# 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.


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## Kelite

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


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## 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)


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## 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.


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## mstaylor

headcrab said:


> 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.


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## gafftapegreenia

I have another answer...


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## chausman

gafftapegreenia said:


> I have another answer...



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.


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## sarahsliefie

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


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## 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.


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## 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.


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## 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?


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## 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.


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## 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?


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## 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.


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## shiben

HiThere said:


> 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.


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## shiben

MPowers said:


> 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.


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## Dionysus

shiben said:


> 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.


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## 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.


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## metti

David Ashton said:


> 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.


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## ship

David Ashton said:


> 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?


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## derekleffew

ship said:


> There is a difference between "Batten pipe" and Sch. 40 pipe. ...
> 
> Also a note of Batten pipe being a different formulation than Sch.40. Different purposes and different materials used for it's construction. ...


[user]ship[/user], I thought we'd had this debate before. This pdf, http://www.jrclancy.com/Downloads/Batten%20Load.pdf , from JRClancy, would seem to indicate that batten pipe IS 1-1/4", 1-1/2", 2" Sched. 40 *OR* Sched. 80 pipe. (See also link below. Secoa's catalog.pdf is similar.) If you have documentation stating otherwise, please direct us to it. 

(Now I don't mean to imply that anyone should call up his/her local plumbing supply house and order some sticks of 21' 1.5" Schedule 40 steel pipe and start hanging it. I know of one stage rigging install company that used a very special pipe that came sanded smooth and pre-finished with a black scratch-resistant paint, and was only available in lengths up to 17'.)


metti said:


> ... Some theatres do use I truss (also called flat truss and I am sure other names) ...


 I think the generally-accepted term is "truss batten," or more specifically Two pipe truss batten.


ship said:


> ...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.


A batten clamp is a much different animal than a batten splice. (I intend to start a thread on that when this one is done. EDIT: See http://www.controlbooth.com/forums/scenery-props-rigging/22901-methods-splicing-pipe.html .)


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## mstaylor

I have no experience in theatres with fly systems but I do supply equipment for national touring companies that come into arenas. We supply the trusses, motors and curtains to simulate a theatre in an arena. We use a lot of ladders to replace what would normally be a scenic batten in a regular fly system. Those are basically 2 inches top and bottom.


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## MPowers

This is getting so far off the OP topic, I hate to reply but, I can't help myself.

> We use a lot of ladders to replace what would normally be a scenic batten in a regular fly system. Those are basically 2 inches top and bottom.



When you say 2 inches, are you refering to I.D. or O.D.? Pipe and tubing originally manufactured to carry a fluid (water, oil, gasoline, air, natural gas, et. al.) is measured by the I.D. as this is what affects the volume/flow rate at a given presure. 1 1/2" black pipe is 1.9" od, virtually the same as the 2" O.D. of truss tubing.


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## MPowers

ship said:


> 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.


There is NO difference between schedule 40 pipe and batten pipe. Check with J.R Clancy, SECOA, H&H et.al. Just to make sure we are all talking about the same thing, pipe intended for carrying fluids either in liquid form or gaseous form are measured and denoted by the inside diameter (I.D.). This is because that is the measurement that is relevant to the volume and flow rate of a fluid at a given pressure. Thus 1 1/2" pipe has an outside diameter of 1.9" virtually the same as 2" tube used for trusses. While many different sizes of pipe have been used and are currently in use, the most common is 1 1/2". Both Schedule 40 and schedule 80 are used with schedule 40 being the far more common. 2" pipe is not in common use as very few cast iron "C" clamps will fit around it. 1" or 1 1/4" are suitable for curtain track backbones where the support points are 5' on center, 1 1/4" is suitable for lighting battens if the support points are no more than 8' apart. Both 2" pipe and schedule 80 pipe are usually (not always) an inefficient solution to heavy loads and/or long spans between support points. Double pipe battens, Ladder truss (or Flat Truss) battens, made of two schedule 40 1 1/2" pipes are usually a better solution. Double battens are two separate pipes hung by a double pipe bracket, but not mechanically connected. Ladder Truss battens are two pipes connected with 1/4"x2" plates about 10" long welded between the pipes on 4' to 5' centers. The 1" pipe listed in Fuchs old book supported homemade strip lights that weigh a fourth of today's units and fed by 2 to 6 14ga asbestos covered wires, about one tenth the weight of today's SO multicable. 


ship said:


> 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.


