Motorized Fly System
- Thread starterAxlD
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Euphroe
Member
Nope. But most of the schools I've visited have signs of crashed sets. Sometimes you have to look close. Sometimes the stoprail is obviously bent, or a section has been replaced, damage at the top of the welch blocks, or the T-bar behind. I've seen damaged arbors, sets that were chained off/abandoned. Signs of crosbies jammed against loft blocks when pipes gridded at speed.
Talk to guys that do rigging renovations in older school districts. You see all kinds of stuff, like the dysfunctional hermaphrodite double-single purchase system I described above. Or the house that had this strange left-lay wire rope . . . a little resarch revealed it to be 6x6x7 "tiller rope", 1/4" with a strength of 2500bls. You could almost bite through it, an easy one-handed cut with C-7s. Plow steel, with fiber cores in each strand plus the center.
Even in large IA houses, I've seen a lot of hairy struggling and near-accidents on what should be basic operations.
Recently I filled in as flyman at an unfamiliar venue, for a TV shoot. The welch blocks were in a deep well, so I found an 8' 2x4 on the loading dock to poke down and release the welch blocks. I was doing this to snub a set, when a couple of the TV studio guys asked what I was doing. I started explaining the snubbing process and they knew about all that, said they worked CW often. But they did not know that welch blocks could be released by pressing down on them -- "Learn something new every day!" they said. How they'd been working linesets without ever slacking the purchase lines I'm not sure . . . Plus this venue was a (well-funded, probably ASTC-designed) high school theater. How were the students releasing the welch blocks? They probably weren't.
One school I renovated had money left over from a seismic retrofit and spent it on new rigging. When I arrived for a survey, an abatement company was prepping to remove the fire curtain. I asked, and they had *no idea* about that 1400lb counterweight it was attached to. Their plan was to build 65' scaffold to the grid, enclose the entire thing in plastic, try to get negative pressure, and just cut the fire curtain from the batten.
I pointed out the counterweight to the GC. I offered to rig the FC batten so it could be safely lowered, and to deal with the counterweight. He hired me to do that.
The abatement contractor built an 8' enclosure to receive the fire curtain on the ground, and negative-pressurized it. But they ALSO built the 65' enclosure to the grid, which they could never successfully get negative pressure. The small enclosure was inside the large one.
The 65' enclosure was redundant, and the contractor knew it. But they built it because the abatement consultant had already charged the district $50,000 for the *design* of the unneeded enclosure. To not build the (giant, expensive) failure would reveal that the $50,000 was a wasted boondoggle.
Next job I arrived at, the same abatement contractor was on-site building an 8' enclosure. They learned that much. But they still hadn't reckoned on the counterweight. Fortunately I arrived before they tried moving and cutting away the fire curtain, so I got to do that one, too.
Talk to guys that do rigging renovations in older school districts. You see all kinds of stuff, like the dysfunctional hermaphrodite double-single purchase system I described above. Or the house that had this strange left-lay wire rope . . . a little resarch revealed it to be 6x6x7 "tiller rope", 1/4" with a strength of 2500bls. You could almost bite through it, an easy one-handed cut with C-7s. Plow steel, with fiber cores in each strand plus the center.
Even in large IA houses, I've seen a lot of hairy struggling and near-accidents on what should be basic operations.
Recently I filled in as flyman at an unfamiliar venue, for a TV shoot. The welch blocks were in a deep well, so I found an 8' 2x4 on the loading dock to poke down and release the welch blocks. I was doing this to snub a set, when a couple of the TV studio guys asked what I was doing. I started explaining the snubbing process and they knew about all that, said they worked CW often. But they did not know that welch blocks could be released by pressing down on them -- "Learn something new every day!" they said. How they'd been working linesets without ever slacking the purchase lines I'm not sure . . . Plus this venue was a (well-funded, probably ASTC-designed) high school theater. How were the students releasing the welch blocks? They probably weren't.
One school I renovated had money left over from a seismic retrofit and spent it on new rigging. When I arrived for a survey, an abatement company was prepping to remove the fire curtain. I asked, and they had *no idea* about that 1400lb counterweight it was attached to. Their plan was to build 65' scaffold to the grid, enclose the entire thing in plastic, try to get negative pressure, and just cut the fire curtain from the batten.
