Electrics / Rigging Question, take 2

[derekleffew]

A multiple choice question arose recently regarding the proper order of hanging lights and loading a counterweight fly system's arbor. Two of the four answers were clearly wrong and easily dismissed. Of the other two, one was to hang half the lights on the batten, then load half the weight on the arbor. The other was to hang all the lights, then load all the weight.

The "correct" answer was the former. I was taught, some thirty-plus years ago, to do the latter. Discuss.

 

[blackisthenewblack]

Didn't the Blue Man Group incident occur due to premature loading of pig iron?

I am assuming that we are talking about a line set that is bottomed out to working height and not hovering due to some set piece being in the weight.

 

[MarshallPope]

Under normal circumstances with a loading bridge at max height and the batten bottomed out, I was taught to always load the batten first and then the arbor. Now, this isn't to say that there have never been times that we've told the loaders to go ahead and put some weight on while we were sorting out an issue on deck, but I've never stopped hanging on the batten to allow the arbor loaders to catch up. That is, or course, with an ideal system - when the loading bridge is at half travel, all bets are off.

 

[Mike Cloobeck]

I also have been taught by former mentors to load all of the fixtures first to assess total weight before loading the arbor. Why has this changed and what benefits does it allow?

 

[gafftapegreenia]

I have worked in some spaces where is is physically impossible to grid the arbor and hang lights. Thus, I understand the hang some weight some method. Also, it is in these places where a "mid rail" becomes extremely valuable.

Then there are those sad cases where a space has no loading rail, it's nearly impossible to hang all the lights first without some sort of mechanical aid.


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[techieman33]

I've also been taught to fully load the pipe first. And since a lot of the light hangs I do only have 3 or 4 people involved it would suck to have to go up and load some weight halfway through hanging fixtures on each pipe. If I have dedicated weight loaders though I'll go ahead and have them load half the weight after fixtures are hung and while we are cabling things to speed things up.

Didn't the Blue Man Group incident occur due to premature loading of pig iron?

Depending on the space there really isn't any other option for that electric. The fixtures aren't hung on the pipe, they actually sit ~20 feet below the pipe on a piece of flat truss. So if you can't reach the arbor from a mid bridge, or don't have one then you have to pre-load the arbor/s. That electric is 1700+ lbs so they usually have to marry a couple of linesets to hang it.

 

[techieman33]

Like wise, one could take an empty batten all the way out and toss 500# on the arbor. I don't know why one would do this though...

New guy hazing?

 

[Mike Cloobeck]

But isn't standard practice half load batten then half arbors?

 

[josh88]

Like I said in the last thread I don't follow the half and half rule. I just play it as needed, generally that's less than half the way. My personal rule is that if it takes 2 people to hold it in balance then you probably should have already added the weight. I try to keep the out of balance weights to a minimum and just adjust as needed. If that means I have to do it three times and it all takes a bit longer, that's some extra time I'd rather take.

Then again, I also haven't had the advantage of a loading bridge everywhere I've been.

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[Footer]

But isn't standard practice half load batten then half arbors?

Not any place I have ever worked, from the small community theatres to the 100+ lineset road houses. I have also never seen this in any of my rigging texts.

@MPowers, could you shed some light on this one? I have never heard of this practice. I guess the idea is to not put too much pressure on the stop block... but any rigging system should be designed to hold entire load the batten is capable of on the stop block.

This also introduces an easy out of weight situation. Now instead of calculating just the final weight, you now have to caculate what is "half" weight. You then have to ensure that you communicate to the flyman correcting when you have reached half... and they have to ensure they have only loaded half. Pretty dumb. Adds more steps to the in. Adds more chances of something going wrong. I have also never heard of a failure of a batten that is into the deck.

I hope this is not the guys who write the ETCP test just wanting to change general practice of the industry... this is a dumb method that could cause more harm then good. Hang the pipe. Weight the batten. Take it out.

 

[SteveB]

Our loading gallery and CW system is such that you cannot fully load the arbor when the pipe is at it's lowest position as the loader cannot reach the top of a fully loaded arbor. Thus we frequently have to calculate and partly load, hoping we guess close, then finish adding fixtures, bull out the pipe, add all the weight and check. Ditto on a a strike, partly unload while the pipe is 6-7ft, or so above deck, partly unload arbor, let pipe drift in, finish arbor unload, then strip pipe.

