278 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



DETAIL A MESH TAPER OF FRONT SECTION OF NET 

 B0TT0M(2) SIDES(2) TOP 



-150 



132- 



SUPPORT LINES V NYLON ^faA DOUBLE BRASS RINGS 



18"D1A DOUBLE RINGS 



/z MESH NYLON 244 MESHES LONG 

 ^ HUNG 2 1 ON HEADROPE ^-OOC- 



STRAMIN LINER 



4 



T 



'*> d07 NtlUN I/^NYLOnI— ' 6'-0- 



FRONT VIEW 



SIDE VIEW 



Figure 9.- — Construction details of tlie 10-foot Isaacs-Kidd trawl net. 



pressed to stainless rings (shown in detail "B," fig. 

 9). 



The midregion of the net, 7 feet 4 inches in 

 length, consists of a circular tapered section of 

 %-inch mesh No. 207 nylon, detachable from both 

 front section and cod end by a system of double 

 rings lashed together with No. 207 nylon twine. 

 Rings are of 14-inch brass rod, 24 inches in dia- 

 meter at the front of the section, 18 inches in 

 diameter at the after end. Four equally spaced 

 support lines of 3-strand ^i^-'mch nylon are eye- 

 spliced into a ring at each end of the section. 



The cod end is a circular tapering section, 10 feet 

 in length, of i/2-incli mesh No. 207 nylon. The last 

 6 feet of this section is lined with stramin, coarse 

 silk grit gauze, or fine-meshed nylon netting, which 

 is attached at its forward margin to the main net. 



Diving Vane 



Plans of the diving vane are shown in figure 10. 

 The body of the vane is formed of i/g-inch steel 

 plate, 24 inches in width and 10 feet 10 inches in 

 length, bent at the midpoint to form an angle of 

 140°. The leading edge (section A-A, fig. 10) is 

 reinforced by a 1 x 2-inch channel iron welded to 

 the underside of the plate. A streamlined entry 

 is formed by pressing a li/^-inch angle iron to 

 shape and welding it to the plate and chamiel as 

 shown. The leading edge is faired at the after- 

 side by a strip of i/g-inch plate 2 inches wide 

 welded to both the channel iron and the plate. All 

 of these welds are continuous and the entire lead- 

 ing edge assembly is made watertight to avoid cor- 

 rosion from the inside. Holes 34-inch in diameter 



