Lifting Slings and Inspections
In the world of hoisting and rigging, lifting slings help workers safely lift heavy objects. However, they can fail in certain situations and cause injuries. Luckily, you can avoid these problems with regular inspections.
Round slings have load-bearing fibers or core yarns protected by a woven outer jacket. This makes them durable and versatile. They can fit around various shapes and sizes of loads and grip them with choker hitches, basket hitches and vertical hitches.
Weight and Strength of the Load
When selecting a lifting sling, it is important to know, or at least estimate accurately, the weight of the load. This will help you select a sling that has sufficient strength to safely lift the load and prevent overloading.
It is also important to understand how the load’s weight and shape will affect the sling’s capacity. For example, if the load has sharp corners or projections that could damage a sling, a thicker material may be required to protect it from such damage.
The reach and angle of the sling will also have an impact on its capacity. The greater the angle between a sling leg and the horizontal, the more stress will be placed on that sling leg, which will reduce its ability to carry the desired load. This is why it is important to keep the sling angle as large as possible, and if necessary, distribute the load across multiple legs of the sling.
Ally chain lifting slings are designed for rugged environments and jobs, and they are one of the toughest lifting solutions available. They can handle high temperatures, abrasions and collisions. They are versatile and can be used in vertical, choker or basket hitches. They are also available with a variety of fittings, including classic sling hooks, self-locking hooks and swivel hooks. When choosing an alloy chain sling, look for those with a Working Load Limit of up to 400 pounds or more.
Center of Gravity
The location of the center of gravity, also known as the CoG, is one of the most important aspects of lifting a load. It determines how much the load will tilt when lifted and can cause major problems for a crane, if it is not positioned correctly. This is why determining a load’s CoG should be among the first questions asked before any lift is attempted.
The CoG should be placed directly above the load’s point of attachment. The load should lifting slings not be placed closer to one side than another as this can create dangerous balancing issues and cause instability during the lift.
If the load is not evenly distributed, it may be necessary to block the heavy end of the load with wood or a block and tackle in order to balance the weight during a turn. The block can then be removed once the load is repositioned.
When using slings, it is recommended to inspect them before and after every use to ensure that they are free of any defects or damage. Any sling that is damaged, weakened, or worn out should not be used and replaced as soon as possible. Even small abrasions or wear can cause the sling to fail during lifting and can result in fatal injuries. In addition, the slings must be properly cared for and stored to prevent damage during storage.
Load Distribution
When more than one sling is used to lift a load it is important that the weight is properly distributed between the legs of the slings or slings. If the legs are not evenly loaded, stress can build up in a localized area which could result in the sling or the load breaking.
To prevent this from occurring, a good understanding of the different types of sling configurations is required. The most common are the vertical and basket configurations.
In a vertical configuration, the hoist hook lifting slings will be located directly above the centre of gravity. This will make a level lift, preventing dangerous tilting of the load during the hoist and reducing stresses in the sling legs.
For basket or choker configurations, the sling should be passed through or wrapped around the load at the points indicated by the rigging diagram. It is vital that these points are secure and can not slip or slide during the lift.
It is also important to consider the effect of sling angles on the load capacity. For example, if you are lifting a 2,000 lb. load and using a two-leg sling, the sling legs must be able to support that load at a 60 degree angle. If the angle is higher, that load will need to be supported by more sling legs.
Safety
Regardless of their size or type, all flat lifting slings require proper inspection and maintenance procedures. This ensures their continued use and safety. Regular inspections include determining the working load limit (WLL), padding corners, edges and protrusions; checking the tag to see that the sling is rated adequately for the lift; and ensuring that shackles, rings and other hardware fit properly. Makeshift links and shop fabricated attachments are not acceptable. Slings should not be twisted, tied into knots or joined by knotting and must be free of abrasion.
Ensure that all eye splices are large enough to provide an angle at the splice that is not greater than 60% of the rope’s rated diameter. The spliced eye should also be free of cuts, areas of extensive fiber breakage along the length of the rope and areas covered by fuzz or whiskers that reduce the effective rope diameter to more than 10%.
Avoid exposure to extreme temperatures, as even alloy chain slings are susceptible to heat damage and can weaken or melt. Protective coverings and sling protectors can help ensure the longevity of these slings, and they must be stored in a cool, dry environment. In addition, all slings need to be inspected for damage before and after each lift. It is also recommended that only one person controls the lift or gives signals to the hoist or crane operator.