Hanging track for side tabs

[JLNorthGA]

Forged eye bolts?

I picked up some 3/8" forged eye bolts, rated at 1200 lbs.

I have some 3/8" x 1 5/8" (1/2" OD) steel anchors from Red Head. These are rated for overhead fastening.

Question - I was contemplating mounting them into the side of the concrete rib. Should I do that or mount them vertically?

The total load is less than 200 lbs (tab curtains, track, chain, carriers, etc.). The turnbuckles are forged.

 

[MPowers]

Re: Forged eye bolts?

If the location is right, I'll always take a shear loading condition over an overhead tension loading. For general mechanical anchoring devices with an embedment of about 3" or less, shear strength is similar to tension strength, IF, the product is installed per manufacturers recommendations and directions. However, that said, there is a lot more room for error in a shear loading condition. Direct pull-out tension conditions are either correct or on the floor. I have seen shear loading fasteners loose enough to pull out with your fingers if the load is removed but still "hanging" in there as long as the load is applied. That doesn't mean that one shouldn't be concerned about the correctness of the installation, but there is less chance of a catastrophic failure if either the substrate or the fastener deteriorates over time. The Shear loading condition allows time to discover and correct the problem during regular inspections.

 

[JLNorthGA]

Wimping out.... Plan B for hanging curtain track.

I really was uncomfortable using the bucket lift to go up to the ceiling. The sway at 37' was "interesting". I drilled a couple of holes up at that level, but.... I was reasonably comfortable up to 25' or so, but beyond that....

Plan "B" - Mike's Welding will supply us with four 8 x 8 steel plates with welded loops - with four drilled holes. They will also supply us with several L brackets. I am going to mount the plates on the walls using sleeved anchors (3/8") and adhesive. I am going to mount the L brackets on the walls. The track will be attached to the L brackets. I was going to use chain and turnbuckles to "level" the track. The chain will be on the diagonal.

I was planning on two chains for the track. The chains will go from about three feet on either side of the center to about 6' up from the track level. Sort of making a suspension bridge. The track length is 23' or so.

Does this sound reasonable?

 

[kicknargel]

Re: Wimping out.... Plan B for hanging curtain track.

I think I can picture the setup, though if you could post a quick diagram it would help. You really should analyze the forces on the components of the system. With the chain at an angle, the force on it (and the pullout force on the anchors) increases exponentially. (As the angle approaches horizontal, the force required to suspend the track approaches infinity.) I can't recommend enough "Structural Design for the Stage," by Alys Holden and Ben Sammler. It will teach you how to do the calculations. Or maybe someone here would volunteer / be hired to spend an hour on it.

Also, of course the hardware fabricated by the welder is not rated. It's not forged and hasn't undergone any testing.

I know it can start to seem like there's a reason to say "no" to every idea. In the world of rigging, pessimism must prevail.

 

[JLNorthGA]

Re: Wimping out.... Plan B for hanging curtain track.

I think I can picture the setup, though if you could post a quick diagram it would help. You really should analyze the forces on the components of the system. With the chain at an angle, the force on it (and the pullout force on the anchors) increases exponentially. (As the angle approaches horizontal, the force required to suspend the track approaches infinity.) I can't recommend enough "Structural Design for the Stage," by Alys Holden and Ben Sammler. It will teach you how to do the calculations. Or maybe someone here would volunteer / be hired to spend an hour on it.

Also, of course the hardware fabricated by the welder is not rated. It's not forged and hasn't undergone any testing.

I know it can start to seem like there's a reason to say "no" to every idea. In the world of rigging, pessimism must prevail.

Fortunately we have a structural engineer who volunteers at the playhouse. He did the calculations and the design. Admittedly he was more used to building factories and facilities than rigging, but he is quite knowledgeable. The welder's hardware is not rated, that is the only thing that I have any worry about.