GB729114A - Improvements in or relating to apparatus for spreading and controlling trawl nets and the like - Google Patents

Abstract

729,114. Trawl boards. CHANT, J. Feb. 1, 1951 [Aug. 24, 1950], No. 21001/50. Class 48: A trawl board consists of a plurality of sealed air tubes 9 assembled within a frame to form a corrugated surface, on each side of the board, at least some of the tubes being removably supported in the frame. The frame is rectangular and is formed by a sealed head tube 2 and an open-ended keel tube 1, both tubes being bent at their forward portions and butt welded at 3. Transverse plates are welded to the head and keel tubes, two 7, 8 at the front, one 6 at the middle and two 4, 5 at the rear of the board. The sealed air tubes forming the surfaces of the board are disposed with their ends located between the front and rear transverse plates and are held in position by an end plate 10 pivoted to the rear transverse plates and held in closed position by a bolt 14. The rear transverse plates 4, 5 and the end plate 10 may be replaced by a plate of U-section pivoted to the keel tube. Two sealed air tubes 9a disposed on opposite sides of the longitudinal centre line of the board are welded to the head and keel tubes and to the transverse plates 4, 5, 6 and each is provided with three cleat plates 15, 16, 17 extending through the tube and apertured on both sides of the board for the reception of pins 18 for connecting V-shaped frames 19, 20 to the board. The two tubes 9a may be at equal or unequal distances from the longitudinal centre line of the board and the legs of the V-frames may be unequal or equal. Two sealed air tubes 9b adjacent the keel tube may be divided by partitions 25 into forward and rear compartments which may be flooded at will. The keel tube, the head tube and the two sealed air tubes 9a carrying the cleat plates are made of heavier gauge than the other tubes. The keel tube may be replaced by a solid bar. Specification 625,083 is referred to.