• Rigging Primer

    by  • August 22, 2014 • Articles, Education, Featured Articles, Member Contributions, Uncategorized

    IATSE 205 ETCP RIGGING STUDY RESOURCES

    BY JOE MARTIN

    DISCLAIMER

    THE RESOURCES AND TIPS GIVEN IN THIS GUIDE ARE NOT ENDORSED BY ETCP OR ANY ORGANIZATIONS RELATED. THIS IS MERELY A GUIDE TO FIND INFORMATION AND REINFORCE INFORMATION THAT IS RELATED TO STAGE RIGGING AND COVERS KNOWLEDGE THAT WILL BE USEFUL IN TAKING THE EXAM.  UNDER NO CIRCUMSTANCES USE THIS KNOWLEDGE WITHOUT PROPER EXPERIENCE AND TRAINING. JOE MARTIN AND IATSE ARE NOT AFFILIATED WITH ANY OF THE MANUFACTURERS LISTED. ALL MANUFACTURER LINKS ARE FOR THEIR SUPERIOR INFORMATION AND REPRESENT INDUSTRY STANDARDS. THIS DOCUMENT WILL NOT BE PUBLISHED OR DISTRIBUTED OUTSIDE OF IATSE UNLESS PERMITTED.

    FORWARD

    Hello Brothers and Sisters of the 205! I have created this guide in hopes that all in our local who want to pass the ETCP Theater and Arena Rigging exams have the resources necessary to pass with flying colors.  As someone who is a certified Theater Rigger, I have taken the exam and know what it takes to acquire the title. While individual study is necessary, the essential key to success is group study. Throughout the year, I will be holding study sessions for everyone who is interested in testing for the certification. These sessions will be mostly on the math aspects of the test, as most experienced riggers can already pass the general knowledge portions. Those with an interest in rigging but not the test should attend the Beginner Rigging Class, as everyone in the field deals with rigging on a daily basis. I encourage everyone to dig deep into the knowledge pool of rigging. The principles that we use in stage rigging apply to many other trades, and will serve you well in your career. Much of it comes straight from high steel ironwork and ship/crane rigging. In your studies, it is also important to brush up your knowledge of mathematical and general physics. Everything we do as riggers is directly related to the properties of gravity and geometry/trigonometry. A solid background in these subjects will be a big help. I wish everyone success in their journey, and I am always here to help! If you have any questions, please contact me here.

    RIGGING PRACTICE, TERMINOLOGY, AND MATHEMATICS

    Unfortunately, the information that needs to be given in this section can not be pulled from a website. That used to be the case, but some of the authors listed below figured out that this information is valuable, and should be compensated for their time and effort in compiling it. While I know the books are pricey, they are the definitive texts in the field. Any serious rigger with intensions of moving on up in the entertainment world needs this information. You will have it for life. The texts here should be studied more than anything above. The respective books on Arena and Theater are mostly what the ETCP test is written from, and have the most official  information on the subject to date.  The math book by Delbert Hall is a fantastic addition to your arsenal. While Arena Rigging and Stage Rigging Handbook: 3rd Edition explain the math, Delbert teaches it in a way that doesn’t blow most humans minds. The book is totally optional, but will help immensely.  When the book was a website a few years ago, I used it to study and I would have been much worse off without it.

    Stage Rigging Handbook: 3rd Edition -For Theater test takers

    Harry Donovan’s Arena Rigging – For Arena test takers

    Rigging Math Made Simple – All disciplines

    Continue for links containing detailed manufacturer information on rigging materials.

