Return-Path: X-Processed-By: Virex 7 on prxy.net X-Real-To: stagecraftlist [at] theatrical.net Received: by prxy.net (CommuniGate Pro PIPE 4.2.5) with PIPE id 4882231; Wed, 03 Nov 2004 03:01:00 -0800 X-ListServer: CommuniGate Pro LIST 4.2.5 List-Unsubscribe: List-ID: Message-ID: From: "Stagecraft" Sender: "Stagecraft" To: "Stagecraft" Precedence: list Subject: Stagecraft Digest #184 Date: Wed, 03 Nov 2004 03:00:38 -0800 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Disposition: inline X-Spam-Checker-Version: SpamAssassin 3.0.1 (2004-10-22) on prxy.net X-Spam-Level: X-Spam-Status: No, score=-4.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.0.1 X-TFF-CGPSA-Version: 1.4f2 X-prxy-Spam-Filter: Scanned For info, archives & UNSUBSCRIBE, see --------------------------------------------------- Stagecraft Digest, Issue #184 1. Nov. 2 - VOTE by Mike Brubaker 2. Re: Nov. 2 - VOTE by "Stephen E. Rees" 3. Re: Jaxsan 600 by thetd222 4. Re: Nov. 2 - VOTE by "Hall, Delbert L." 5. Re: Nov. 2 - VOTE by IAEG [at] aol.com 6. Re: Bizarre Multiple Catastrophic Truss Failure by "Shawn Nolan" 7. Re: Nov. 2 - VOTE by Herrick Goldman 8. Re: Bizarre Multiple Catastrophic Truss Failure by Bill Sapsis 9. Re: Nov. 2 - VOTE by IAEG [at] aol.com 10. Michael Powers by "Stephen E. Rees" 11. IAAPA / ORLANDO by IAEG [at] aol.com 12. Re: Nov. 2 - VOTE by Greg Bierly 13. Re: Jaxsan 600 by Boyd Ostroff 14. Re: Write only memory by Mark O'Brien 15. Re: Febreeze scentstories by Mike Voytko 16. Digest Message Numbering by Mark Harvey 17. Re: Bizarre Multiple Catastrophic Truss Failure by "Cyr, Dale" 18. ETC Express boards: internal battery? by "Jon Ares" 19. Re: ETC Express boards: internal battery? by Dale Farmer 20. Re: Digest Message Numbering by Noah Price 21. Re: Febreeze scentstories by "Scott Boyle" *** Please update the subject line of your reply to use the subject *** line of the message you are replying to! Please only reply to *** one message subject in each reply. ---------------------------------------------------------------------- Message-Id: <6.1.1.1.0.20041102074232.01c66a98 [at] mail.insightbb.com> Date: Tue, 02 Nov 2004 07:43:43 -0500 From: Mike Brubaker Subject: Nov. 2 - VOTE In-Reply-To: References: Just a friendly reminder to all of you here in the United States: Go to the polls, VOTE. Mike ------------------------------ Message-ID: <4187893B.5080004 [at] fredonia.edu> Date: Tue, 02 Nov 2004 08:18:51 -0500 From: "Stephen E. Rees" Subject: Re: Nov. 2 - VOTE References: Yes Indeed! Vote early and often ;) Best, Steve Mike Brubaker wrote: > > Go to the polls, VOTE. > > Mike ------------------------------ Message-Id: <200411021328.iA2DS2C4022094 [at] smtp.unc.edu> From: thetd222 Subject: RE: Jaxsan 600 Date: Tue, 2 Nov 2004 08:28:00 -0500 When I was in Atlanta, we got it at National Insulation. (It was about $60 = a 5 gal bucket.) It came in two grades, trowelable & sprayable. It is a roofing compound that may be available through a local building/insulation/etc supplier. The Henry's elastometric stuff that Home = Depot sells is similar, but Jaxsan 600 is a little thicker & holds up to we= ar better. Rosebrand also sells it, but it is expensive. - Will Leonard Assistant Technical Director PlayMakers Repertory Company Center for Dramatic Art UNC - Chapel Hill O: 919-843-9817 C: 919-423-9162 Sometimes you just have to ask yourself: WWJCD? (What would Johnny Cash do?) = My website: http://WillTheTD.tripod.com ------------------------------ Subject: RE: Nov. 2 - VOTE Date: Tue, 2 Nov 2004 08:29:28 -0500 Message-ID: From: "Hall, Delbert L." Me too. -Delbert Delbert L. Hall, President Hall Associates, Inc. Phone: 423-773-HALL Web: www.flyingfx.com -----Original Message----- Yes Indeed! Vote early and often ;) Best, Steve Mike Brubaker wrote: >=20 > Go to the polls, VOTE. >=20 > Mike --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.786 / Virus Database: 532 - Release Date: 10/29/2004 =20 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.786 / Virus Database: 532 - Release Date: 10/29/2004 =20 ------------------------------ From: IAEG [at] aol.com Message-ID: <1f1.2e845557.2eb8e622 [at] aol.com> Date: Tue, 2 Nov 2004 08:31:14 EST Subject: Re: Nov. 2 - VOTE In a message dated 11/2/04 8:30:23 AM, HALLD [at] mail.etsu.edu writes: > >Yes Indeed! Vote early and often ;) > >Best, >Steve that's a grand tradition here in Tampa, , , I assure you ! very best, Keith Arsenault ------------------------------ From: "Shawn Nolan" Subject: Re: Bizarre Multiple Catastrophic Truss Failure Date: Tue, 2 Nov 2004 08:53:35 -0500 Message-ID: All, (sorry for the late reply, I've had some trouble getting the list to accept my emails...) As regards the "Bizarre" truss failure posted by Dale Cyr, I think this failure was not bizarre at all but, highly predictable and inevitable. I suspect that several things were going on. 1. I think they probably exceeded the allowable span for the load. Extrapolating from the info on the load table as shown in the photo, the allowable bending moment for this truss is apx. 8,100 lb.ft. to 8,400 lb.ft. Say we use the average of 8,250 lb.ft. as the allowable value (note: I have included the self weight of the truss in my calcs). For a 65' span, the allowable UNIFORM LIVE LOAD is about 9.1 pounds per foot. This would give a TOTAL LOAD, UNIFORMLY DISTRIBUTED of 591 pounds. Even without accounting for the slenderness of the truss, the load is very close to the raw, theoretical capacity of the truss. In addition, IT MUST BE NOTED, that the truss, at 65' long, is VERY SLENDER. When a beam-like (like a horizontal truss) element is loaded, the top of the beam (in this case the top chord) is placed in compression. We all empirically know that, if you have a tall skinny column (imagine a 2x4 that is 10' tall, trying to support a thousand pounds...it is apparent that it will buckle...) that is not properly braced, it will fail. If you have a well braced column, however (take the 10' 2x4 and brace it securely and stoutly at 1' intervals...much better chance of it holding the load) you can support a much higher load. The top chord of the truss is acting like that slender column. You might say that it is braced by the bottom chords. This is true, up to a point. At some point, the ENTIRE ASSEMBLY also becomes too slender. Consequently, even though I calculated an extrapolated capacity for 65', it is VERY LIKELY THAT MY CALCULATION IS WRONG! I did not consider slenderness (somewhat complicated) but, suffice it to say, there is a reason the manufacturer publishes a span limit of 50'. 2. I think that the unusual rigging of the spansets induced torsional forces into the truss. These trusses are generally intended to be loaded uniformly. Torsion is not allowed! 3. Rigging of the curtain from the top chord would also tend to induce torsion into the truss. The mass of the curtain would tend to impart a horizontal component into the bottom chord of the truss, as it draped past that chord. 4. If it was rigged the same way as the "20 to 30 times" before, why did it fail now? There are a few possibilities: A. Dale Cyr states that the rigging of the spansets was "unusual". The attachment of the span sets may have induced some torsional tendencies (however small) into the truss arrangement. B. Since Dale was not on site, he may not really know if it was "done the way it has always been done". C. It is pertinent to point out that, apparently, the trusses have been seeing some torsional forces for some time (as evidenced by the "rocking" of the trusses when placed on a flat floor). This indicates that the trusses have likely been being overstressed for some time. D. Was there some other load we don't know about that just put this over the edge? Were the motors different, such that the load upon starting and stopping (shock load) was greater than was seen before? Did the operator "bump" the motors too much, setting up either a vibration or a shock load greater than "normal"? Was this just the night when, for a variety of subtle reasons, that the trusses, loaded well beyond the limit of their design capacity, finally exceeded their yield strength and decided to let go? 5. I believe that this 65' span, rigged with two motors, was well beyond the design capacity of the truss. It did not fall down earlier due to a combination of luck and, the fact that, while the trusses were WELL BEYOND their capacity, the design factor had not been totally exceeded. (Note: Most manufacturers do not publish their "design factors" for good reason. If this is published, someone will say, "Hey, I've got another 50 pounds per foot before it breaks! Go ahead! Load it up!!) Design factors are complicated; they are a function of many variables having to do with material, connections, tube shape and wall thickness, usage, etc, etc, etc.... On this night, the combination of the "unusual" rigging of the span sets, perhaps connected with the slightly heavier drapes due to the humidity, perhaps combined with "bumpy" motors, resulted in finally truly exceeding the capacity of the truss. Both of the trusses failed at mid-span. This had nothing to do with bad welds or bad construction. When