# Tab Curtain Question



## SVF (Sep 26, 2019)

Hi All 

So my theatre does not have a fly system so all our curtains must be on ADC track as a bi part traveler system. For our production I am renting a Tab curtain that comes in 2 panels. Is there a way to rig these panels as a standard traveler and then once they are closed, use it as a tab curtain. I am ok if i have one person on each side have to pull the tab feature ropes on either side of the stage to get the opening raise in the middle. I just am not sure the best way to make this curtain track on and off stage as a bi part traveler and then use it as a tab curtain once closed.


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## RonHebbard (Sep 27, 2019)

SVF said:


> Hi All
> 
> My theatre does not have a fly system, all our curtains must be on ADC track as a bi-part traveler system. For our production, I am renting a Tab curtain that comes in 2 panels. Is there a way to rig these panels as a standard traveler and then once they are closed, use it as a tab curtain*?* I am ok if I have to have one person on each side to pull the tab feature ropes on either side of the stage to get the opening to raise in the middle. I'm just not sure the best way to make this curtain track on and off stage as a bi-part traveler and then use it as a tab curtain once closed.


 @SVF Your query spawns several others. What about your rented Tab curtain makes it a Tab curtain? 
I understand it'll be delivered in two panels, and hopefully with grommets and / or ties across its top to anchor and support its top from one of your existing traveller tracks. If it has been truly manufactured to function as a tab curtain, it should / will arrive with a series of stout rings, or at the very least, loops of fabric sewn securely onto the rear of its two panels to capture your operating lines. Within approximately three or four feet above deck level an EXTREMELY stout ring will be sewn SECURELY to each curtain half in a manner to neither rip from, nor tear a hole through, either half of your rented tab curtain. 
A butch sheave would be attached two or three feet either side of centre on your existing traveller track; said sheave MUST be capable of supporting approximately 40% of the weight of each half of your tab curtain. 
If all of the foregoing is dealt with, the matter of rigging your curtain to operate as both a tab and a traveller should be a comparatively simpler matter. 

Google's likely your friend here. Consider Googling the on-line sites of a few of the major curtain fabricators and suppliers, I suspect you'll be able to find a wealth of useful info' likely including photo's and operating line diagrams. Companies such as Rose Brand and Bella Tex come to mind. 
Let me employ Control Booth's 'Bat Call' to summon the attention of a few of our more knowledgeable posters to your query. 
From safely north of Donald's walls: 
Toodleoo! 
Ron Hebbard @Van @What Rigger? @BillESC Would you care to comment on @SVF 's post*???*


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## SVF (Sep 27, 2019)

Thanks @RonHebbard. It is an actual tab curatin as it has all the rings sewn in etc as you said above so it is meant to be a tab feature. I was just cruious how to do it if i have the curtain rigged on travler track coming in and out throughout the show vs dead hung on a batten. Anyones help is much appricated.


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## BillConnerFASTC (Sep 27, 2019)

You need to be able to tie off traveler operation when you want tab operation. An anchored stand with cleat or rope lock (don't laugh - I've used rope locks on traveler lines a number of times) would work.


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## JChenault (Sep 27, 2019)

One thing I might be concerned about that I have not seen mentioned. 
You will need a pulley attached to a carrier in your track in order to make the tab work. A standard carrier might be too flimsy to handle the load ( depending on weight, height, etc of drop. You might want to look at getting a more substantial carrier for the pulleys. ( I know rosebrand has them. Probably pretty easy to find if you look around)


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## RonHebbard (Sep 27, 2019)

BillConnerFASTC said:


> You need to be able to tie off traveler operation when you want tab operation. An anchored stand with cleat or rope lock (don't laugh - I've used rope locks on traveler lines a number of times) would work.


 For *@SVF* 's benefit. possibly someone will post a photo of their favorite, simple to fabricate, line lock suitable for traveller operating lines and / or operating lines on counter-weighted system pipes. I'm thinking of one of the simple designs, possibly one fabricated from a 12" x 4" scrap of 3/4" plywood with a slot for the operating-lines cut half-way across 1.5 to 2 inches from one end of the ply and a 3/8" threaded open-eye hook bolted securely through the opposite end of the scrap of ply. 