I pointed out the counterweight to the GC. I offered to rig the FC batten so it could be safely lowered, and to deal with the counterweight. He hired me to do that.
The abatement contractor built an 8' enclosure to receive the fire curtain on the ground, and negative-pressurized it. But they ALSO built the 65' enclosure to the grid, which they could never successfully get negative pressure. The small enclosure was inside the large one.
The 65' enclosure was redundant, and the contractor knew it. But they built it because the abatement consultant had already charged the district $50,000 for the *design* of the unneeded enclosure. To not build the (giant, expensive) failure would reveal that the $50,000 was a wasted boondoggle.
Next job I arrived at, the same abatement contractor was on-site building an 8' enclosure. They learned that much. But they still hadn't reckoned on the counterweight. Fortunately I arrived before they tried moving and cutting away the fire curtain, so I got to do that one, too.
Euphroe
Member
Sorry, that sounded like a dig on the ASTC or Bill, and I didn't mean it that way. I meant it was a really nice, well-equipped facility, one that could be hired out for TV events and such. It was recently renovated and in excellent condition, and undoubtedly designed by a professional.
The designer put the welch blocks in a well to get travel without resorting to double-purchase. It was a good system, just required a little careful handling.
I don't remember seeing a bent stoprail there.
kicknargel
Well-Known Member
I'm not really even weighing in here, other than to try to bring focus to a fundamental question. I think the uneasiness of the 1000 lb lock is that it allows a practice that is inherently unsafe - leaving linesets out of balance, with a single point of failure (the lock). A 50 lbs lock requires that any out-of-balance condition be temporary and attended to. There's not imperial evidence which system is safer in actual practice. I think I system that was more analogous to Sawstop, which was a failsafe but didn't affect best practice, would be the ideal. I'm not putting my hand into that saw blade no matter how good you tell me the safety device is. But I'll be glad it's there if I do it accidentally.
BillConnerFASTC
Well-Known Member
Does the SureStop brake the purchase line or the lift lines or both?
At the core the biggest issue I have with the super rope lock is the idea that an out-of-balance situation could be left unattended indefinitely. I would expect that to be common in a house w/out a dedicated TD. Or if it were to fail, or a purchase line fails then you could have as much as 1,000# going to the deck.
I would think many would be encouraged to not reweight during light hangs (run it up with the genie) forget about it after the show run is over and it continues unbalanced.
That all being said, I've experienced being on deck while hanging and running my HS crew. Distractions happen and they are less apt to keep their concentration than most. We have never had an incident, but insurance is always nice.
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At the core the biggest issue I have with the super rope lock is the idea that an out-of-balance situation could be left unattended indefinitely. I would expect that to be common in a house w/out a dedicated TD. Or if it were to fail, or a purchase line fails then you could have as much as 1,000# going to the deck.
I would think many would be encouraged to not reweight during light hangs (run it up with the genie) forget about it after the show run is over and it continues unbalanced.
That all being said, I've experienced being on deck while hanging and running my HS crew. Distractions happen and they are less apt to keep their concentration than most. We have never had an incident, but insurance is always nice.
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Jay Ashworth
Well-Known Member
For more on "less protection" see item 4 in this article:
6 Little-Known Driving Tips That Could Save Your Life | Cracked.com
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6 Little-Known Driving Tips That Could Save Your Life | Cracked.com
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Jay Ashworth
Well-Known Member
Sorry: [HASHTAG]#5[/HASHTAG]
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Sent from my SPH-L720
Just so you know, I believe the phrase is "empirical evidence".
BillConnerFASTC
Well-Known Member
kicknargel
Well-Known Member
Oops. In my defense I was on my second distinct plane trip of the day. And why wouldn't the one that's about empires be the one that starts with a "e?"
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Jay Ashworth
Well-Known Member
Such a good question that I deeply resent your having thought of it first. 
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Euphroe
Member
If having out-of-weight sets is inherently unsafe, then CW sets are inherently unsafe. The nature of CW sets is that payloads are added/removed, during which the set is often hundreds of pounds out of weight.