something fails due to being overloaded in bending, it fails at mid-span. This would have happened whether or not there was a 5' section was at mid-span. The fact that, in several places, material ripped apart and plates bent tends to indicate GOOD WELDS. Remember, when you exceed design capacity, initially you are just "biting into" the design factor (the factor of safety). Look up the capacity for a 2x10 joist at a 10' span. Can you put more load on this joist than the tables recommend before it breaks? Absolutely! Is it a good idea? NO!!! Allowable design stresses are intended to prevent failure due to the inevitable unknowns that exist in the real world. Things such as imperfect manufacturing, varying material strengths, slight overloads, human error, etc... are the reason that design factors exist. If something is loaded, to the best of everyone's ability, to it's allowable capacity, then, if you miss calculating the load by 5%, everything will still be o.k. However, if you have a truss, loaded right up to it's ultimate capacity (well beyond a reasonable design load) and you "add 5% load" either due to actual additional load or due to torsion, shock load or whatever then, that truss WILL FAIL! So, in conclusion, I think this was an accident waiting to happen. I think that, if the manufacturer truly knew the nature of the loads and the rigging they would say "NO WAY!". If the manufacturer publishes a span limit (apparently clearly indicated on the truss...) then, those guidelines should be followed. If a user wants to try and exceed those guidelines, they should get a FORMAL ANSWER FROM THE MANUFACTURER OR A LICENSED STRUCTURAL ENGINEER IN WRITING. The industry as a whole continues to be very lucky with failures of this type. If accidents continue to happen, it is inevitable that our luck will run out. There are many smart and knowledgeable people working in this industry, which includes, I believe, most of us. If you think something looks or "feels" wrong, if your gut tells you it's wrong, you are probably right! Please pay attention to these things, it may be you, your best friend or your kid sitting at the concert who gets injured or worse. What we do takes vigilance, discipline and knowledge. We all have the ability to apply these things to insure that we can all sleep at night. I am not pointing fingers at anyone. I know that none of us would intentionally do anything dangerous but, I think that surely someone must have wondered about exceeding the published span or, thought that this rig seemed to "have a bit more deflection than seemed reasonable" or, "seemed a bit more bouncy than usual". If you think a rig has a problem, I would encourage you to say something. Politely, insistently, say something. Don't just let it go. O.K. Done preaching for today. Shawn Nolan, P.E. Entertainment Structures Group A Division of Steven Schaefer Associates 10411 Medallion Drive, Suite 121 Cincinnati, OH 45241 (513) 699-2571 direct line (513) 542-3300 main line (513) 542-5540 fax (513) 706-3125 mobile Shawn.Nolan [at] EntertainmentStructures.com www.EntertainmentStructures.com ------------------------------ Date: Tue, 02 Nov 2004 08:59:34 -0500 Subject: Re: Nov. 2 - VOTE From: Herrick Goldman Message-ID: In-Reply-To: Yeah Keith you tell your friends and neighbors we're gonna hold Florida personally responsible if you guys screw this up again! Maybe we'll sell you all to Cuba. On 11/2/04 8:31, "IAEG [at] aol.com" wrote: > > that's a grand tradition here in Tampa, , , I assure you ! > > > > very best, > > Keith Arsenault > > -- Herrick Goldman Lighting Designer, NYC www.HGLightingDesign.com "To the scores of silent alchemists who wreak their joy in darkness and in light bringing magic to life, we bow most humbly. "-CDS ------------------------------ Date: Tue, 02 Nov 2004 09:06:20 -0500 Subject: Re: Bizarre Multiple Catastrophic Truss Failure From: Bill Sapsis Message-ID: In-Reply-To: on 11/2/04 8:53 AM, Shawn Nolan at ShawnN [at] entertainmentstructures.com wrote: > (take the 10' > 2x4 and brace it securely and stoutly at 1' intervals Hmmmm. Now we're supposed to use Stout to support loads? I know I use stout to get a load on, but never tried to support a load with it. <>. On a different note, I want to thank Shawn for taking the time to draft up that response. Not only was it well versed, it responded directly to the situation without a lot of digression and me too-ism. This is yet another example of a list member spending his/her own time (ie: money) to freely offer expert advice to this list. The response that Shawn sent in