Seaching Deeper

This article presents the history of Alvin, the first US-built, manned deep-ocean submersible. The 42-year-old submersible, which is operated by the Woods Hole Oceanographic Institute is heading toward retirement. According to one of the expert, Alvin had one of its periodic overhauls recently; however, the craft cannot be upgraded to do much more than it does now. In its lifetime, the little submersible has located a lost hydrogen bomb in the Mediterranean Sea, explored deep-sea hydrothermal vents, surveyed and helped photograph the Titanic, and accidently gave scientists vital feedback about decay in the deep. Alvin has made more than 4000 dives. On a 1977 expedition, researchers aboard Alvin near the Galapagos Islands explored vents emitting superheated water at depths of 7000 feet. The lunches that spent the months in Alvin's hold remained strangely intact, including a barely decomposed bologna sandwich. This led researchers to the discovery that matter decomposed differently in the deep, which in turn gave conservationists arguments against dumping waste in the sea.

Development and Testing of an A-Sized Rapidly Deployable Navigation and Communication GATEWAY Buoy

A rapidly deployable, intelligent GATEWAY buoy system, capable of both air and sea deployment, has been developed to aid in the navigation and communication of Autonomous Underwater Vehicles (AUVs). The device is based around the A-sized (sonobuoy) standard and is deployable from aircraft, helicopters, ships and submarines using pressure and gravity launch tubes or charge-activated devices. The system consists of Florida Atlantic University (FAU) and Woods Hole Oceanographic Institute (WHOI) acoustic modems, both capable of providing Long Base Line (LBL) positioning, Global Positioning System (GPS) Wide Area Augmentation System (WAAS), and Radio Frequency (RF) communications. It utilizes a combined parachute and anchor, a low drag inflatable buoy, and an intelligent scope-adjusting mooring line spool. The design is based around a “fire-and-forget” methodology which, when the system is turned on and launched, requires no initial knowledge of the operating environment. The interoperable acoustic communication (ACOMMS) system can be operated at ranges up to 3000 meters and can achieve a true data rate of up to 860 bits-per-second using reliable spread-spectrum frequency modulation. The LBL positioning system operates sequentially and does not preclude acoustic communications. Switching between protocols (FAU or WHOI) is achieved through an automated process or is requested via RF commands. The mechanical system is modular and compact. The system is capable of operating in depths between 5 m and 200 m, in conditions up to sea state 3, and in currents up to 1.5 m/s. The mooring is versatile and able to hold in bottom types ranging from mud and sand to broken rock and reef.

The Bismarck Encounter

The authors of this paper have been fortunate to have had the opportunity to assist Dr. Robert Ballard of Woods Hole Oceanographic Institute and the Quest Group in the discovery and analysis of the Bismarck wreck in June 1989. Although we did not participate in Dr. Ballard's expedition aboard the Star Hercules, we gave advice and counsel to his personnel and did much of the photo interpretation. We were greatly aided by two of the Bismarck survivors, former German Ambassador Baron von M(Jllenheim-Rechberg (former LCDR, German Navy), the senior surviving officer, whom we assisted in the republishing of his book, and Mr. Josef Statz, who was the sole survivor from the Damage Control Central on the Bismarck[1]. 3 These two men worked tirelessly with the authors and assisted in the preparation of drawings by Mr. Thomas Webb of various views of the damaged Bismarck, which shows her just before her capsizing. These views of the damaged Bismarck were prepared after many hours of intensive study of the videotapes and still photography brought back by Dr. Ballard's team from the wreck site some 15 317 ft below the water surface, 600 miles west of Brest, France. A number of these views have been published in various magazine articles and books [2–5].