The most common size of pipe for stage border lights was 1 1/2" as smaller on a 40' run could not provide enough gas at the end opposite the feed. Gas piping in houses and buildings was indeed used as conduit in the early days of electricity replacing gas in indoor lighting, but not on stage. The pipes were only above the stage, flexible rubber tubes fed to a "Gas Table" a large control center with valves and wheels that was the gas equivalent of a backstage dimmer board. Gas lighting was a lot more than just holes drilled into a pipe. As early as 1820 it became obvious that plain holes quickly rusted shut from the H2O byproduct of a gas flame. It was also obvious that the cone shaped flame produced by a round hole was very inefficient in producing visible light. The result was a ceramic insert was screwed into the hole and the shape of the opening was altered to produce flat flames of differing shapes. Over 200 patents were granted for inserts that produced different sizes and shapes of flame. The most common for theatrical use was the "Bat Wing" flame. A secondary reason for the 1 1/2" size for the gas pipe was that it was self supporting and did not need to be hung from another support member. As electricity replaced gas there were many "combination" units make and sold. Check out the combination unit in this old Clancy catalog. Look on the 3rd catalog page.
http://library.constantcontact.com/download/get/file/1102258086690-159/Theatre+DesTech+Fall10.pdf


ship said:


> 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


Hoses to supply gas to the battens were very similar in size and manageability as today's multicable electric feeds. They were a lot lighter however, gas being a bit lighter than multiple #12 copper wire and insulation. Yes, fly systems were in use before gas light but mots pieces of scenery were flown directly from the lift lines. System battens were rarely used. Battens were wooden and
commonly made of 2 pieces of what we would call 1x3 or 1x4 today, sandwiched around the tops of drops and remained permanently with the drop. Batten clamps that look a bit like a pair of tongs would clamp around the batten and a 5 pound sand bag kept the lift lines taught when the drop was removed.

ship said:


> 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


2" pipe was cheaper than what?? Not cheaper than wood, not cheaper than 1 1/2" pipe.


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## MPowers

> Also a note of Batten pipe being a different formulation than Sch.40. Different purposes and different materials used for it's construction.


Batten Pipe is NOT different in structure or formulation that Schedule 40, it *IS* schedule 40.


> 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 per-say -



You are correct, in today's rigging, a joint in a batten must be made by an internal sleeve, 18" long minimum (18" is the size sleeve sold by Clancy, SECOA, H&H etc. and spec'd by most architects for new installations.) The sleeve is fastened to the pipe with two fasteners on each side of the joint, usually at 90 degrees apart. Most common fasteners are 3/8 grade 5 bolts or 5/16 hardened roll pins. Welding is also acceptable, but I dislike it. For welding, holes are drilled in the pipe but not the sleeve and the welder then "plug welds" the holes.


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## mstaylor

The ladders I am referring to is basically a side from a box truss. You have to more points on it or it will bow and flip on it's side. I only mention it to show a modern alternative, it is apples and oranges.


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## derekleffew

Like these, mstaylor?


Tomcat - sky


Ladder Truss*Applied Electronics

Interesting that I've worked in Las Vegas arenas and ballrooms for twenty years and never seen it used.


mstaylor said:


> ...You have to more points on it or it will bow and flip on its side. ...


Many years ago, when truss battens (MPowers' definition) were just starting to be popular in counterweight fly systems, there was some ruckus about bowing in the US/DS plane under certain conditions. I think USITT did a study on it. Did that ever get resolved, MPowers?


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## mstaylor

The heavy duty style pictured from Applied. I have used the Applied ladders but the ones I use are a little heavier but I don't know who makes it. I have used the spigoted type that you showed from Tomcat but I can't remember where, maybe something Feld.


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## MPowers

> Many years ago, when truss battens (MPowers' definition) were just starting to be popular in counterweight fly systems, there was some ruckus about bowing in the US/DS plane under certain conditions. I think USITT did a study on it. Did that ever get resolved,.......?



