The sign blank and its mounting hardware become a structural component of the sign assembly upon impact. Slip base and frangible coupler designs of multiple-sign-support systems require the sign panel hardware, and the upright signposts, to provide the
|
TABLE 7.15 Bolt-Tightening Specifications for Slip Base Design
|
a.
|
Specifications
|
in U. S. Customary units
|
|
|
Post size,
|
Bolt
|
Clamping
|
Torque,
|
|
in X lb/ft
|
size, in
|
force, lb
|
ftlb
|
|
S3 X 5.7
|
K
|
920-1380
|
7-11
|
|
S4 X 7.7
|
К
|
920-1380
|
7-11
|
|
W6 X 8.5
|
5-8
|
1740-2660
|
17-19
|
|
W6 X 12
|
5-8
|
1740-2660
|
17-19
|
|
W6 X 15.5
|
5-8
|
1740-2660
|
17-19
|
|
W8 X 17
|
5-8
|
1740-2660
|
17-19
|
|
W8 X 20
|
5-8
|
2400-3600
|
17-19
|
|
W10 X 21
|
5-8
|
2400-3600
|
31-46
|
|
W10 X 25
|
5-8 or 5-8
|
2400-3600
|
31-46
|
|
W12 X 27
|
3-4 or 7-8
|
2400-3600
|
31-46
|
|
>30 lb/ft
|
1
|
2400-3600
|
44-55
|
|
b. Specifications in SI units
|
|
Post size,
|
Bolt
|
Clamping
|
Torque,
|
|
mm X kg/m
|
size, mm
|
force, N
|
N-m
|
|
S76 X 8
|
14
|
4092-6139
|
10-15
|
|
S100 X 11
|
14
|
4092-6139
|
10-15
|
|
W150 X 13
|
16
|
7740-11,832
|
23-25
|
|
W150 X 18
|
16
|
7740-11,832
|
23-25
|
|
W150 X 23
|
16
|
7740-11,832
|
23-25
|
|
W200 X 25
|
16
|
7740-11,832
|
23-25
|
|
W200 X 30
|
16
|
10,676-16,014
|
23-25
|
|
W254 X 31
|
20 or 22
|
10,676-16,014
|
42-62
|
|
W254 X 37
|
20 or 22
|
10,676-16,014
|
42-62
|
|
W305 X 40
|
20 or 22
|
10,676-16,014
|
42-62
|
|
> 45 kg/m
|
27
|
10,676-16,014
|
60-75
|
|
|
FIGURE 7.51 Design of friction plate. (See Table 7.16 for dimensions.)
|
|
TABLE 7.16 Specification of Friction Plate Design
a. Specification in U. S. Customary units; dimensions in in; see Fig. 7.51
|
Post size, in X lb/ft
|
Bolt
diameter
|
Bolt
length
|
F
|
G
|
H
|
J
|
K
|
L
|
N
|
d
|
t
|
|
S3 X 5.7
|
|
112
|
312
|
112
|
112
|
252
|
134
|
52
|
12
|
946
|
14
|
|
S4 X 7.7
|
12
|
112
|
312
|
112
|
112
|
252
|
134
|
52
|
12
|
526
|
12
|
|
W6 X 8.5
|
12
|
112
|
352
|
2
|
112
|
4
|
214
|
72
|
12
|
526
|
12
|
|
W6 X 12
|
12
|
112
|
352
|
2
|
112
|
4
|
214
|
72
|
12
|
’/6
|
12
|
|
W6 X 15.5
|
52
|
112
|
452
|
212
|
114
|
6
|
312
|
114
|
52
|
1X6
|
34
|
|
W8 X 17
|
52
|
112
|
452
|
212
|
114
|
514
|
234
|
114
|
52
|
1X6
|
34
|
|
W8 X 20
|
34
|
132
|
434
|
212
|
112
|
514
|
234
|
114
|
34
|
13-16
|
12
|
|
W10 X 21
|
34
|
1
|
514
|
3
|
112
|
534
|
234
|
112
|
34
|
13-16
|
12
|
|
W10 X 25
|
34
|
152
|
514
|
3
|
112
|
534
|
234
|
112
|
34
|
13-16
|
12
|
|
W12 X 27
|
34
|
152
|
514
|
3
|
112
|
612
|
312
|
112
|
34
