LOAD RATING CHART INTERPRETATION
In the following pages are examples of a load chart,
these example charts may differ from the chart sup-
plied with your crane. Always use the load rating chart
supplied with the crane to interpret the conditions and
limitations that exist when making a lift with the crane.
The determining factors are lifted load, radius, boom
angle, working position, hoist line reeving, tire pres-
sure, travel data, use of a jib, and any other special
conditions that exist, such as wind velocity, soil condi-
tions, etc.
DEFINITIONS OF LOAD CHART TERMS
Lifted Load:
The lifted load is the total weight of all the items sus-
pended on the wire rope.
Example
Hook block 750 lbs.
Slings 215 lbs.
Object Lifted 19,000 lbs.
Lifted Load 19,965 lbs.
Radius:
The radius is the horizontal distance from the center of
the swing bearing to the center of the lifted load.
Deflection of the crane boom will tend to increase the
radius as the load is lifted. To minimize this, use the
combinations of boom angle and length shown in the
load rating chart. Do not allow the radius to exceed that
given for the rated load.
Boom Angle :
The boom angle is the angle of the boom measured
from horizontal. Use the angles shown to approximate
the loaded radius, but do not rely solely on a boom an-
gle indicator to determine radius. Always measure the
actual radius when determining main boom capacities.
Front and 360°:
The “crane working position” diagram is a view looking
straight down on the crane with the upperstructure and
the boom removed. The “front” of the crane is always
the end opposite the engine.
“Front” when the crane is on outriggers is the area in-
side the are bounded by lines from the centerline of ro-
tation through the front outrigger vertical jack cylinders.
“St. over Front” when operating on tires means the
boom and load must be positioned straight to the front
of crane and not swung to right or left.
360° means the load can be swung to any position
around the crane.
Deducts:
The “on outriggers” rated capacities are for lifting over
the main boom point. Jibs, if so equipped, are in the
stowed position. Any specialty items attached to the
boom head should be removed. In certain instances, it
is advantageous, from a job set-up point of view, to lift
over the boom point with the jib erected. In these in-
stances, it is necessary to make deductions from the
rated loads shown in the load rating chart to determine
the correct rated load. Hook blocks or any specialty
items should be removed from the jib point when lifting
over the main boom point.
Also, there are deductions for jib operation due to hook
blocks hanging on the main boom point. In this circum-
stance, reduce the jib capacity by the weight of the
hook block and/or other specialty items hanging from
the main boom point.
OPERATING PROCEDURES
Revised: October 20053 - 23RT700
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