Loosening bolts before landing truss on ground

[Dagger]

we always lower truss to working height and strip lights, cables etc. and then land truss on ground before unbolting.
I was wondering if when everything is stripped from truss ,would it be safe to only loosen bolts and then land the truss on ground?

 

[brucek]

I wouldn't. I guess you could loosen some top bolts that are in compression....unless they're near a lift point and are not in compression. I just dont see any advantage of doing it unless you are really trying to bend some endplates so you can get new shinny truss from the shop.

I have no problem pulling safety pins on pinned truss just before landing to save some back pain, because it wont change the geometry of the truss in the air. Loosening bolts will.

This is only my opinion....and is not based on any engineering

 

[Lextech]

Bad idea. All it takes is one bolt to have its nut forced in an unnatural way and strip it's threads. New York State Fair 25 or so years ago someone missed putting a wrench on one nut on a lighting truss. Come load out the truss came down and the nut was stripped. 20 minutes with a sawzall, two battery packs and 60+ IA hands watching they finally got the grade 8 bolt cut. Land it before loosening.

 

[egilson1]

Nope. Won’t work the way you want it to, since there will always be load on the truss so long as each section is not supported. And that leads to what Lextech describes.

 

[cbrandt]

I've had to force stripped nuts off more times than I can count. It is not worth your time and stress to save the bending over. Not to mention the additional wear and tear on the trusses. If you want to save bending and other things, find a safe case or dolly to land the empty truss on. Truss should never move with loose bolts. It is a BIG lever.

 

[TimMc]

we always lower truss to working height and strip lights, cables etc. and then land truss on ground before unbolting.
I was wondering if when everything is stripped from truss ,would it be safe to only loosen bolts and then land the truss on ground?

No. Structural integrity should be maintained until the unit is landed and the lifting points disconnected.

edit ps: Why TF would anyone propose such an unsafe and ill-advised procedure?

 

[Footer]

Thats more work. You now have to touch each bolt twice. 1st rule of being a stagehand is never do more work then you need to do. 2nd rule is don't get killed or kill anyone. This dumb plans breaks the first two rules.

 

[danTt]

If you're looking to not have to work on the ground so much--consider landing it on road cases--one per piece, to take it apart. It's probably more work than necessary but might be worth the ergonomic gains.

 

[Richard Green]

Yep. This falls under the category of "I can't believe nobody thought of this before!!!! " They did. There's a reason nobody does it this way. All the previous posts have it dead on. It's a shortcut that takes twice as long- IF everything goes right.

 

[EdSavoie]

If the bolts are loose, all the stresses will bear on the small surface area where the bolt and the edge of the hole make contact, instead of being distributed through the entire contact area of the two plates (and the washers).

In terms of forces, you're turning it from a well distributed connection into a bolt guillotine.