|
13-16
|
12
|
|
b. Specification in
|
SI units; dimensions
|
in mm;
|
see Fig. 7.51
|
|
|
|
|
Post size,
|
Bolt
|
Bolt
|
|
|
|
|
|
|
|
|
|
|
mm X kg/m
|
diameter
|
length
|
F
|
G
|
H
|
J
|
K
|
L
|
N
|
d
|
t
|
|
S76 X 8
|
13
|
38
|
80
|
38
|
29
|
67
|
35
|
16
|
13
|
15
|
6
|
|
S100 X 11
|
13
|
38
|
80
|
38
|
29
|
67
|
35
|
16
|
13
|
15
|
6
|
|
W150 X 13
|
13
|
38
|
92
|
51
|
29
|
102
|
57
|
23
|
13
|
15
|
6
|
|
W150 X 18
|
13
|
38
|
92
|
51
|
29
|
120
|
57
|
23
|
13
|
15
|
6
|
|
W150 X 23
|
16
|
38
|
112
|
64
|
32
|
152
|
89
|
32
|
16
|
18
|
10
|
|
W200 X 25
|
16
|
38
|
112
|
64
|
32
|
134
|
70
|
32
|
16
|
18
|
10
|
|
W200 X 30
|
19
|
45
|
121
|
54
|
38
|
134
|
70
|
32
|
19
|
21
|
13
|
|
W254 X 31
|
19
|
45
|
134
|
76
|
38
|
146
|
70
|
38
|
19
|
21
|
13
|
|
W254 X 37
|
19
|
48
|
134
|
76
|
38
|
146
|
70
|
38
|
19
|
21
|
13
|
|
W305 X 40
|
19
|
48
|
134
|
76
|
38
|
165
|
89
|
38
|
19
|
21
|
13
|
|
|
FIGURE 7.52 Design of hinge plate. (See Table 7.17 for dimensions.)
|
|
TABLE 7.17 Specification of Hinge Plate Design
|
a.
|
Specification
|
in U. S. Customary units; dimensions
|
in in; see Fig. 7.52
|
|
|
|
Post size,
|
Bolt
|
Bolt
|
|
|
|
|
|
|
|
|
|
in X lb/ft
|
diameter
|
length
|
S
|
U
|
V
|
X
|
Y
|
Z
|
d
|
t
|
|
S3 X 5.7
|
|
158
|
334
|
258
|
158
|
152
|
138
|
58
|
586
|
956
|
|
S4 X 7.7
|
12
|
158
|
334
|
258
|
158
|
152
|
138
|
58
|
586
|
956
|
|
W6 X 8.5
|
12
|
152
|
454
|
4
|
158
|
2
|
254
|
78
|
58
|
956
|
|
W6 X 12
|
12
|
152
|
454
|
4
|
158
|
2
|
254
|
78
|
55б
|
956
|
|
W6 X 15.5
|
58
|
152
|
5
|
6
|
158
|
252
|
352
|
158
|
55б
|
|
|
W8 X 17
|
58
|
112
|
5
|
558
|
158
|
252
|
234
|
158
|
55б
|
|
|
W8 X 20
|
38
|
138
|
552
|
558
|
152
|
252
|
234
|
158
|
32
|
%
|
|
W10 X 21
|
38
|
138
|
6
|
538
|
152
|
3
|
234
|
152
|
32
|
%
|
|
W10 X 25
|
38
|
138
|
6
|
538
|
152
|
3
|
234
|
152
|
756
|
13
/16
|
|
W12 X 27
|
38
|
178
|
6
|
652
|
152
|
3
|
352
|
152
|
726
|
13
/16
|
|
b. Specification in
|
SI units; dimensions
|
in mm;
|
see
|
Fig. 7.52
|
|
|
|
|
Post size,
|
Bolt
|
Bolt
|
|
|
|
|
|
|
|
|
|
mm X kg/m
|
diameter
|
length
|
S
|
U
|
V
|
X
|
Y
|
Z
|
d
|
t
|
|
S76 X 8
|
13
|
38
|
95
|
67
|
29
|
38
|
35
|
16
|
15
|
8
|
|
S100 X 11
|
13
|
38
|
95
|
67
|
29
|
38
|
35
|
16
|
15
|
8
|
|
W150 X 13
|
13
|
38
|
108
|
102
|
29
|
51
|
57
|
23
|
15
|
6
|
|
W150 X 18
|
13
|
38
|
108
|
102
|
29
|
51
|
57
|
23
|
15
|
8
|
|
W150 X 23
|
16
|
38
|
127
|
152
|
32
|
64
|
89
|
32
|
18
|
8
|
|
W200 X 25
|
16
|
38
|
127
|
133
|
32
|
64
|
70
|
32
|
18
|
8
|
|
W200 X 30
|
19
|
45
