Fixed Lifting Frame 1

[ALREMAN]

Could anyone point me to the design and/or OSHA requirements for a lifting frame? It is a gantry design made of stainless tube steel. It has one purpose and that is to lift a hinged section of conveyor out of the water for inspection. There are no trollies on this frame, just a fixed lifting point with an electric hoist attached. I need to provide a load rating for this frame, but I'm not sure what the FOS should be, and if there are other requirements. Any help would be appreciated.​

 

[JStephen]

I can't exactly visualize what it is you're building, but would it fall under the scope of ASME B30-20 and ASME BTH for below-the-hook lifing equipment? If so, that will specify factors of safety, etc. Not sure if it covers stainless, come to think of it.

 

[ALREMAN]

Thanks for the quick reply. The setup is two A-frames supporting a horizontal beam. At the center of the beam is a fixed attachment for a hoist to connect to. The bottom of the A-frames are welded to steel beams that span a pit of water. I have a copy of BTH but I didn't think it would apply since it is "above the hook". However, there isn't much difference. Maybe the attachment point is designed according to BTH and the structure to the AISC code? What do you think?

 

[dhengr]

ALREMAN:
Take a look at the codes and stds. for crane design. Most of them don’t deviate much from the AISC Manual, in terms of steel design and AWS in terms of welding. They load test to 1.25 or 1.5 times the design loading. But, they also expect regular maintenance and inspection, the more so if the equipment is constantly exposed to a bad environment. You might consider putting your hoisting equip. at the middle of the horiz. overhead beam in some sort of a well ventilated ‘dog house’ to keep it dry and out of the weather.

It could also be two pipe legged “A” frames, leaning in toward the hoisting equip., thus shortening the overhead beam span, and improving the stability in the direction of the beam axis.