(For those playing along at home You hold the length of ply vertically at approximately waist height with the slotted end down and the end with the hook up and facing towards the operating lines. Slip both operating lines all the way into the slot then lift the other end of the plywood up forcing a pair of close to 90 degree bends into the pair of operating lines, hook the open eye-hook around both operating lines and MISSION ACCOMPLISHED: 
The open-eye hook keeps the plywood standing vertical while the slot in the plywood securely captures both the operating lines with a pair of nearly 90 degree reverse bends 3/4" apart. Simple, easy to fabricate from scrap wood, and only the cost of one 3/8" threaded open eye hook, two hex nuts, two flat washers and a lock washer to be thorough *or* spring the extra few pennies for a pair of Ny-Locks. 
There are other easy designs bent from 1/2" diameter steel rod but not every shop as the ability to crank smooth tight bends into 1/2" diameter steel rod. 
*@Van @What Rigger?* @anyone else Have you any comments or other cheap 'n cheerful, yet easy, quick and damage-free designs to pass along*??*
Toodleoo! 
Ron Hebbard


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## RonHebbard (Sep 29, 2019)

JChenault said:


> One thing I'd be concerned about that I have not seen mentioned:
> You will need a pulley attached to a carrier in your track in order to make the tab work. A standard carrier might be too flimsy to handle the load ( depending on weight, height, etc of drop. You might want to look at getting a more substantial carrier for the pulleys. ( I know Rose brand has them. Probably pretty easy to find if you look around)


 *@SVF* In addition to *@JChenault* 's sage advice in post #5 above, three more thoughts for you: 
- 1; Using two operators when operating in tab mode will likely permit simpler routing of the hand-lines to operate the tab function. 
- 2; Having the operator on SR operate the SL half of the tab while the operator on SL operates the SR half of the tab offers several advantages: 
a; Reduced stress on the travelling sheaves described in post #5 above. 
b; Somewhat less effort required on the part of the operators to hoist the tab. 
c; Having the operators lift the opposite halves will pull the two halves tighter together at the top rather than trying to pull them apart. 
d; This offers the additional advantage of less stress on the traveller operating lines and less need for a line lock on the traveller lines to immobilize them while operating in tab mode. 
- 3; Twisting the traveller operating lines around each other several times prior to applying a line-lock will automatically increase friction between the two traveller operating lines further aiding in keeping them immobilized during tab operation. 
Sounds simple enough when you say it fast. 
Toodleoo! 
Ron Hebbard


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## Painterspoon (Jan 23, 2020)

I'm currently in a similar predicament. And some of what you said is a smear of letters and words to me, but I will do my best to catch up.

We are doing Les Mis in June. I'm all there is with the exception of conducting the pit, although I have done that too.
One big pain is going from barricades to sewer to bridge for Javert's suicide to wedding, so I was going to use a new grey chameleon scrim and strategic lighting. But I would like to be able to roman blind the scrim just in case (I haven't fully thought out the staging yet - this revolution is still just a twinkle in the eye). My scrim does not come with tabs. I would have to attach those myself, and then the scrim would be attached to our mid traveler track (but not function as a bi-part curtain).

The scrim is thankfully extremely light, but I'm wondering what might be the best way to affix the tabs...or should I throw out the whole idea and just leave the scrim hung and figure out how to stage this with the scrim permanently in place? And then, I promise Ron - I will try reading your instructions fast in hopes it sounds simple.

-Melissa


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## RonHebbard (Jan 23, 2020)

Painterspoon said:


> I'm currently in a similar predicament. And some of what you said is a smear of letters and words to me, but I will do my best to catch up.
> 
> We are doing Les Mis in June. I'm all there is with the exception of conducting the pit, although I have done that too.
> One big pain is going from barricades to sewer to bridge for Javert's suicide to wedding, so I was going to use a new grey chameleon scrim and strategic lighting. But I would like to be able to roman blind the scrim just in case (I haven't fully thought out the staging yet - this revolution is still just a twinkle in the eye). My scrim does not come with tabs. I would have to attach those myself, and then the scrim would be attached to our mid traveler track (but not function as a bi-part curtain).
> ...


