of Trawl Design Parameters
is meant for calculations in the process of design of
rope-net section of pelagic and bottom trawls. The
Programme accounts for peculiarities of species
behaviour, trawler traction force and general fishing
conditions. Design procedure is based on parameters of a
prototype gear and ground dynamic parameters.
The Programme is used at pre-design and design stages of
construction. It provides the following procedures:
- substantiation of the main parameters of a new trawl on
the basis of behaviour and distribution of targeted
species and conditions of operation;
- investigation of possibilities of adjusting already
existing trawls for the new conditions of operation;
- choice of the most suitable prototype (from the existing
Data Base); alterations to a trawl design (procedure of
adding or removing net plates, alteration of their
dimensions, trying different mesh-size of nets);
- calculation of main design parameters on the basis of
corresponding parameters of a prototype trawl; precision
of calculations is determined by structural and
geometrical similarity of a designed trawl and its
- obtaining a number of versions of a designed trawl
configuration and choice of the optimum model on the
basis of the criterion of the effectively trawled volume
of water or catchibility coefficient;
- calculation of geometrical and physical parameters of the
trawler-otter boards-trawl system for identification of
the necessary spreading force of a trawl board at
specified speed of trawling.
The programme supports an open Data Base of the existing
trawls (used as prototypes) and trawl designs, as well as
traction values of different trawlers. It provides graphic
interface for work with drawings of trawl tailoring. It provides
the following calculations:
- identification of the parameters of a designed trawl
mouth, providing specified probability of overlapping of
its area with the area of a fish shoal lateral
- calculation of combinations of main trawl parameters
(size, speed, resistance, weighted mean diameter of
twines and ropes) on the basis of trawler traction;
- calculation of trawl parameters, providing equal
catchibility of a prototype and a new trawl;
- calculation of main parameters (speed, loading of
footrope, moving horizon) of a deep-water trawl;
- choice of models, satisfying requirements determined by
peculiarities fish behaviour and optimum in relation to
- calculation and visualisation of the interconnection of
the system vessel-warp-otter boards-cable-trawl.
The programme is run in Windows 3.1 environment and has a
friendly interface, meant for engineers. Dialogues for entering
data are supplied with the schemes, explaining the essence of
required values. The results of calculations are shown on
Image 1: Entering
structural and geometrical parameters of a prototype trawl.
Image 2: Calculation
of main trawl parameters, provided by trawler's traction.
Image 3: Calculation
of acting forces and position of otter boards and trawl in a
specified mode of operation.
Upload the demo version of the
CAD/CAM Laboratory, Commercial Fisheries Dpt.
of Kaliningrad State Technical
University for Fisheries.
Russia, 236000 Kaliningrad , Sovietsky procpect 1,
Phone +7(0112)463818. BBS/Fax +7(0112)465487,
FIDONet 2:478/3 Fishwar BBS.