The original concern was raised because some people thought they could save original installation costs by reducing the number of loft blocks and hardware and install labor. As most of you know a box truss can span considerable distances between pick points, 40' or more depending on the size and construction of the box truss. Double pipe battens or pipe ladder truss can not. Double pipe battens connect only by raceway brackets
http://www.etcconnect.com/docs/docs_downloads/manuals/Connector_Strip_Assembly_Instructions_RevC.pdf 
see page 3/4 and look at the brackets type 22 thru 26 should be supported on the same centers as a single pipe batten, i.e. 10'-0" spans for 1 1/2" sched 40 pipe. Pipe ladder truss with welded plate connections
http://www.jrclancy.com/Downloads/ProductCatalog-RiggingAccessories.pdf
see page 1., can handle spans up to 50% greater than single pipe of the same size, depending on a number of factors. The welded plates allow the pipes to transfer and share US/DS bending moments between the two pipes, the hanging brackets do not. In short, what should be obvious but apparently was not at the beginning, is that: A ladder truss IS NOT a box truss. Once that was determined, it was no longer an issue.


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## MPowers

> I know of one stage rigging install company that used a very special pipe that came sanded smooth and pre-finished with a black scratch-resistant paint, and was only available in lengths up to 17'.)



It is still standard pipe to start. We do the same for specific installations. The special sanding is simply factory sand blasting to clean and scour the pipe prior to painting. The shorter lengths are due to the painting process and the size of the paint booth. We can paint the pipe with industrial grade heavy equipment paint (John Deere or Caterpillar) in full 21' lengths. However as we do not have a large assembly line and curing ovens, it is a very time consuming chore and occupys a great deal of shop space. When a client wants a color or when powder coating is the best answer we have two paint companies that we work with. One has a curing oven 18' long (17' pipes) The other has an oven 20'-6" long (20'-0" pipes) which one we use depends on color, time and which length works out best for the particular installation.


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## MPowers

Quick note, my description of double pipe battens included a ULR for ETC brackets

> Double pipe battens connect only by raceway brackets
> http://www.etcconnect.com/docs/docs_...tions_RevC.pdf


If anyone reads carefully they will see the information states the brackets be spaced at no more than 5'-0" apart. That is how far apart the brackets must be to support the raceway, not how often the assembly must be supported from above. Typically, every other bracket is attached to a lift line which are on 10'-0" centers. I.e., the lift lines support the pipe(s) on 10' centers and then the pipe(s) in turn support the raceways on 5' centers. Hope that clears up any misunderstanding.


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## derekleffew

derekleffew said:


> 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?


Now that a week has passed, anyone may answer.


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## ship

derekleffew said:


> ship, I thought we'd had this debate before. This pdf, http://www.jrclancy.com/Downloads/Batten%20Load.pdf , from JRClancy, would seem to indicate that batten pipe IS 1-1/4", 1-1/2", 2" Sched. 40 *OR* Sched. 80 pipe. (See also link below. Secoa's catalog.pdf is similar.) If you have documentation stating otherwise, please direct us to it.
> 
> (Now I don't mean to imply that anyone should call up his/her local plumbing supply house and order some sticks of 21' 1.5" Schedule 40 steel pipe and start hanging it. I know of one stage rigging install company that used a very special pipe that came sanded smooth and pre-finished with a black scratch-resistant paint, and was only available in lengths up to 17'.)
> 
> I think the generally-accepted term is "truss batten," or more specifically Two pipe truss batten.
> 
> 
> A batten clamp is a much different animal than a batten splice. (I intend to start a thread on that when this one is done.)


 
Got me on forgetting, thanks and re-learned so as to remember.


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## ship

MPowers said:


