30
Aug
Damaged Equipment: What to Look For
In this article, we’ll share several real examples of wire rope, slings and rigging hardware, that our inspectors have removed during an inspection. We’ll walk you through the reasons each device should be removed from service and identify the applicable industry standards for each device.
To identify and remove unsafe devices, it’s important to regularly assess your equipment according to relevant Australian Standards which can be found here.
WIRE ROPE
Wire rope will eventually deteriorate as a result of abrasive wear, wire breaks, loss of lubrication, corrosion and consolidation of the core. Damage is not always easy to see. AS1666 states that each wire rope sling should be inspected prior to use to ensure it is in a safe condition. It should also be inspected by a competent person every 12 months.
Regular pre-use inspections of wire rope are necessary. Some common observations that may indicate that your wire rope is unsafe and should be serviced or discarded are: corrosion, a one-third reduction in outer wire diameter, damaged fittings (e.g. hooks, latches, rings, links etc), distortion, kinking bird caging, or other evidence of damage to the wire rope structure and excessive broken wires.
Why should this be removed from service?
This image shows a portion of a wire rope that displays kinking and broken wires—both of which are criteria that warrant removal from service.
Although a certain ratio of broken wires are permitted, the kink damage alone meets removal from service criteria for a wire rope sling. Kinks are places where the rope has been unintentionally bent to a permanent set and cannot removed without creating a weak section in the wire. Discarding is best.
Why should this be removed from service?
This image shows a corroded wire rope. Corroded wire rope will lose its strength and flexibility. Corroded wire surfaces will form fatigue cracks much faster than protected surfaces.
The damage can also be seen with broken wires and a bird caged. Bird caging is one of the most severe forms of distortion observed in rotation-resistant wire rope and is often caused by a mismatch between rope diameter and drum groove dimensions. Bird caging calls for the immediate removal of the rope from service.
SYNTHETIC SLINGS
A synthetic web sling is one of the most common pieces of rigging equipment found on site due to their versatility. Synthetic slings can be made from polyester, nylon, or high-performance materials and are lightweight, easy to rig, and extremely flexible.
Why should this sling be removed from service?
This web sling is non-compliant for several reasons. First, slings cannot be used when there is severe chaffing to the surface of the sling causing damage to the outer yarn.
Secondly, this flat/webbing sling is showing signs of severe transverse abrasion or cross-cutting which is often the result of slings being fed through under a load and catching on foreign objects or steel or from constant rubbing against a hard or abrasive surface when it is underslung.
Why should this sling be removed from service?
This round sling has a tear in both the outer cover and inner cover, resulting in the inner load bearing core protruding through to the surface. This is cause for immediate discard.
Also, there are cuts to the selvedge or tightly woven outer edge of the sling. A small cut can result in a severe loss of strength.
SHACKLES
Shackles are often used for critical and intensive lifting and rigging applications and thus it’s extremely important to make sure you know the signs of damage.
For more information about shackles download our “Safe Use of Shackles” (PDF) which outlines the care and safe use of shackles.
Why should these shackles be removed from service?
The damage to this shackle has completely bended and elongated the shackle. This was likely caused by excessively overloading the shackle to the point of breaking.
There are also extensive gauges and wear marks at the top of the shackle, some of which has caused the markings to become unclear as well as obviously reducing the material thickness and strength of the shackle.
Why should this device be removed from service?
This image shows a shackle connected to a hook where the weight of the load has been too heavy, resulting in total bend and distortion of the shackle. The pin has also become loose and this is often a sign of side loading.
The hook is also damaged with the throat closing out of allowable tolerances which suggests the same overloading event has caused the damage to both the hook and the shackle.
The connector is also suggestive of this as it had completely seized.
OTHER LIFTING HARDWARE
Rigging hardware used for lifting purposes including links, rings, swivels, turnbuckles, hooks, eyebolts, hoist rings, wire rope clips, wedge sockets, and rigging blocks must be also carefully inspected for damage. Destruction of any damaged hardware so that it cannot be re-purposed, is the most effective way of disposal.
Why should this lifting point be removed from service?
This lifting pad eye was found on the working deck of a vessel. It shows obvious signs of heavy corrosion to the point where parts of the weld and eye itself had started to come away reducing both the material thickness of the eye and compromising the integrity of the weld deeming it unfit for use without repair or total replacement.
Why should this alloy chain be removed from service?
When you look closely at this section of an alloy chain, you can see that there is both corrosion and deep gouges in several links. This damage was likely caused from misuse and abuse to the sling and warrants removal from service.
You can also notice the link in the centre of the picture (6th full link from the bottom) is twisted. This if often due to overloading or with lifting being made around a sharp edge.
TO SUMMARISE
As you can see from above, there are a vast amount of defects and these may not easily be detected. However, identifying and removing unsafe lifting and rigging equipment is critical to maintaining a safe work environment and avoiding accidents and costly fines. At Ranger we perform certified rigging inspections and can provide lifting and rigging training for your employees. Contact us today to book an inspection or call us on 1300SLINGS.
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