Question Regarding Scrim Rigging

[Lambda]

This coming school year, one of the things I'm doing is going through our rigging system, and removing old spot lines, unrated and underrated components, and generally optimizing for safety and efficiency.
One thing that has me puzzled is the scrim rigging. I have never seen a proper scrim rig, and have been unable to find pictures of one on the internet.
Our scrim has one end attached to a dead-hung batten (which, oddly enough, is actually riveted to supports coming out of the proscenium wall), and has the other end attached to a moving batten. When flown in all the way, the batten has to come down to the deck, and when flown out, it has to come all the way to the ceiling.
It seems to me that the right way to rig it would be to attach it to a moving batten, and simply weight the bottom end. Then the batten only has to travel half the height of the fly tower.
I drew this up, I think it explains it better than I can write:

I know, it's one of those "if you have to ask, you shouldn't be doing it" things, but I really see no other way to find out how to do it right!

 

[65535]

Only thing I'll put in; at our theatre an overly heavy bottom baton combined with being left flown and never tied up (until recently) has left the scrim stretched badly on either end.

 

[Van]

You are correct in stating " If you have to ask, you shouldn't be doing it"... That said, your second diagram is a "more traditional" way of rigging < hanging> and flying any type of drop. Sometimes, however, Scrims require an additional frame around them to pull them tight. I don't really know why someone would trip a scrim in such a manner. Technically it's not really tripped it's simply being flown from the bottom. Perhaps it was rigged for a particular production where they wanted that look, of it being drawn backwards and out. Odd.
Anyway, Glad you asked. Thanks for joining and looking for advice. I'm not going to lecture or anything, but as far as your 'Occupation' listing goes, being a Rigger is like being Pregnant; you either are or you aren't, there ain't no 'Somewhat'. I think it's very commendable that you want to learn more and that you are attempting to clean up and maintain your facility. Spend a lot of time reading, even more time studying, and then as much time as possible watching a profesional do the rigging before you make any changes to anything .

 

[derekleffew]

Lambda, I suspect you're using the term "scrim" wrong. It is but one type of drop or backdrop, and is often, erroneously, used interchangeably with cyc or cyclorama. Notice how some of the previous terms have a dotted yellow underline? Click on the word to be taken to the wiki definition. I only point this out because often a scrim needs framing or support on all four sides (post#2, see hourglassing), unlike most other backdrops.

Now, what you've drawn, quite nicely , in the first illustration is a "tripped drop" (tripping)--a method used quite often in venue s that do not have "full fly" (height of grid equal to or greater than twice the height of the proscenium. Which is what would be required in your second drawing. And is apparently what you have:

...Above the stage, we have 7 linesets, 2 of which move (+ the fire curtain). There is no grid, the ceiling of the fly loft is exactly twice the height of the proscenium as it is. All blocks and lines are inconveniently attached to the ceiling. ...

In any case, there's nothing inherently wrong with a tripped system. Perhaps it was done as it was easier than gaining access to the higher ceiling.

Type "tripping a drop" into the search box, and read the threads returned.

 

[Lambda]

Thank you for responding.

Originally Posted by Derekleffew

Lambda, I suspect you're using the term "scrim" wrong. It is but one type of drop or backdrop, and is often, erroneously, used interchangeably with cyc or cyclorama. Notice how some of the previous terms have a dotted yellow underline? Click on the word to be taken to the wiki definition. I only point this out because often a scrim needs framing or support on all four sides (post#2, see hourglassing), unlike most other backdrops.

I am pretty sure it would be considered a scrim. It's made of black sharkstooth material, and it's partially transparent. It hangs further downstage than a cyc, just downstage of second electric.
You're right about the hourglassing, it does look quite bad. In the last production, the set masked the sides of it (somewhat of a false proscenium), but when I untied it and flew it in (what I suspect was the first time in upwards of 10 years) it had two leg curtains rigged confusingly to cover the sides. (they didn't fly out with the scrim again, whatever once attached them had been taken off.)

*yes, the bottom batten is uneven in this picture. This was the first time we flew it in, and I hadn't adjusted anything yet.

Originally Posted by Van

I'm not going to lecture or anything, but as far as your 'Occupation' listing goes, being a Rigger is like being Pregnant; you either are or you aren't, there ain't no 'Somewhat'.