 *@Painterspoon* Hello young Missy Spoon; are we back to chatting about curtains or have we progressed to how can I quickly fly my "chameleon scrim" out and in again sans any severe wrinkles when I don'have a fly tower, fly space and counter -weighted fly pipes?? 
Toodleoo! 
Ron Hebbard


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## Painterspoon (Jan 24, 2020)

Yeah, the latter.



However, I recognize the fly-in after the fly-out is not within the realm of possibility.

haha


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## BillConnerFASTC (Jan 24, 2020)

I'm not sure I know what a chameleon scrim is. Is it sharkstooth scrim? If it's new, and you sew tabs to it, it won't be worth much; the sewing and subsequent pulling on those tabs will ruin it.

You're hanging it on a track but it doesn't have to track, correct? 

It is likely possible you could modify the track arrangement to allow the scrim to travel in one direction, but some effort and skills required.

There could be a means to raise it by lifting the bottom and gathering it into a bundle, but different effort and skills.

Too many unknowns for me to see best solution from afar. Generally, though, if you want a cloth drop to be there or not, nothing simpler or safer than a track with enough run off space for it to stack out of sight.


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## RonHebbard (Jan 24, 2020)

Painterspoon said:


> Yeah, the latter.
> 
> 
> 
> ...


 *@Painterspoon* Consider researching "oleo drops", it's 'old school' but fairly simple and has worked well for decades. 

We've chewed oleo's to death on the Control Booth Forum at least twice in my memory. Some folks have an alternate name for the technique, it dates back to vaudeville days. This MAY link you to a one thread: https://www.controlbooth.com/search/6043/?q=oleo+drops&o=date

Personally I've used the method at least twice in a church basement dinner theatre with zero fly space, they made it work well and as quickly as they could fly them out and gravity could drag them back in. 
It was pretty amazing to watch the drops "fly" when you KNEW there was no fly space. 
The production I'm recalling "flew" two different drops in the same show; in this case, the drops were painted muslin or cheap-ish fabrics from our bargain sewing supplies neighborhood and rigged with ball bearing "rescue pulleys" from Mountain Co-op; the pulleys weren't cheap but they were superb quality, good value for the cost, and worth it amortized over a few productions. 
*EDIT: @Painterspoon Note: Link added.*
Toodleoo! 
Ron Hebbard


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## Painterspoon (Jan 24, 2020)

BillConnerFASTC said:


> I'm not sure I know what a chameleon scrim is. Is it sharkstooth scrim? If it's new, and you sew tabs to it, it won't be worth much; the sewing and subsequent pulling on those tabs will ruin it.
> 
> You're hanging it on a track but it doesn't have to track, correct?
> 
> ...



No, it's not sharkstooth. It's a very lightweight material that allows for appear/disappear effects: https://www.studio-productions-inc.com/colors.html

My track meets in the middle, but maybe I could just hang it off one side so it travels. I know raising and dropping causes issues when it's not designed for that. It's also best if this scrim stays flat so it doesn't grab any light spill.


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## Painterspoon (Jan 24, 2020)

RonHebbard said:


> *@Painterspoon* Consider researching "oleo drops", it's 'old school' but fairly simple and has worked well for decades.
> 
> We've chewed oleo's to death on the Control Booth Forum at least twice in my memory. Some folks have an alternate name for the technique, it dates back to vaudeville days. This MAY link you to a one thread: https://www.controlbooth.com/search/6043/?q=oleo+drops&o=date
> 
> ...



Thanks. I was exploring oleos to death on here a few years ago when I was considering doing Chess and having oleos for the flags. I built a mini version just for kicks. maybe I will revisit this...I may have to reinforce the top. This stuff is like cotton candy in sheet form.


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## RonHebbard (Jan 24, 2020)

Painterspoon said:


> Thanks. I was exploring oleos to death on here a few years ago when I was considering doing Chess and having oleos for the flags. I built a mini version just for kicks. maybe I will revisit this...I may have to reinforce the top. This stuff is like cotton candy in sheet form.


