Modular

Modular trawls represent constructions containing certain standard elements-modules.

At present four versions of designing modular trawls are being developed.

The first and the second versions of modular trawls allow reducing resistance and controlling the trawling speed. Among these are sectional modular trawls, modules of which are located in longitudinal and cross-sections over the surface of nets.

Sectional trawls (а.с. No. 648186, а.с. No.1203163) are based on the ‘herringbone’ of the following constructive solutions:

• Maximum use of longitudinal ropes for reducing trawl resistance;
• Arrangement of section both along and across the covering of the trawl in order to control the trawling speed;
• Use of additional side inserts for changing the shape of a trawl;
• Use of various combinations of standard elements in fish lines and trawl wings to make possible a form changeability of a trawl mouth.

Positive results were obtained in the course of introducing mid-water sectional rope trawls with longitudinal braces for vessels of BMRT, RTMS types 113/480 m and 134/576 m.

Thus, the trawling speed of the 78/448 m trawl on vessels of BMRT-type is by 0.8 knots higher, which allowed for a 20% increase in the catch.

The third version of a modular trawl а.с. 1340702 provides for a change of a trawl shape due to various numbers of modules plugged into upper and side panels.

The fourth version of a modular trawl is implemented through using changeable attachments (а.с. 1018607) adapted to the fishing volume and fishing zone and allows unifying front parts of a trawl.