TM 10-3950-672-10
Precautions must be taken to ensure that the crane is not working or parked over any underground services (gas mains,
water mains, electrical lines) or where this is necessary, the services must be adequately protected.
IMPORTANT Always consider the wire rope, hoist cable, pendant cables, tag lines, etc. as conductors of electricity.
EXERCISE EXTREME CAUTION AND PRUDENT JUDGMENT WHENEVER ELECTROCUTION HAZARDS EXIST
OPERATE SLOWLY AND CAUTIOUSLY.
Federal law prohibits use of cranes closer than 10 ft (3.048 m) to power sources to be safe, double that (i.e. 20 ft [6.096
m]).
Comply with all federal, state, and local laws and regulations.
It is not necessary to touch a power line or power source to become electrocuted. Electricity, depending on magnitude,
can jump or become induced into a crane. "Low" voltages can also be dangerous.
Be alert.
Keep all parts of the crane (ropes, lines, hook block, and load) at least 20 ft (6.096 m) from the power line.
Slow down crane operations.
Whenever a load, wire rope, crane boom or any portion of a crane contacts or approaches too closely to an electrical
power source, everyone in, on, and around the crane can be seriously injured or killed!
THE ONLY SAFETY WAY TO OPERATE A CRANE IS TO STAY AWAY FROM ELECTRICAL SOURCES!
Assume that every power line is "hot." Appoint a reliable and qualified signal person, equipped with a loud signal whistle
or horn and voice communication equipment, to warn the operator when any part of the crane or load moves near a
power source. This person should have no other duties while the crane is working.
Warn all personnel of danger. Allow no unnecessary personnel in the area. Permit no one to lean against or touch the
crane. Permit no one including sling men or load handlers to hold load, lines, or rigging gear.
Even if the crane operator is not affected by an electrical contact, others in the area may become seriously injured or
killed.
The use of boom guards, proximity devices, insulated hooks, links, or mechanical limit stops does not assure safety.
Even if codes or regulations require the use of such devices, failure to follow rules listed here may result in serious injury
or death. You should be aware of some of the limitations of the devices.
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