TM-5-5420-279-10
Section II. BRIDGING SITE PREPARATION
Where tactically and strategically possible, perform a preliminary study and site selection checks to
determine the proposed location of the bridge prior to marking out the site.
Preliminary Study
Carry out intelligence gathering and reconnaissance of the proposed bridge location.
Intelligence Gathering
Refer to intelligence studies and reports, maps, aerial photographs and personal aerial
reconnaissance. If possible, seek the advice of friendly local civilians.
Site Reconnaissance
NOTE
For additional information on site reconnaissance, refer to Appendix H.
1.2.3.1
Reconnaissance is required to:
(1)
select a suitable site,
(2)
select the bridge center line,
(3)
measure the gap, bank heights and bank transverse and longitudinal slopes.
1.2.3.2
The following considerations apply to the selection of a suitable site:
(1)
For normal build sites, a minimum size of 49.2ft (15m) wide (perpendicular to the
gap) by 134.5ft (41m) long is required (see Figure 1. 12).
(2)
For restricted build sites, a minimum size of 35.8ft (10.9 meters) wide (perpendicular
to the gap) by 73.65ft (22.45m) long is required (see Figure 1. 13).
(3)
The maximum bridge gap ('AR' span) is not to exceed 131.2ft (40m) (see
(4)
The maximum longitudinal slope on the home bank should not be steeper than 1 in
20 in either direction (see Figure 1. 9).
(5)
The maximum lateral slope on the home bank should not exceed 1 in 20 (see Figure
(6)
Bank height difference `H' to comply with either:
40 meter bridge. The far bank is not to be more than 9.8ft (3m) higher or 9.8ft (3m)
lower than that of the home bank when measured from the horizontal projection of
the home bank.
or
20 meter bridge. The far bank is not to be more than 6.5ft (2m) higher or 6.5ft (2m)
lower than that of the home bank when measured from the horizontal projection of
the home bank (refer to Figure 1. 10).
