Sling Rating Calculation Tutorial (Uniform Load Method)
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- čas přidán 8. 04. 2017
- A step-by-step guide on calculating the Safe Working Load (SWL) - i.e. Rated Capacity - of multi-leg sling/lifting accessory arrangements using Uniform Load Method.
This is very helpful for anyone who is involved in lifting operations for suspended loads (i.e. slinger/rigger, crane operator, lifting supervisor, lift planner, etc.), and will assist in preparing for carrying out these roles or attending a course in the future.
Presented by Kevin Bennison - Lead Trainer and Managing Director at SWL Training Limited.
Your questions on this, or any other lifting matters, are welcome and we will always do our best to answer them for you. Contact us through our website, through social media or by using the contact details displayed on our website.
www.swltraining.com/
Thanks for watching. - Jak na to + styl
This video was BRILLIANT! You explained it so easy. Thank you!!!
From someone who didn’t finish school and went into lifting… never really got taught about this stuff,literally hook it on and go.
This is explained so simple!!!
Massive shout out Kev, I reached out before and when I do my AP I 100% will be making the trek up to you!!!!!
I work within arigging and lifting operation workplace and although I work to all the safety guidelines of the plans and equipment specs, I’m ashamed to say I have a real hard time grasping the mathematics and basic physics behind load lifting. Not the brightest of people when it comes to classroom learning and this is the best broken down explanation of the stuff I need to know. So thank you very much
Thank you for watching Andre. Of course it can be difficult to grasp some of the mathematics when it is not explained clearly. We all have different learning styles, and it's simply a case of understanding what works for you.
Yes, I agree, I am Appointed Person, I recently obtained the ticket ALLMI, and let me tell you something. I got better informed by you in this video than the course I took with them.
I have been a class 2 lorry driver and hiab operator for over 12 years. At my 56 years of age, at this stage it is very difficult for someone to impress me, but you made it very easy to understand.
I have subscribed because I want to see how you start this process.
Currently, I am building my template for elaborating lift plans.
So pleased to hear that - thank you!
@@InspHigher It is what it is, it is that simple.
Excellent video as always. I have many questions but I will focus on one at a time. Do I require a basic lifting plan for any lift? If so, does it need documented?
@@frankgault7845
"Do I require a basic lifting plan for any lift?"
The question is ill formed, it should have been, do I need a liftplan for a basic lift?
The answer is no.
Ok, we need to know if you are talking as a crane operator or management.
Generally, if it is a basic lift, then you follow your crane manufacturer's recommendations
On a basic lift, the crane operator should be able to do the job without any paperwork, as long as he is happy with the crane, himself, the location and the instructions of the client.
I hope this helps.
Thanks for the reply. I agree that the question was a bit misleading.
Brilliant video, thankyou very much for this.
I honestly wish the training courses Iv been on had explained it like this
A bundul of thanks. My dear Teacher. Wonderful Training
Amazing job there. Every single point came out well with detailed explanation.
From the initial part of the video, I want to point out that the red material attached (pad eye) increased from one to two. This also added to the total load weight.
However, the illustration was clearly understood.
Thanks
Thanks very much Isaac…I appreciate you watching and commenting.
Good point; however, the lifting brackets were less than 1kg each - so, they’re fairly insignificant really.
If that is it. Cool👍
Brilliant this Kevin - Thank you
Brilliant ty,,been a supervisor for over a year and ive only really understood PROPERLY the mode factors after watching your vids...a big thanks 👍
You're welcome William - my pleasure.
You're Rigging Supervisor, sir?
@@MohamedGamal-oj7qs Yes - supervisor, planner and trainer.
Excellent tutorial many thanks for this video.
Thank you Paul - glad you found it useful.
Very well explained, many thanks for this video
You're welcome Farouk - glad you found it useful.
great explanation! thanks
Absolutely fantastic video. I learnt a lot.
Very well done and I hope there’s more to follow.
Thanks Rhysnoronha
Well explained and informative.
great job. everything very clear. thanks
Thank you Cocobongo LT. Glad you found it helpful.
Good explain , thank you teacher .
في قناتي مقاطع مهمه للريقر.
Awesome delivery thank you
Thanks very much Glenn - really appreciate it.
thanks a lot for tutorial, good explain
Surprised by the negative feedback. I thought the sound was fine. Even my Yankee ears followed every word. The opening demonstration using scales was the best I have seen. The speaker spoke clear, no pauses, no echo that many youtube videos suffer from. The explanation of the mode factor was very good. The repeated emphasis on the answer being for one sling strength and the fact that 4 pt lift can't have equal loads, so treated as 3 sling, could be a lifesaver. On a related topic I watched a video of a tower erection disaster. It was not a sling failure but the workers did not know how to calculate what the lift point (makeshift U-bolt of some kind) should be. I believe 5 were killed and the entire communication tower fell. If there is not an engineer there, workers having the basics will improve the odds of everyone going home at the end of the shift. Great tutorial!
Thanks very much for your feedback, and I'm pleased you enjoyed the video Joseph.
We do understand and respect that different people may have different views and experiences.
