If hooks are used to attach cages or buckets to the socket or thimble of a hoisting rope, the hooks shall be self-closing.
Code of Federal Regulations
(Sec. 101, Federal Mine Safety and Health Act of 1977, Pub. L. 91-173 as amended by Pub. L. 95-164, 91 Stat. 1291 (
30 U.S.C. 811
))
Code of Federal Regulations
[48 FR 53242, Nov. 25, 1983]