 *@Painterspoon* Sounds yummy! 
Toodleoo! 
Ron Hebbard


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## BillConnerFASTC (Jan 24, 2020)

Painterspoon said:


> No, it's not sharkstooth. It's a very lightweight material that allows for appear/disappear effects: https://www.studio-productions-inc.com/colors.html
> 
> My track meets in the middle, but maybe I could just hang it off one side so it travels. I know raising and dropping causes issues when it's not designed for that. It's also best if this scrim stays flat so it doesn't grab any light spill.


Sharkstooth scrim is the classic material for being transparent or opaque - the appear and disappear. I really don't know what this is. Looking at the link, it looks like a spun plastic fibre and I'd be skeptical if it drapes, as in for tab rigging or track uses. It might roll like an olio drop. Have you hung the Chameleon Scrim?

I assume by your track "meets in the middle" it's a typical bi parting traveler track - for two curtain halfs to overlap when closed or stack half to each side when open. When I said "modify the track arrangement" I meant one half off stage and splicing then and changing the rigging so it went one way, or leave it as walk along and don't mess with rigging other than removing hand line. A picture of the track and might be able to help with details.


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## Painterspoon (Jan 25, 2020)

I have an older white Chameleon scrim that I've used in several shows. It works well for effects and projections and it is full disappear when lit in front. I just bought a new Chameleon though that is mid-grey because I don't want to shove a white sheet in everyone's face for a dark show like Les Mis. 
And yes, our three traveling curtains are all bi-parting.
I don't think I'm comfortable with changing the rigging. The tracks and the lines in them seem pretty finicky and are pullied from off-stage left. Not knowing anything, I'd probably mess something up terribly (this is when I play "I'm just a lowly arts teacher" card haha)
I wonder about hanging a vertical light gauge 25' aluminum pipe from the mid-traveler track and manually traveling the scrim, like with a long tool that someone can use to catch at the top (loose zipties or something) and push it along the pipe at the top, so as not to tear it from the sides. I can hide the bulked up scrim behind a leg, which I'll be adding a scenic image/backdrop to.

I think traveling is probably more fail-safe than an oleo setup. It would take a lot of work and materials for me to get an oleo to work. (sorry Ron Hubbard - toodleoo to the olio - I'm not worthy)

The main thing I'm stuck on is that I want to clear the scrim out of the way for the big barricade scenes and use all the depth and upstage I can get, then I have a few minutes prep time of dragging bodies around in the sewers, somewhere off the apron. During sewer time, I want to bring the scrim back out, so that I can stage Javert's suicide behind it and use some "effects" (front projection of starry night gobo), with an animation of upward-rushing air and a fadeout to make it look like he is falling. The alternative is for the kid to just leap off the back of the set onto a crash mat, but my anticipated Javert actor kid (haven't nailed down the casting yet, but I'm 95% sure I know who it will be), has a history of concussions, and I'd rather not addle his brain any more than it has been addled already. The added huge downside is that the kid has diabetes, and every concussion has severe impacts on how his body uptakes insulin...he needs shots right into the spine during concussion recovery. So yeah - long story short - I want to "artify" the suicide and eliminate a jump and needles in the spine. 

Plus, my budget is miniscule and I have no more to spend on scrims. have to save it now for...oh...everything else. 

Sorry to be so wordy. I appreciate the expertise and generosity of CB!

-Melissa


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## BillConnerFASTC (Jan 25, 2020)

You could hang a track but not sure you can slide it along pipe hung - getting rings or whatever past the hangers and 25' will need intermediate supports.

I have twice done a stretched wire rope. Takes some basic skills to be sure it's anchored securely but one anchor either end is simple. Mechanically inclined parents needed! Then basic shower rings or similar. 

Both times I did it we treated it as an intentional design, and had actors move it visible to the audience. It seemed to be effective.


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## JChenault (Jan 26, 2020)

I once saw a show where they used wire rope stretched tight. It was in view of the audience so they tightened it up to try and make it not droop in the center.

