Slings and Rigging Gear: Preventing a Lethal Next Use
By Pat M. Stark, CHST, Safety & Health Consultant
I often find slings and rigging gear in poor condition both in general industry and construction operations. In many cases the slings or rigging gear have such a deteriorated condition that their next use could prove lethal. But how do you know when the next use could be lethal?
You can test your knowledge of slings and rigging gear condition safety by taking the following quiz. If you’re a manager, supervisor, foreman or have any safety responsibilities assigned to you, ask workers who use slings or rigging gear some or all of these questions. See how well you both understand the answers and follow safe procedures. Most of these questions and answers are based on basic federal OSHA standards.
1. In construction, how often should you inspect slings and all fastenings and attachments?
2. In both construction and general industry chains are to be of alloy strength and these slings must have permanently affixed identification (usually in the form of tags). What must this identification state?
3. Regarding broken wires in a wire rope sling, what are the removal criteria in construction, and what are the removal criteria in general industry?
4. A basic class of a wire rope sling is 6x19. What does the 6 represent? What does the 19 represent?
5. What is meant by the term “reach” as a chain sling identification element?
6. What is meant by a “lay” in a wire rope? (Note: It really has three definitions related to wire rope.)
7. In addition to the daily inspection requirements, OSHA requires chain slings to have recorded inspections. How often does OSHA require these recorded inspections of chains?
8. Why are the rated capacities listed in the charts in OSHA standards important?
9. On a chain sling in general industry, what is OSHA’s allowable bend in a hook from its plane?
10. Name two removal criteria for synthetic web slings?
Note: Answers to quiz are found below.
For more detailed information, the OSHA standards (CFR 29 1926 Subpart H-“Material Handling, Storage, Use and Disposal”) and the general industry standards (CFR 29 1910 Subpart N “Material Handling and Storage”) provide federal regulations on slings and rigging gear. These OSHA standards are based on older consensus standards such as ANSI/ASME. There are more current consensus standards, such as ASME B30.9-2003 (or newer) Slings; ASME B30.10 (most recent) Hooks, and B30.20 (most recent) Below-The-Hook Lifting Devices that provide safe work practices, inspection criteria, etc. on slings and rigging gear.
1. Each day before use. 1926.251(a)(6)
2. Construction. Size, grade, rated capacity and sling manufacturer. 1926.251(b)(1); general industry-size, grade, rated capacity and reach. 1910.184(e)(1).
3. Construction. Wire rope shall not be used if in any length of 8 diameters, the total number of visible broken wires exceeds 10% of the total number of wires. 1926.251(c)(4)(iv); general industry- 10 randomly broken wires in one rope lay or 5 broken wires in one strand in one rope lay. 1910.184(f)(5)(i).
4. 6= number of strands; 19= approx number of wires in each strand
5. Reach is the effective length of an alloy steel chain sling measured from the top bearing surface of the upper terminal component (i.e. the master link) to the bottom bearing surface of the lower terminal component (i.e. hook bowl). 1910.184(b)(Note: By knowing the reach, during inspection of chains if the reach dimension is increased then this is indication of elongation of the sling and reason for removal from service).
6. Lay signifies the direction of rotation of the wires which form the strands in a wire rope (i.e. regular lay, lang lay); lay = signifies the direction the strands are laid around the rope core (i.e. right or left); lay = a linear measurement that is one complete revolution around the core of the wire rope.
7. Construction. It can vary on frequency of sling use, severity of service, nature of lifts being made, although, shall in no event be at intervals greater than once every 12 months. 1926.251(a)(6); general industry- It can vary on frequency of sling use, severity of service, nature of lifts being made, although, such inspections shall in no event be at intervals greater than once every 12 months. 1910.184(e)(3)(i).
8. The main reason is that lifts beyond these rated capacities can lead to failure of the slings or rigging gear, and also because it’s federal law in construction and general industry standards NOT to exceed these rated capacities. 1926.251(a)(2), 1926.251(f)(1), and 1910.184(e)(5), 1910.184(f)(1), 1910.184(i)(5).
9. 10 degrees. 1910.184(e)(9)(ii). In construction, OSHA refers to following the manufacturer’s recommendations for safe working loads of the various sizes and types of hooks. 1926.251(f)(2), and in many cases the manufacturer will states this same 10 degrees bend from plane of hook. The 2003 ASME B30.9- Slings publication refers to ASME B30.10 Hooks for removal criteria. In the 2005 ASME B30.10 Hooks removal criteria, it states that if any visible apparent bend or twist from the plane is detected it is to be repaired or replaced.
10. Construction and general industry- acid or caustic burns; melting or charring of any part of the sling surface; snags, punctures, tears or cuts; broken or worn stitches; distortion of fittings. 1926.251(e)(8) and 1910.184(i)(9).