PITA ?, sometimes, but we are used to it.




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[venuetech]

Off hand i would say this half n half method may have something to do with possible distortion of the arbor. With the arbor hard against the stop, the normally rectangle arbor could be forced into a parallelogram shape by the loaded lines. in practice the construction of most arbors is stout enuf to prevent such distortion.
So before I start getting flack about this let me state that this is just a theory presented for discussion as to why that method was stated as correct. In day to day practice I just load the pipe, then balance the load like most folks here.

 

[Footer]

Our loading gallery and CW system is such that you cannot fully load the arbor when the pipe is at it's lowest position as the loader cannot reach the top of a fully loaded arbor. Thus we frequently have to calculate and partly load, hoping we guess close, then finish adding fixtures, bull out the pipe, add all the weight and check. Ditto on a a strike, partly unload while the pipe is 6-7ft, or so above deck, partly unload arbor, let pipe drift in, finish arbor unload, then strip pipe.

PITA ?, sometimes, but we are used to it.




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Ironicly our electrics don't have a stop block... you can actually crash them into the deck if you want to. Thankfully we have never stripped a pipe since I have been there so its not really an issue. Not really sure why they were rigged this way, but it is the way it is. So, we also have to play the bounce game.

 

[Footer]

Off hand i would say this half n half method may have something to do with possible distortion of the arbor. With the arbor hard against the stop, the normally rectangle arbor could be forced into a parallelogram shape by the loaded lines. in practice the construction of most arbors is stout enuf to prevent such distortion.
So before I start getting flack about this let me state that this is just a theory presented for discussion as to why that method was stated as correct. In day to day practice I just load the pipe, then balance the load like most folks here.

Ya, that was my theory as well.

If that is the case, I have never seen an arbor pop the t-bar because of it. I would think if this was real, we would have heard about it before... and there would be signage everywhere about it.

 

[cmckeeman]

I have never heard of the half method and it seems silly and kind of dangerous to me. the closest i could imagine is one of the fly rails i will work on doesn't have a load bridge so we have to load some on the batton, over haul it out, load some weights, friction the baton in and repeat until it's in weight but that still isn't half then half.

 

[gafftapegreenia]

Our loading gallery and CW system is such that you cannot fully load the arbor when the pipe is at it's lowest position as the loader cannot reach the top of a fully loaded arbor. Thus we frequently have to calculate and partly load, hoping we guess close, then finish adding fixtures, bull out the pipe, add all the weight and check. Ditto on a a strike, partly unload while the pipe is 6-7ft, or so above deck, partly unload arbor, let pipe drift in, finish arbor unload, then strip pipe.

PITA ?, sometimes, but we are used to it.




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My University was a similar situation. We had a mid rail/pin rail and an upper loading rail. If the arbor was all the way at the loading rail, the batten was nearly sitting on the floor. If the arbor was at the mid rail, then the batten was a few feet above head height. Thus, effective working high for our electrics put their arbors between the mid rail and the loading rail. After four years of dealing with that, its a luxury to go into a space where all the lights can be hung before loading the arbor.

 

[soundman]

Last year I passed the ETCP arena rigging test. To my frustration there were more than a few questions like this on the exam. Questions that had two possible correct answers with no room to explain why you would do one over the other. The best thing to do when you sit for the exam is flag the question and write in the comments your thoughts. It won't help you on your exam but it will improve it for the community at large.

 

[MikeJ]

Off hand i would say this half n half method may have something to do with possible distortion of the arbor. With the arbor hard against the stop, the normally rectangle arbor could be forced into a parallelogram shape by the loaded lines. in practice the construction of most arbors is stout enuf to prevent such distortion.
So before I start getting flack about this let me state that this is just a theory presented for discussion as to why that method was stated as correct. In day to day practice I just load the pipe, then balance the load like most folks here.

I understand that this is a theory, but if it actually is the case anywhere, then the system needs to be de-rated to avoid this.

 

[MikeJ]

Also, I think its worth noting that ANY rigging advice found on the internet should be taken with a TRUCKLOAD of salt.