| 摘要 |
By a trawl door (1) with a principally rectangular, preferably angularly shaped plate (2) and with adjustable hatches for adjusting the active surface areas of the trawl door the adjustable hatches have been placed at each side of a central longitudinal axis of the plate (2), a smallest hatch (10) being positioned at the middle of the lowermost portion (6) of the plate (2) in operation, and a hatch (18) with a size of about the double being positioned at the middle of the upper portion (4) of the plate (2). Hereby an almost universal trawl door is obtained which can easily be readjusted for almost any thinkable fishery, since the trawl door (1) with completely closed hatches (10, 18) gives a maximal spreading and a minimal spreading by completely open hatches. |