Our aim is to get more useful information out to the lifting industry, and feedback like this encourages us to continue.
very informative. many thanks
Very Well Explained again
Thanks again Johnny.
Thanks , great explination
This is honestly amazing and never really understood it. Took the time to watch this video and it amazing thank you so much. I am off to work to upset some people now. Do you have any recommendations for a pocket book I can keep on me?
My pleasure - I'm glad you like it.
Yes, you can order one of our Lifting Operations Pocket Assistants from www.InspHigher.co.uk
Great video learnt a lot thank you
Glad you liked it Simon - thanks for watching.
Thank you good lecture carry on
Thank you Danish - glad you enjoyed it.
Good work
Hi. If is a rectangular load and a round load and I'm lifting using vertical basket hitch method the loading factor is double in both situations? (Using webbing slings for example)
Thank you
Excellent explanation thank you sir,
Glad you enjoyed it - thank you!
Excellent tutorial thanks! I sub'd to the channel as a result👍🏽
Thanks very much Jag...appreciated!
Thank you
Hello, how would these principles apply to the lifting anchors, for example most anchors have a SWL of 2.5t. in my example my slab ways 5t, i have 4no anchors which have a SWL of 2.5t. my question is because there is 4 chains connected thats why the anchors wont pull out? i.e. load distributed across all anchors?
Excellent I thinking doing my crane supervisor on your centre
Thanks very much A H. We don't provide the Crane Supervisor course directly. We do produce supporting material for the role, but our main focus for training is Appointed Persons and management.
Thanks.
Hi there. great video. You seem very clued up and I really enjoyed this video, forget the haters who leave silly replies. Can i just ask, what about if you are working with a 4 leg chain set, and the tag has maximum info, rather than bare minimum like nowadays. And the tag states that if using 1 leg, vertical, like a drop chain with no choke, just attached to a lifting point of an accessory, that it has the equivalent of a single leg chain? It seems that no one wants to put there name to it. For instance a single leg of a 6.7t set of 4 chains can lift 3.15t. I have seen this stamped on numerous 4 leg chain tags in the past, but nowadays they just state the minimum info on the tags, and not what 1 leg vertical will do. Obviously all chains are made to the same spec, the only difference is the alloy grade which upgrades the capacity when going to grade 10 alloy for instance. In your time, have you honestly not seen a tag state ( on 10mm grade 8) that 1 leg vertical will do 3.15 with the other 3 hung up?? Im very interested to hear your reply. Best regards
Hey , it would be great to hear your feedback please?
Apologies for taking so long to reply…I don’t keep up with these comments too much really.
Is that Richard?
Yes, I have occasionally seen the single leg rating marked in accordance with what you describe - and have even marked them myself at times (with having done the relevant quals).
However, codes of practice recommend using a portion of the overall WLL in accordance with the number of legs used.
So, in absence of marking, when using a single leg of a 4-leg 6.7t set, it would be recommended to apply a maximum load of 1.68t
Great Video M8
Thank you - our pleasure.
Just been refreshing my knowledge..This video really helped thank you.
So if I hung up 3 legs of a 4 legged set-up..would i just need to divide the wll by 2.1 to find the max load I could lift on 1 chain ?
Hi AtroGamer...thanks very for watching. In theory, yes, that's correct. However, Codes of Practice state that, if the values for reduced number of legs are not marked, you are to use the percentage of WLL according to the number of legs used. i.e. One leg of a four-leg assembly = 25% of overall WLL
@@InspHigher That’s true to an extent.. it clearly states in LEEA that using that equation the slings/chains will not be used to their maximum potential, if you do want to use the accesory to its maximum potential the mathematics must be worked out by a competent person.
@AGB…of course. ‘Competent Person’ is perhaps subjective though - particularly on a public forum; using the relevant portion of WLL is clear-cut 👍
Very informative video. However, I have a question. As I understand, and as you’ll see on the label of most webbing slings, when you choke a load with a sling, you are to reduce the safe working load limit by 20%. So the question is, if I use two chain slings, attach them to two flat webbing slings, and then choke the load with the webbing slings, how would I calculate the swl?
Assuming the webbing slings have a lower swl than the chain slings, would i use the unified load method to determine the swl of the webbing slings then deduct 20% from it?
Thanks for your question Oputaossai. Let's say that you were using a 4.25t WLL 2-leg set of chains and two 3t WLL webbing slings in a choke hitch.
(3t x 1.4 = 4.2t) 4.2t x 0.8 (20% reduction)= 3.36t
As 3.36t is lower than the WLL of the chains, this would be your maximum safe working load in that configuration.
Great video thanks, I have a AP61 course in Feb 2019 and I need as much advice as possible..
How did your AP course go Gary?
@@InspHigher passed it thanks to your great videos... keep up the good work
Hi sir please can you advise me how to make empressevs rigging lifting plan pls?
Can you please explain how are you coming up with these mode factors. Thanks bin advance
They’re derived from trigonometry and are publicised in relevant codes of practice (LEEA, etc.)
Hi mate you said you was going to do a video on uneven loads. Can't find that on you're channel? Get stuff btw
Hi Keven, thanks for very useful lesson. I've just got one question. If we use 4 slings as you show on your drawing with 60° angle but with transverse spreader / lifting beam will it still be 2.1 factor applicable or the weight will be spread different way geometrically?
