CARLAD.RICHTERS
RelayinTimesSquare,SuperBowlXLVHalftimeShow)andmorethanadozenRoyalCaribbeancruiseships.
SCOTTFISHER
Scott Fisher is the founder of Fisher Technical Services and a pioneer in the development of theatrical and rigging automation systems. A 25-year veteran of the entertainment industry, Scott and the Fisher Technical team have provided cutting-edge automation systems to hundreds of theaters, theme parks, motion pictures, andattractions,andthesystemsandtechniquesdevelopedatFisherTechnicalcontinuetobeusedthroughout theentertainmentworldtoday.
DANCULHANE
Dan Culhane is currently the technical business development manager at SECOA Inc Prior to this he spent more than 11 years as SECOA’s engineering manager He is an ETCP-certified rigger for theater and a subject matter expert. Dan has spent 15 years as a technical director working for theatres across the country includingtheGuthrieTheaterandtheChildren’sTheatreCompany,inMinneapolis,MN
He serves on the PLASA Technical Standards Program, Rigging Working Group and chairs the task group revising the standard for fire safety curtains He is a member of the Stage Lift Working Group Dan also is on the board of directors for USITT and serves as treasurer. He is a member of the UL Standards Technical Panel for Fire Doors (STP 10), and serves as an alternate committee member to the NFPA TechnicalCommitteeonFireDoorsandWindows
EDDIERAYMOND
Eddie Raymond is a lifelong San Francisco Bay Area resident, graduating from and attending postgraduate work in education at UC Berkeley He has been a stagehand with Local 16 of the IATSE since 1975 After graduating the Apprentice Program at Local 16, Eddie became involved as a member of the examining board in1981andservedasthechairofthatcommitteefrom1984untilFebruaryof2014.Since1981hehasbeena leader in the progressive improvement of stagehand training in Local 16 as well as in the International Alliance Currently he serves the IATSE as a member of their Career Advancement Program, providing trainingandadvisingtheIA’sExhibitionandEntertainmentJointTrainingTrust.
Eddie was a co-chair of PLASA’s ETCP rigging certification program and sits as a member of the ETCP Council. He is the second term chair of PLASA’s North American Regional Board and sits on PLASA’s governingbody
CHRISHIGGS
Chris Higgs provided rigging for theatre, corporates, television, and concert touring from the early 1970s to themid-1990sandisoneofthefoundersofentertainmentriggingtrainingintheUK.TotalTrainingstarted in1998,aspartoftheTotalSolutionsGroup,anddeliverstrainingcoursesintheUKandoverseasinrigging, work at height, rescue, and inspection, amongst other associated subjects The Total Training three-day riggingcourseisuniqueintheworld,beingheldatleastthreetimesmonthlythroughouttheyear.
BILLSAPSIS
gallery, grid deck, loading bridge, arbor, standard pipe battens, truss battens, electric battens, light ladder battens, tab battens, lines, line-sets, jack lines, hemp lines, nylon lines, cables (wire ropes), steel bands, proof coil chains, rope locks, swage (compression) fittings or cable clips, trim chain, shackles or turnbuckles (which can be moused), pipe clamps, counterweight systems, electrical hoists (or winches), drum winches, tension blocks,headblocks,loftblocks,muleblocks,andprogrammablelogiccontrollers(PLCs)
Andtheterm“runaway”doesnotrefertoarecalcitrantteenager
And when this language is used in EntertainmentRiggingforthe21stCentury, each author makes sure that thedefinitionsarecleartousall
Today’s riggers not only need to understand this strange language, they also need to provide proof to employers that they understand and rig competently In other words, many employers today want to see evidencethattheriggers theyhirehavehadsomeformaltraining.Thesimplerésuméofpast jobsmaynot be enoughinthe21stcentury
Theatrical riggers used to learn their trade by the seat of their pants, working with older riggers who also learned by the seat of their pants Today, there are formal training programs, the most important of which is the certified training offered by the Entertainment Technicians Certification Program (ETCP) These programs,originatedbytheEntertainmentServicesTechnologyAssociationandrunnowbyPLASA,require their candidates to pass a rather tough test In other words, today’s riggers should have professional certificationsinadditiontoexperience
Employers like certification programs because it helps protect their liability after an accident The human toll and damages caused by major rigging accidents almost always result in lawsuits. If employers can show that they hired people with rigging credentials backed up by certifying agencies, they at least cannot be accusedofhavinghiredincompetentlabor
Entertainment Rigging for the 21st Century covers these kinds of training programs in Chapters 11 and 12, by Eddie Raymond and Chris Higgs They cover training resources and issues in both the USA and the UK
And the fact that there are two chapters, one for North America and the other for our pals across the pond, illustrates that today’s entertainment riggers are conforming to, and aware of, both local and international standards
Standards for various types of equipment and the development of protocols for use of the equipment are now being developed under the watchful eye of PLASA These standards will be referenced repeatedly by authorsofthevariouschaptersinEntertainmentRiggingforthe21stCentury.
