Why pipe for battens?

[derekleffew]

Another QotD submitted by a reader:

Why do we use pipe as battens to hang scenery and lights from? A tube is not the strongest or stiffest or most efficient shape, pipe is not designed as a weight bearing structure. So, why do we use it?

Remember, if you consider yourself a professional, wait one week before answering, to give the students a chance.

 

[Kelite]

(I am looking forward to our savvy readers answering this riddle, Derek. Good question!)

 

[gafftapegreenia]

Just some thoughts on pipe:

It can be threaded and attached to make longer pipe.
It existed before truss.
Truss takes up more room than batten.
A round pipe rolls off of obstacles easier.
A square tube or any other shape with edges would put high pressure points on whatever method is used to attach them to the lift lines. (Hemp, wire rope, chain)

 

[headcrab]

It's round, allowing many more mounting angles. I can hang a light on a square tube, but I only get four positions to play with.

 

[mstaylor]

It's round, allowing many more mounting angles. I can hang a light on a square tube, but I only get four positions to play with.

But you have to consider the disadvantage to round, overhanging can cause roll or deflection. Carry on.

 

[gafftapegreenia]

I have another answer...

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[chausman]

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Ok then...Why did they use round tube to start out with?

Edit: MY guess would be that a round tube would be less likely to ruin rope when hung over it. And tradition. And to answer my own question (kind of) round tube, was easier to make then square tube.

 

[sarahsliefie]

The price. due to the mass production of pipe for plumbing needs it is much cheaper then rod stock or square tube.

 

[skienblack]

I don't think anyone addressed the structural advantage to a pipe over tubing. You cant really crush a pipe when hanging lights or scenery while you could easy dent tube compromising its integrity.

 

[metti]

I have always been under the impression that pipe was originally used because it is readily and affordably available due to it being a necessary material for other, larger, industries (plumbing).

Also, for the record, pipe CANNOT be threaded and attached via its threads when used in structural applications (IE our application). I'm pretty sure that a batten would be derated to almost nothing if a threaded coupler is used to attach two shorter pieces of pipe to make one batten. Welding or, more practically, a pipe splice is the appropriate method for attaching pieces of batten.

 

[ship]

Seen quite a few older lights especially of the UK version that were studded to bolt to square box tubing. Pipe as more a US concept?

And "Batten Pipe" how is it different than Sch. 40?

 

[MPowers]

Having posted the original Q, I obviously can't answer yet. However, I'd like to help keep the thread going in the right direction and thus I'll comment on a couple of answering posts.

And "Batten Pipe" how is it different than Sch. 40?

Standard Batten Pipe IS Schedule 40 pipe. Primarily 1 1/2" I.D., occasionally 1 1/4" or 2", occasionally schedule 80.

It can be threaded and attached to make longer pipe.

...... pipe CANNOT be threaded and attached via its threads ....... Welding or, more practically, a pipe splice is the appropriate method for attaching pieces of batten.

Threaded couplings were considered acceptable up and until the '60's. I stopped using them after witnessing a failure in 1969 but I'm not sure just when they became universally unacceptable. If anyone has historical data, I'd be interested in seeing it. Today, internal splice sleeves, commonly 18" long and fastened at each end by two (total 4 per joint) grade 5, 3/8" bolts, plug welds or hardened roll pins is the norm.

But you have to consider the disadvantage to round, overhanging can cause roll or deflection.

If a batten is hung by a pipe batten clamp Pipe Clamps Rolling is minimized and a tie off leg can eliminate it almost entirely.

Now, back to the original Q. people are listing pro's and cons for the use of pipe, but they are avoiding the question. Why did we start using it in the first place?? Hint, study history of stage lighting.

 

[HiThere]

postulating

before electic lighting theaters used gas ilumination those "lights" used pipes to carry the gas to the jets.
when theaters transitioned to electric lights they used the old gas pipes for mounting and running of power.

am I close?

 

[David Ashton]

In W Australia, during most of the last century the standard stage batten was made of Oregon pine, because it was available in long lengths.

 

[shiben]

postulating

before electic lighting theaters used gas ilumination those "lights" used pipes to carry the gas to the jets.
when theaters transitioned to electric lights they used the old gas pipes for mounting and running of power.

am I close?

Im gonna go with this as the most likely reason. I also think I heard that somewhere. Having an installed network of supports would probably be the best way to go. I also have a feeling that it was pretty common at the time of the transition, and everyone figured well, it works, dont screw with it.

 

[shiben]

Threaded couplings were considered acceptable up and until the '60's. I stopped using them after witnessing a failure in 1969 but I'm not sure just when they became universally unacceptable. If anyone has historical data, I'd be interested in seeing it. Today, internal splice sleeves, commonly 18" long and fastened at each end by two (total 4 per joint) grade 5, 3/8" bolts, plug welds or hardened roll pins is the norm.

So our electrics in one of the spaces I work in orriginally had threaded connectors on them. At some point, someone came by and tack welded all the threaded sleeves onto the pipe. No idea if its safer, but I have been told that the failures were why this was done.