Sets crash when the pipe gets stripped, the crew can't handle the imbalance, and the arbor comes down partially or completely out of control, and grids the pipe. This sometimes happens because the top weight in the arbor is too high, so the flyman tries to slip the arbor down a couple of feet and underestimates the difficulty. Sometimes there's no "crash", only an arbor that the flyman can slow down, but not stop or reverse. Then the flyman unloads the arbor at deck level and saunters off to change his underwear.
If you leave a loaded 1000lb arbor at grid level hanging on a Restrictor, *you've left the pipe at the deck*. Who leaves a pipe at 5' trim indefinitely?
A worse scenario is accidentally stripping the wrong arbor at deck level, and leaving a loaded batten at the grid. The risk of doing this with a Restrictor is no worse than with a paleo-lock. Anybody who trembles at having the loaded batten hanging on rated 1000lb lock until later noticed should consider the alternative. Make the same mistake with a paleo-lock and it would *certainly* fail; the arbor would start running as the crew unloaded it, putting at risk both the rail crew and anybody caught under the falling batten.
Interesting note: because the Restrictor holds 1000lbs does not mean every arbor weighs 1000lbs after installing Restrictors. Sometimes arbors only weigh 450lbs, or 234lbs, even after installing Restrictors.
My question (rephrased) was, how does it hold up when the crew treats it like a dead hang? If it locks 1,000# why would you ever need to reweight your lx? What kind of abuse does a purchase line or t track that was only designed for 50# take when it's loaded down and left for 6 months til someone notices? Is it designed for that abuse?
I'm in agreement with you, the concept of this safety hardware sounds great and preventing runaways while still allowing HS kids to run the ropes is awesome. I'm just wondering (since there's an apparent dearth of actual data on either for or against and a conflict of anecdotal evidence) as to the cost-benefit of standard vs super vs braking headblock. I'm still thinking the headblock has an advantage if for nothing else than to give that "Oh S***" feeling to the kid who just dropped the ball.
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I'm in agreement with you, the concept of this safety hardware sounds great and preventing runaways while still allowing HS kids to run the ropes is awesome. I'm just wondering (since there's an apparent dearth of actual data on either for or against and a conflict of anecdotal evidence) as to the cost-benefit of standard vs super vs braking headblock. I'm still thinking the headblock has an advantage if for nothing else than to give that "Oh S***" feeling to the kid who just dropped the ball.
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BillConnerFASTC
Well-Known Member
I disagree that manual counterweight rigging is inherently unsafe or that out of balance conditions are common. Saying that's its OK is irresponsible. The scenarios described are examples of non-competency.
Euphroe
Member
You re-weight your LX to get it to fly at all, that's why. If it's out of weight a Restrictor won't cause somebody to fly it before re-weighting. If it's locked with a Restrictor, you can't release it to fly it.
Don't treat it like a dead-hang. If you can't trust the crew with a Restrictor, then you *really* can't trust them with a paleo-lock and a broomstick. They could equally stupidly walk away from an imbalanced set that has no 1000-lb mechanical backstop.
Purchase line is not designed only for 50#, it is supposed to be specced to handle imbalanced sets by being snubbed. Whether you twist the parts of line, Uncle Buddy them, hitch them with cord, jam a broomstick in them, they're still carrying the weight of the imbalance. T-track should not be seeing much load for most of its length if the sets are plumb. The T-track at the welch blocks might see load if you reverse an imbalance (severely batten heavy). Rails are supposed to be designed so that you can snub off heavy loads. The difference is that with a Restrictor you can't release an imbalanced set; with a paleo-lock and snubbing system, you can release an imbalanced set and crash it.
(I've seen a lot of worn, dried-out manila in school theaters, but you wouldn't re-install that rope in a Restrictor, and would check the rail anchorage, etc.)
The drawback of a Restrictor that I can see is if you lock the Restrictor and remove either payload or arbor weight beyond what you can tug on the purchase line, you'll need a lifting mechanism like a comealong or tackle to overhaul the set enough to release the Restrictor jaws; a lowering brake won't help at that point. The answer is to not lock the Restrictor in the middle of such a move; which is no loss, because there would be no point in setting a 50lb paleo-lock either.
I can't speak to the SureStop, haven't used them. But am skeptical because line speed and runaway set are not equivalent. I've seen out-of-weight arbors descending that the flymen could not stop, but they could slow.