Infact,PLASAitselfistheresultofamergerbetweenUKandUSAorganizations Andtheirstandardsare accredited here and in Europe. In North America, PLASA standards usually receive American National Standards Institute (ANSI) accreditation In Europe, PLASA works closely with the British Standards Institute in the UK and the European Committee for Electrotechnical Standardization (CENELEC)
PLASA is also a major contributor to the development of international standards through the International StandardsOrganization
Whileallthissoundstechnical,thewritershavemadeiteasytounderstandbyprovidingdefinitionsoftheir
terms, diagrams and drawings, and formulas. Even non-riggers like myself, can follow these chapters and learn Andtokeepourinterest,thebookispepperedwithpersonalobservationsandstoriesofactualincidents experiencedonthejobbythoseauthorswhoarealsoriggers.
Entertainment Rigging for the 21st Century is not just for riggers and rigger wannabes I personally think it also belongs in the library of theatrical safety professionals, regulatory personnel, theatre administrators, writers who address theatre and entertainment subjects, or anyone who wants to know what’s really going on intheatresandarenastomakeallthosewonderfulthingshappenonstageandabove
MononaRossol
ForceDistribution
Force distribution analysis is arguably the most important activity performed by a production rigger. This analysis must be done in some form to determine the force at each hang point for creating a rig plot and, in addition, many times this analysis must be performed to determine whether or not the support structures are beingoverloaded.AlthoughtheInternetandsmartphoneshavemadetheprocessofpreplanningmucheasier, there is no app for force distribution estimation In many cases, the time required for this activity is a very significant portion of the total preplanning of the show for the rigger In this section, we will examine the formulas and techniques for estimating the resulting forces at the supports caused by applying loads to a truss orbeam
Thereareseveralimportantconceptsthatneedtobeputintocontextpriortoanycalculation.
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Force,weightandload:Force is an action on a body caused by another body that tends to cause motion It can be direct from physical contact or indirect such as the force of gravity When a motion causing force is resisted by an equal and opposite force a static force exists. It is these static forces which are the subject of our analysis in this chapter The US customary unit for force is the pound-force (lb) The SI (metric) unit is the Newton (N) Weight is simply a measure of the force of gravity on an object The wordload, although widely used by riggers, is more general and less succinct in its definition. In general termsitisthesumofallforcesactingonanobject
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Simplysupportedspan: A simplysupported span is a beam or truss supported by two supports where the ends of the beam or truss are free to rotate Imagine a truss supported by a chain hoist at either end As the load increases between the hoists, the truss is free to deflect more than if the beam were fixed at the endstopreventfreerotation.SeeFigure1.1forexamplesofsimplysupportedspans.
Cantilever: In a cantilever at least one of the supports is not at the end of the beam and there is loading outside of the two supports such that both supports are on the same side as the load. See Figure 1.1 for anexample
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Pointload(PL):Apointloadcreatesaforcethatisconcentratedinasinglepointorverysmallareaalong thelengthofthebeamortruss
Uniformlydistributedload(UDL).Asopposedtoapointload,auniformlydistributedloadcreatesaforce thatisevenlyspreadoverasignificantportionofthelengthofthebeamortruss
CenterofGravity(CG) Thecenterofgravityisthesinglepointatwhich,ifanobjectissupported,itwill remain in equilibrium The CG of a UDL, which is located at the center of the UDL, will be used to calculatetheforcesdistributedtothesupportsresultingfromtheforceappliedbytheUDL.
Thisandallthefollowingproblemswillbesolvedinastep-by-stepfashion.
Rounding
Rounding is useful in some cases, but must be done only after evaluating the benefits For a rigger, a force of 781.25 may convey a false sense of accuracy, since most of our measurements of weight lack precisionorareestimatestobeginwith
Inthischaptertheroundingconventionusedwillbetolooktotherightofthedigitbeingrounded. If that number is less than five, do nothing to the rounded digit and drop all digits to the right. If the number to the right of the rounding digit is five or greater, increase the rounding digit by one and drop all digits to the right. If changing the rounding digit changes it to zero, then increase the digittotheleftbyone.
Be very careful when rounding numbers and then using the rounded numbers for further computations. Rounding a distance to the nearest foot and then using the rounded number to calculate a force can change the force by tens if not hundreds of pounds in some cases In this chapter, any calculation that results in a number with more than three digits to the right of the decimalwillberoundedtothreedigits.Theroundednumberwillbeusedinanyfuturecalculations.
If a rounded number is used in a calculation, notice will be given to the reader so that both our calculationswillresultinthesameanswer.
SOLUTION
STEP 1: ORGANIZETHEDATA
Writetheequationswithspacebelowforsolving:
Makeatableorlistofthesymbolsfortheknownvaluesusedintheequations(S,D1,D2,FA)
Belowthese,addtheanchoragelabels,inthiscaseA1 andA2 SinceP,thelocationofthePL,iscloserto
A1,A1 willbethelocationofF1 andA2 willbethelocationofF2
STEP 2:INSERT VALUESAND SOLVE
Using Figure 12, insert the values next to the symbols on the list Until you are familiar with the meaningofthesymbols,refertoTable1.1fortheirdefinitions.
SubstitutethevaluesfromyouradjacentlistintotheformulasforF1 andF2 andsolveforF1 andF2
TransferthevaluesforF1 andF2 to the appropriate spaces on your table of symbols, rounding as desired
• • Figure1.5
Figure1.6 Tips NotethatinthisproblemPisclosertoA2,soF1 islocatedatA2 andF2 islocatedatA1.
A critical look at the problem would reveal that point P is located three-tenths of the way across the span. Note that the solution for the force at the far support F1 is 90lb, or three-tenths of the applied
