Methods for the Theoretical Calculation of Wing and Door Spread of Bottom Trawls

Source - Journal of Northwest Atlantic Fishery Science, Volume 16: 41-48
ISSN-0250-6408

 

Dalmendray Gómez, J. and Valdés Jiménez, J.R. 1994. Methods for the Theoretical Calculation of Wing and Door Spread of Bottom Trawls. J. Northw. Atl. Fish. Sci. 16: 41-48. https://doi.org/10.2960/J.v16.a4

 

Baranov's (1969) and Carrothers' (1980) methods of theoretical calculation of trawl door spread and methods to calculate the wing spread are discussed. Baranov's formula was simplified and a correlation between the net drag of the trawls (as a measure of the system's size), and the differences between the measured values of door spread and its calculation by Baranov's equation was found, thus making it more accurate. For four-fifths of trawl nets under study the value of those differences were below 7%. It was evident that Baranov's formula fitted better than that of Carrothers' for the experimental door spread values of the sample. An empirical formula is proposed for estimating wing spread of bottom trawls. The differences between calculated and measured wing spread values are under 17% in 90% of cases. Since the order of accuracy obtained with described formulae is within the range of variation of experimental results, the level of agreement is felt to be acceptable.

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Language - English
Publisher - Northwest Atlantic Fisheries Organization (NAFO), Dartmouth, N.S., Canada
Publication Date - July 1994
Publication Type - Journal Article

Citation: Dalmendray Gómez, J. and Valdés Jiménez, J.R. 1994. Methods for the Theoretical Calculation of Wing and Door Spread of Bottom Trawls. J. Northw. Atl. Fish. Sci. 16: 41-48. https://doi.org/10.2960/J.v16.a4