Clew inspection

[GBtimex]

Dear Riggers,

I was cleaning out my storage the other day and came across a great deal of rigging equipment. Everything from wire nuts that came from china to cable that looked like it was brand new when Civil was was going on. Needless to say a lot of this stuff has left my theatre since I have no idea what the ratings on it are and rust has no place in over head rigging.

I did come across a few clews though and I am not sure about. Most are in good shape but some are really rusted (see pic). I could not find a manufacturer and the only thing written on any of them was " 46 P". I was wondering if anyone knew anything about these things and if they should be trashed or saved. The rusty one is going away no matter what but any thoughts on the clean ones?



Thanks Gbtimex,

 

[Footer]

Those clews look usable. However, without inspecting the springs and jaws look like there is really no way to tell. Do you have any loft blocks that take rope laying around? Do you have a rope head block? Do you have a ton of multiline II laying around? If not, I would say get rid of them.

 

[GBtimex]

I do have some loft blocks and a head block or two but no multiline II to speak of. The springs are still "springy" and they close down and bite pretty well. I have not seen these in use in my theatre before and to be honest I am unsure when we would. Is there a situation where you could see these being useful in a single purchase counterweight house?

 

[derekleffew]

From http://www.controlbooth.com/forums/scenery-props-rigging/25449-hemp-rigging-system-pointers.html :

All trim clamps are clews, but not all clews are trim clamps.

 

[Footer]

I do have some loft blocks and a head block or two but no multiline II to speak of. The springs are still "springy" and they close down and bite pretty well. I have not seen these in use in my theatre before and to be honest I am unsure when we would. Is there a situation where you could see these being useful in a single purchase counterweight house?

Unless you have sand bags, a pin rail, all the blocks, good rope, and all that type of stuff there is no reason to keep them. If you know of a hemp house in the area, they might want them, but otherwise they are pretty useless.

 

[MPowers]

First, toss the rusty pieces immediately or sooner. If you can assemble a good clamp from completely un rusted parts, it would possibly be OK. The only way to tell would be to put the clamp on a pull frame and subject it to 5 times the rated load. If it handles that with out visible deformation, then you can use it. Now, what you have shown in the pictures is a trim clamp, NOT a clew. They are not interchangeable. The triangular "Loop" which is at the bottom, is not designed to be an attachment point for a haul line. It is designed to clip sand bags to. The device is designed to handle the counterweight load and to allow the rigger to "trim" or adjust the length of individual lines in a hemp style rigging. The spring loaded pawls allow individual lines to be pulled through the device one at a time, without changing the trim of any other line. This was invented to offset the large response natural fiber ropes have to humidity changes. If the change was, for example 1 % , longer of shorter, a 50 foot rope would change 6", a 100' rope would change 12". So if you short line is 35' from the rail to the head block, 5' to the short line block and 10' down to the scenery at high trim, the rope length between the weight and the scenery is 50'. The long line is the same 35' up to the head block and the same10' down, but it is clear across the stage, 50' away. The long line is 100' long. Day one is dry and sunny, 95F and 45% humidity, the lines are trimmed to make the scenery level. Day two is 85F, rainy and the humidity is 95% . Now your level piece of scenery is 6" low on the long side. So you use the easy trim and pull the long line through 6" and the rest, depending on how many lines you system has, are pulled proportionally to level the batten. It shouldn't take you too long to figure that about once a week the entire trim clamp has to be lowered as it climbs up the lines with each trim.

To tie off a load when using a trim clamp, you still tie off the group of lines, not a single haul line to the trim clamp. The reason for this is if the trim clamp should ever fail, the load is still tied off. As it is unlikely all the pawls would fail at once or all 3 adjusting bolts would fail at the same time, the sand bags would simply creep down the ropes until they hit the rail. If the trim clamp is used as a clew and has a failure, the scenery falls on the stage and the sand bags fall on the rail or whatever is below it.

A Clew is a piece of hardware designed to attach a number of lift lines and then attach one or two haul lines to actually pull the load. In effect, a counterweight arbor is a very specialized clew.

Clews can be used with GAC, rope of different sizes, turnbuckles, etc. A trim clamp must be used with a fiber rope (natural or synthetic) of the size specified on the clamp. Usually 3/8" smallest to 5/8" as the largest.

Back to your original question. use only with hemp style rigging or spot line applications. Discard all parts with rust unless your are a certified metallurgist that can legally vouch for the structural integrity of the parts. Hope this helps.

 

[Van]

I've been trying, all day, really hard, to come up with a bad pun about Clues and Inspectors and it just wont come.

 

[chausman]

I've been trying, all day, really hard, to come up with a bad pun about Clues and Inspectors and it just wont come.

Inspect you cleu-so you don't kill someone? Sounds better in person.


---
- Sent from my iPad using Tapatalk

 

[GBtimex]

Well that clears things up a bit!

Thanks for the advice and education. Storage finds often raise 2 questions in my mind: "How long has this been here?" and "WHY IN THE HELL DO WE HAVE THIS?". We are not a hemp house nor are we in place were we need a trim clamp of this nature. Most of these are destined for a class room or a trash bin. I just wanted to hear from someone better versed in the hardware before I got rid of them.

Thanks again,

GBTimex

 

[GBtimex]

Inspect you cleu-so you don't kill someone? Sounds better in person.


---
I almost titled this post as "Clew-less manager in need of help" or "Screw this Clew" but thought it too silly to post for a subject... Better luck next time for jokes.