California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 4 - Construction Safety Orders
Article 14 - Construction Hoists
Section 1605.12 - Hoisting Wire Rope and Sheaves
Current through Register 2024 Notice Reg. No. 38, September 20, 2024
(a) Breaking Strength. All hoisting wire rope shall be of such breaking strength as to provide a minimum factor of safety of seven. The factor of safety (F) shall be calculated by the following formula:
where
S = Manufacturer's rated breaking strength of one rope.
N = Number of parts of ropes under load.
W = Maximum static load imposed on all ropes with the platform, cage, or bucket, and its rated load at any position in the hoistway.
(b) Wire Rope Inspection.
A representative of the user of the material hoist shall be appointed and this representative shall keep written reports of the rope condition on file at the work site. The representative shall have the authority to order wire rope replacements and keep unsafe wire rope from being used.
Inspection periods shall be set-up for each material-hoist wire rope. The frequency of inspection shall be determined by consideration of environment, degree of hazard to materials, frequency of operation, and the frequency with which the rope is subjected to its capacity limits. Inspections shall be made not less often than once each 30 days.
The working length of the wire rope shall be unwound from the hoist drum. Thorough inspection shall be made of the rope sections that pass over sheaves, drums, or contact saddles, or which make opposing turns. The rope close to end attachments shall be carefully inspected.
A used wire rope shall be thoroughly inspected prior to installation.
The wire rope on equipment that has been idle or shutdown for a period of one month or more shall be completely inspected prior to operation.
Sheaves, guards, guides, drums, flanges, and other surfaces contacted by wire rope during operation should be examined at the time of inspection. Any condition harmful to the rope in use at the time should be corrected.
(c) Wire Rope Removal and Replacement.
Wire rope with one or more of the following defects shall be removed or replaced immediately:
Six randomly distributed broken wires in one rope lay, or three broken wires in one strand in one rope lay, shall be cause for replacement. (A rope lay is the length along the rope in which one strand makes a complete revolution around the rope.)
(d) Wire Rope Installation. Hoisting ropes shall be installed in accordance with the wire rope manufacturer's recommendations. The hoisting ropes shall be secured to the drum by clamps or by an approved equivalent means.
(e) Drums and Sheaves.
Table 1 Groove Radii for New and Reconditioned Sheave Grooves |
||||
Wire Rope, Nominal Diameter |
Groove Minimum |
Root Radius Maximum |
-- |
|
1/4 |
.140 |
.150 | ||
5/16 |
.170 |
.180 | ||
3/8 |
.205 |
.215 | ||
1/2 |
.265 |
.275 | ||
5/8 |
.330 |
.340 | ||
3/4 |
.390 |
.400 | ||
7/8 |
.460 |
.475 | ||
1 |
.525 |
.540 | ||
1 1/8 |
.585 |
.600 | ||
1 1/4 |
.655 |
.670 |
Table 2 Minimum Ratio of Rope Diameter to Sheave Tread Diameter |
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Diameter of Hoisting Rope (Inches) |
Minimum Tread Diameter of Sheaves* (Inches) |
|||
1/4 |
5 |
|||
5/16 |
6 1/2 |
|||
3/8 |
7 1/2 |
|||
1/2 |
10 |
|||
5/8 |
12 1/2 |
|||
3/4 |
15 |
|||
7/8 |
17 1/2 |
|||
1 |
20 |
|||
1 1/8 |
22 1/2 |
|||
1 1/4 |
25 |
* Based on 20 times rope diameter.