Hydrostat

hydrostat [′hī·drə‚stat]

(engineering)

humidistat

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Hydrostat 

an underwater apparatus that is lowered on a cable from a support vessel in order to conduct underwater research and work. Hydrostats are chambers constructed from strong materials, such as aluminum-magnesium alloys and fiberglass-reinforced plastics. They are usually spherical or cylindrical and large enough to accommodate one to three operators. A hydrostat with a cylindrical chamber was first built by Hartmann (USA) in 1911.

Present-day hydrostats are equipped with systems for air regeneration, devices for underwater observation, lighting equipment, scientific research instruments, and motion picture cameras. Cables are used to provide electric power and telephone communication. Hydrostats assigned to underwater work such as raising sunken ships have devices that fasten onto the work object and manipulators that are controlled from inside the hydrostat (for example, the work chambers RK-680 [USSR] and Discoverer [USA]). Sometimes hydrostats are equipped with a propeller, in order to permit limited movement while the chamber is submerged. Hydrostats now in use for deep-sea research include GG-57 and the observation chamber NK-300 (USSR) and the observation chamber Galeazzi (Italy). The maximum depth of submersion for present-day hydrostats is 300 m. Large-scale development of hydrostats for depths greater than 300 m is not expected in the future, since the lowering on a cable from a surface vessel limits the range of a hydrostat’s use. Hydrostats are now universally being replaced by autonomous apparatus and equipment.

REFERENCE

Diomidov, M. N., and A. N. Dmitriev. Pokorenie glubin. Leningrad, 1964.

N. P. CHIKER