Interesting, I am admittedly not the most experienced rigger.
Honestly this is me trying to take a step in showing our faculty here that students can have ideas and execute on them independently I even hand drafted the plans to present the thing.
Rigging Question (Tieing off a line set)
- Thread starterwemeck
- Start date
Interesting, I am admittedly not the most experienced rigger.
Honestly this is me trying to take a step in showing our faculty here that students can have ideas and execute on them independently I even hand drafted the plans to present the thing.
Im sorry if I offended.
Im still interested in the facts of the thing.
So, they are unsafe, Is it because they don't work or because they are easily misused(which i guess means don't work in another way)?
Maybe start working on a new platforming system or how to use steel flats. Draw up plans for a new sheet good or stick lumber rack using steel.
Both actually. In order to get the thing on you have to put it under tension. If the line does slip it can be thrown off.... basically sending the thing spinning at whoever is on the rail. There is also a lot of force being put on the pivot on the piece. I prefer this over a broom handle stuck in the rope but a simple snub line does this easier, safer, and quicker. Choke the rail, wrap the purchase lines together, do a quick rolling hitch (http://en.wikipedia.org/wiki/Rolling_hitch), and you are done.
I've found it sometimes makes sense to take advantage of the fact that our lock rail is about 20' above stage and our loading bridge is ~20' above that. As such we are able to adjust weight on the arbor in the middle of the travel as opposed to the top or bottom. I've been told (and from experience feel as though) this is a safer way to hang heavy soft goods and tall pieces since we can attach the tall pieces when they are upright and adjust the weight of the arbor for the soft goods as more weight goes onto the batten. It doesn't always make sense, depending on the size of the piece we are hanging, but it does prevent a wider margin out of balance. What is the general experience in this type of setup (single purchase btw).
Whatever you can do to midigate an out of weight condition is great. When loading in or out would always rather have something pipe heavy so I can control where it lands. I used to be the welder for several rep theatres... and was usually there when anything I built went into the air. I always called it low knowing that I could bring it back in if it did not leave the deck.
BillConnerFASTC
Well-Known Member
Plus uncle buddies put forces into the t-bar they are not designed for. Don't use them is my strong recommendation.
porkchop
Well-Known Member
The problem, and why they still get used from time to time, is that often they do work... until they don't anymore that is and with something like this that is hand made and in no way properly designed by a qualified engineer there's no way of predicting when and/or under what conditions it won't work anymore. When rigging you want to have a very good idea of exactly what the forces and limitations on your system are, and with something like a line lok there's just no way to know. Then you're just falling into the "it's worked every other time" danger area.
cmckeeman
Active Member
Maybe my understanding of how they are used is flawed, but how do they do this?
BillConnerFASTC
Well-Known Member
If you twist the handlines, it puts much greater force on the welsh or take up block than it is rated for when it is the T. I didn't include the full "comment" but this does apply to T-bar systems with the block attached to the T, not to systems where the block is anchored to the floor, but those do sometimes - or often - permit adjustment up and down and I wouldn't trust that to resist the forces of twisting the ropes. I've moved really big things by twisting rope in a similar fashion and its a lot of force in a hurry.
PS - Maybe not clear but its the T (or J or whatever) guide that is the concern primarily.
PS - Maybe not clear but its the T (or J or whatever) guide that is the concern primarily.
Question- So in this case the prussik wouldn't do that same force since it's transferring the pull of the arbor to the rail instead of the tension block? So if you twist the handlines with a broom handle or metal rod and tie off wouldn't it exert a similar force as an Uncle Buddy?
BillConnerFASTC
Well-Known Member
Yes I'd group broomsticks, etc. here - all basically turnbuckles or tourniquets.
An arbor can be safely held to an anchor point that is designed for the load, like the lock rail if it is designed for it or even the welsh block if it's mounting is designed for it. T-bar and it's commonly aluminum cousins are, to the best of my knowledge and according to some of the best and brightest in the business, not designed for those forces, which if you look at it you realize are bending forces on that fairly small T-bar - like 1 1/2 X 1 1/2 X 3/16. In my work, I put an eye on the bottom of the arbor rated for the full load so there is a good anchor there, and have the rail rated for upward forces equal (but NOT every lineset all at once please).
