Don’t Cut Corners—Understand Your Roundslings
As industry prepares to welcome an updated roundsling standard, Ashley Thacker, general manager at Ranger Lifting, issues an important safety message.
Having recently joined Australian Standards (AS) Committee ME-025 Lifting Tackle, I’m looking forward to the imminent publication of AS 4497:2017, covering roundslings made of synthetic fibre. It represents an update of AS 4497.1 and 4497.2 (both 1997), and contains important information about using such slings below the hook.
It’s timely therefore to look again at round slings and urge end users to use the new standard’s publication as a prompt to ensure relevant personnel have access to the required literature, knowledge, education, and training.
First, what is a round sling? As the new standard will say, it is an endless sling comprising a load-bearing core of high-tenacity continuous-multifilament yarn that is completely enclosed in a woven cover, with or without end fittings.
Round slings are an incredibly useful rigging tool. They support the load with a soft, flexible contact surface that minimises damage to the load; plus they are light and easily stored (we’ll come back to storage).
However, they are more susceptible to physical and environmental damage than some other types of sling and, as such, it’s important that they are only used by competent professionals who understand the equipment and its intended purpose.
Round slings are a safe, efficient, tool but sometimes they are wrongly disparaged because they have been used incorrectly and the damage caused may have led to an incident. I’ve even known of some sites where their use has been restricted because of safety concerns. This is indicative of poor education and a lack of training, not the limitations of round slings per se.
For example, because round slings encourage a concentration of contaminants, they are generally not appropriate for use in chemical environments. If they are employed in such a place I would sooner point the finger of blame at the facility and its management, rather than suggest there was something wrong with the rigging gear, should an accident happen.
AS 4497:2017 will be comprehensive but with the above in mind I want to highlight three sections from it, covering protection, inspection, and storage. I’m not suggesting these areas are more important than any other, but I do detect a lack of knowledge in some sectors on how round slings are best protected, inspected, and stored. In each case there is much more detail in the standards:
Synthetic roundslings are susceptible to damage by cutting or abrasion when attaching to a load with sharp edges or abrasive surfaces. In these circumstances, additional protection may be required.
The standard will say, to protect against cutting or localised damage, loads that have corners with a radius of less than three times the compressed thickness of the sling shall be provided with cut protection. Where corners have a radius of less than the compressed thickness of the sling, the protection, under load, shall increase the radius to at least the compressed sling thickness.
Protective sleeves and pads can also be used to provide an increased resistance to heat or protection against damage from weld spatter, abrasion, or cuts. If the sleeve is sewn to the sling, it shall be of the same fiber material, and have the same mechanical and chemical properties as the cover.
Note that a sleeve placed over the woven cover provides protection but has no effect on the breaking force of a sling.
The standard will reference two types of inspection: prior to each use and periodic.
Every time a sling is to be used, the user shall inspect it and be satisfied that the sling does not show any signs of damage that could affect its safe use. Any damage or faults in round slings that may detract from the safe operation of the sling shall constitute a reason to discard the sling. I’ve blogged before about the importance of clearly marking rigging gear for disposal so it isn’t put to use by mistake.
Do not use a sling if there is any sign of a cut, snagging, heat or chemical damage, excessive wear, damaged seams, defects or presence of grit, abrasive materials, or other deleterious (likely to cause harm or damage) matter.
At intervals of service of not more than three months, a competent person shall inspect the slings. For heavily used slings the inspections should be more frequent. Earlier commentaries have also stressed the point of tailoring an inspection program for a site and its lifting applications.
For each sling, a record of every periodic inspection and the details of periodic inspections shall be kept. The record shall include the identity of each item, identity of inspector, the date of inspection, and the outcome of the inspection.
Proper storage is essential for the prevention of deterioration and damage to slings. As the new standard will state, there is a variety of criteria for appropriate storage, including a clean area free from dirt and grit; absence of condensation or moisture; out of direct sunlight (particularly important here in Australia); and a provision to keep slings off the ground and away from any surface that may corrode them.
It is advisable to store slings on gratings, racks, stands or special coil pegs.
AS 4497:2017 is likely to be published on 50+ pages, which should suggest to end users that there is a lot of protection, inspection, storage, usage, and other detail that needs to be understood when applying these products beneath the hook of a crane or hoist.
Supported with the right knowledge, round slings are one of the safest, most useful rigging products on a jobsite. Of course, as is the case with any item of lifting gear, disastrous consequences can await anyone applying a product not fit for purpose.
Thank you for reading.
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