> There is NO difference between schedule 40 pipe and batten pipe. Check with J.R Clancy, SECOA, H&H et.al. Just to make sure we are all talking about the same thing, pipe intended for carrying fluids either in liquid form or gaseous form are measured and denoted by the inside diameter (I.D.). This is because that is the measurement that is relevant to the volume and flow rate of a fluid at a given pressure. Thus 1 1/2" pipe has an outside diameter of 1.9" virtually the same as 2" tube used for trusses. While many different sizes of pipe have been used and are currently in use, the most common is 1 1/2". Both Schedule 40 and schedule 80 are used with schedule 40 being the far more common. 2" pipe is not in common use as very few cast iron "C" clamps will fit around it. 1" or 1 1/4" are suitable for curtain track backbones where the support points are 5' on center, 1 1/4" is suitable for lighting battens if the support points are no more than 8' apart. Both 2" pipe and schedule 80 pipe are usually (not always) an inefficient solution to heavy loads and/or long spans between support points. Double pipe battens, Ladder truss (or Flat Truss) battens, made of two schedule 40 1 1/2" pipes are usually a better solution. Double battens are two separate pipes hung by a double pipe bracket, but not mechanically connected. Ladder Truss battens are two pipes connected with 1/4"x2" plates about 10" long welded between the pipes on 4' to 5' centers. The 1" pipe listed in Fuchs old book supported homemade strip lights that weigh a fourth of today's units and fed by 2 to 6 14ga asbestos covered wires, about one tenth the weight of today's SO multicable.
> 
> The most common size of pipe for stage border lights was 1 1/2" as smaller on a 40' run could not provide enough gas at the end opposite the feed. Gas piping in houses and buildings was indeed used as conduit in the early days of electricity replacing gas in indoor lighting, but not on stage. The pipes were only above the stage, flexible rubber tubes fed to a "Gas Table" a large control center with valves and wheels that was the gas equivalent of a backstage dimmer board. Gas lighting was a lot more than just holes drilled into a pipe. As early as 1820 it became obvious that plain holes quickly rusted shut from the H2O byproduct of a gas flame. It was also obvious that the cone shaped flame produced by a round hole was very inefficient in producing visible light. The result was a ceramic insert was screwed into the hole and the shape of the opening was altered to produce flat flames of differing shapes. Over 200 patents were granted for inserts that produced different sizes and shapes of flame. The most common for theatrical use was the "Bat Wing" flame. A secondary reason for the 1 1/2" size for the gas pipe was that it was self supporting and did not need to be hung from another support member. As electricity replaced gas there were many "combination" units make and sold. Check out the combination unit in this old Clancy catalog. Look on the 3rd catalog page.
> http://library.constantcontact.com/download/get/file/1102258086690-159/Theatre+DesTech+Fall10.pdf
> 
> Hoses to supply gas to the battens were very similar in size and manageability as today's multicable electric feeds. They were a lot lighter however, gas being a bit lighter than multiple #12 copper wire and insulation. Yes, fly systems were in use before gas light but mots pieces of scenery were flown directly from the lift lines. System battens were rarely used. Battens were wooden and
> commonly made of 2 pieces of what we would call 1x3 or 1x4 today, sandwiched around the tops of drops and remained permanently with the drop. Batten clamps that look a bit like a pair of tongs would clamp around the batten and a 5 pound sand bag kept the lift lines taught when the drop was removed.
> 2" pipe was cheaper than what?? Not cheaper than wood, not cheaper than 1 1/2" pipe.


 
I stand corrected, and thanks for the history.


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## bradleywolak

True it can overhang, but most are designed to roll back to prevent overhang. In our theatre, all our pipes are designed with that in mind. Sort of a safety thing i guess.


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## David Ashton

with respect to gas lighting it may seem strange to modern people that crude fish tail and other gas flames could produce much light, but in the pre-war era town gas was full of impurities and would burn with a bright flame, the impurities in the flames also deposited vast amounts of sooty residue, when gas became cleaner they had to fit mantles to emit more light but these created a much greener colour.


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## Angurn

> 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?


 
Your question is not fair because you contradict the answer. A tube is the strongest compared to a solid pipe wieght for weight. A square or any other shape is out of the question as they have edges and edges are not practical and are weak. Imagine seeing a square tunnel(maybe a triangle but not a square)

Another qoute from another forum.


> Depending on the thickness of the tube wall of course, a tube will be able to support more weight than a solid round bar of equal diameter. This is because the closer the material is to the centre of the bar, the more "dead weight" it is.
> A tube is not so different from an I-beam, but an I beam is a bit simpler to understand.
> With an I-beam under load, the top plate of the beam is in compression and the bottom is in tension. The bit in the middle, the web, is really doing more to maintain the spacing between the top and bottom parts than anything else. In fact, at the middle of the web, there is no stress at all. You can drill a series of holes along the middle of the web, and you won't weaken the beam. But if you notch the top or bottom plates, look out!


