lifting hole on beam web

[delagina]

I have the "traditional" lifting lug design guide.
but in this case the lifting sling will go through the thickened web of beam all the way thru the other beam of this skid.
any design guide for this this type

 

[JStephen]

It would simplify the design if there were a cross member at that point, otherwise, presumably, you'll have various lateral and torsional loads depending on exactly how the sling contacts the beams.
I've tried to attach via shackles so I didn't have to worry about how sharp that edge is. I wonder if the sling manufacturers can specify a minimum radius to avoid sling damage?

 

[dhengr]

Delagina:
I would use a full length 6 or 8" dia. pipe btwn. the two WF skids, through their webs and canti. out beyond the tips of the top flgs. by about 6 or 8" on each end. They should have a cover pl. (cap pl.) on the pipe ends a few inches bigger in dia. than the pipe to prevent a sling from sliding off the ends. There might also be some stiff. pls. btwn. the pipe and the WF web and flgs. to help support the pipe canti.

 

[NS4U]

I have not seen a guide for this as I think it is uncommon. Is the lifting contractor proposing this? I have a lot of questions about the actual feasibility of this given the sharp edge and 90 degree corner shown. When i design skids that need to be lifted I design a lifting lug that cantilevers off the skid beam and add a crossing beam to the skid to resist the moment. The lug can be bolted (removable) or welded (permanent). Welded is generally easier to get to calc out in my experience.

 

[delagina]

Dhengr, the other skid goby got that pipe you are saying. But that looks like a heavier skid with additional access platform on the skid.

The goby i used didnt have a pipe and looks similar in weight to my skid.
Im the one doing the skid.

I want to know the potential issues of this.
Having lifting lug on top flange or side of beam can be a trip hazard if not cut.

This one looks clean if will work

 

[Lomarandil]

Putting softeners on the flange tips is easy and negates the issue there. On the doubled web edges it's a bit trickier. What type of sling are we talking about? What magnitude of load? What service class?

Agreed that you likely want a cross member between WFs near the rigging point, although this is less crucial if the rigging height is at the centroid of the beams (just weak axis effects, not torsion).

Dhengr's idea is a good one so long as your situation won't be sensitive to slight load imbalances due to sling lengths (field made slings especially aren't very precise). Uses twice as many short slings, but you don't have to worry about threading a sling through a hole (tougher than you'd imagine with slings of any significant capacity). Or do you mean the sling to be permanently part of the skid?

In some ways, lifting through the webs is easier than a traditional lifting lug as long as your web thickness isn't an issue (small loads, web doublers or HP sections) and load instability isn't a concern.

----
The name is a long story -- just call me Lo.

 

[delagina]

Ns4u, can you provide sketch of what you usually use

 

[CANPRO]

delagina, please see sketch. Could something like this work for you? Your sling will still come up at the same location with this method and it eliminates the sharp edges and having to feed your slings through the holes.

 

[delagina]

Thst can be tripping hazard though if not cut. And it needs to be long to be above the grating.
I should just weld lfiting lug on the beam top flangr instead thst would be simpler and field cut it instead.

 

[CANPRO]

I see, I misunderstood the nature of the tripping hazard you were trying to avoid. Could you move the angle to the bottom flange of the beam? Then you could put a shackle in the angle and then the sling would run vertical just past the edge of the top flange.

 

[12345abc6ttyui67]

What sort of load magnitude? For small loads we often use a bolted padeye or lifting bracket which can easily be removed. I wouldn't propose using a bolted padeye for 'big' loads though.

What about proprietary items like swivel hoist rings, eye bolts, etc? Again, these are easily removed to avoid the tripping hazard after installation.

 

[dhengr]

Delagina:
What ever you do, don’t give us any of the real engineering design info., that would let us hone-in on some of the important parts of the problem. Some dimensions, loads, member sizes, etc. really help us to visualize the real problem. Otherwise, you have one guy guessing and expounding on a 1 kip load and the next guy is talking about 1000 kips and 36 WF side sills/skids, and they are all just guessing and talking past each other. In any case, the hole in your WF web will probably not be a round hole with a doubler pl., those don’t take to slings very well. It will more likely be a 2 or 3" high, by 8 or 10" long slotted hole which will take and load the sling better. Then, take a 7 - 9" long piece of 4 or 5" dia. std. pipe and cut it longitudinally into quarter sections to be used as edge softeners on your slotted holes. You do have to be able to get in under the top flg. to weld these edge softeners to the WF webs. I don’t go out of my way to design tripping or unsafe features into my structures, but are we designing walkways or equip, skids here? I’ve never seen a skid that you couldn’t trip on or fall off of, and hurt yourself, if you are not careful, but they do have to be lifted.