![]() |
Code of Federal Regulations (Last Updated: July 5, 2024) |
![]() |
Title 30 - Mineral Resources |
![]() |
Chapter I - Mine Safety and Health Administration, Department of Labor |
![]() |
SubChapter O - Coal Mine Safety and Health |
![]() |
Part 77 - Mandatory Safety Standards, Surface Coal Mines and Surface Work Areas of Underground Coal Mines |
![]() |
Subpart O - Personnel Hoisting |
![]() |
Wire Ropes |
§ 77.1431 - Minimum rope strength.
-
§ 77.1431 Minimum rope strength.
At installation, the nominal strength (manufacturer's published catalog strength) of wire ropes used for hoisting shall meet the minimum rope strength values obtained by the following formulas in which “L” equals the maximum suspended rope length in feet:
(a) Winding drum ropes (all constructions, including rotation resistant).
For rope lengths less than 3,000 feet:
Minimum Value = Static Load × (7.0−0.001L)
For rope lengths 3,000 feet or greater:
Minimum Value = Static Load × 4.0
(b) Friction drum ropes.
For rope lengths less than 4,000 feet:
Minimum Value = Static Load × (7.0−0.0005L)
For rope lengths 4,000 feet or greater:
Minimum Value = Static Load × 5.0
(c) Tail ropes (balance ropes).
Minimum Value = Weight of Rope × 7.0
[48 FR 53241, Nov. 25, 1983; 48 FR 54975, Dec. 8, 1983]