As I remember they pulled the concrete anchors right out of the wall


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## RonHebbard (Jan 26, 2020)

JChenault said:


> *I once saw a show where they used wire rope stretched tight. It was in view of the audience so they tightened it up to try and make it not droop in the center.
> 
> As I remember they pulled the concrete anchors right out of the wall.*


 *@JChenault * Not to veer TOO far. In a similar manner, a friend used to borrow a local goup's mirror ball once a year for his church's annual young peoples' party. The mirror ball was a British Furse approximately 24" in diameter, aluminum and glass (not plastic) covered, with a 120 volt internal rotator; not exactly a light weight orb. Year after year, one of his church members would stretch plastic coated clothes line perhaps 60' across the width of the curch from a polished brass hand rail on one choir loft to its mate on the opposite side. My buddy was a bus driver who worked until 1:30 a.m. Keith would finish work then go to his church around 2:00 a.m. and use a 12' ladder to suspend the mirror ball from the center point of the taught clothesline then spiral an extension cord around the taught line to a 120 volt receptacle in one of the choir lofts.
The first few years, he borrowed a pair of 6 x 22 Altman 360Q's and hung one on either choir loft hand rail to cross light the ball, often in green and red for Christmas.
After getting away with this for several years, Keith wanted to up the intensity on the ball by eliminating the Altman 6 x 22's and replacing them with a pair of small ACL pars c/w 120 to 24 volt transformers. The pair of ACL's, and their transformers, were added to the taught clotheline approximately 3 or 4 feet either side of the mirror ball. A second extension cord was spiraled out with a two-fer added to power the ACL's. A Variac was positioned in one of the choir lofts to vary the intensity of the ACL's.
Keith wasn't using any old extension cords, no. Keith was borrowing 12 or 14-3 black Cabtire with Twist locks, a twist lock two-fer and three twist to parallel blade adapters to power the ball rotator and ACL's.
Miraculously Keith and his young peoples' group got away with this for another year or two.

Keith wanted to up his game one more time. The local amateur group didn't own any color scrollers or wheels but Keith knew where he could borrow two more ACL's. One night / morning, Keith rolled in after work at 2:00 a.m. and hung four ACL's, two either side of the mirror ball. Each ACL had its own step down transformer and Keith borrowed a second Variac so he could swap color pairs from within one of the choir lofts.

*Think about it:* The taught plastic coated clothesline sagged a little more each year becoming essentially a 160 degree bridle 60' bridle supporting a 24" glass covered mirror ball with its internal rotator, plus four ACL's, each with their own step down transformer.
The first year Keith hung four ACL's, he vacated around 4:30 a.m. with everything neat and tidy prior to the cleaners arriving around 6:00 a.m.

The cleaners were somewhat surprised to find a mirror ball and four ACL's et al in the middle of the church's central aisle in a tangled mess.
The priests were STARTLED to find one of the polished brass hand rails torn from its choir loft and laying in one of the church's side aisles.
I'm sure I've posted of this at least once before, perhaps *@egilson1* and / or *@What Rigger?* would care to comment*??*
Had this not been a church with God watching, she likely would've let the whole abortion fail several years sooner.
Toodleoo!
Ron Hebbard


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## Painterspoon (Jan 26, 2020)

RonHebbard said:


> *@JChenault * Not to veer TOO far. In a similar manner, a friend used to borrow a local goup's mirror ball once a year for his church's annual young peoples' party. The mirror ball was a British Furse approximately 24" in diameter, aluminum and glass (not plastic) covered, with a 120 volt internal rotator; not exactly a light weight orb. Year after year, one of his church members would stretch plastic coated clothes line perhaps 60' across the width of the curch from a polished brass hand rail on one choir loft to its mate on the opposite side. My buddy was a bus driver who worked until 1:30 a.m. Keith would finish work then go to his church around 2:00 a.m. and use a 12' ladder to suspend the mirror ball from the center point of the taught clothesline then spiral an extension cord around the taught line to a 120 volt receptacle in one of the choir lofts.
> The first few years, he borrowed a pair of 6 x 22 Altman 360Q's and hung one on either choir loft hand rail to cross light the ball, often in green and red for Christmas.
> After getting away with this for several years, Keith wanted to up the intensity on the ball by eliminating the Altman 6 x 22's and replacing them with a pair of small ACL pars c/w 120 to 24 volt transformers. The pair of ACL's, and their transformers, were added to the taught clotheline approximately 3 or 4 feet either side of the mirror ball. A second extension cord was spiraled out with a two-fer added to power the ACL's. A Variac was positioned in one of the choir lofts to vary the intensity of the ACL's.
> Keith wasn't using any old extension cords, no. Keith was borrowing 12 or 14-3 black Cabtire with Twist locks, a twist lock two-fer and three twist to parallel blade adapters to power the ball rotator and ACL's.
> ...



