As Structure engineer, We design, calculation integrity of the structure and keep our structure safe, as well as for lifting and rigging equipment. In our calculation, Our Client Said that safety factor for sling should use 5.01 based on code BS EN 13414-3.
After investigating with a calculation, finally, we need 84 mm diameter sling. However, our market has not available for a sling with a diameter more than 60mm. it should an alternative way to get diameter 84mm. that is using cable laid grommet and additional note that vendor has IMCA M179.
What is Cable Laid grommet or grommet in general term?
Cable laid grommet is a special type of sling which forms a continuous loop. Grommets either have a wire rope body or a body map up of six strands which are laid helically around a strand core. either a hand splice or a mechanical splice then forms an endless sling body.
In my opinion that cable laid grommet are sling (continuously loop) with no visible splice join. to gain cable laid grommet with a specific length, at least need 5 times strand length to be twisted and screw in core strand.
According to BS EN 13414-3 calculation as follows:
Zp as a coefficient of utilization ( safety factor) with calculate Zp = 6.33 -0.22 d and also state that for grommet diameter less than 60mm, Zp shall be not less than 5.
Based on IMCA M179 Calculation as follows:
Based on among those 2 comparisons, seems likes similar. however, there is a discrepancy. BS EN 13414 doesn't consider bending factor. except for this case, using IMCA and BS EN are similar.
Next post, We will discuss with derivation calculation between those 2 codes comparison.
-IMCA M179
-https://johnhemsley.wordpress.com/cable-laid-grommets/
-BS EN 13414-3
-Internal Discussion with Mr Adhi, Mr Wahyu and Mr Sinung
1 Comments
thank you sir for the information, maybe someday we can work together.
ReplyDeleteHi, thanks for reading stuff like this, get me your perspective about this article. Thanks :)