Created by peter.roberts
about 10 years ago
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THE SWL OR SAFE WORKING LOAD OF A SLING IS THE MAXIMUM LOAD THAT CAN BE LIFTED BY THAT SLING MAKING A STRAIGHT LIFT.SO... THE LOAD FACTOR FOR A STRAIGHT LIFT = 1
IF THE LIFT IS NOT A STRAIGHT LIFT AND MULTIPLE SLINGS ARE USED OR, THE LOAD IS REEEVED, THE SLINGING GEAR ARE SUBJECTED TO A CHANGE IN THEIR CAPACITY TO LIFTIN ORDER TO COMPENSATE FOR THESE CHANGES WE HAVE TO CHANGE THE SWL OF THE GEAR.WE DO THIS BY MULTIPLYING THE SWL OF THE SLINGING GEAR BY THE LOAD FACTOR APPROPRIATE TO THE SLING SETUP
CONSIDER THE RECTANGULAR LOAD ABOVE.If a blue sling synthetic sling was used with a WLL of 8T then that lift capacity would be halved and become 4T because of the square reeve load factor of .5SWL = (WLL/Angle Factor)
Basket hitches simply cradle the load without a reeve (eor loop) around the load. The Load Factor for a basket hitched round load is 2 as long as there is a no angle in the sling.For a rectangular load it is 1 as long as there is no angle in the sling.
ANGLES PLACE STRESS ON THE SLINGING GEAR. The greater the angle the greater the stress. The way we counter or mitigate these stresses is by using ANGLE FACTOR figures in our calculations.There are a number of possible scenarios and an according figure which can be used to ensure that the load is slung safely and within the capacity of the lifting gear.
Both of the above loads are basket slung and display a load angle.Imagine that the rectangular load is slung with a 2T green synthetic sling. Let's say that we measured the angle of the sling to be 30 degrees. The load must now not exceed .97 x 2T.So capacity of that sling setup (basket hitch) slung with a load angle of 30 degrees is 1.94T
NOTE THE ANGLE FACTORS FOR A RANGE OF ANGLES WHEN DIRECTLY SLINGING A LOAD
NOTE THE ANGLE FACTORS TO BE USED WHEN USING AN ENDLESS LOOP TYPE SLING
Single sling
Load factors
basket hitches
angle factor
angle factor 2
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