I don't feel like such a doink now!


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## RonHebbard (Jan 26, 2020)

Painterspoon said:


> *I don't feel like such a doink now!*


 *@Painterspoon* Up here north of Donnie's walls true doinkdom takes years to acquire and master. 
I wish you continued luck with your goals. (Know when you're being ragged MERCILESSLY.) 
Toodleoo! 
Ron Hebbard


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## What Rigger? (Jan 26, 2020)

RonHebbard said:


> For *@SVF* 's benefit. possibly someone will post a photo of their favorite, simple to fabricate, line lock suitable for traveller operating lines and / or operating lines on counter-weighted system pipes. I'm thinking of one of the simple designs, possibly one fabricated from a 12" x 4" scrap of 3/4" plywood with a slot for the operating-lines cut half-way across 1.5 to 2 inches from one end of the ply and a 3/8" threaded open-eye hook bolted securely through the opposite end of the scrap of ply.
> 
> (For those playing along at home You hold the length of ply vertically at approximately waist height with the slotted end down and the end with the hook up and facing towards the operating lines. Slip both operating lines all the way into the slot then lift the other end of the plywood up forcing a pair of close to 90 degree bends into the pair of operating lines, hook the open eye-hook around both operating lines and MISSION ACCOMPLISHED:
> The open-eye hook keeps the plywood standing vertical while the slot in the plywood securely captures both the operating lines with a pair of nearly 90 degree reverse bends 3/4" apart. Simple, easy to fabricate from scrap wood, and only the cost of one 3/8" threaded open eye hook, two hex nuts, two flat washers and a lock washer to be thorough *or* spring the extra few pennies for a pair of Ny-Locks.
> ...


Well, there's a few things in here I'm not clear on and the sort of DIY nature of all the things we're talking about here gives me definite pause. Anyone got a quick sketch of what you're hoping the end result will be? Any photos of the venue this is to be done in?


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## What Rigger? (Jan 26, 2020)

RonHebbard said:


> *@JChenault * Not to veer TOO far. In a similar manner, a friend used to borrow a local goup's mirror ball once a year for his church's annual young peoples' party. The mirror ball was a British Furse approximately 24" in diameter, aluminum and glass (not plastic) covered, with a 120 volt internal rotator; not exactly a light weight orb. Year after year, one of his church members would stretch plastic coated clothes line perhaps 60' across the width of the curch from a polished brass hand rail on one choir loft to its mate on the opposite side. My buddy was a bus driver who worked until 1:30 a.m. Keith would finish work then go to his church around 2:00 a.m. and use a 12' ladder to suspend the mirror ball from the center point of the taught clothesline then spiral an extension cord around the taught line to a 120 volt receptacle in one of the choir lofts.
> The first few years, he borrowed a pair of 6 x 22 Altman 360Q's and hung one on either choir loft hand rail to cross light the ball, often in green and red for Christmas.
> After getting away with this for several years, Keith wanted to up the intensity on the ball by eliminating the Altman 6 x 22's and replacing them with a pair of small ACL pars c/w 120 to 24 volt transformers. The pair of ACL's, and their transformers, were added to the taught clotheline approximately 3 or 4 feet either side of the mirror ball. A second extension cord was spiraled out with a two-fer added to power the ACL's. A Variac was positioned in one of the choir lofts to vary the intensity of the ACL's.
> Keith wasn't using any old extension cords, no. Keith was borrowing 12 or 14-3 black Cabtire with Twist locks, a twist lock two-fer and three twist to parallel blade adapters to power the ball rotator and ACL's.
> ...


As for this, yeah, sounds like someone accidentally (or unwittingly) made a 60' flat bridle. And as we know (or perhaps are learning for the first time), in a 160 degree bridle as Ron says, the load on _each leg _(that is, each side of the string assuming the load is in the middle) is equal to _300%_ of the actual object hanging in the middle. So if the object is 100 pounds....
In a 180 degree bridle (a flat bridle), the resultant load on each side of the bridle could well push to 1000% (one thousand percent) of the load. Suddenly, disco balls are more deadly than decorative.