I have a really nicely made uncle buddy here in the theater left by the previous theater manager, who was a wizard with metal work. My electrics are motorized so I only use it while loading weight for hanging drops or if I need to bring a traveler down to the deck to work on it for some reason.
@BillConnerASTC are you saying that they should never be used even for light duty? Not to argue with you, I truly am curious about this... Jay Glerum liked them enough to print drawings of them in "Stage Rigging Handbook" so that you can make your own so that's a pretty strong endorsement on his part. Perhaps what you are describing is something we have learned in recent years that wasn't known when he printed the book?
@BillConnerASTC are you saying that they should never be used even for light duty? Not to argue with you, I truly am curious about this... Jay Glerum liked them enough to print drawings of them in "Stage Rigging Handbook" so that you can make your own so that's a pretty strong endorsement on his part. Perhaps what you are describing is something we have learned in recent years that wasn't known when he printed the book?
BillConnerFASTC
Well-Known Member
BillConnerFASTC
Well-Known Member
OK. I asked my engineer friend (yes - he can lawfully put "PE" in his signature - not just a super theatre tech) and he replied:
"I have twisted my share of hand lines using just a broomstick and the Uncle Buddy is just a more elegant means of doing the same thing. In either case the imbalance load goes into the floating floor block instead of the rail. Floor blocks are typically not designed to take as much as the head lock or the rail so there is potential for overload if the set is seriously out of weight. I know of a couple failures that have occurred over the years due due to (gross)overloads pulling the floating blocks out of the tee bank. For substantial loads I would recommend using a capstan or a prussick to the rail instead. "
So I still take the "just say no" . Maybe, just maybe, some of us are so good that we would never ever twist it too much, but by example and by leaving it where less "qualified" individuals might try it, don't. If there weren't other acceptable means, I might be more tolerant, but there are.
PS - and if that from one major company is not enough, this from another stage rigging expert:
"I know for a fact that they will slip very suddenly and violently at about 400 pounds. Not a pretty sight or feeling. I have seen a line set creep when they are used and the loader is dropping counterweights onto the arbor. That does not instill confidence their ability to hold a load. I do not like how the load is transferred to the floor block shoes that were never designed to hold that kind of load."
QED
"I have twisted my share of hand lines using just a broomstick and the Uncle Buddy is just a more elegant means of doing the same thing. In either case the imbalance load goes into the floating floor block instead of the rail. Floor blocks are typically not designed to take as much as the head lock or the rail so there is potential for overload if the set is seriously out of weight. I know of a couple failures that have occurred over the years due due to (gross)overloads pulling the floating blocks out of the tee bank. For substantial loads I would recommend using a capstan or a prussick to the rail instead. "
So I still take the "just say no" . Maybe, just maybe, some of us are so good that we would never ever twist it too much, but by example and by leaving it where less "qualified" individuals might try it, don't. If there weren't other acceptable means, I might be more tolerant, but there are.
PS - and if that from one major company is not enough, this from another stage rigging expert:
"I know for a fact that they will slip very suddenly and violently at about 400 pounds. Not a pretty sight or feeling. I have seen a line set creep when they are used and the loader is dropping counterweights onto the arbor. That does not instill confidence their ability to hold a load. I do not like how the load is transferred to the floor block shoes that were never designed to hold that kind of load."
QED
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Uncle Buddies work. As with all things, they need to be used correctly, and there may be better solutions depending on the use. This is why people are trained, and not just anybody can run a fly rail. Caveats and alternatives have been posted above. If your professor simply said that they don't work, with no explanation, then they have done you a disservice. In school, of all places, people should be encouraged to ask WHY. Footer was not actually asking if you were qualified, he was simply being condescending. In my reading of ControlBooth, BillConnerASTC seems to know a lot about fly systems and rigging, so his advice should carry a decent amount of weight. Bill, thanks for your input, and your willingness to consult other professional and experts, in order to form a well informed opinion on the matter. I hope that others take note of your thorough research and humble attitude.
soundguy99
Member
Hi Guys,
Just wondering about what people use to lock their linesets from moving in a heavily unbalanced situations either when loading or unloading, or over weight situations where you don`t line set to move.