Yes, use the mode factor of 2.1 - unless you are familiar with the trigonometrical method of rating.
Hi bro,, plz coordinate with me.. I want to talk u regarding some lifting engineer question..
Great video but what about using two x two legger chain as a four legged
Hi Dave…
You multiply the two-legged angled WLL by 1.5, as only three legs are to be counted.
e.g. if using 2 x two-loggers, each with 7.5t WLL at 90 degree included angle…
7.5 x 1.5 = 11.2t WLL
Nice, interested in your online course
Hi Kevin,
Please correct me if Im wrong...... so the tension in the sling becomes 6.3 so for example to pick up a 6 tonne load I could use 2 x 4.5 tonne slings which could lift a total of 12.6 tonnes altogether? Many thanks
That depends on the angle Wendy. Just follow the formula - Uniform Load Method has been made relatively simple to avoid the need for trigonometry.
If you're lifting a 6te load on two slings within 90 degrees, it would be: 6te divided by the mode factor (1.4) = 4.29te minimum WLL per sling.
What about 6 point lift using spreader beam is it 0.7 mode apply for each leg?
It depends on the anticipated share of load and how the slings are positioned on the load Aleksandr. If you have four angled slings, with two vertical slings in the centre, I'd recommend using the mode factor of 2.1 for the four angles slings, then the two centre slings would be best to be able to cope with the entire load weight between them. This is allowing for worst case of course, and more accurate planning/calculation would allow the use of smaller slings.
I think we devide And thin multiply what I've seen other videos,, what totally is exactly or this is your other solution
Do you consider how the load is slung ,example choked? Please could you breath through ❤
Can someone tell me why? It's not to do with leverage is it?
For last example 4.53te WLL ,
Is the tension on sling also 4.53te?
If not how to calculate tensoin on sling?
If the angle is within 90 it’s fine. Think so,,,as that’s how you know which mode factor to use in calculation
sir what's mode factor of 30 & 45 deg? plz reply fast, i am still waiting for my previous!
That would be done using the Trigonometrical Method of rating, which is not covered in this video.
Just one question..Surely with angles over 90 the mode factors should increase given the tention
They decrease - which will result in a lower rated capacity for the configuration to allow for the increased tension.
sir how i can get the mode factor table? or can you send me. plz reply.
Apologies for the late reply. You can order the pocketbook which contains the table at www.InspHigher.co.uk
How do you get 1.5 under 90-120 angle
Because each sling leg is good for 0.5 x WLL at up to 60 degrees from vertical, and you calculate for three legs taking the weight of the load in a four-leg assembly. 3 x 0.5 = 1.5
Great explanation thanks 🫡
swl training lifting operations pocket assistant book how do I go about getting one please
You can now order the 2nd Edition at www.InspHigher.co.uk
What happened Mr. Kaven ? You haven't been posting videos for few years now. Did you open a new channel?
Just busy with my actual training. I’ll try to do better 😄
@@InspHigher yeah Mr Kaven pull your finger out 🤣🤣🤣👍
👍 one
Please How do I get a copy of the small booklet ?
Hi Sam...it's available to order from our website: www.insphigher.co.uk
whats the deference between WLL and SWL?
We're just about to upload a video on this very subject Vishnu.
@@InspHigher thank you sir
So if you have 4 vertical slings are you saying the mode factor would still be 2.1?
I have watched this video twice and I am now certain that although the information presented isn’t clear, it’s good information to eventually learn, the presentation is horrible.
Well, thanks for sitting through it twice - even with your discomfort.
I was very new to making videos when I done this one, and my primary objective was to get content out that was helpful to people. Indeed, many people have found it helpful, and still do - regardless of the quality. It's fair to say that I've improved since doing that one! :-D
Interesting facts, but the sound quality is bad, also the distracting background of the block wall is a poor presentation. The projector slide should have much darker colours such as black - because it's difficult to see on this format or simply use a wipe board. It was not clear in the presentation where the figures come from; 1.4, 1, 2.1, 1.5 are what?
Hi Kim,
Thank you very much for your feedback. We appreciate you taking the time to watch and comment.
We agree that the sound quality could be better and, with an increased budget, the setting and resources could also be improved. However, our intention was to get some information out into the public domain that assists people in carrying out these calculations, as there is currently little information available.
In the coming months, we will be launching products that are professionally filmed and designed. The tutorials are really just my way of getting information out there for free.
With regards to the mode factors, these are based on the Sine value of 45 degrees and 60 degrees, then multiplied by the relevant number of legs. These mode factors are part of a harmonised method of rating, called the 'Uniform Load Method'.
Best wishes.
Excellent tutorial, many make this complicated. If you don't know what units he's talking about Kim, you've researched the wrong subject (He clearly starts with, and repeats throughout, the term 'Mode Factor') . Go read a book on coaching, you need it desperately - Great video Kevin.
Seriously Kim this is a Excellent video and very well explained i just think your being to pernickety
I really liked it (and your others) I am involved in many lifting operations and use the same methods.