|
140
|
133
|
38
|
64
|
70
|
32
|
21
|
10
|
|
W254 X 31
|
19
|
45
|
152
|
146
|
38
|
76
|
70
|
38
|
21
|
10
|
|
W254 X 37
|
19
|
48
|
152
|
146
|
38
|
76
|
70
|
38
|
21
|
11
|
|
W305 X 40
|
19
|
48
|
152
|
165
|
38
|
76
|
89
|
38
|
21
|
11
|
|
rigidity necessary for proper operation. This includes providing sufficient resistance to activate the hinge and to prevent intrusion of the sign and impacted support into the passenger compartment. Proper hinge activation also requires that no portion of the primary sign, or any supplemental signs, be attached to the support posts below the hinge. In addition, no portion of the sign panel should extend lower than 7 ft (2100 mm) above ground level.
Fastening of sign panels to multisupport sign systems usually requires the use of stiffeners to provide the required rigidity. The exception to this is for relatively small surface area signs, which require multiple supports because of their shape, and for wooden signs. Consult state specifications for installation requirements. Clamps are used to fasten the stiffeners to S — or W-shaped beam posts, eliminating the need to drill into the post itself. Fastening details using aluminum Z-bar as the stiffener were presented in Fig. 7.43, with other common methods presented in Figs. 7.44 and 7.45. U-channel posts can also be used as stiffeners for large signs. When U-channel is used, it should be galvanized and should weigh no more than 2.5 lb/ft (3.7 kg/m). U-channel of 2.0 lb/ft (3 kg/m) is sufficiently strong to withstand wind loads of 70 mi/h (130 km/h).
Figure 7.53 presents the configuration of stiffeners for various sign sizes on a dual multiple-support system. Signs with a height of 24 in (600 mm) or more should be reinforced with two stiffeners placed a distance of one-fourth the sign height from the top and bottom of the sign. The stiffeners should not extend closer than 2 in (25 mm) to the sign edge. Supplementary signs, added to the bottom of the primary sign, should
|
FIGURE 7.53 Example showing placement of sign stiffeners. Dimensions shown as mm. Conversions: 25 mm = 1 in, 50 mm = 2 in, 64 mm = 2.5 in, 76 mm = 3 in, 155 mm = 628 in, 305 mm = 12.І/2 in, 190 mm = 7% in, 380 mm = 1594 in, 610 mm = 2442 in, 1220 mm = 48 in, 1850 mm = 72 in.
|
be attached to the sign stiffeners and not to the posts. Signs should never be allowed to extend above and below the hinge at the post. Extending the sign at the hinge can cause the hinge to bind and improper operation upon impact.
