MANNED SUBMERSIBLES, SENSOR SYSTEMS, AND EQUIPMENT

Most shallow submersibles were originally developed for offshore commercial projects to perform a wide variety of underwater tasks, including survey, inspection, construction, and search and recovery. A major portion of this work was related to the oil industry, although some shallow submersibles have been configured for science activities.

Table 2.1
Time and Space Sampling from Data Acquisition Platforms
(Modified from Dickey)

Scientific and research applications for manned submersibles generally increase as a function of depth. Extensive oceanographic and undersea research using manned submersibles was initiated in the early 1970s during Project FAMOUS (French-American Mid-Ocean Study) on the Mid-Atlantic Ridge at depths of 3,050 m (10,000 ft), during which over 100,000 photographs were made and nearly 1,300 kg (3,000 lbs) of carefully selected geological samples were collected by Alvin and two French submersibles. In addition, water samples were collected and a data logger was developed to automatically record depth, altitude, heading, and time (Karahl 1990). Since that time, numerous submersibles have been developed by various countries (specifically France, Russia, Japan, and the United States), including several having 6,000 m capability. The French and Russian scientific-type submersibles, consisting of the Cyana, Nautile, and Mir submersibles, will be described in the following section. Other Russian and Ukrainian submersibles are discussed in other chapters.

The French manned deep-sea submersibles Cyana (3,000 m) and Nautile (6,000 m) have conducted extensive subsea projects because of their manipulative capabilities and various work packages. A large variety of equipment has been developed for scientific purposes, including rock, sediment, water sampling, and in-situ measurements.

Nautile is a relatively low weight (18.5 tons), titanium-hulled submersible designed by IFREMER and DTCN, and has been used extensively for undersea research. It has two manipulators and a retractable sample basket. The high payload of 300 kg allows the installation of extra equipment, tools, and sampling capability. Sensors and instrumentation include Doppler log, pressure sensor, subbottom profiler, and sonar. To date, the Nautile has conducted approximately 700 dives with around 120 dives per year scheduled. Cyana has a single five-function manipulator and a sample basket with a 50 kg payload. Sensors and equipment include an echosounder and scanning sonar. Cyana has made approximately 1,500 dives.

Both French submersibles have a large variety of tools, equipment, and instruments to carry out complex operations and experiments. These include: water samplers, temperature and conductivity probes, a sediment corer, a hydraulic hammer for rocks, a rock corer, a vacuum sampler, a tracer injector, and miscellaneous cutting tools (Michel et al. 1989).

Russia and Ukraine presently own and operate 20 or more submersibles, and have several deep versions (two 4,000 m and one 6,000 m) under construction that have been delayed by funding. These are discussed in Chapter 4 of this report. Mir I and Mir II, among the world's deepest diving submersibles (6,000 m class), were delivered to the USSR Academy of Sciences by Rauma Oceanics of Tampere, Finland, in December 1987, when they underwent successful sea trials to 6,170 m.

These submersibles are constructed from high-strength maraging steel and have a 100 kWh battery capacity that provides extensive (in excess of 14 hours) on-bottom time, considerably longer than any other deep diving submersible. The Mir submersibles are effective platforms for deep water activities; each can be equipped with a wide range of scientific equipment and sensors, depending on intended use (Mikhaltsev 1989). Table 2.2 is a listing of sensors, samplers, and equipment. It is believed that most of the equipment and sensors were obtained from international suppliers. The collected data can be recorded by an integrated data acquisition and navigation recording system. Side scan sonar and a subbottom profiler provide geological information. It is the opinion of some scientists that the Mir submersibles and their support ship, the R/V Keldysh, comprise the best equipped and most capable research tool for deep-sea research (Johnson 1993).

Table 2.2
Mir Submersibles


Published: June 1994; WTEC Hyper-Librarian