Slings Get Noticed Washington DC

In the surfacing industry, cranes and hoists are often used to aid in the movement of large materials or products. These types of equipment typically use slings to hold their suspended loads. Some shops may also use slings attached to fork trucks to move materials. Improper selection or use of slings can result in sling failure or load slippage, which in turn can lead to injuries or death along with property damage.

OSHA recently issued a new guide on the selection and use of slings for handling and moving materials. This document updates the 1975 OSHA standard by including information on synthetic round slings and newer grade materials being used in alloy steel chain and wire rope slings.

Because OSHA's standard was not as current as other industry standards, sling manufacturers have begun manufacturing and marking slings in accordance with American Society of Mechanical Engineers (ASME) standard B30.9-2003, Slings.

The recent guidance document is a combination of OSHA's sling standards, ASME's consensus standard and other relevant information. Specifically, this guidance document includes information on synthetic round slings, which were not covered in OSHA's sling standards.

Problems with sling use include improper choice of sling or attachments for the type of load or the environment; worn or damaged slings and attachments including cracks, kinks, bends, cuts, gouges and frayed fibers; improper storage of slings; and misuse of slings by resting loads on the sling, dragging of slings across abrasive floors or similar misuse.

The guide describes a variety of slings, including alloy steel chain, wire rope, metal mesh, natural fiber rope, synthetic fiber rope, synthetic web and the commonly used synthetic round slings. The latter is an important addition, since it is not covered in the current OSHA standard.

Synthetic Round Slings

Synthetic round slings are popular because they offer strength, convenience, load protection and economy. The guide discusses the most commonly used synthetic round slings, which are made of nylon- or polyester-type yarns (Figure 1). Each synthetic material has its own unique properties. Certain synthetic materials perform better than others in specific applications and environments. Be sure to check with the manufacturer before using a synthetic sling in and around chemical environments.

Slings are labeled for the core material and the cover material if different from core material. Information will also be given for the rated load based on the type of hitch and the angle. Slings are also typically marked with the name or trademark of the manufacturer and the manufacturer's part number or other numerical code.

Rated loads (capacities) for synthetic round slings are as shown in Figure 2. Rated loads are based on material strength, design factor, type of hitch, angle of loading and the diameter of curvature over which the sling is used. The closer the angle of use is to vertical, the higher the load rating. For angles not shown in the table, or for angles of choke less than 120 degrees, the guide recommends that you use the next lower angle or ask a qualified person to calculate the rated load.

Fittings

Ensure that mechanical fittings used with a synthetic round sling are compatible with the mechanical and environmental requirements of the sling. These fittings should have a rated load at least the same as the round sling and be able to sustain twice the rated load of the sling without visible permanent deformation. Their surfaces should be clean, and sharp edges removed.

Inspections

OSHA's sling standard has always required that slings, fastenings and attachments be inspected for damage or defects each day before use. In addition, the new guidance recommends periodic inspections of synthetic round slings at yearly intervals for normal use, or monthly to quarterly for severe service. In no case should the periodic inspection interval be greater than 12 months. Look for:

• Missing or illegible sling identification
• Acid or caustic burns
• Evidence of heat damage
• Holes, tears, cuts, abrasive wear or snags that expose the core yarn
• Broken or damaged core yarns
• Welding splatter that exposes core yarns
• Knots in the round sling body, except for core yarn knots inside the cover
• 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 the continued use of the sling

Where any such damage or deterioration is present, remove the sling or attachment from service immediately. Repairing synthetic round slings properly is difficult to do and is not recommended.

Use And Storage Of Synthetic Round Slings

When using synthetic round slings, keep all parts of the human body away from the areas between the sling and the load and between the sling and the crane or hoist hook. Personnel should never stand in line with, or next to, the legs of a sling that is under tension, and must not stand or pass under a suspended load.

Use and store slings in an area where they will not be subjected to mechanical, chemical or ultraviolet damage. They should not be kept in areas with extreme temperatures.

Chemically active environments can affect the strength of synthetic round slings. Consult the manufacturer before using a sling in such environments and be sure that the cover is the same yarn as the load-bearing core.

Long-term exposure to sunlight or ultraviolet radiation can also affect the strength of polyester round slings. Consult the sling manufacturer for proper retirement criteria for polyester round slings subjected to long-term storage or use in sunlight.

Do not allow polyester round slings to be used in contact with hot objects or at temperatures in excess of 194 °F, or below -40 °F. Some synthetic yarns do not retain their breaking strength during long-term exposure above 140 °F.

Rigging Practices

When lifting with a sling, ensure that it is hitched to control the load and that the load is balanced to prevent slippage. Personnel must be alert for possible snagging. Slings must not be constricted, bunched or pinched by the load, hook or any fitting. Sharp edges in contact with slings should be padded adequately to protect the sling. If using a choker hitch, the choke point should only be on the sling body, never on a splice or fitting.

Never rest your load on the sling or pull a sling out from under a load when the load is resting on the sling. Do not drag loads with a sling, and specifically do not drag slings on the floor or over abrasive surfaces. Never shorten or lengthen a sling by knotting, and avoid uses that twist or kink the sling. Always avoid shock loading.

In summary, OSHA has not changed its rules on slings, but has, rather, issued this guidance that adds discussion on one of the most commonly used slings today, the synthetic round sling. This article is meant as an overview. You should consult with your sling manufacturer to get specific recommendations and restrictions for your particular choice of synthetic round sling.

For further information regarding OSHA Compliance requirements for the surfacing industry, visit www.technetrainonline.com, or contact TechneTrain Inc. at 800-852-8314. Techne Train offers a line of training programs and reference manuals to assist businesses in meeting compliance with OSHA regulations.