I realize during operation you have the actual line sets locks usually done from the fly rail, and that they should be properly balanced during operation.
Thats being said however, sometime there are those rare situations where youre dealing with an situation when your loading or unloading a pipe with extremely heavy loads (ie 700lbs +/-) and you do not want that pipe to move.
Or you could have an out of balanced situation (ie 100 or 200lbs +/-), that you are unable to balance for what ever reason, but don`t need to operate it, just secure it or lock it down so the pipe will not move. Typically electrics, movers set peices, that are going to be either heavy during the load and unload process or out of balanced situation that may not have to be moved.
I have seen some crazy creative "modified solutions) , to this problem over the last few years that the various touring flymen use, that may or Not be "legal".
I am just wondering what other people do when they encounter these issues.
Is there such thing as an actual Lineset lock besides the operational lock that you can purchase to make it more secure and safe during the loading and unloading, or do you just use the operating ope lock, and load and unload from the loading gallery.
Just something I have seen from these flymen from traveling productions that come through, just though what others do.
Any thoughts are greatly appreciated,
Thanks,
soundguy
Just wondering about what people use to lock their linesets from moving in a heavily unbalanced situations either when loading or unloading, or over weight situations where you don`t line set to move.
I realize during operation you have the actual line sets locks usually done from the fly rail, and that they should be properly balanced during operation.
Thats being said however, sometime there are those rare situations where youre dealing with an situation when your loading or unloading a pipe with extremely heavy loads (ie 700lbs +/-) and you do not want that pipe to move.
Or you could have an out of balanced situation (ie 100 or 200lbs +/-), that you are unable to balance for what ever reason, but don`t need to operate it, just secure it or lock it down so the pipe will not move. Typically electrics, movers set peices, that are going to be either heavy during the load and unload process or out of balanced situation that may not have to be moved.
I have seen some crazy creative "modified solutions) , to this problem over the last few years that the various touring flymen use, that may or Not be "legal".
I am just wondering what other people do when they encounter these issues.
Is there such thing as an actual Lineset lock besides the operational lock that you can purchase to make it more secure and safe during the loading and unloading, or do you just use the operating ope lock, and load and unload from the loading gallery.
Just something I have seen from these flymen from traveling productions that come through, just though what others do.
Any thoughts are greatly appreciated,
Thanks,
soundguy
BillConnerFASTC
Well-Known Member
To soundguy 99:
First, 7000 pounds is not a normal counterweight lineset load and the basic hardware used in rigging is not designed for that load, so "really" qualified people are required.
With a loading bridge, it should be possible to keep most sets balanced all the time so do that. If the batten is at low trim, its usually safe to load it and then load weights, as the arbor is against a stop.
Without a loading bridge, and out of balance loads larger than a hundred pounds or so, maybe 75 per OSHA, you really need a bull winch or similar means to mechanically control the out of balance load.
For just locking a load, the lock rail designed for the load - not all are - or other anchor points, and a rope tied to hand lines is the normal acceptable practice.
Sounds like an in house training day could be what you need.
First, 7000 pounds is not a normal counterweight lineset load and the basic hardware used in rigging is not designed for that load, so "really" qualified people are required.
With a loading bridge, it should be possible to keep most sets balanced all the time so do that. If the batten is at low trim, its usually safe to load it and then load weights, as the arbor is against a stop.
Without a loading bridge, and out of balance loads larger than a hundred pounds or so, maybe 75 per OSHA, you really need a bull winch or similar means to mechanically control the out of balance load.
For just locking a load, the lock rail designed for the load - not all are - or other anchor points, and a rope tied to hand lines is the normal acceptable practice.
Sounds like an in house training day could be what you need.
7000lbs exceeds the capacity of ANY fly system I've seen by at least 2. Yes, there are ways to marry linesets (not about to get into that) but require extremely qualified riggers. However marrying 4+ linesets is stupid and dangerous. Get an engineer (PE variety) to determine ratings of beams, get some chain motors and truss and have a qualified and competent rigger rig them. They'll happily hold 7000lbs and are designed to be used that way.