 
As for pipe not being a wieght bearing structure? um? Scaffolding is made out of pipe. A tower crane is made out of pipe. So are wind turbines, flag poles and a variety of other things including structural supports for the reason quoted above. I never saw an answer hence the one month resurrection.


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## MPowers

> ..... A tube is the strongest compared to a solid pipe wieght for weight. A square or any other shape is out of the question as they have edges and edges are not practical and are weak. Imagine seeing a square tunnel(maybe a triangle but not a square)




> Depending on the thickness of the tube wall of course, a tube will be able to support more weight than a solid round bar of equal diameter.




> .......an I-beam under load, the top plate of the beam is in compression and the bottom is in tension. The bit in the middle, the web, is really doing more to maintain the spacing between the top and bottom parts than anything else. In fact, at the middle of the web, there is no stress at all. You can drill a series of holes along the middle of the web, and you won't weaken the beam. But if you notch the top or bottom plates, look out! ......




> ...As for pipe not being a wieght bearing structure? um? Scaffolding is made out of pipe. A tower crane is made out of pipe. So are wind turbines, flag poles and a variety of other things.........


OK, let's take a look at this. First, we have a lot of mis-information quoted here. Some is simply inaccurate, some is incomplete or mis-interpreted. I'll try to shed a little light here.

Angurn does not ask or or question why pipe was chosen in the first place, so I will not address that question in this post. He only questions the statement that pipe is not really a structural item.

He argues that a tube is stronger than a solid rod the same weight, that is true. But that is because the solid rod would be much smaller. For example a solid rod the same weight as a 1 1/2" pipe (1.9" O.D.) would be only about 1" in diameter. However, a square tube or I beam construction is considerably stronger for the same weight and cross section. For example, a 1 1/2" pipe is roughly .824 square inches in cross section and can carry a uniform load of 25 lbs per ft over a 10' span (J.R. Clancy Allowable batten load chart) . A 14 ga. unistrut 
01052011_Unistrut_US 
with a cross section of only .785 sq. inches is rated for 75 pounds per foot over the same 10' span, about 3 times the strength of the pipe. As for the "tunnel" analogy, to make the comparison you would have to place the pipe batten on the floor and apply the loading in compression on the sides and top and no beam loading as tunnels do not span gaps.

He also states that other shapes are "out of the question" and that shapes that have edges are not practical and are weak. The only reason that Square or Edged shapes seem impractical is that the majority of lighting fixtures have clamps designed for the old round gas pipe. There are a number of hardware items available from places like City Theatrical City Theatrical click on accessories then "Track tamer, that are designed to attach stage lights directly to strut or beams, thus making the other shapes practical and not out of the question. 

As for "weak", I-beam and rectangular tube shapes are far stronger than a round tube shape of the same cross section and weight, if the force is applied in line with the beam axis. The advantage of tube is that, while weaker, it is the same strength in all directions. If the forces can be predicted, then a beam placed with the axis in line with the load is stronger than a tube. That is why the majority of bridge and building frames are comprised of beam or rectangular shape members. Note: a piece of angle iron is two rectangular shapes continuously joined along the mating edges.

As for other structures, cranes, scaffold, etc., those are NOT made of pipe, but of structural tubing, which is quite different in terms of alloy, stiffness, moment of inertia, et.al. Crane beams and towers, scaffolding and similar structures are not single pieces of tube supporting weight, they are part of a truss system. The truss system supports the weight. In a scaffold or crane tower the majority of the forces are columnar, i.e. the weight is compressing the tube along it's axis, not perpendicular to it as in a beam loading condition. There are many cranes that have angle iron and square tube support members, not all are built of round tube like concert truss. As for wind turbine towers, those are purpose designed, tapered cylinders, not even close to pipe. They are designed to handle stress equally well in all directions as the rotor head pivots to follow the wind direction, thus the cylindrical shape. 

As for the statement about drilling holes in a beam web and notches in the flange, that is partly true and partly false. Drilling or cutting holes or gaps in a beam web has little or no effect on the strength as it is basically just making a solid beam into a crude truss. The structural purpose of the top and bottom flange is to prevent lateral movement causing the beam to buckle and collapse. Like the web, a great number of holes may be cut into the flange before it's strength is compromised. Notches are another matter. Depending on where they are in relation to the beam's lateral loading, how deep they are, they can severely weaken the structure, but they do not affect the vertical load bearing capacity.

