STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

Hoisting System 611
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DESIGN FACTOR
Figure 4-85. Relationship between design factors and ton-mile service factors [11].*
NOTE: Light loads can cause rope to wear out from fatigue prior to accumulation of anticipated
ton-miles.
'Based on laboratory tests of bending over sheaves.
in the operation. A program should be "tailored" to the individual rig. The
condition of the line as moved through the reeving system and the condition
of the cutoff portions will indicate whether the proper goal was selected. In all
cases, visual inspection of the wire rope by the operator should take precedence
over any predetermined procedures. (See Figure 4-86 for a graphical comparison
of rope services.)