would have cost a considerable amount of money if he was writing for a client. Please do not forget people like Shawn when you go looking for goods and services. Thanks Bill S. www.sapsis-rigging.com 800.727.7471 800.292.3851 fax 267.278.4561 mobile We stand behind, and under, our work. ------------------------------ From: IAEG [at] aol.com Message-ID: <9e.18a2e220.2eb8ee29 [at] aol.com> Date: Tue, 2 Nov 2004 09:05:29 EST Subject: Re: Nov. 2 - VOTE In a message dated 11/2/04 9:00:29 AM, Herrick [at] HGLightingDesign.com writes: >Yeah Keith you tell your friends and neighbors we're gonna hold Florida >personally responsible if you guys screw this up again! Maybe we'll sell >you >all to Cuba. > well, , , ya know, , , there are already Dem and Rep lawyers all over the place. The republicans have already challenged in a couple of counties and the polls have just opened , , the challenge is based on some voter rolls that Jeb Bush tried to purge, ,, the company that provided him the list told him it was terribly flawed and he instituted it anyhow, , the courts overturned it, , and now it's ALREADY the basis for a challenge, , unless something happens and some big electoral votes states go in ways that neither party expects I have a feeling that we might not know the out come for a couple of days at least, , weeks are a possibility very best, Keith Arsenault ------------------------------ Message-ID: <418794AA.70809 [at] fredonia.edu> Date: Tue, 02 Nov 2004 09:07:38 -0500 From: "Stephen E. Rees" Subject: Michael Powers Michael, My Tech Expo notes to you keep bouncing. Please send me your REAL email address so I can fix my address book. All, sorry for the OT bandwidth. TIA Steve ------------------------------ From: IAEG [at] aol.com Message-ID: <5b.5ce5479d.2eb8ef18 [at] aol.com> Date: Tue, 2 Nov 2004 09:09:28 EST Subject: IAAPA / ORLANDO Any one planing on being in Orlando and attending IAAPA in November? let me know, very best, Keith Arsenault ------------------------------ In-Reply-To: References: Message-Id: From: Greg Bierly Subject: Re: Nov. 2 - VOTE Date: Tue, 2 Nov 2004 09:17:11 -0500 > I have a feeling that we might not know the out come for > a couple of days at least, , weeks are a possibility > Keith Arsenault Your a positive thinker. I think we are going to be lucky if the inauguration doesn't have to be postponed. :-) Greg Bierly Technical Director Hempfield HS ------------------------------ Date: Tue, 2 Nov 2004 09:57:11 -0500 (EST) From: Boyd Ostroff Subject: Re: Jaxsan 600 In-Reply-To: Message-ID: References: We have always bought directly from the manufacturer: Plastics Coating Corporation PO Box 1068 St. Albans, WV 25177 304 755-9151 (voice) 304 755-0229 (fax) Boyd Ostroff ooo Opera Company of Philadelphia Director of Design & Technology ooooooo 1420 Locust St, Suite 210 ostroff [at] operaphilly.com ooooooo Philadelphia, PA 19102 http://tech.operaphilly.com ooo (215) 893-3600 x225 ------------------------------ In-Reply-To: References: Message-Id: <7AC8761E-2CE1-11D9-9F9A-000393897332 [at] email.arizona.edu> Cc: marko [at] email.arizona.edu (Mark O'Brien) From: Mark O'Brien Subject: Re: Write only memory Date: Tue, 2 Nov 2004 08:11:32 -0700 Thanking you. Mark O'Brien Opera Technical Director University of Arizona, School of Music Tucson, AZ 520/621-7025 520/591-1803 Mobile On Nov 1, 2004, at 7:18 PM, Kelly Kohls wrote: > Mark, > > Have a look at the bottom of this website: > http://www.ganssle.com/misc/wom.html. > ------------------------------ In-Reply-To: References: Message-Id: <34178870-2CE6-11D9-954C-003065864964 [at] nyu.edu> From: Mike Voytko Subject: Re: Febreeze scentstories Date: Tue, 2 Nov 2004 10:45:21 -0500 My best "scentstory" moment: Listening to NPR in my car, while a commentator talked about the best cup of coffee he'd ever had. As he described the coffee's aroma at some length, I found I could smell it... I figured the guy was a really great storyteller, until I realized I had driven past the Melitta coffee roasting plant (in Cherry Hill, NJ) at that same time... :-) -- Mike Voytko Lighting & Sound Supervisor TSOA Theatrical Production New York University ------------------------------ Date: Tue, 02 Nov 2004 11:39:43 -0600 From: Mark Harvey Subject: Digest Message Numbering Message-ID: <779713.1099395582 [at] nomad52-246.d.umn.edu> In-Reply-To: References: Would anyone else who takes Stagecraft as a digest appreciate having the messages numbered? The messages are numbered in the index at the top of the page, but corresponding numbers do not appear in the body of the messages. Message-Id