stability of picking beam 2

[black79ta]

i am designing a pick beam we own that i can stamp and file per osha regs. i am using the asme bth-1 2005 spec which mirrors the aisc asd spec except with addditional safety factors. but my question is how do you determine what the L length of the beam is? (we are using 20' btw) but the ends are not restrained against rotation in the normal sense. i am inclined to use the spread length due to the fact that the beam is somewhat restrained as it is loaded (spreader cables are shackled to the ends at the top of the beam and the vertical wire slings are attached to the bottom of the beam.) any comments?

thanks

 

[bridgebuster]

Attached is a design example for a lifting beam give to me by a steel erector.

There's also a paper by David Ricker available from AISC. It was published in their journal, 4th Quarter 1991.

 

[black79ta]

thanks bridgebuster, i went thru that paper by Karl de Vries and it was interesting, to see the erector's point of view addressed. i used that method and it verified the 9th ed aisc method i was using. i also had one my friends check it with aisc 13th. so i think i am in good shape. thanks again. i also tried to locate the 1991 article but ran out of time, i will do that another day.

 

[bridgebuster]

yo're welcome; I glad the paper was useful.