Category Archives: Crane & Rigging

Chain Slings

CHAIN SLING INSPECTION
Recommendation: Daily or before each shift, Inspections shall be conducted by a competent person designated by the employer.

Periodic Inspection – OSHA specifies that all alloy steel chain slings shall have a thorough periodic inspection, by a competent person, at least once every 12 months. These inspections must be recorded and maintained for each individual sling.

The inspection schedule should be based on:

  • frequency of sling use.
  • severity of service conditions.
  • nature of lifts being made.
  • experience gained on service life of slings used in similar circumstances.

INSPECTION
1. Clean chain prior to inspection, to more easily
see damage or defects.

 

2. Hang chain vertically if practical, for preliminary
inspection.

Measure reach accurately (bearing point of masterlink to bearing point of hook). Check this length against reach shown on tag. If the “inspected” length is greater than that shown on tag, there is a possibility that the sling has been subjected to overloading or excessive wear.

3. Make a link-by-link inspection of the chain slings for:

A. Excessive wear – If the wear on any portion of any link exceeds the allowable wear shown in Table 6, Refer to (TABLE 6 GR80 AND GR100) remove the sling from service.

B. Twisted, bent, gouged, nicked, worn or elongated
links.

C. Cracks in the weld area of any portion of the link. Transverse markings are the most dangerous.

D. Severe corrosion.

 

E. Check masterlinks and hooks for all of the above mentioned faults; hooks especially for excessive throat opening. Slings showing any of the damage described above should immediately be removed from service and returned to the manufacturer for repair.

TABLE 6 GR80 AND GR100

Nominal Chain or

Coupling Link Size

Minimum Cross-Sectional “C” Dimensional Limit

mm.

in.

mm.

in.

6

7/32

5.2

.205

7

9/32

5.9

.239

8

5/16

6.9

.273

10

3/8

8.7

.342

13

1/2

11.3

.443

16

5/8

13.9

.546

19

3/4

16.3

.643

20

3/4

16.9

.665

22

7/8

19.0

.750

26

1

22.5

.887

32

1-1/4

27.7

1.091

Synthetic Sling

DOL-OSHA 29 CFR 1910.184 AND GUIDANCE ON SAFE SLING USE
 Make a thorough inspection of slings and attachments. Items to look for include:
• Missing or illegible sling identification.
• Acid or caustic burns.
• Melting or charring of any part of the sling.
• Holes, tears, cuts or snags.
• Broken or worn stitching in load bearing splices.
• Excessive abrasive wear.
• Knots in any part of the sling.
• Discoloration and brittle or stiff areas on any part of the sling.
• Pitted, corroded, cracked, bent, twisted, gouged or broken fittings.
• Other conditions that cause doubt as to continued use of a sling.Where any such damage or deterioration is present, remove the sling or attachment from service immediately.
ASME B30.9 REMOVAL FROM SERVICE CRITERIA
  1. Missing or illegible sling identification.
    Section 9-5.7.1 requires that each sling be marked to show the following:

    • name or trademark of the manufacturer
    • manufacturer’s code or stock number
    • rated load for at least one hitch type and the angle upon which it is based
    • type of synthetic material
    • number of legs, if more than one
  2. Acid or caustic burns.
  3. Melting or charring of any part of the sling.
  4. Holes, tears, cuts or snags.
  5. Broken or worn stitching in the load bearing splices.
  6. Excessive abrasive wear.
  7. Knots in any part of the sling.
  8. Discoloration and brittle or stiff areas on any part of the sling, which may mean chemical or ultraviolet/ sunlight damage.
  9. Fittings that are pitted, corroded, cracked, bent, twisted, gouged or broken.
  10. For hooks, removal criteria as stated in ASME B30.10
  11. For other applicable hardware, removal criteria as stated in ASME B30.26
  12. Other conditions, including visible damage, that cause doubt as to the continued use of the sling.
WEB SLING AND TIE DOWN ASSOCIATION REMOVAL FROM SERVICE CRITERIA
SYNTHETIC WEB SLING SAFETY BULLETIN (WSSB-1) 2010
 The entire web sling must be inspected regularly and it shall be removed from service if ANY of the following are detected:

