GB300514A - Trawling gear for fishing at all depths - Google Patents

Abstract

300,514. Dahl, o., and V. D., Ltd. May 10, 1927. Trawling-gear.-A net or nets are connected to a towing device so as to operate at the surface or at a desired height from the sea-beds, the towing device comprising two shear boards E, E<1> or other spreading means, which are towed along the sea-bottom by two warps T, T'. The gear may comprise also a powerful float X or other lifting means connected to the shear boards or the like by cables V, V<1>, The net may be secured either directly (Fig. 10) or by one or two long cables (Figs. 2 and 3) to the warps T, T<1> or cables V, V<1>. As shown in Fig. 2, the cod-end of the net is secured to the cables V, V<1>. In another form of gear, the head rope of the net is secured to the warps T, T<1> and the ground rope is loaded and hangs freely. It is preferred to use spacing and lifting devices at the point of attachment of the net to the hawsers in order to prevent sagging of the hawsers. These devices, Fig. 5, comprise a vertical board 3 and inclined transverse boards 4 with the forward ends raised, braced together by wires 5. In order to ensure contact of the otter boards with the ground, they may have inclined wings or vanes c, Fig. 6, extending from the faces. In place of otter boards, they may be provided open-ended cylinders or prisms E<2>, Fig. 8, connected to the hawser Tt by unequal branches 9-11, 10-11, so as to be drawn along with the axis inclined to the direction of motion, or a ribbed conical roller E<3>, Fig. 9, mounted in a frame 13 with a roller 12 to prevent the frame from dragging on the ground. Specification 284,504* is referred to.