Important Changes to New Roundsling Standard
It’s necessary to note the changes and amendments included within updated or revised standards, such as AS 4497:2017, says Ashley Thacker, general manager at Ranger Lifting.
As explored in my previous commentary, Australian Standards (AS) Committee ME-025 Lifting Tackle is soon to publish AS 4497:2017, a new standard 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.
I’d encourage all industry professionals to pay close attention to the updated standard, indeed, any document that has been improved by experts. There are those who feel that enhanced standards are repetitive and/or only contain alterations to the small print. I disagree. ME-025 Lifting Tackle, of which I am now a member, will release the new standard because it is important that industry adheres to a revised, current document. It isn’t a case of putting a new date on the same information and sending it out again.
AS 4497:2017 will supersede AS 4497.1 Roundslings—Synthetic fibre, Part 1: Product specification; and AS 4497.2 Roundslings—Synthetic fibre, Part 2: Care and use. The objective of the standard is to combine the two previously separate parts for manufacturing and safe use into a single document. Let’s look at just some of the areas that have incorporated important changes that we need to note, in addition to a raft of new figures, tables, and appendices featured within:
- Competent persons
- Effective lengths
- Protective pads and corners
- End fittings and interfacing components
- Working load limit (WLL) tags
- Colour and stripes
- Materials including HMPE (high modulus polyethylene)
- Cut protection
- Engineered lifts
- Connecting to the loads
The entire document is important—all 50+ pages of it—and I’m not suggesting this article counts as a summary or pared down version. However, I do want to take an opportunity as a stakeholder in the industry to point to some detail that I’ll be making sure our personnel understand.
Competency is king
Rightly, the standard features an early definition of competence: A person who has acquired through training, education, and experience, or a combination of these, the knowledge and skills enabling that person to safely and effectively perform the task required. That should be pinned on the wall of your tearoom for everyone to see. Beyond that, it should be etched on people’s brains.
It’s important to understand what competency means related to roundslings made of synthetic fibre. AS 4497:2017 states that persons manufacturing, testing, and using roundslings shall be competent to detect and evaluate defects and weaknesses that may affect the intended performance of a roundsling.
As it pertains to manufacture and testing of roundslings, a competent person shall be provided with the necessary instruction for the tasks they perform. Further, they shall be able to demonstrate competency in these tasks. In the use of roundslings, a competent person shall be able to demonstrate the ability to choose the correct sling and inspect it based on a variety of criteria.
This is more complicated than it sounds. Competency is, after all, hard to achieve. Can an end user assess the mass of the load to be lifted; assess whether the load, inclusive of any lifting points, will withstand the lifting operation; check that the lifting machine or lifting appliance is rated to lift the load; select a suitable roundsling, taking into account condition, geometry, load attachment, and the shape of the load? It’s also important to note the standard’s detail on periodic and post-repair inspection of roundslings.
As I said in my previous article, roundslings are an incredibly useful rigging tool, but they are more susceptible to physical and environmental damage than some other types of sling. Therefore, it’s important to understand the new standard’s content that covers rigging applications so the right sling is applied to the lift in hand and used correctly. To that end, users must have a thorough knowledge of effective lengths; protective pads and corners; plus end fittings and interfacing components.
Remember, protective sleeves and pads are used to provide an increased resistance to heat or protection against damage from weld spatter, abrasion or cuts. The sleeve or pad shall have a suitable protective capability for the purpose that it is designed for. If the sleeve is sewn to the sling, it shall be of the same fibre material, and have the same mechanical and chemical properties as the cover.
End fittings, meanwhile, shall have a working load limit (WLL) of not less than the WLL of the sling. The interface between the cover and the end fitting shall be such that the strength of the sling leg will not be compromised by either overcrowding or the interface contact region. Two end fittings on a sling need not be identical. If a sling is designed for choked slinging, one fitting should be able to pass through the other fitting.
Are you beginning to understand AS 4497:2017’s importance? Let’s continue…
On your marks
The standard says that each sling shall be permanently, legibly marked with key information, including WLL for direct load and various lifting configurations in tonnes or kilograms; fibre material; month and year of manufacture; nominal length in metres; manufacturer’s identification; and more. Further, a section of the label shall be stitched under the cover, which shall also be marked with information from a clause for reference purposes. Other information such as nominal compressed width and nominal compressed thickness may also be included on the label.
The tag is clearly an important part of a sling, as AS 4497:2017 implores. Certain precautionary warnings shall be provided as a minimum upon it, including the need to consult sling manufacturer or supplier for configurations not shown on the sling tag or a relevant load chart. The standard lists many more. The WLL of multi-leg slings shall be stated on the tag attached to the master link. Note that the WLL on the master link tag of the sling assembly shall override the WLLs of the individual components.
The load-bearing core and the sewing thread of roundslings shall be constructed from a high-tenacity continuous-multifilament synthetic fibre. Load-bearing fibres shall have a tenacity of not less than 60 cN/tex (count-related yarn tenacity). Woven covers should be constructed of thermofixed fibres of the same material type as those of the core.
*Typical fibre materials include aramid polyamide, nylon, polyester, ultraviolet-light-stabilized polypropylene, and new or high-performance fibres (including high modulus polyethylene).
Engineered lifts are also referenced by the standard. It says the use of an engineered lift should be considered where any of the following conditions apply: the mass of the load is not evenly distributed; the load has an irregular shape; load sharing devices, such as ramshorn hooks (a hook with two throat openings) or equalizing beams, are to be used; there is a limited duty cycle; the slings are intended for a dedicated or specific use (non-general purpose conditions of use); and any multiple crane lift.
Additionally, many requirements shall apply when connecting to a hook or fitting. The surface of a hook of fitting that is in contact with the sling shall be free from sharp edges, for example. The saddle of a hook or fitting shall be such to accommodate the roundslings without overcrowding. Also, when using a ramshorn hook each saddle shall not directly support more than one-sling leg without a suitable interfacing component, e.g. a master link or bow shackle. Loading shall not be applied to the latch mechanism of a hook and the operation of the hook latch shall not be impeded by the roundslings.
That was just a handful of highlights. How well have you noted the changes to, and content of, AS 4497:2017?
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