Slings - what they are and their types
A sling is a component of the lifting equipment of a crane, gantry or hoist on which the load to be lifted is suspended, supported or lashed. Thanks to the sling, it is possible to move both delicate loads and large, heavy ones. Many different types of components and materials are required to construct such a sling. We can classify slings from various angles. There are two main types: General Purpose - Draw-wire sling
They are manufactured from equal materials. Due to the type of work to be carried out, we have different types of tendon sling:
- Rope slings
They are used both for pulling vehicles (as winches on trucks or off-road vehicles) and for lifting heavy bulky objects. They are a standard accessory in industry and the construction industry. Rope slings are made of stranded steel and galvanised wires. The ropes are braided around a fibre core. They can be classified according to the type of clamp, the number of strands or the type of termination. With regard to the number of strands, there are four types of these slings: one-, two-, three-, four-strand and one-, two-loop.
- Chain slings
They are made of steel chains and are the strongest of all slings. This is why this type of sling is used in jobs which require the transport of very heavy loads (often in industry and construction). They can handle weights from 1 to 100 tonnes. They are used in what is known as material handling. Chain slings are resistant to changing weather conditions and mechanical damage. We distinguish between one-, two-, three- and four-legged slings, single- and double-loop slings as well as hook and link and closed-circuit slings.
- Natural and synthetic fibre webbing slings
Belt slings are light, soft and flexible. They allow a better distribution of forces when the load is pressure-sensitive. They are used for transporting materials with sensitive surfaces.
Special purpose - gripping and hooking
When the use of general-purpose slings is not sufficient, special-purpose slings are used. They are made using a different technology, e.g. special-purpose slings for transporting and handling cylinders, for storing technical gases.
Slings can be used in all kinds of applications. They are often found in heavy industry: metallurgy, factories or metallurgy. But they can also be found in the automotive, armaments or construction industries.
Maintenance and inspection of slings
In order to work safely with slings, regular checks and inspections are necessary. Before using a piece of equipment for the first time, an initial inspection should always take place. This is to check that it can be used for work. Thereafter, the condition of the slings should be checked before each subsequent use. In addition to the daily inspection of the slings, it is compulsory to carry out technical tests (for example, once a year for rope, belt and chain slings and every 6 months for shackles). Proof that a sling has been tested and approved for use is provided by a protocol. Sometimes there is a requirement to mark the test carried out directly on the sling (in the form of a tag or plate).