I designed a couple of special carpet-hoist type systems around Restrictors for arena touring applications. One of these was operated by non-English speaking foreign nationals who were really bad at taking instruction. They operated the systems for hundreds of shows, tens of thousands of moves, without accident or even incident, despite the sets being significantlly "out of weight" by design because, as stated, they were carpet hoist variants. Skilled riggers could not have done these moves with paleo-locks, safely or otherwise.
The above was a highly advanced use, but operated by complete amateurs. That sold me on the utility of Restrictors.
When you install CW rigging in a school, you leave it for 50 - 70 years of students, teachers, staff, operating budgets. Nobody can control for the human element that far in the future. It doesn't matter that you can teach students the correct way to operate it, because you won't be there.
RickBoychuk
Member
I attended the demo drop of the Clancy head block at USITT in Long Beach. I had the opportunity to talk with the young man doing the demo. This is what I remember that I think he told me. Please do your own research to confirm or refute my understanding and memory.
First, the device worked. It stopped the falling load. Kudos.
But after deployment it needs to be adjusted because there is a 'wear item'. After X number of deployments without adjustment, it could stop doing what it is supposed to do. X could be as few as 4 or 5 deployments.
If my understanding and memory are correct, that is not a desirable situation.
I repeat: please do your own research on the issue.
So, I think what the concensus is, we need better training for CW systems and rigging in general. The details about the safety mechanisms are secondary to the issue at hand, improper training. This is not unique at the High School level by any means.
I do believe that the car analogies are correct with concern to the safety mechanisms in theater. They are all designed to prevent catastrophic results when mistakes happen. ABS brakes allow for safer stopping when a situation where proper driving techniques do not allow for safe deceleration. They can confuse improperly trained drivers as they do not all work the same way. Does this mean that we shouldn't have them? I doubt that many experienced drivers who have occasionally needed them would not want them.
When I first joined IATSE, part of my apprentice training was going through a rigging and fall protection course (contractor was brought in to teach the course). This was the first time I was instructed in the use of a harness. Growing up in Colorado, I did a lot of climbing, but never technical climbing. So it took me a bit to trust the harness. Does this make me now less safe because I choose not to do work where I don't have a safety system? We could have a discussion on that separately.
So, we never did find out what caused the initial injuries based on the OP and the question about a motorized system, but in sticking with the CW system, there are merits to both of the safety systems proposed here (Tiffin locks and Clancy head block). If we are solely concerned with runaways, then the head block may suffice. If we are concerned with loading practices, the Tiffin device may help (assuming that the runaways happen as the lock is released). I haven't used or seen demonstrations of either of these devices, so I won't comment on the actual use of either of them.
I do believe that the car analogies are correct with concern to the safety mechanisms in theater. They are all designed to prevent catastrophic results when mistakes happen. ABS brakes allow for safer stopping when a situation where proper driving techniques do not allow for safe deceleration. They can confuse improperly trained drivers as they do not all work the same way. Does this mean that we shouldn't have them? I doubt that many experienced drivers who have occasionally needed them would not want them.
When I first joined IATSE, part of my apprentice training was going through a rigging and fall protection course (contractor was brought in to teach the course). This was the first time I was instructed in the use of a harness. Growing up in Colorado, I did a lot of climbing, but never technical climbing. So it took me a bit to trust the harness. Does this make me now less safe because I choose not to do work where I don't have a safety system? We could have a discussion on that separately.
So, we never did find out what caused the initial injuries based on the OP and the question about a motorized system, but in sticking with the CW system, there are merits to both of the safety systems proposed here (Tiffin locks and Clancy head block). If we are solely concerned with runaways, then the head block may suffice. If we are concerned with loading practices, the Tiffin device may help (assuming that the runaways happen as the lock is released). I haven't used or seen demonstrations of either of these devices, so I won't comment on the actual use of either of them.
I am a middle school theatre teacher with no background in rigging. The system in my theatre just does lights. I know it is not set up right and not correctly weighted having tried it once. The district has no one to train me in its use. I am suggesting a motorized system for safety. I know some stupid 12 year old will do something to it and cause an accident. Sometimes the fear of death does not work as middle schoolers feel they are immortal. It seems that motorized is the way to go in this case. Opinions...
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