ARMY TM 5-5420-212-10-1
MARINE CORPS TM 08676A-10/1-1
(2)
Double story bridges (2E + 1 thru 2E + 12 bay ). The bank height above flowing water or obstructions in
the gap should be a minimum of 2 ft (0.6 m).
(3)
Link reinforced bridges. The bank heights above flowing water or obstructions in the gap should be a
minimum of 12.0 ft (3.7 m). In addition, there must be no obstacle intruding above a plane inclined 20 degrees downward
in the gap for a distance of 15 ft (4.6 m) from each AR Peg as shown below (fig. 3-4).
FIGURE 3-4. Bank clearance-link reinforced bridges
If the bank height is less than 12.0 ft (3.7 m) the rules in (a) and (b) below apply.
(a)
For bridges 2E + 14 bays and below there is no limit on bank height as long as the current does not
exceed 5 fps (1.5 m/s) in which the reinforcing links can be immersed during launching and before tensioning.
(b)
For bridges 2E + 15 bays and above there is no limit on bank height as long as the current does not
exceed either:
1
3.5 fps (1.0 m/s) in which case the reinforcement can be immersed only during launching and
before tensioning.
2
The current speed is shown in Table 3-4.
TABLE 3-4 Maximum current velocity v bridge length
2E + No.
22
21
20
19
18
17
16
15
14
13
of Bays
Bridge
ft
162
156
150
144
138
132
126
120
114
108
Length
m
49.4
47.6
45.7
43.9
42.1
40.2
38.4
36.6
34.8
32.9
Current on
fps
1.64
1.64
3.08
3.67
3.93
4.29
6.95
7.67
8.43
8.43
immersed links
m/s
0.5
0.5
0.94
1.12
1.2
1.31
2.12
2.34
2.57
2.57
3-13
