6. Gantry and/or live mast in the highest position.
7. Quadrant of operation (that is, over the side, over
the rear capacities).
Load Rating Chart
Atypical load rating chart is shown in figure 12-47.
To determine the capacity of the crane by using the load
chart, the operator must know the length of boom, the
load radius, the boom angle, and if the lift is to be
performed over the side or over the rear.
When performing lifts using the boom angle
indicator that indicates an angle not noted on the load
chart, use the next lower boom angle noted on the load
chart for determining the capacity of the crane. For
example, using the load charts in figure 12-47, the crane
is rigged with 60 feet of boom, and the boom angle
indicator indicates a boom angle of 57 degrees. A
57-degree boom angle load capacity is not noted on the
load chart, so you must use the next lower noted boom
angle of 53 degrees for determining the capacity of the
crane.
NOTE: Do not rely on the boom angle indicator for
radius accuracy when lifts exceed 75 percent of the rated
capacity. Measure the radius to avoid the possibility of
error.
When using a radius measurement not noted on the
load charts, use the next longer radius measurement
noted on the load chart for determining the capacity of
the crane. For example, using the load charts in figure
12-47, the crane is rigged with 50 feet of boom, and the
radius measurement is 32 feet. A 32-foot radius
measurement is not noted on the load charts, so you must
use the next longer radius measurement of 35 feet noted
on the load chart for determining the capacity of the
crane.
The number of part lines reeved on the main hoist
block can affect the capacity of the crane. If the crane
is capable of being reeved with an eight-part line and the
reeving is changed to a six-part line, the capacity of the
crane changes. On newer models of cranes, the capacity
for different parts of line configurations is noted on the
load charts. On older models, you must refer to the
manufacturer’s manual.
The load chart provides the capacity of the crane
with outriggers set and without outriggers. “Outriggers
set” means the outriggers are fully extended and the
weight of the crane is off of the suspension system or
the tires are off the ground. If a situation arises where
the outriggers cannot be fully extended, you must use
the without outriggers load capacity ratings.
NOTE: Load capacities change when swinging
from each quadrant of operation, such as from over the
rear to over the side.
SAFE LIFTING
The following factors are basic guidelines to
perform safe daily crane operations:
1. Determine the weight to be lifted and the crane
required to make the lift safely.
2. Travel the proposed route the crane will follow
to and from the project site, and complete the Crane Lift
Checklist.
3. Obtain the travel permits if required.
4. Brief operators and riggers on the specifics of
the lift and travel conditions.
5. Inspect the crane area setup for stability and safe
operating area
6. Fully extend the outriggers and use them
according to the manufacturer’s instruction.
7. Check the crane for levelness.
8. Inspect all rigging hardware.
9. Select the proper sling with sufficient capacity
rating.
10. Center the sling in the base (bowl) of the hook
to avoid hook point loading, and ensure the hook block
is always placed over the center of the load to eliminate
shock loading of the slings or cranes, resulting from load
shifts when a lift is made.
11. Make ample safety allowances for unknown
factors.
12. Stand clear of and do not walk under suspended
loads.
13. Boom deflection.
All crane booms have
deflection. When the load is lifted off the ground, the
boom will deflect, causing the radius to increase.
Increased radius may cause overloading of the crane.
14. An uncontrolled swinging load can cause the
radius to increase.
15. Clean operating area. Water coolers, excess
tools, grease, soda cans, and other unnecessary items
should be kept outside of the operating area of the crane.
Water coolers must be kept off the crane to prevent
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