Hope this helps a bit.-


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## Angurn

Fair enough. I typed the post in haste and paraphased quite a bit. I was just trying to show that round pipe whether structural or the scheduled pipe(battens) is a efficient shape.(the latter part of the question assuming tube meant round) As for edges being weak I was trying to state that a round edge distrubates the weight better than an edge. Sure the square tubing is stronger on the flat side but start putting to much pressure in the corners and you get in trouble. Either way I rambled on in this post and my last one....

My guess:

Pipe is most likely used because it does not twist over long spans. Some battens are +/- 50ft battens lift lines every +/- 10ft.(Safe guards could be put in place to keep other shapes from twisting) or since fly rail systems orginally came from sailors and wood battens were round that is the shape they stuck with.

Or was this question anwsered and I glazed over it


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## derekleffew

Angurn said:


> ...Or was this question anwsered and I glazed over it


 

HiThere said:


> 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?


HiThere proposed the generally-accepted answer. The truthfulness and historical accuracy is a matter for theatre historians.


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## Angurn

I introduced myself to these forums with a foot in my mouth after reading older posts again I realized I glazed over the answer. 

Just to add, for nuts like me, to the gas lighting history here is a link to edison monthly discussing the shift away from gas lighting. By changing the google(book) parameter I.E. Edison Monthly Theater to Edison Monthly Theater Lighting you can get more articles.

If the link fails it is Edison Monthly 1917 Volume 9 page 338 by New York Edision Company.

The Edison monthly - Google Books


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## MPowers

Gas Light was developed in the late 18th century and by 1815 there were commercial gas generating plants that piped gas to homes and businesses. One of the first uses of gas in the entertainment industry was in Paris, circa 1816. The first gas light units were simply long pipes with a lot of holes drilled in them, hung over the stage and fed by rubber hoses. It became obvious very quickly that the holes rusted up and with the holes on top, most of the light was blocked by the pipe. It also became obvious that the open flame was a fire hazard, especially as scenery then was all wood and fabric and flameproofing was still 100 years or more away. Improvements included ceramic tips to form and shape the flame and short stems to place the flame to the side of the pipe. Other improvements included corrugated tin heat shield/reflectors and wire cages.

The introduction of electricity did not replace gas overnight. In fact many stage, businesses and homes were still lit with gas after WWI. At the beginning there were many electric/gas combination units. Check out this old J.R. Clancy catalog from 1893 and look on page 3
http://library.constantcontact.com/download/get/file/1102258086690-159/Theatre+DesTech+Fall10.pdf
You can see the gas jet stems and the bare bulb lights in the combination unit. After the turn of the century, the exact date is highly debated among historians and many inventors and entrepreneurs have tried to take credit for inventing the first single units. What is known is that as theatres changed to electricity, the gas pipes were still there and simply left in place especially if they were the combination units. As spotlights and purpose built trough type strip lights were developed, the gas pipe that was there was the obvious place to hang them. As single units were developed and lenses and reflectors were added, it became clear that chain and standard plumbing fittings were impractical as a clamping/hanging device and someone developed the "C" clamp we all know and love/hate today. I have never studied the history of the "C" clamp, if anyone has real documented information on this I would be interested. 

As lighting equipment developed in the first quarter of the 20th century, more lighting positions were added and by now many of the units had clamps that attached to pipe. Most old hemp systems did not have battens of any kind, wood or other. The battens were a permanent part of drops sandwiched to the tops and lift lines were attached directly to the drops or hard scenery as needed. Wood battens were not suitable to hang lights and they were weak when it came to supporting the point loads imparted by lighting equipment and cable, so pipe was used. At the time the number of lights and the structure of scenery did not impose the loads we experience today. Pipe was much stronger than wood and no one thought to get engineers involved or anticipate the loads we impose on rigging systems today. If they had, it is possible we might have a batten shape similar to an I beam or back to back strut as battens today. Touring shows also began to request house battens for flying drops so they could tour with folded goods instead of a drop rolled on a 40' long top batten of double 1x3. 