 

[Dionysus]

So our electrics in one of the spaces I work in orriginally had threaded connectors on them. At some point, someone came by and tack welded all the threaded sleeves onto the pipe. No idea if its safer, but I have been told that the failures were why this was done.

The main danger due to threaded pipe connections is NOT the connector turning and un-doing (thus made safer to tack welding). The real problem is the material REMOVED in the threading process, or the threading process in general. The threaded portion of the pipe is MUCH weaker than the rest of the structure. If there is going to be a point of failure it is usually on the "last" thread.

 

[David Ashton]

reading this thread again there is a difference in terminology, a batten here is used to hang drapes or scenery, while a spotbar is used to hang lights, our spotbars are normally truss sections with the sockets in the top and pipe on the bottom.

 

[metti]

reading this thread again there is a difference in terminology, a batten here is used to hang drapes or scenery, while a spotbar is used to hang lights, our spotbars are normally truss sections with the sockets in the top and pipe on the bottom.

That makes sense. In America, the term batten is used to refer to both those used for scenery and electrics for lights. Some theatres do use I truss (also called flat truss and I am sure other names) for battens but 1 1/2" Sched 40 pipe is vastly more common.

 

[ship]

reading this thread again there is a difference in terminology, a batten here is used to hang drapes or scenery, while a spotbar is used to hang lights, our spotbars are normally truss sections with the sockets in the top and pipe on the bottom.

There is a difference between "Batten pipe" and Sch. 40 pipe. Also, I note in the older days often 2" Sch. 40 pipe was used for pipe battens or support. On the other hand, in 1929, Fuch's was listing 1" Sch. 40 as sufficient for strip lights in the home built section. 1" Sch. 40 also used often in gymatoriums in the 30's and 40's for supporting lighting and drape.

In all cases, it's listed as water pipe not gas pipe - though the same pipe in use. Gas pipe I would think often would be much smaller in size so that would be a nope unless like 1" down to 1/2" or less in size. Gas piping was used for electrical conduit runs as a replacement for wiring but not for batten pipe. This unless in some research unknown - the batten pipe for a fly system on say a gas jet boarder light was 1.1/2" and also used for rigging it. Doubtful I think in that it wouldn't be adjustable short of tapped holes in it and rubber hosing run to the jets and batten if movable. A lot of fittings and hose so as I would think not reliable. Besides, fly systems were in use long before the gas jet came into use, it wouldn't follow say now obsolete pipe left over, it would follow use what was in stock and locally available for for say water pipe and long lengths new. Given three rigging points per 30' as a norm, it could be thought that 2" pipe for lighting battens was cheaper and easier given conditions given the span and added loading of individual fixtures and cable, that the 2" Sch.40 pipe came into use. This as opposed to adding more blocks and pickup lines which might not be easy to install on an arbor. Weight was larger and it pushed the limits of the rope but most battens were mostly static anyway and even often not rope locked down.... Seen a 1926 boarder light batten system in a Hemp house with pin rail - but the battens were counterbalance fly rail and seperate. No rope locks and indeed the old rope broke as the fixtures came in to 6' above the stage max travel. Batten lights were counter balanced on install, no reason to rope lock them in that the weight didn't change it would seem.

Possible as in 1929 it was hemp rope and or "flexible" wire rope - meaning probably bronze sash cord in use with hemp blocks. Such wouldn't be sparking assuming some amount of gas leakage in use. But still very doubtful that any batten was either gas pipe in use or left over gas pipe of sizable length or dia. that wasn't used for wiring for electric.


David, What you call spot bars we would call an "Electric" that has a raceway above with outlets or cords to plug in, and a pipe batten below it. Same pipe to hang scenery as lights so why different term in what's used to hang them? Truss a completely different thing.

Also a note of Batten pipe being a different formulation than Sch.40. Different purposes and different materials used for it's construction. Proper battens are with batten pipe and splices. Perhaps welding of batten pipe is acceptable - don't know, not a rigger in a modern days sense. Problems in welding agreed isn't it un-screwing persay - though I have seen that in pipe grid, more about the material removed. Welding theoretically could help in bypassing that part of the pipe now thinner if high strength couplers were used, but normal water pipe couplers suffer from the same problem. The weld would be strong in transferring load thru the weld to the coupler, but the coupler even with added material of the thread is now the weak point. Thinking it's possible to do so, but high pressure steel couplers would be needed to do so.

1/2" Sch. 80 pipe is great for side arms by the way, but the ETC clamp won't fit it - have to go with Altman for a clamp that will fit 1/2" Sch.80 pipe.

Seen some sleeving done with 2" Sch.40 pipe at like 24" long over the years. Was much more impressed by such a concept than the early/mid 90's batten clamps that were only like 12" long. Glad to hear the clamps are longer now or if they were always 18", not impressed in needing to be longer.


Hey... I'm a study of stage lighting history, (currently making a "home built" ten light bunch light by way of study), beyond advantages of pipe being round in better for hemp, and more easily available... Realize I'm a 'pro' as it were, I have studied and perhaps missed the actual reason. Perhaps give another week but do tell, what are we missing?