It’s time to start work for the day and you go to get the web sling you always use out of the back of your truck. Since it is the one that you use on a daily basis, you don’t think much about the sling tag that is starting to fade, or that is starting to look a little worn and dirty because, after all it gets used all the time and occasionally gets left on the ground. You don’t think about the freezing temperatures that hit last week overnight or the exposure to sunlight over the weekend while it was not being used. For the most part the sling looks pretty good, there are no cuts or apparent singular deficiencies that would cause it to be removed from service.
So you use it with no fear. Then one day, that sling fails. What? How could this be? There was no apparent singular factor that indicated there was going to be a failure, could accumulation of wear and tear be at fault?
While slings are tagged by the manufacturer with a Working Load Limit (WLL) according to the hitch type, they are also manufactured with a design factor (DF). The WLL and DF didn’t change but the sling’s breaking strength did–reducing with each time it was used above the WLL, with each time it froze and thawed, and with the exposure to UV rays from being stored in the back of the truck. Each factor played a part, resulting in a failure and sometimes that failure is well below the WLL.
It is human nature to take little risks now and again but taking a risk with your rigging gear shouldn’t be something you are willing to do. It is for this reason the ASME standards note not only specific removal conditions for each type for slings or rigging hardware, they also include an overarching statement “other conditions, including visible damage, that cause doubt as to the continued use.”
This is why the key to ANY inspection isn’t just about checking for individual rejection criteria, but also looking at the overall condition. You must determine if there are so many small areas of concern, that don’t yet meet the individual stated rejection criteria, but together could cause it not to be able to support the rated capacity. If that is the case, then go ahead and tag it out of service—especially if it is a periodic inspection—you must not only think about the next lift but all the lifts until the next scheduled periodic inspection.
Two other key factors that will help keep your rigging program safe:
- Making sure that workers are trained on the proper use of slings and rigging, including environmental factors, use of softeners, D/d ratios, the impact of sling angle stress, etc.
- Storing rigging in a manner to keep it from being damaged, such as out of the elements, hung up, away from environmental concerns, etc.
The material handling industry is not a place where you want to face your fears or test the final factor. You must stop and consider all the possibilities to keep yourself and your job site safe. Remember Safety through Education is more than just our motto, it is our guiding principle. If you need to schedule rigging inspector training or are looking for a reputable company to provide inspections, look no further–call 800-290-0007 or request a quote.