Table 1 .-Pole circumference SF (safety factors)
Original
circumference
Reduced circumference
(inches)
(inches)
SF4
SF3.5
SF 3
SF2.65
SF2.5
SF2
SF1.5
30.0
28.7
27.3
26.1
25.6
23.8
21.6
31.0
29.7
28.2
27.0
26.5
24.6
22.3
32.0
30.6
29.1
27.9
27.4
25.4
23.0
33.0
31.6
30.0
28.8
28.2
26.2
23.8
34.0
32.5
30.9
29.6
29.1
27.0
24.5
35.0
33.5
31.8
30.5
29.9
27.8
25.2
36.0
34.4
32.7
31.4
30.8
28.6
25.9
37.0
35.4
33.6
32.3
31.6
29.4
26.6
38.0
36.3
34.5
33.1
32.5
30.2
27.4
39.0
37.3
35.4
34.0
33.3
31.0
28.1
40.0
38.3
36.3
34.9
34.2
31.8
28.8
41.0
39.2
37.3
35.7
35.1
32.5
29.5
42.0
40.2
38.2
36.6
35.9
33.3
30.2
43.0
41.1
39.1
37.5
36.8
34.1
31.0
44.0
42.1
40.0
38.4
37.6
34.9
31.7
45.0
43.0
40.9
39.2
38.5
35.7
32.4
46.0
44.0
41.8
40.1
39.3
36.5
33.1
47.0
45.0
42.7
41.0
40.2
37.3
33.8
48.0
45.9
43.6
41.8
41.0
38.1
34.6
49.0
46.9
44.5
42.7
41.9
38.9
35.3
50.0
47.8
45.4
43.6
42.7
39.7
36.0
51.0
48.8
46.3
44.5
43.6
40.5
38.7
52.0
49.7
47.2
45.3
44.5
41.3
37.4
53.0
50.7
48.2
46.2
45.3
42.1
38.2
54.0
51.6
49.1
47.1
48.2
42.9
38.9
55.0
52.6
50.0
47.9
47.0
43.7
39.6
56.0
53.6
50.9
46.8
47.9
44.4
40.3
57.0
54.5
51.8
49.7
48.7
45.2
41.0
58.0
55.5
52.7
50.6
49.6
46.0
41.8
59.0
56.4
53.6
51.4
50.4
46.8
42.5
60.0
57.4
54.5
52.3
51.3
47.6
43.2
PERMISSIBLE REDUCED CIRCUMFERENCE SAFETY FACTORS
No single pole shall have SF less then 2.65
No H-structure shall have SF less than 2.65 and no pole shall have SF less than 2.
For H-structures, add the SF's for each pole and divide by 2 to obtain the structure SE For tension-type
structures (dead ends), no pole shall have SF less than 2.65.
No H-structure shall have SF less than 2.65 and no pole shall have SF less than 2.
For H-structures, add the SF's for each pole and divide by 2 to obtain the structure SE For tension-type
structures (dead ends), no pole shall have SF less than 2.65.
reduction is determined, subtract it from the
original (SF 4) circumference to arrive at the
reduced cimumferences against table 1.
original (SF 4) circumference to arrive at the
reduced cimumferences against table 1.
For more than one external decay pocket,
determine the reduction for each
determine the reduction for each
pocketseparately and add them to get the total
reduction.
reduction.
5.3.3. Hollow heart. - When hollow heart is
found, determine the shell thickness and
found, determine the shell thickness and
(FIST 4 - 6)
10