TM 5-5420-280-10
0012 00
SITE REQUIREMENTS AND LAYOUTS (Contd)
g. Local Weather Conditions.
Ensure the strength and direction of prevailing winds will not hamper
deployment or usage of the bridge. The deployment should not commence
in wind speeds in excess of 33 mph (15 m/sec). Ensure that heavy rainfall
will not cause problems on the launch site or cause a rise in the water
levels when crossing rivers, streams, etc.
5. Launch Condition Requirements -- Shore conditions are used to
determine the crossing site. Perform the following procedure if the desired
launch site is uneven and would inhibit launching the bridge otherwise.
WARNING
Hazard to personnel and equipment is increased if
bridge is launched into less-than-ideal site. Site must be
inspected and prepared to be within the operating
limits of the bridge pallet launcher and the bridge.
Failure to adequately prepare site could result in
damage to equipment or possible injury or death to
personnel.
CAUTION
A rack launch, where far and rear shore banks are side-
to-side and slopes are opposite each other, should be
avoided. Uneven ground can cause bridge to twist.
Excessive twist (more than (10%) can permanently
damage bridge.
NOTE
Bridge (with no load) will settle to its maximum safe
limits without lifting. If any corner of bridge lifts from
ground or is not fully supported by ground, perform
steps 1 through 4.
(1) Grade or fill entire site until grade is 10% or less.
(2) Grade or fill entire site until side slope is 5% or less.
(3) Remove large stones and fill in low spots until launch and retrieval
areas are reasonably flat.
(4) After launching bridge, but before load is applied, check below bridge to
ensure that area between near and far shores is clear of obstructions to
a depth of 9 in. (23 cm). Bridge will bend (deflect) downward to a
negative camber when load is applied and must not contact any solid
object.
END OF WORK PACKAGE
0012 00-8