FISH TRAWLING DEVICE Russian patent published in 1995 - IPC

FIELD: commercial fishing. SUBSTANCE: trawl towed by the trawler is comprised of a net bag with mouth and coded parts, and an acoustic radiator connected thereto. The fish-blocking acoustic field built up by the radiator in the form of a conical surface with the internal (central) angle embraces the perimeter of the net bag mouth and the water zone in front of the net bag. Two deflecting apparatuses towed at the opposite sides of the trawler have acoustic radiator with the antenna direction pattern in the form of a half-disc oriented towards the sea bed. The antenna turning angle in a horizontal plane relative to the diametral plane of the trawler ensures that the total angle between the horizontal axes of the direction patterns of acoustic radiator antennas of the deflecting apparatuses on both ship's sides should be directed towards the trawl and be numerically equal to, or somewhat smaller than, the internal angle of the fish-blocking field of the trawl acoustic radiator. The transverse distances between the trawler and each deflecting apparatus are determined by taking in account the inclined distance between the trawler and the acoustic radiator of the trawl and of the internal angle of the fish-blocking field of the trawl acoustic radiator. EFFECT: improved design. 2 dwg