1. A. No hoisting rope on a friction hoist shall be used in a shaft or winze of a mine where, in any part of the rope:

   1. 1. The existing strength has decreased to less than 90% of the original strength of the rope.
   2. 2. The extension of a test piece has decreased to less than 60% of its original extension when tested to destruction.
   3. 3. The number of broken wires in any section of the rope equalling the length of one lay of the rope exceeds six.
   4. 4. Marked corrosion occurs.
   5. 5. The rate of stretch in a friction hoisting rope begins to show a rapid increase over the normal stretch noted dur­ing its service.

2. B. No tail rope, guide or rubbing rope shall be used in shaft where, in any part of the rope:

   1. 1. The existing strength has decreased to less than 75% of the original strength of the rope.
   2. 2. The extension of a test piece has decreased to less than 60% of its original extension when tested to destruction.
   3. 3. The number of broken wires in any section of the rope equalling the length of one lay exceeds six.
   4. 4. Marked corrosion occurs.

Historical Note

Adopted effective April 7, 1976 (Supp. 76-2).