required for a specific lift and the tip height necessary, he can calculate the
required boom length and angle needed for the lift, He then checks the Rated
Lift Capacity Chart for the specific boom length and radius to find out if the
crane is capable of performing the lift safely. Or, on the other hand, if the
boom length and angle are known, the radius can be determined from the
A lifting area diagram is included as part of the chart to outline lifting areas.
An examination of the lifting area diagram shows the slewing limits and
outrigger locations in reference to the axis of rotation.
The last major portion of the Rated Lifting Capacity Chart is the section
concerning notes to lifting capacities. Be sure to read all notes carefully so
you understand what each one means. The chart also gives weight
reductions for Grove load handling devices such as hook blocks, which must
be taken into consideration as part of the load. Remember, any other load
handling devices such as chains, slings, or spreader bars must also be
considered, and the weight of these devices must be added to the weight of
The following is an example of how to
compute a lift. Use the Rated Lifting Capa-
TYPICAL TASK FOR A SCAMP CRANE.
The object is to remove the main transmission from aCH-54 helicopter at a
weight of 3400 pounds.
Strategic placement of the crane allows for an on-outrigger lift at 15 foot
radius (horizontally measured distance between the axis of rotation of the
crane turntable and the center of the helicopter rotor mast). With the
transmission rigged for lifting and the hook block (128 pounds) and required
slings (100 pounds) in place over the rotor mast, a boom length of 30 feet
(marked on sides of boom fly section) is found to be necessary for the desired
tip height to swing the load clear of the aircraft.