut was able to secure a line and safety slings toAlvin and wrap a nylon net around its hull, allowing it to be hauled up byMizar.Alvin was towed, submerged at 40 feet (12 m), at a speed of 2 knots (3.7 km/h), back to Woods Hole.[7]
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In 1973,Alvin's pressure hull was replaced by a newer titanium pressure hull. The new hull extended the submersible's depth rating.[8]: p36 [clarification needed]
With a new, stronger pressure hullAlvin could now reach the floor of the rift valley of this seafloor spreading center. In the summer of 1974 American and French scientists joined inProject FAMOUS to explore the creation of new sea floor at this spreading center.[9][10] The French provided submersiblesArchimède andCYANA. A total of forty-four dives were completed that succeeded in defining the crustal accretion zone[11] in the floor of the rift valley.[12]
Marine geologists usingAlvin in thePacific Ocean discovered deep-seahydrothermal vents and associated biologic communities during two expeditions to oceanspreading centers. In 1977 scientists inAlvin discovered low temperature (~20 °C) vents on theGalapagos spreading center east of those same islands.[13] During theRISE expedition in 1979 scientists usingAlvin discovered high temperature vents (380 °C) popularly known as ‘black smokers’ on the crest of theEast Pacific Rise at 21° N.[14] These discoveries revealed deep-sea ecosystems that exist without sunlight and are based onchemosynthesis.[13]
Alvin was involved in the exploration of the wreckage ofRMS Titanic in 1986. Launched from her support shipRV Atlantis II, she carried Dr.Robert Ballard and two companions to the wreckage of theWhite Star LinerTitanic, which sank in 1912 after striking aniceberg while crossing the North Atlantic Ocean on her maiden voyage.
Alvin, accompanied by a smallremotely operated vehicle (ROV) namedJason Jr., was able to conduct detailed photographic surveys and inspections ofTitanic's wreckage. Many of the photographs of the expedition have been published in the magazine of theNational Geographic Society, which was a major sponsor of the expedition.
The Woods Hole Oceanographic Institution team involved in theTitanic expedition also explored the wreck of theUSS Scorpion (SSN-589), aSkipjack-classsubmarine armed withnuclear torpedoes, which sank off the coast of the Azores in 1968 in uncertain circumstances.Alvin obtained photographic and other environmental monitoring data from the remains ofScorpion.
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Over the years,Alvin has undergone many overhauls to improve its equipment and extend its lifetime. In 2001, among other equipment, motor controllers and computer systems were added. The currentAlvin is the same as the original vessel in name and general design only. All components of the vessel, including the frame and personnel sphere, have been replaced at least once.Alvin is completely disassembled every three to five years for a complete inspection.[15] A new robotic arm was added in 2006.
In June 2008 construction started on a stronger, slightly larger personnel sphere which was used to upgradeAlvin, before being used in an entirely new vehicle.[16] The new sphere was designed, and then forged from solid titanium ingots in two equal halves at Ladish Forge,Cudahy, Wisconsin. Then the 15.5 tonnes of titanium was machined and assembled, utilizing five view ports (instead of the previous three) and is designed for depths of over 6,000 m (20,000 ft), whereAlvin's original depth limit was 4,500 m (14,800 ft).[17] This, along with a general upgrade of support systems, instruments and materials. These upgrades allowAlvin to reach 98% of the ocean floor.[18]
After one last dive to assess damage to theGulf of Mexico's seafloor after theDeepwater Horizon disaster,Alvin was refitted further, starting January 2011.[19] Alvin began an extensive rebuild, which featured new cameras, lighting, and an enlarged titanium personnel sphere. This three-and-a-half-year effort to upgrade the vessel implemented the core infrastructure to eventually increase its depth capability from 4,500 meters (14,800 ft) to 6,500 meters (21,300 ft).[20] In 2014, an extensively refittedAlvin conducted verification testing in the Gulf of Mexico, and was certified to return to service.[21][22] In March and April 2014,Alvin was used to explore the site of the 2010 Deepwater Horizon oil spill.[23]
Starting in 2020, the second phase to upgrade Alvin for 6,500 meters (21,300 ft) operation began; the 2014 rebuild with new, larger titanium, personnel hull and rebuilt structural frame being the first phase. In this phase, Alvin received new titanium ballast spheres, a second Schilling manipulator arm, a 4K imaging system, several new syntactic foam modules, an upgrade to the hydraulic system, and new thrusters. During 2022, Alvin successfully completed sea trials and was certified for operating down to 6500 meters.[20]
As of 2024,Alvin is in active service, operated by the Woods Hole Oceanographic Institution. The research shipRVAtlantis serves as its support ship.[24]
Like most deep submergence vehicles,Alvin is normally transported on board its support vessel. It is launched shortly before a dive, and recovered after the dive, using a suitablelaunch and recovery system (LARS) mounted on the support vessel. The support vessel is usually theR/VAtlantis, but several others have been used.
Alvin uses four 208-pound (94 kg) steel weights (~1.7 cubic feet of steel) to provide negative buoyancy for the trip to the ocean floor.Alvin contains aballast and trim system, but the steel weights allow deep dives to be achieved more rapidly. These weights are jettisoned on each dive and left at the bottom.[25][26]
Shipwrecks and maritime incidents in 1968 | |
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| Other incidents |
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| National | |
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