Basically, when electricity came along, there was pipe where the lights needed to go. As electric units were developed and expanded, the desired locations for lights already had pipe there, so hang or attach the lights to the pipe, and so on. The choice of pipe was one of availability and convenience, not one of structural consideration, strength or anything else.
HTH.


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## DuckJordan

If edges are so week explain a triangle stronger than a circle but has three edges. This for discussion and not ment as an attack to anyone. I understand its fairly infeasable to use triangular piping in a lighting environment but what about its strength?

sent from my Droid incredible using tapatalk.


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## MNicolai

DuckJordan said:


> If edges are so week explain a triangle stronger than a circle but has three edges. This for discussion and not ment as an attack to anyone. I understand its fairly infeasable to use triangular piping in a lighting environment but what about its strength?
> 
> sent from my Droid incredible using tapatalk.



What Angurn appeared to be getting at was that loading a flat surface is very different from loading a curved surface. Think of a dome or of a tunnel.

If you constructed a tunnel with a square or rectangular cross-sectional shape, either the top of the tunnel has to be extremely sturdy or posts need to be constructed to prevent the roof from caving in. All of the load is applied directly to the flat area of the ceiling via gravity.

With a circular cross-section, the curvature of the walls (since there isn't really a "ceiling", per say) actually redirects the forces placed upon them such that they transfer those forces due to gravity along the walls and into the ground on either side of the cross-section.

Also consider the dome of the Florence Cathedral:






The horizontal diameter at the base of the dome is 43m (141 ft). A flat ceiling where the dome is, without any supports from below, would certainly collapse under its own weight. However, the shape of a dome causes the forces of gravity to exert forces that push outward from the center of the dome instead of inward (perpendicular to the structure, as would be the case with a flat roof), therefore distributing the forces safely into the structure at the base of the dome.


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## derekleffew

MPowers said:


> ...I have never studied the history of the "C" clamp, if anyone has real documented information on this I would be interested. ...


_The Untold History of the Ubiquitous C-Clamp_. Sounds like a perfect Masters Thesis for someone. Can't be certain, as the Kliegl archives is missing catalogs between 1936 and 1950, but I would think the cast-iron lighting C-clamp was in use before WWII. I'm sure STEVETERRY and/or dramatech were using them long before that.

See also the thread http://www.controlbooth.com/forums/question-day/13556-whats.html .


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## derekleffew

Saw this on another forum and thought it semi-relevant,

> "Many people believe a 1900 box got it’s name from the fact that it originally was 19 cubic inches. In trying to track that back, I couldn’t find any proof of that but the first reference I saw to 1900 was in the 1917 Central Electric Supply Catalog where they referred to these boxes as 1900 Combination Gas and Electric Boxes. The name seems to have come from the part number given by the Bossert Company. One means of early wiring was to use abandoned gas pipe as the wireway and the manufacturers offered products to accommodate this need. Since this was so common early on, they got the name Combination Gas and Electric Boxes. The gas connection was accomplished by using the 1/2" knock-out and closing the cap with a 3/8" flange on the box cover. The image above shows a section from the 1917 catalog describing these boxes. It shows part numbers for the generic LIST#, Sprauge Manufacturing, The Bossert Co and Chicago Fuse respectively."
> 
> Author unknown.


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## MPowers

> One means of early wiring was to use abandoned gas pipe as the wireway and the manufacturers offered products to accommodate this need.


Back in 1969, I actually came across this practice. Living in Brookline, Boston, My wife and I rented an apartment in a 1920's house converted into apartments. The conversion was a bit hap-hazard and very much landlord DIY. My wife started having headaches and one day she swore she heard hissing from the wall sconce, a real gaslight sconce converted to electricity. A bit of investigation showed she was right and that the hissing was gas that would sustain a flame like a weak pilot light. I broke into the basement which was padlocked and discovered an incredible rat's nest and maze of old pipe and tube plumbing and knob and tube wiring. in several places the wire was stuffed into a pipe and the end caulked shut. It looked like the old gas light pipes were used as conduit when it changed over and some where after WWII when natural gas was installed for cooking, some of the old gas lines were used for that. The result was gas was all over the house. Luckily the basement had several broken out windows and was open to the outside air. We warned the other residents, called the police, rented a U-haul and moved out within a couple of hours. Never looked back. It was a miracle the house didn't explode or burn down.


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