Helper lineset?

MRW Lights

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Joined
Jan 4, 2017
Location
NYC
Just speculating but it may be sharing the counterweight load for the electric lineset.
Yup, that's it. Standard practice and really necessary with movers / cable in counter weighted fly systems. Especially when you get to do custom rigging I love to put a line set offset upstage married and trim it to land about 12" above the electric at the in trim. You can run your cable / data on this line set and make things really neat clean as well. Makes troubleshooting and hanging fixtures almost dreamy.
 

danTt

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Joined
Aug 24, 2011
Location
NY
I find marrying counterweight sets to often lead to unsafe rigging. Generally increasing arbor capacity is safer.
I don't think anyone will argue with you about ideal. That being said, it's a lot more likely to get a venue to marry arbors than in is to get them to renovate the fly system.

As long as you're working safely with qualified people it's fine within the WLL of the equipment, especially for non moving linesets. It's when you get into multi-married battens on working pieces that things start getting questionable.
 

BillConnerFASTC

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Jan 30, 2010
Location
Clayton NY 13624
I will continue to advocate for doing what is right and best, not for what we can get away with. Hard sciences, athletics, and other disciplines in academia don't give in nearly as easily as the performing arts, and especially theatre. I suspect it's because we are creative in our approaches and uses of materials. Still, I'd urge everyone to ask for great facilities and systems and equipment and materials, and not be so eager to settle for last place support.
 

egilson1

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Feb 25, 2009
Location
Boston, MA
Can you marry line sets safely? Yes. But there is a lot involved. You need to do the proper load calculations to ensure that you’re not overloading individual components of each line set. It’s better to try and treat each line set as a separate system, such as hanging fixtures on one line set, and then all the cable on an adjacent line set and only have the pigtails of the fixtures jump the “gap” between them.
 

danTt

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Joined
Aug 24, 2011
Location
NY
Can you marry line sets safely? Yes. But there is a lot involved. You need to do the proper load calculations to ensure that you’re not overloading individual components of each line set. It’s better to try and treat each line set as a separate system, such as hanging fixtures on one line set, and then all the cable on an adjacent line set and only have the pigtails of the fixtures jump the “gap” between them.
This is certainly a better solution, although I think you'd still end up marrying the sets together to avoid moving one batten further than the cables lengths support.
 
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danTt

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Aug 24, 2011
Location
NY
I will continue to advocate for doing what is right and best, not for what we can get away with. Hard sciences, athletics, and other disciplines in academia don't give in nearly as easily as the performing arts, and especially theatre. I suspect it's because we are creative in our approaches and uses of materials. Still, I'd urge everyone to ask for great facilities and systems and equipment and materials, and not be so eager to settle for last place support.
As a consultant, that's your job, and you certainly should do so--and everyone in the industry should continue to bring up the benefits of renovation when discussing these problems in a big picture-long term sense.

That being said, I can tell you exactly how well it would go if my designer sent in a plot requiring married battens and I told my production manager that we needed to rennovate the theater to support it. That's not to say that there aren't other methods of avoiding it--a rental or purchase of motors and truss comes to mind if this is a regular recurring problem, or splitting the weight reasonably between the pipes and locking/marrying them for spacing and physical constraints, each of which have their own potential issues, though much more managable then a full venue rennovation.
 
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Ben Stiegler

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Aug 3, 2017
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Sf Bay Area
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BillConnerFASTC

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Location
Clayton NY 13624
To me it means a second arbor - often shorter than the prime arbor - installed in guide system just under and connected to prime arbor, with handline retied - so in effect a longer arbor. Usually for electrics, no travel or trim or loading issues. For tall items, like a heavy wall (personal experience), you may have to cut and retrim lift lines, or pick up from bottom of piece.
 
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tjrobb

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May 14, 2009
Location
Cedar Rapids, Iowa
O/T, this reminds me of a cue-to-cue where, after the third retake, a voice cried from the flies: "can we PLEASE do this without flying the wall?!"

Seems the director didn't remember the 1200lbs wall was flying out each take, so the gent was basically doing laps with the dang thing. And yes, manual counterweight.

The director not only let the wall stay in place, she called an early break for the fly crew.
 

Ted jones

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May 6, 2014
Location
Chicago
To me it means a second arbor - often shorter than the prime arbor - installed in guide system just under and connected to prime arbor, with handline retied - so in effect a longer arbor. Usually for electrics, no travel or trim or loading issues. For tall items, like a heavy wall (personal experience), you may have to cut and retrim lift lines, or pick up from bottom of piece.
Bill,

Agreed. But we should caution our audience that these stunts are performed on closed roads with professional drivers.

Adding the trailer arbor is a good solution BUT, if you are going to consider it, be sure and go back to the manufacturer of the head block and find out what load they designed for it. If the set has a 1,400 LB capacity arbor and the HB was engineered for, say 1,800 LB, you don't have a lot of room. Exceeding the design load is not recommended. You should also investigate the loft blocks. And be conscious of where you apply the weight on the battens. Keep in mind that older systems, +15 years, may not have as robust a design factor as most manufactures have now. Typically, the manufacturers I deal with now want to know what the capacities are before they quote. One 2,400 LB set will be a special if all the rest are 1,600.

If the blocks have a manufacturing sticker on them, you should be able to go back to the builder with a job name and approximate date to request the information.

Follow the load path from one end to the other and be sure that your safety factors are accounted for at every part. Be more sure of the actual loads, not a guestimate.

Ted
 

tjrobb

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Joined
May 14, 2009
Location
Cedar Rapids, Iowa
Bill,

Agreed. But we should caution our audience that these stunts are performed on closed roads with professional drivers.

Adding the trailer arbor is a good solution BUT, if you are going to consider it, be sure and go back to the manufacturer of the head block and find out what load they designed for it. If the set has a 1,400 LB capacity arbor and the HB was engineered for, say 1,800 LB, you don't have a lot of room. Exceeding the design load is not recommended. You should also investigate the loft blocks. And be conscious of where you apply the weight on the battens. Keep in mind that older systems, +15 years, may not have as robust a design factor as most manufactures have now. Typically, the manufacturers I deal with now want to know what the capacities are before they quote. One 2,400 LB set will be a special if all the rest are 1,600.

If the blocks have a manufacturing sticker on them, you should be able to go back to the builder with a job name and approximate date to request the information.

Follow the load path from one end to the other and be sure that your safety factors are accounted for at every part. Be more sure of the actual loads, not a guestimate.

Ted
I feel this goes to the time we pulled the lock rail out of the floor with our winch (winch used as we don't have a loading rail). Coincidentally, we were striking the wall mentioned in my previous post.

Said lock rail is now bolted THRU the floor to the concrete tees.
 
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