Safe Working Loads

[smithson1984]

Hi Folks,

I am unsure as to what weight I should stamp a S.W.L. on a pad-eye.

It is designed to hold a dead weight of 5 tonnes however when addition factors are added (skew loads, dynamic loads etc.) this rises to 8.76 tonnes. I'm not sure whether I should have the former or the latter stamped on the pad-eye. Officially the SWL is 8.76 tonnes but I don't want a crane operator to think that they can lift 8.76 tonnes dead weight.

Perhaps I should be stating a SWL and a rated capacity or something similar.

Any thoughts or advice would be greatly appreciated!

Many thanks in advance,

Ian

 

[chief]

if it designed fOr 5T SWL, and tested to overload as per regulations], it should be stamped to 5T.

Offshore Engineering&Design

 

[chicopee]

I am confused is the 5 tons or 8.75 tons the safe working load? did you design and manufacture the padeye? Where is the padeye going to be used? show us a sketch of the item because the term padeye is misused too often.

 

[smithson1984]

Hi Folks,

Thanks for the responses.

Chicopee, I think I am confused also!

I have taken the SWL load to basically mean the maximum load that the pad-eye is designed to take (this may be incorrect). This is the dead weight * a skew factor * dynamic amplification factor * environmental loading factor. So my dilemma is do I stamp the pad eye with simply the dead weight load (5 tonne) or the load which accounts for the other design factors (8.76 tonne). If the former, then I risk that if the crane operator has a load cell on the rig then a gust of wind could take it beyond the dead weight value and he/she could deem it unsafe to lift. If the latter, the crane operator may think he/she can add further weight to the lift which they shouldn't.

Is this making any more sense?

Cheers,

Ian

 

[desertfox]

Hi smithson1984

If the safe working load is 5T then that is the safe load it can lift period, the 5T in my opinion includes skew factors, wind etc.


“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[chicopee]

As desertfox stated the SWLs are determined by applying factors of safety to the braking loads. Your padeye is to be marked 5 tonnes. With a dead weight of 8.76 tonnes, the number of 5 tonnes padeyes will depend on their arrangement to the dead weight.

 

[DSB123]

What load has it been tested for??

 

[smithson1984]

Hey guys,

Thanks for the responses. It's greatly appreciated.

We pull tested each pad-eye (of four) to 15 tonnes which was essentially the 8.76 tonnes with a 1.75 safety factor on top.

Cheers,

Ian