  • If sling identification tag is missing or not readable.
  • Holes, tears, cuts, snags or embedded materials.
  • Broken or worn stitches in the load bearing splices.
  • Knots in any part of the sling webbing.
  • Acid or alkali burns.
  • Melting, charring or weld spatter on any part of the web sling.
  • Excessive abrasive wear or crushed webbing.
  • Signs of ultraviolet (UV) light degradation.
  • Distortion, excessive pitting, corrosion or other damage to fitting(s).
  • If provided, exposed red core yarn. However, if damage is present and red yarns are not exposed,
    DO NOT USE the sling.
  • Any conditions that cause doubt as to the strength of the web sling.
WEB SLING INSPECTION
Warning - Web Sling Inspection Notice If any damage such as the following is visible, the sling shall be removed from service immediately. Photos depict examples of sling damage, but note they are extreme examples provided for illustration purposes only.

 

Web Sling Wear Indications

Wire Rope

Wire Rope Sling Inspection Criteria

WIRE ROPE SLING INSPECTION
A specific procedure for sling inspection is the best safeguard against injury, death and property damage. It is important that you employ a three stage level of inspection to ensure that slings are inspected with appropriate frequency. It is also important that all inspections must be done by trained and qualified personnel.
To detect possible damage, you should perform a visual inspection of the entire sling by making all parts of the sling readily visible. If necessary, remove dirt and grime so wires and components are visible. Look for any of the conditions listed in the Removal from Service Criteria. The following example depict some of the types of damage, but note that they are relatively extreme examples provided for illustration purposes only.
If you identify ANY of these types of damage, remove slings from service immediately, even if the damage you see is not as extensive as shown. Slings that are removed from service must be destroyed and rendered completely unusable. Never ignore sling damage or attempt to perform temporary field repairs of damaged slings. It is very important that slings are regularly and properly inspected. If you are not sure whether or not a sling is damaged, DO NOT USE IT.
SLING TAG REQUIREMENTS
Identification Requirements- ASME B30-9, Section 9-2.7.1 states: Each sling shall be marked to show:

  1. Name or trademark of manufacturer.
  2. Rated load for at least one hitch and the angle
    upon which it is based.
  3. Diameter or size.
  4. Number of legs, if more than one..
Sling identification should be maintained during the life of the sling by the sling user.
WIRE ROPE SLING REMOVAL FROM SERVICE CRITERIA
 Do not inspect Wire Rope slings by passing bare hands over the wire rope body. Broken wires, if present, may puncture hands.

Slings shall be inspected throughout their entire length for evidence of damage. Wire Rope Slings shall be removed from service if any of the following is visible:

  1. A)  Missing or Illegible Sling Tag.
  2. B)  Broken Wires
For cable-laid slings: 20 broken wires per lay.

For 6 part braided slings: 20 broken wires per braid.

For eight part braided slings: 40 broken wires per braid.

Either the broken wire or broken strand count shall apply separately to the one braid length or one lay length in cable-laid slings.

  1. C)  Severe localized abrasion and scraping.
  2. D)  Kinking, crushing, birdcaging or any other damage resulting in damage to the rope structure.
  3. E)  Evidence of heat damage, usually manifested by metallic discoloration or the presence of internal lubricant.
  4. F)  End attachments that are cracked, deformed or worn to the extent that the strength of the sling is substantially affected.
  5. G)  Severe corrosion of the rope, end attachments or fittings.
  6. H)  For hooks, removal criteria, as stated in ASME B30.10.
  7. I)  For other applicable hardware, removal criteria as stated in ASME B20.36.
  8. J)  Other conditions, including visible damage that cause doubt as to the continued use of the sling.
SLING DAMAGE EXAMPLES
 If you identify ANY of these types of damage in a sling, remove it from service immediately, even if the damage is not as extensive as shown. Slings that are removed from service must be destroyed and rendered completely unusable. Never ignore sling damage or attempt to perform temporary field repairs of damaged slings. It is very important that slings are regularly and properly inspected. If you are not sure whether or not a sling is damaged, DO NOT USE IT.
WIRE ROPE SLING CONSIDERATIONS
Follow OSHA, ASME, Association, Industry and Manufacturer Guidelines. Be sure to read and understand the following information relative to proper sling usage: