FOS
FOS
(OP)
I have been asked design some lifting beams that will be used to transfer material from a slab on grade and onto a trailer. My client has purchased a machine specifically for this task. The intent is to use a system of tubes spaced 5'-0" o.c to place the material on in the shop. Once a load is complete the equipment will come in and hoist all of these tubes at once and place them on a flatbed. The client wants to pick up a maximum of 50 kips with a trailer that is approximately 48' long.
I know rigging has a FOS of 5:1. I also know Steel has a general FOS of 1.67:1. So, if these were combined together we would end up with a FOS of 8.33:1. I'm not sure if this is appropriate or not (combining the FOS). How should the FOS be handled in this instance? I want to be conservative but not too conservative.
I know rigging has a FOS of 5:1. I also know Steel has a general FOS of 1.67:1. So, if these were combined together we would end up with a FOS of 8.33:1. I'm not sure if this is appropriate or not (combining the FOS). How should the FOS be handled in this instance? I want to be conservative but not too conservative.






RE: FOS
RE: FOS
RE: FOS
RE: FOS
RE: FOS
AISC FOS + impact will be well below 5:1.
John,
I'm not using it the client is. I will remind him of what is required but that is up to them to mark it up. They should be aware of the requirement as this is something they do on a regular basis however, the machine is new.
RE: FOS
RE: FOS
Don't try and mix and match FOS between rigging and the beams. Your rigging should all be rated to include the FOS needed (which is usually 5), and per the BTH-1 you get your own fun FOS on the beams.
Sounds like these are going to get a lot of uses - don't forget fatigue.
RE: FOS
RE: FOS