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## TimMc (Jan 27, 2020)

What Rigger? said:


> As for this, yeah, sounds like someone accidentally (or unwittingly) made a 60' flat bridle. And as we know (or perhaps are learning for the first time), in a 160 degree bridle as Ron says, the load on _each leg _(that is, each side of the string assuming the load is in the middle) is equal to _300%_ of the actual object hanging in the middle. So if the object is 100 pounds....
> In a 180 degree bridle (a flat bridle), the resultant load on each side of the bridle could well push to 1000% (one thousand percent) of the load. Suddenly, disco balls are more deadly than decorative.



A little exercise I've done that requires 2 stout persons, and 2 spring "pull scales", some rope, and 2, 5, and 10 lb weights. Use a 5-ish foot length of rope to one scale, then another 10 foot length on the other side. Have your 2 stout persons stretch the rope at shoulder height and then hang the second scale from the center, and start adding weight under it. Have the stout folk try to keep the rope taught as the weight is increased and note the horizontal scale readings. Then get them up a few feet over the floor and simulate a 90° (45° legs) with the same increasing load and note the scale reading in the bridle leg. It's an eye-opener and surprised the human anchor points at the tension required to keep the line horizontal with the smallest weight.


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## danTt (Jan 27, 2020)

What Rigger? said:


> As for this, yeah, sounds like someone accidentally (or unwittingly) made a 60' flat bridle. And as we know (or perhaps are learning for the first time), in a 160 degree bridle as Ron says, the load on _each leg _(that is, each side of the string assuming the load is in the middle) is equal to _300%_ of the actual object hanging in the middle. So if the object is 100 pounds....
> In a 180 degree bridle (a flat bridle), the resultant load on each side of the bridle could well push to 1000% (one thousand percent) of the load. Suddenly, disco balls are more deadly than decorative.


Does it push 1000% of the load as a result of the weight or as a result of the force necessary to keep the line horizontal? I'm not a genious, but I feel like one of the reasons you see such high force numbers at a flat bridle is because lines will naturally deflect if the force isn't there to keep them horizontal.


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## Ben Stiegler (Jan 27, 2020)

RonHebbard said:


> *@Painterspoon* Up here north of Donnie's walls true doinkdom takes years to acquire and master.
> I wish you continued luck with your goals. (Know when you're being ragged MERCILESSLY.)
> Toodleoo!
> Ron Hebbard


@RonHebbard how would one even attach an ACL to clothesline and maintain aim and focus? I pray, not with clothespins??


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## BillConnerFASTC (Jan 27, 2020)

As I said, I was a part of the team doing this once, and in charge another time. I'm sure there was 6-12" if sag. And it was a light weight curtain - scrim like. But a 30-50 pound curtain is at 1000% only 300-500 pounds - not much for wire rope and anchors. Not like Ron's buddies hanging lights and mirror balls.


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## RonHebbard (Jan 27, 2020)

BillConnerFASTC said:


> As I said, I was a part of the team doing this once, and in charge another time. I'm sure there was 6-12" if sag. And it was a light weight curtain - scrim like. But a 30-50 pound curtain is at 1000% only 300-500 pounds - not much for wire rope and anchors. Not like Ron's buddies hanging lights and mirror balls.


Also, the weight of your scrim is spread across the entire (or close to it) length of the taught wire, at least until it's all gathered at one end. 
Clearly this is appreciably different than applying all of the weight in the centre of the taught wire. 
Toodleoo! 
Ron Hebbard


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## BillConnerFASTC (Jan 27, 2020)

RonHebbard said:


> Also, the weight of your scrim is spread across the entire (or close to it) length of the taught wire, at least until it's all gathered at one end.
> Clearly this is appreciably different than applying all of the weight in the centre of the taught wire.
> Toodleoo!
> Ron Hebbard


And I'm not sure a 15' high scrim "falling" is a terrible hazard. But still needs competent people to rig, no matter how simple and straightforward. Does depend a lot on what the construction is. The one I did myself was anchored to major columns and I was not worried by a few small turnbuckles and 1/8" or maybe 3/32" wire rope pulling the building down.


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