Courtesy of Will Dunn
So you have decided to perform a lift with the use of lifting slings. Which ones should you chose? Webbing slings, round slings, wire rope or chain slings? Truthfully, the choice is yours, obviously.
If you are reading this article it is most likely because you are not in the habit of making mistakes, especially when they involve lives at risk if for instance the load dropped due to improper slinging. Good, you are aware!
All types of lifting slings should be issued a certificate of conformity before being used, this should meet all LOLA requirements, if your sling does not have a certificate it is not safe for use until inspected by qualified personel such as an inspection body.
Lets start by looking at wire rope slings. Manufactured from strands of wire rope twisted and crimped together to form a suitable sling usually with eyes at each end, wire rope is made to order and you can pretty much request any setup you desire. Many people like wire rope slings because it is seen as a strong safe secure rigging method however we all realise that slings are only as safe as their safe working load, if a wire rope sling says SWL 5T and you put a ten ton load on it do not be surprised if it breaks, ‘you are what you rate!’
Round slings are endless polyester strops enclosed with hard wearing seamless sleeves are colour coded to their specific safe working load (unless made specifically for the entertainment industry, they are usually black to make them less sightly). Round slings are the softer choice for lifting slings, offering less damage to smooth or polished surfaces, perfectly ideal for lifting objects in a choke position such as tubes and pipes, featuring very low stretch. Endless round straps are the most cost effective strop to purchase.
Webbing slings are flat belt straps with flat eyes at each end. Usually manufactured to duplex level featuring double ply for extra safety. Made from 100% polyester webbing and colour coded to the relevant safe working load, supplied with certificates as standard (or they should be). Webbing slings are commonly used over chains and wire ropes due to their ability to be more flexible and lighter, they will also offer little damage to the load to help reduce scratching and denting to loads being lifted. Wide flat webbing offers greater surface contact.
Chain slings – the most common grades are grade 80 and grade 100 slings. Grade 80 slings are the most cost effective but if you require lighter higher quality slings with increased safety you may require grade 100. Chain slings are sometimes used in conjunction with webbing or round slings. However they are mostly used to lift very heavy bulky loads on a regular basis, most overhead cranes lift their loads with chain slings when used intensively. Chains will not wear as easy as fabric alternatives and are seen by some as a safer alternative.
To conclude, Lifting slings and chains can be selected to suit the load better than other but ultimately it is the choice of the crane operator (or rigger).