io THE; COLORADO EXPERIMENT STATION 



body of the tie wire after the wraps have been made. This is known 

 as the "special tie." 



The strongest and perhaps the most satisfactory system of 

 tying in the wire is the "double tie." The tie wire is bent into the 

 form of a long staple, straddled over the line wire and both ends 

 passed through a hole in the post. One end is brought to either 

 side and wrapped about the line wire at the face of the post. This 

 system insures a solid fastening and is equal in strength to any 

 ordinary wood post fastening. 



The holes in the posts are formed by No. 6 wires being placed 

 in the post while it is soft. These wires are called "Tie Hole Pins." 

 (See Fig. i.) They are removed from the poured post after the 

 cement has set for 24 hours. The pins are removed from the 

 tamped posts immediately before the molds are removed. 



The following table shows the comparative holding strength 

 of various wire fasteners, as determined by the tests : 



Taper of Posts. To obtain the maximum strength with 

 the least amount of material, the cement post must be so shaped 

 as to have its greatest strength at the ground line. 



By making the post of uniform size from the base to the 

 ground line, no material is wasted. The post may then be tapered 

 from the ground line to the top. It has been found that in a 5-inch 

 post which projects 4 feet above the ground, a taper of one inch on 

 each side from the ground line to the top, insures almost equal 

 strength throughout. This design gives more strength with less 

 material than those with the continuous taper. 



