Figure 1-17.Minimum safe distance for working around energized conductors.
The primary killer of riggers and those
persons handling loads is electrocution caused by
the contact of the boom, load line, or load of a crane
with electric power lines. When working with or
around cranes that are within a booms length of any
power line, you must ensure that the power to that
section of line is secured. If for some reason this cannot
be accomplished, a competent signalman must be
stationed at all times within view of the operator to
warn him when any part of the machine or its load is
approaching the minimum safe distance from the
power line (fig. 1-17). You must also exercise caution
when working near overhead lines that have long
spans, as they tend to swing laterally because of the
wind, and accidental contact could occur.
The safe working loads of hoisting equipment
apply only to freely suspended loads on plumb hoist
lines. If the hoist line is not plumb at all times when
handling loads, then additional side loads will
endanger the stability of the equipment. In
circumstances such as this, structural failures can result
without any warning (fig. 1-18).
Never use kinked or damaged slings or hoist wire
ropes. To provide maximum operating efficiency and
safety, you should give all slings and fittings thorough
periodic inspections as well as daily inspections for
signs of wear and abrasion, broken wires, worn or
cracked fittings, loose seizing and splices, kinking,
crushing, flattening, and corrosion. Special care should
be taken in inspecting the areas around thimbles and
Figure 1-18.Incorrect lifting procedures.