Slings, safe lifting equipment for the handling of cargo


Have you ever wondered what a sling is? It’s a very useful piece of lifting equipment and your big ally when loading heavy weights onboard a ship. It’s versatile, flexible, resistant and easy to use. Would you like to know more? Keep reading!

What is a sling?

Slings are tools designed to help us lift, hoist, tow or transport heavy loads. It’s an indispensable assistance when loading any kind of cargo on a ship in a safe manner, and it reduces the amount of effort needed too.

It allows a load to be hooked to a traction or lifting point. It’s made of synthetic fibre or wire rope with metal devices such as hooks, shackles, links or rings at its end. Different types of sling can be found depending on its application, working load, composition, slinging mode, length, etc.

Different slings for different working loads. It depends on the material the tool is made of. Polyester is usually employed for light or fragile loads. It provides smoothness and finesse and it’s incredibly resilient. It also stretches 3% at rated capacity.

Loading cargo on a ship would be an arduous task to perform without the help of slings. You would need to come up with an alternative method, and chances are it would be more costly, more difficult or less effective than the use of a lifting sling.

How is a lifting sling used?

The use of lifting slings is a very easy and intuitive process. First step is always to check the condition of the sling before use. If a lifting sling is found to be damaged it is better to discard it completely. If it were to break while in use the load and the safety of the workers would be compromised. Once it is inspected and proven to be in mint condition, the lifting procedure can be analysed.

A series of factors need to be taken into account: the actual weight of the load, the place where the lifting will happen, etc. If it’s outside and windy the lifting procedure won’t be safe enough. It is also not recommended to exceed the Working Load Limit (WLL) of the lifting sling, it could be damaged or break completely.

When establishing the load limit it is also important to consider the angle the manoeuvre will take place at. If the tension force through the sling becomes too strong it could tear the material and drop the load.

The slings must be securely attached to the load providing maximum control. The appropriate method of rigging depends on the type of load, its transportation or its weight, and it is key to a successful lifting operation. The centre of gravity must also be considered, if the load isn’t restrained correctly it could swing and tear the material or damage the goods.

Sling materials

Different materials adapt to different load weights, the material of which the sling is made of is very relevant to the task at hand. There is always a suitable lifting sling that fits the needs and gets the job done.


It’s a synthetic plastic fibre derived from petroleum. It is low cost, lightweight, flexible, is water and abrasion resistant, and stands colour fading and bacterial growth. It can also be combined with other fabrics in order to adapt it to a specific task. Additionally, it can be customised via sublimation.

Polyester lifting slings are the right choice to work close to sea. No risks derived from the humidity or mould/mildew growth, the sling resists those. It may not be a perfect material, but it withstands a great range of loads without damage or break. Numerous advantages that make it well worth acquiring.

Polyurethane slings
Polyester lifting slings are the right choice to work close to sea.


Steel lifting slings are made out of steel wire. They consist of several wires making up a strand and several strands wrapped around. Steel lifting slings stand out for their resistance to the elements and can lift heavy loads. In addition, they are available in a variety of configurations.

eslingas de acero
Steel lifting slings stand out for their resistance to the elements and can lift heavy loads.

Sling maintenance

Proper maintenance of lifting slings is essential in order to keep the material in top condition. Otherwise, the performance and safety will be compromised. They should be stored off the ground and away from mechanical devices, and not be left on the ground with heavy loads stacking or being dragged over them, polyester slings will suffer from fraying and steel slings could fracture.

The hooks, links, etc. need to be round so the sling slides safely. If there was an obstruction, the lift would be compromised and the sling damaged. It is not recommended to use more than one hook per sling.

The load weight must be equally distributed among the slings. Doing so will prevent excessive stress and possible damage or break. They should not rest at tight angles, edges or along sharp ends during the lifting process. If it’s found to be imperative, edge and cut protection must be used.

You should avoid exposing slings to extreme temperatures such as above 100º C or below -40º C. Slings are susceptible to damage when exposed to extreme heat or cold and the strength of the material can diminish and become brittle. They should be stored clean and dry if they are to remain in good condition for a long time.

In conclusion, now you know a little bit more about a lifting sling and its uses. Very heavy loads can be safely and efficiently lifted thanks to it. At Suisca Group we provide everything a ship may be in need of, we are manufacturers of steel slings and we are certified by Lloyd’s Register. We treasure more than 30 years of experience in selling and distributing lifting slings.