Rigging Slings Load Testing

The Engineer/Surveyor from the company that supplies lifting equipment failure/collapse indemnity insurance cover will be able to advise.

The equipment should be covered by insurance. In order for that to happen, the identifiers on each piece of equipment need to be in a General Register at the facility, and the periodic inspection reports that the insurance company issues should be available and relate to the items so identified.

The periodic inspection reports will advise the current safe working load and the intervals between inspections. Any equipment that is not covered with a current inspection certificate needs to be withdrawn from use immediately, and not brought back into lifting service until an appropriate report becomes available. Otherwise, the facility is not insured in the event of lifting equipment failure.

if its anything like the chain hoists in the ship yard, there is no testing, just periodically replacement from the documented time period.

Working at the plant now, we a people come in to Certify our hoists yearly. (just like the shipyard)

Call your supplier.

ASME B30/ ANSI B30.9 / ASA B30.2 the standard

also good information in DOE's Hosting and Rigging Manual

or ASME B30.20-2003 for Below the hook lifting devices

And a great help in utilization is from Brookhaven National laboratory " Basic rigging workbook"

Great response GURU, I didn't even think about 1910.184.

Thanks. Even a blind hog finds the occasional acorn.

Yep, those who ignore OSHA may find their butts in a collective sling.

Thanks for the feedback. I have read this standard but it does not cover load testing annually. This standard only recommends visual inspection.

According to:

Department of the army technical manual / TM5-725

Inspection

Slings should be inspected periodically and condemned when they are no longer safe. The use of unsafe slings may cause serious damage to personel or equipment in case of failure under load. Fiber or rope slings deteriorate rapidly when exposed to the weather, or when fibers of the rope are broken or cut by sharp edges. Chain slings should be inspected for broken, cut or distorted links. The hooks on slings should be inspected for cuts, cracks, or indications of a tendency to spread open. Wire rope slings are weakened by broken wires, and should be removed from service when 4 percent of the total number of wires in the rope are found to have breaks within the length of one rope lay.

With care, a wire rope sling can used for a long period of time. Since all sling legs are subject to damage from cutting by sharp edges or abrasion, all sharp edges on objects to be lifted should be carefully padded to reduce damage to the slings. Wood blocking, heavy fabric or old rubber tires can be used as padding.

Method of computing tension in sling leg:

T= W. V

___ X. ___

N. L

T= Tension

N = Number of legs

W = Weight, Pounds

V = Vertical Distance, Feet

L. = Length, Feet

Sorry, I don't have the ability to draw out the method of computing.

Maybe James Stewart can assist me with that.

Sorry, but the only things we lift here can be lifted without slings, we use cabling and straps though, and the attached load has to be balanced. We can only do 35 ton lift (typically what is lifted is the upper half shell of a steam turbine), but the most demanding lift (IMHO) is the turbine rotor out of the housing without striking the diaphragms.

I think there is a bit more to the math for sling lifts, as the distance between support points must figure into the secant tension of the straps. Shipbuilders, and shipwrights, port repair services, will know far more about this than I can imagine.

I did learn that in Sitka, Alaska, before every sling lift (by the most massive dock lift in Alaska), a diver must check the positioning of the slings so that no damage to the hull, or underwater structures of the boat or ship takes place. Protecting the sling from sharp edges apparently also goes without even saying.

Much of what you do in regards to inspection and load tsting will depend on your internal safety policies, whcih should be influenced by safety standards and advice from renown safety organisations, many of whcih have been listed inthe previous answers.

In the oil patch, which is my domain, we have to inspect, test and colour code ALL lifting equipment, that is, slings, wire ropes, and various handleing tools used in the oil industry, to ensure safety as a number 1 priority.

With that said, you can 'google' what you need to know and there are many courses you could attend to give you the knowledge you need.

follow this LINK to see a basic overview and get you on the right road.

Depending on your location, you can look to find a local inspection company such as TUV, who are one of the best in the world. They can also advise you as to the correct course of action.

One final thing, well done for recognising a safety issue and now you know that you need to have your slings inspected, make it happen.