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Subchapter 17. Mine Safety Orders
Article 36. Hoisting Equipment

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§7135. (19-21). Hoisting Ropes--Safety Factor and Inspections.

(a) Every hoisting rope used on a mechanically driven hoist shall be made of steel or alloy steel. The rope center may be fiber.

(b) Hoisting ropes shall be of adequate size to handle the intended load and shall have the following safety factors:


                       Minimum                Minimum 
                     safety factor       safety factor when 
Length of rope        of new rope      rope must be discarded 
500 feet or less......... 8                      6.4 
500 to 1000 feet......... 7                      5.8 
1000 to 2000 feet........ 6                      5.0 
2000 feet and more....... 5                      4.3 

(c) The safety factor of a new rope shall be calculated by dividing the breaking strength of the rope as rated by the manufacturer by the sum of the maximum load to be hoisted, plus the total weight of the rope in the shaft when fully let out.

(d) (19-128) No rope shall be used for hoisting or lowering men:

(1) If there are six broken wires in one strand of a rope lay.

(2) If the wires on the crown are worn to 65 percent of their original diameter.

(3) If more than 3 wires have been reduced by wear more than 30 percent in cross section are broken in 1 strand of a rope lay.

(4) If marked corrosion appears.

(5) If minimum safety factor falls below that specified in subsection (b) of this section.

(e) (19-120) At least once every three months, every hoisting rope used for hoisting or lowering men shall be carefully inspected by a competent man designated for that purpose:

Such inspection shall consist of:

(1) Carefully examining the exterior of the rope throughout its entire length.

(2) Cutting off a section from the load end of the rope at a point not less than 5 feet above the highest part of the rope connection to the conveyance.

(f) The interior of the section of hoisting rope cut off in compliance with subsection (e) of this section shall be carefully examined for fatigue, wear, corrosion, or breaks.

(g) (19-120) If, upon inspection, any hoisting rope is found to be below any requirement set forth in this section, it shall forthwith be removed from service as a hoisting rope.

(h) Serious damage may be caused to the hoisting rope by shaft accidents, such as pulling the shaft conveyance into the sheave, piling up rope on a stopped conveyance, or by kinking or running over the rope when the conveyance is derailed.

In event of an accident which may have caused damage to the hoisting rope, such rope shall not be used to hoist or lower men until it has been inspected by a competent man and found to be safe.

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