If you’re a rigger, you know the importance of using the right hardware when operating lifting equipment. In conjunction with using a crane or lift, lifting slings are used attached or wrapped around the object being lifted. Lifting slings are used to minimise damage to the objects being lifted.
As with other rigging hardware, there are different lifting slings for different job applications. Picking the right lifting sling is key to any lifting application.
While having the right hardware is important, using lifting slings safely and being aware of other precautions are all things a rigger should know before purchasing & using them.
Types of Lifting Slings: Advantages and Disadvantages
There are essentially three types of lifting slings. They’ve been designed to meet certain job requirements. Each one has its own advantages and disadvantages.
1. Wire Rope Slings
The most popular of all lifting slings, the wire rope sling is strong and flexible. It can withstand heavy use, while not deteriorating as quickly as other types. The wires are usually made of carbon steel, with 16 to 26 wires making up a strand. The advantage of a rope made with many wires is that it increases its fatigue resistance.
Wire rope slings have been designed to withstand long periods of bending. Being sturdy ropes, they also have a central core which provides additional support when bending. The disadvantage of wire rope slings is that they are non-repairable. If they are damaged, they need to be discarded.
2. Synthetic Slings
These slings are made either from nylon or polyester fibre. Woven together to create straps, synthetic slings are flexible and lightweight. They are also strong and versatile. Being made of synthetic fibres, their advantage lies in using them when lifting expensive or sensitive objects. The design prevents scratches and other damage.
Synthetic slings, however, are prone to being torn or cut easily. They are also susceptible to UV rays, chemicals and hot temperatures, increasing their likelihood of being damaged.
3. Chain Slings
Chain slings are your strongest types of rigging slings. They’ve been designed to be flexible and durable while withstanding extreme temperatures & corrosive chemicals. They can be used often without the wear and tear typical of wire rope & synthetic slings. Chain slings can be repaired or replaced if damaged.
Designed to handle heavy-duty lifting, chain slings are used in steel mills and heavy machinery warehouses. They are ideal for machinery carrying out repetitive lifts.
The disadvantage of the chain sling is that they are heavy and can easily be damaged if crushed. They are the most expensive option compared to wire rope slings and synthetic slings.
Inspecting Lifting Slings for Safe Use
As with any other rigging equipment, the safe use of lifting slings is important. The following inspection tips should be used to ensure safety:
- Particularly when it comes to rope slings, lifting slings lose their strength over a period of time. The rigger needs to determine the rope’s safe working load limit prior to each job.
- An inspection should be carried out ascertaining any damage such as kinking, corrosion, tears or breakage in the lifting sling. Depending on the lifting sling type, the sling must be removed from service to be repaired or discarded.
- Discoloration in synthetic slings is an indication of damage to the sling. Frayed edges are also an indication of wear and tear.
- Chain slings must be used carefully at all times. A single broken link can lead to a serious accident or damage of the object being lifted. Bends, elongation or any other kind of deformation in the chain sling must be noted and the sling removed from service for repairs.
- If the designated person responsible for repairs and maintenance of lifting slings is unable to carry out the repair work, the lifting sling should be returned to the manufacturer for repairs.
Precautions When Using Lifting Slings
Before using a lifting sling for any job, make sure you apply the following precautions:
- Determine the safe working load capacity
- Before loading, ensure the space allows for free movement of the lifting equipment
- Don’t be tempted to overload by leveraging the power
- Check all lifting hooks meet safety requirements
- Protect slings from sharp objects or corners
- Avoid exposure to heat and corrosive chemicals
- Do not throw or drop lifting slings
- When operating lifting equipment, it’s a good idea to have a person watching on the ground
- Warning signs and safety tapes will prevent people from walking under lifting equipment with loads
Final Thoughts
A rigger is responsible for the correct use and management of lifting equipment and its accompanying hardware. Part of that responsibility is ensuring that all rigging equipment is safe to use, is maintained and repaired when necessary & that all precautions are followed through.
Make sure you have all of this in place before your next project.
