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: 
WIRE FASTENERS 
(See description of same) 
KIND 
OF 
POvST 
No. Ebs. 
Required 
to Pull 
Fastener 
REMARKS 
Ordinary 1 % inch staple 
New 
Cedar 
425 
Average of 3 pulls. 
Staple was well driven into post. 
Single special tie 
Cement 
520 
Average of 2 pulls. Fence wire broke. 
Double tie 
Cement 
510 
Average of 2 pulls. Fence wire broke. 
Double staple 
Cement 
245 
Average of 3 pulls. Staples pulled. 
No. 14 wire 
plain single tie 
Cement 
115 
Average of 2 pulls. The wire untwisted. 
No. 14 wire around post 
Cement 
110 
Average of 3 pulls. The wire untwisted. 
Cast staple holder with 
ordinary 1 % inch staple 
driven into it 
Cement 
85 
Ave. of 2 pulls. Staple pulled out of holder. 
Cold shut-link in 
single staple 
Cement 
83 
Dink opened in every case. Ave. of 3 pulls. 
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. 