The only reason I put "somewhat" in there is that I'm only in the position by circumstance, and I'm nowhere near officially qualified. I'm here simply because I'm the only one (in years, I suspect) to take the time and figure out how the system works. So it's my responsibility to learn as much as I can and gather as much experience as I can so that I can keep things running safely (and train someone else to do the same once I leave). Because, I have to admit, this being a high school theater, some very questionable things have gone on in the past. I have a copy of the stage rigging handbook in the budget, and if it's denied, then I'll buy it anyway. If you could recommend any other literature we could get, I'd appreciate it.

 

[derekleffew]

Your use of the term scrim was correct. One thing I don't get though is, aren't the liftlines in view when the scrim is in playing position?

...If you could recommend any other literature we could get, I'd appreciate it.

Lots of great information on fly systems here: JRClancy.com/Reference.

 

[Lambda]

Your use of the term scrim was correct. One thing I don't get though is, aren't the liftlines in view when the scrim is in playing position?

They are indeed in view. But they're 1/16 inch black aircraft cable. Nearly impossible to see behind the black scrim. We have the same lift lines for the white scrim, but since that scrim acts as our cyclorama and is only ever lit from the front, they are nearly invisible as well.
Come to think of it, the aircraft cable might be 1/8 inch. Either way, it's very hard to see unless you are standing upstage of it.

 

[Van]

I still don't get why it's tripped, from your drawing it appears there is enough gallery space to store it with out needing to trip it.

 

[chausman]

I still don't get why it's tripped, from your drawing it appears there is enough gallery space to store it with out needing to trip it.

Maybe at some point in the past, the director, or someone, decided they wanted to keep the scrim from swaying back and forth, but were afraid that hanging the pipe from the scrim would rip the scrim, so they tripped it. Or they liked the look of it flying in like that for whatever reason.


---
- Sent from my iPad using Tapatalk

 

[kicknargel]

"...Above the stage, we have 7 linesets, 2 of which move (+ the fire curtain). There is no grid, the ceiling of the fly loft is exactly twice the height of the proscenium as it is. All blocks and lines are inconveniently attached to the ceiling. ..."

This would indicate that the fly loft is not quite tall enough to fly the scrim all the way out (unless there's a valence that cuts into the proscenium significantly) so the tripping arrangement allows the scrim to trip out to masked (by folding the scrim in two). That's my guess, although if your drawings are accurate to scale, then who knows?

 

[Lambda]

"...Above the stage, we have 7 linesets, 2 of which move (+ the fire curtain). There is no grid, the ceiling of the fly loft is exactly twice the height of the proscenium as it is. All blocks and lines are inconveniently attached to the ceiling. ..."

This would indicate that the fly loft is not quite tall enough to fly the scrim all the way out (unless there's a valence that cuts into the proscenium significantly) so the tripping arrangement allows the scrim to trip out to masked (by folding the scrim in two). That's my guess, although if your drawings are accurate to scale, then who knows?

To that effect, the drawings are to scale. The fly loft is just tall enough to fly it all the way out. The way it's rigged doesn't allow it to take any less space. When fully flown out, the top of the scrim ("top" as it would appear when flown in) is right where the bottom would be if it were rigged traditionally. That's why I asked about it here, it made no sense to me.
Thinking about it now, it could be that whoever rigged it all those years ago might not have known that the fly loft was tall enough, and thought that by rigging it this way it would fit better. After all, we only have 20-foot tape measures in our inventory.
Along these lines, I was thinking I would put together a "specs" book, containing measurements and ratings of everything.

 

[derekleffew]

...Along these lines, I was thinking I would put together a "specs" book, containing measurements and ratings of everything.

An excellent way to get to know your space, as well as provide assistance to future users.

See Venue Tech Info Packet - ControlBooth .

 

[kicknargel]

Yup, looks like it's that way due to poor or nonexistent planning.

 

[Lambda]

In any event, I'm going to re-rig it, not tripped. Now, the lift lines are attached to the scrim's bottom batten, which is actually sewn into the scrim (and, I'm guessing, isn't generally supposed to have lift lines attached to it). I'll rig another batten to the lift lines and attach the top of the scrim to it. That way, if we want to we can fly something else, like a drop or a projection screen, we can.