ARMY TM 5-5420-212-10-1
MARINE CORPS TM 08676A-10/1-1
3-16
DOUBLE STORY 2E + 13 thru 2E + 22 BAY DESIGN w/o LRS
The procedures that follow are for designs of DS 2E + 13 through 2E + 22 Bay MGBs (wo/LRS) on normal sites
only where water level or any obstructions are at least 2.7 m below bank heights.
a.
Measure the AR Gap (para.. 3-10a)
b.
Select a bridge (para. 3-10b and Table 3-24)
TABLE 3-24. DS MGB 2E + 13 through 2E + 22 bays (w/o LRS)
AR Gap Ranges
(a)
MLC*
(b)
2E + No. of Bays
(c)
Bridge Length L
(d)
R Distance
(e)
Nose Const
(f)
28.3 - 30.9
60(T)
13
32.9
27.7
6N1
30.2 - 32.8
50
14
34.8
29.0
32.0 - 34.6
40
15
36.6
29.0
7N1
33.8 - 36.4
40
16
38.4
29.6
35.6- 38.2
30
17
40.2
29.6
8N1
37.5 - 40.1
30
18
42.1
29.6
8N1
39.3 - 41.9
24
19
43.9
35.1
6N1
41.1 - 43.7
24
20
45.7
38.7
+
43.0 - 45.6
20
21
47.6
38.7
3N2
44.8 - 47.4
16
22
49.4
40.5
* See step k. Slope Check and Table 1-1 for crossing restrictions. (T) = Tracked
c.
Bridge length
Read and note the number of bays and bridge length, Table 3-24 columns (c) and (d).
d.
R Distance
Read and note the R Distance, Table 3-24 column (e).
e.
Nose configuration
Read and note the nose configuration, Table 3-24 column (f).
f.
Key construction points
Identify, locate, and take elevations at the key construction points. These constructions points are explained below
and shown in Figure 3-13.
(1)
F Peg-Designates the location of the far bank end of bridge (outer edge of bankseat beam). Initially
placed 0.6 m (minimum acceptable) from the A peg on the far bank. This 0.6 m, between the A and F pegs is the amount
of bridge that will bear on the far bank, and is known as the far bank bearing.
(2)
A Peg-Edge of firm ground on the far bank.
3-35
