TM 5-3810-306-10A lifting area diagram is included as part of the load chartto describe over-the-side, over-the-rear, and over-the-front lifting areas. The lifting area diagram shows that thelocations of the outrigger stabilizer cylinders in the fullyextended position are used to mark the boundaries of thelifting areas.The last major portion of the load chart is the sectionconcerning notes on lifting capacities. Be sure to read allnotes carefully so you understand what each one means.The weights of any load handling devices must be addedto the weight of the load.NOTEThe following is a typical example of alifting problem and how to compute a lift.However, numbers used in the examplemay not coincide with the loadchart inthe crane cab.The problem is to lift a container weighing 22.4 tons to aheight of 46 feet at a radius of 27 feet. Determinewhether or not the lift can be made safely. The rangediagram shows the lift can be made using a boom lengthof 60 feet. A check of the on outrigger-360 degrees loadchart at a 27 foot radius with a 60 foot boom lengthshows the crane has a lifting capacity of 48,000 pounds.It appears from the listed capacity that 22.4 tons (44,800pounds) can be lifted. But wait! The listed weight of allload handling devices such as slings, chains, spreaderbars, or other rigging must be added to the load weight inorder to obtain the actual weight of the load being lifted.For the purpose of this example we will assume thatthese load handling devices weigh 1500 pounds andmust be added to the load weight (i.e., 44,800 + 1,500 =46,300 pounds). Therefore, the total load weight of46,300 pounds can be lifted since the total weight ofthe load is less than the (48,000 pounds) maximumcrane capacity in this configuration. Following the initialcalculation, the load chart should be rechecked to assurethat the crane is capable of making the lift. Also note theladen boom angle (found in parentheses under theweight capacity of the load chart) will be approximately55.5 degrees.DON’T FORGETLOAD CHARTS REPRESENT THE ABSOLUTEMAXIMUM ALLOWABLE LOADS, WHICH ARE BASEDON EITHER TIPPING OR STRUCTURAL LIMITATIONSUNDER SPECIFIC CONDITIONS. KNOWING THEEXACT RADIUS OF OPERATION, BOOM LENGTHAND BOOM ANGLE SHOULD BE A PART OF YOURROUTINE PLANNING AND OPERATION. ACTUALLOADS, INCLUDING NECESSARY ALLOWANCES,SHOULD BE KEPT BELOW THESE CAPACITYFIGURES.WORKING AREAS MUST BE ADHERED TO WHENDETERMINING ALLOWABLE LOAD FROM LOADCHART(S).IF THE CRANE IS NOT LEVEL, LOAD CAPACITIESARE REDUCED WHEN LIFTING ON THE LOW SIDE.DON’T BE MISLED BY OPTICAL ILLUSIONS. USEYOUR BUBBLE LEVEL.IF YOU FEEL THE CRANE IS BEGINNING TO TIP,LOWER THE LOAD WITH THE HOIST LINE ANDRETRACT OR ELEVATE THE BOOM TO BRING THELOAD IN. NEVER LOWER OR EXTEND THE BOOM,THIS WILL AGGRAVATE THE CONDITION.WHEN USING THE HOIST AVOID SUDDEN STOPS.INCREASED LOADING WILL RESULT AND COULDCAUSE TIPPING OR A STRUCTURAL FAILURE.EVEN IF A HYDRAULIC LINE BREAKS ON THE LIFTOR TELESCOPE CYLINDER(S), THE CRANE WILLSTILL FUNCTION SUFFICIENTLY TO GET THE LOADDOWN.MAXIMUM LIFTING CAPABILITY OCCURS AT THESHORTEST RADIUS, MINIMUM BOOM LENGTH ANDHIGHEST BOOM ANGLE.2-42
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