Rigging incident Adele concert

[DuckJordan]

Well I can tell you that those free fall acidents with motor still attached are negligible even with a brake broken you'll see a slowish decent rather than a crash to the ground. I've noticed a lot of the motors coming out of prg no longer have the dead end attached to the motor. As a note about bag failures its fairly easy to spot a shitty bag and they don't fail too often either. Likely as it was going up the chain stacked itself and positioned to free run out of the bag 1-2' of chain out of the bag will pull the rest up and out with it. See chains run a lot during roof season on some not so watchful roof techs.

 

[BillConnerFASTC]

Overhead lifting* is exactly the purpose for which these devices are intended. What do you feel is unsafe? What would you propose instead?

*Definition, via the wiki:

Oh no. Until a few years ago the basic chain motor all were labeled NOT FOR OVERHEAD LIFTING. Too many people injured by dropped loads for my comfort.

 

[JonathanHarpur]

https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjF6f2f6OPLAhVEUBQKHY-JD9YQtwIIHzAB&url=https://www.youtube.com/watch?v=_dQJBBklpQQ&usg=AFQjCNH9MnhHDra0nGPpu1oCY0mr3oX0Pg&sig2=LZEzBah0YT4KN0K5Cy5-2A

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[DuckJordan]

Not quite Jonathan, We don't see the Mould Effect here, since the connecting links can just about 180, however. It does show how the weight of a chain can pull the rest of the links out of a container and onto the floor.

 

[JonathanHarpur]

Not quite Jonathan, We don't see the Mould Effect here, since the connecting links can just about 180, however. It does show how the weight of a chain can pull the rest of the links out of a container and onto the floor.

That second part was more my point, really. To a certain degree, chain can act like a liquid in a siphon. As long as the weight of the chain outside the bag is heavy enough to pull more chain out - and barring any knots, twists or pinches - likely as not, it'll all run out, once it starts. There's a generalized term for that kind of ongoing kinetic reaction, but I can't quite put my finger on it.

 

[Thetechmanmac]

There's a generalized term for that kind of ongoing kinetic reaction, but I can't quite put my finger on it.

I do believe the term you are looking for is chain reaction. No pun intended!
From google- "a series of events, each caused by the previous one."

 

[JohnD]

Some updated info from out friends across the pond:
http://www.blue-room.org.uk/index.php?showtopic=66838
Post #8 is the one I am thinking of, and I wonder if @ontoprigger posts here under another nickname.

 

[bobgaggle]

I'm curious now, if not a chain motor, what do you use for overhead lifting? Or would you use the motor to get it up in the air and then dead hang?