TM-5-5420-279-10
Limitations as to use due to Environmental Conditions
3.8.1.1
The material from which the slings are manufactured is polyester (PES). Polyester is
resistant to chemical attack from mineral acids but can be attacked by strong alkalis. Take
contaminated slings out of service at once, thoroughly soak in water, and allow to dry
naturally. In case of any doubt about the security of any sling following
contamination remove from service and destroy.
3.8.1.2
Beware of formation of ice at low temperatures, which can have an abrasive or cutting
effect on the slings.
3.8.1.3
When bridge modules are stowed, water can pool in the inside of the panels. As the
opening slings hang down inside the panels, they can become frozen to the panel in cold
weather.
3.8.1.4
During non-operational periods when the system is stored at temperatures below 32
degrees Fahrenheit (0 degrees Centigrade) or when freezing is expected to occur, to
prevent the slings freezing to the insides of the bridge sections, all the module opening
slings should be pulled out from the modules so that they hang externally.
CAUTION
Transportation of bridge modules with incorrectly stowed slings may cause system damage.
3.8.1.5
Prior to transportation, all straps must be re-inserted, using the module sling tool if
necessary.
3.8.1.6
Slings should be protected from prolonged exposure to direct sunlight or sources of ultra-
violet radiation.
Checks Prior to Each Use/Period of Use for Webbing Slings
3.8.2.1
Prior to each use, the sling should be inspected for:
a)
any defects
b)
correct identification and specification.
3.8.2.2
In addition to the statutory examination by a competent person, the responsible person
should make regular in-service inspections. The interval between inspections will depend
on the conditions of service but as slings can be damaged in use, the operative should
visually check them on each occasion prior to slinging the load. If any of the following
defects are found the sling should be withdrawn from service and referred to a competent
person:
a)
Surface chafe. In normal use some chafing will occur and is unavoidable. If
this is confined to the surface fibers as opposed to the yarns it has no effect
on the safe use however in extreme cases the faces of the webbing can
become so worn that the outer yarns are severed.
