capacities, outrigger beams must be
extended to provide maximum leveling
of crane. Remove all weight from tires
before lifting on outriggers.
Use sight level bubble indicator to ensure crane is
You can also use the load line to
determine the levelness of the crane. It
should always lie in the center of the
boom. Check at two points 90 degrees
The importance of properly leveling a
crane cannot beoverstressed. A crane
only slightly out-of-level can quickly
encounter a tipping condition.
After crane has been set-up, make a dry run before
making the first lift. Become familiar with all factors
peculiar to job site. Know what moves to make
BEFORE attaching first load.
USING YOUR LOAD CHART (REFER TO APPENDIX
One of the most important tools of every
crane is the load chart found in the
crane operators cab. It contains
information which must be thoroughly
The load chart contains a 360 degree on- outriggers
capacity chart and an on-rubber capacity chart.
The capacity charts are divided into capacities limited by
structural strength and capacities limited by stability. This
is shown by the bold lines across the chart. Capacities
above the line are limited by structural strength and
capacities below the line are limited by crane stability.
The chart shows the radius of the load in a column at the
left. The radius is the distance between the centerline of
rotation of the crane and the center of gravity of the load.
Various boom lengths are listed across the top, ranging
from fully retracted to fully extended. The boom angle (in
degrees) required for the given lift is shown in
parentheses below the maximum total weight which can
be lifted. Note that the boom lengths in between the
increments shown should always be treated as if the
boom was extended to the next longer length. For
example, if the load chart has capacities for 50-foot and
55-foot boom lengths and the actual length of the boom
in use is 52 feet, then the maximum capacity will be
listed under the 55 foot boom length because the boom
is beyond 50 feet in length.
Another important section of the load chart is the range
diagram. The range diagram shows the tip height at each
boom length, angle and radius. If the you know the
radius required for a specific lift and the tip height you
can calculate the required boom length and angle
needed for the lift. Check the capacity chart for the
specific boom length and radius to find out if the crane is
capable of performing the lift safely. If the boom length
and angle are known, the radius can be determined from
the range diagram.