is not information that is particularly helpful to me, but if it were possible, a Message Number would be a great time saver. Thanks! ____________________________________ Mark Harvey Associate Professor, Lighting and Sound Design University of Minnesota Duluth www.d.umn.edu/~mharvey ------------------------------ Subject: RE: Bizarre Multiple Catastrophic Truss Failure Date: Tue, 2 Nov 2004 10:21:59 -0800 Message-ID: <407DF7D68DD30440B5CEB70ED234D1CF0316E25D [at] excuswa100.americas.unity> From: "Cyr, Dale" shawn: can you share the method you used to do the calcs? dale cyr Training Supervisor IATSE Local 93 Spokane Wa -----Original Message----- From: Stagecraft [mailto:stagecraft [at] theatrical.net] On Behalf Of Shawn Nolan Sent: Tuesday, November 02, 2004 5:54 AM To: Stagecraft Subject: Re: Bizarre Multiple Catastrophic Truss Failure For info, archives & UNSUBSCRIBE, see --------------------------------------------------- 1. I think they probably exceeded the allowable span for the load. Extrapolating from the info on the load table as shown in the photo, the allowable bending moment for this truss is apx. 8,100 lb.ft. to 8,400 lb.ft. Say we use the average of 8,250 lb.ft. as the allowable value (note: I have included the self weight of the truss in my calcs). For a 65' span, the allowable UNIFORM LIVE LOAD is about 9.1 pounds per foot. This would give a TOTAL LOAD, UNIFORMLY DISTRIBUTED of 591 pounds. Even without accounting for the slenderness of the truss, the load is very close to the raw, theoretical capacity of the truss. =20 ------------------------------ Message-ID: <000301c4c109$85152b40$0600000a [at] BRUTUS> From: "Jon Ares" References: Subject: ETC Express boards: internal battery? Date: Tue, 2 Nov 2004 10:26:50 -0800 Does anyone know if there's an internal battery in the Express series of boards to keep the clock running? Specifically the 48/96? I'm working with a place that has an 'old' one (old-style power connector, and didn't have the software update until I installed it) - and the clock resets to 12:00AM, Jan. 1, 2000 every time it's powered down. Does anyone know what the battery is, if there is one? -- Jon Ares Program Director, West Linn HS Theatre Arts www.hevanet.com/acreative http://www.wlhs.wlwv.k12.or.us/aresj/theatre/index.htm ------------------------------ Message-ID: <41880371.33D50A04 [at] cybercom.net> Date: Tue, 02 Nov 2004 17:00:17 -0500 From: Dale Farmer Subject: Re: ETC Express boards: internal battery? References: Jon Ares wrote: > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > Does anyone know if there's an internal battery in the Express series of > boards to keep the clock running? Specifically the 48/96? I'm working with > a place that has an 'old' one (old-style power connector, and didn't have > the software update until I installed it) - and the clock resets to 12:00AM, > Jan. 1, 2000 every time it's powered down. > > Does anyone know what the battery is, if there is one? Have you looked at the manual and/or called ETC support? --Dale ------------------------------ In-Reply-To: References: Message-Id: <5184993A-2D1B-11D9-A3E7-000A958ABBF8 [at] theprices.net> From: Noah Price Subject: Re: Digest Message Numbering Date: Tue, 2 Nov 2004 14:05:33 -0800 On Nov 2, 2004, at 9:39 AM, Mark Harvey wrote: > Would anyone else who takes Stagecraft as a digest appreciate having > the messages numbered? The messages are numbered in the index at the > top of the page, but corresponding numbers do not appear in the body > of the messages. Message-Id is not information that is particularly > helpful to me, but if it were possible, a Message Number would be a > great time saver. It's a popular request, but requires some new programming to customize the digests. It's definitely on the "to do" list! Thanks, Noah -- | Noah Price | http://stagecraft.theprices.net/ | | Stagecraft Mailing List | stagecraft-web [at] theprices.net | ------------------------------ From: "Scott Boyle" Subject: RE: Febreeze scentstories Date: Tue, 2 Nov 2004 17:41:57 -0600 Organization: Carroll College Message-ID: <001801c4c135$8abf8050$73db688c [at] cc.edu> In-Reply-To: One of the first summer stock jobs my wife worked was in Clinton, Iowa. In letters she would talk about never being hungry and during a visit I found out why. There was a Hormel dog food factory located basically across the street from one of the main grocery stores in town. You'd get out of the car and any thought of food would quickly leave. Scott M. Boyle ------------------------------ End of Stagecraft Digest #184 *****************************