    COMMON RIGGING MATERIALS

    Here are links to many of the major manufacturers that provide rigging hardware for the entertainment industry. The information you are looking for are the material data that specifies weight capacity, tolerances, and acceptable uses. Arena applicants should pay special attention to shackle, chain motor, and wire rope specifications, while Theater applicants need to pay special attention to hardware used in a counterweight system (i.e. batten clamps, tracks, hand line, 1⁄4” wire rope, trim chain, loft blocks, head blocks, and SCH40 1 1⁄2 pipe)

    Types of Shackles:

    This page shows what types of shackles you might encounter out in the field. Anchor shackles are what we most commonly use, you will likely never see chain shackles out in the entertainment world outside of special circumstances. If you do see a chain shackle, remember they are only to be used with one rigging attachment. A bridle hung from a chain shackle will place a side load on the straight vertical members causing an unsafe situation. Remember that an anchor shackle can only be used in a bridle if the bridle angle is more than 30 degrees. Anything less will be considered a side load on the shackle. For example, when we do low-low bridles at the Erwin center, we use a pear ring to make the apex of the bridle to prevent side loading of the hardware.

    Master/Pear rings:

    Make sure you scroll all the way on this page. It covers a variety of hardware from different manufacturers you will see in the field. As described above, this is the hardware you need to use for any bridle over 30 degrees or when there are more than 2 rigging attachments in the shackles bell. While it is not recommended you do so, sometimes the only way to get a point where you need it is through the utilization of this hardware. As long as you are using a Master/Pear ring that is rated at least 5:1 the tension you are placing on the bridle, all is well.

    Wire Rope/Eye Bolts/Chain/Hooks/Turnbuckles/Swages/Clips/Thimbles/Snatch blocks:

    Here is one of the greatest resources I have ever found on the subject of wire rope. Contained is not only strength ratings of many different types, but explanations of the reasoning behind structural design with wire rope as well as most everything it attaches to. Not only does it give the raw info, it lays out theory behind safe usage. All disciplines of rigging should study this well.

    This page lists many of the common ropes used in counterweight and hemp systems today. Multiline II is the most common, you can see it in use at the Long Center. Stage Set X is also a variety you see in the McCullough Theater at UT. Other ropes listed on this page are much less commonly seen, but it is nice to know of their existence and material properties in case you are ever faced with a project that requires rope with a special application. These ropes come from manufacturer New England Ropes, which has been the standard in quality for entertainment industry rope needs. Most theaters you go into with a counterweight system will likely have New England Ropes, which is handy to know when ordering replacement line. When it comes down to your personal hauling line, generally any polybraid or polyester rope between 1⁄2” and 5/8” diameter with over 2000lbs tensile strength will get the job done. Your rope needs to pull through a pulley easily, and provide a good gripping surface without being hard on your hands. Do not purchase rope from a big box hardware store however temping it may be. The rope sold there is mass produced in China and does not come with an official tensile breaking strength or material data sheet. Make sure the rope you are buying is rated and batch tested. You can find rope for the same price as Home Depot through Rose Brand that is solid core polybraid and carries an official rating. Even cheaper if you buy a spool, which I highly recommend. (Custom colors!)

    Track Hardware/Counterweight Hardware and Operation/Pipe Attachments:

    H&H Specialties has a veritable gold mine of information on these subjects in their catalogs. Diagrams, rules of use, in depth explanation of track weight capacities and hanger spacing are all here. The PDF on Counterweight Rigging isn’t very exiting visually, but is a fantastic guide for the beginner, and a great refresh for the experienced. Spend some time here.

    Steel/Pipe:

    Check out this website to look up information on common steel material you will rig on in theaters and arenas. As a rigger, it is useful to know more than the average bear about building structure and the materials that comprise your theater/arena specifically. Always consult the building engineer in regards to the actual strength of the beams. Every building is different. In no way should the tensile strength of any material be used as a means of rating a system.

    Fantastic article about chain grading and the reasoning behind chain grading. It even gives you the formula for calculating tensile strength of chain. As long as you know the size and grade, you can calculate the strength rating of any chain. Also provides links to spec sheets for every grade of chain. Note that anything under Grade 80 is not suitable for overhead lifting. Example of deck chain used in Arena rigging.

    Chain Motors:

     Here you have the bread and butter of the entertainment rigging industry, the classic CM Lodestar motor series. Most road shows and rental houses will have a small army of these in varying lifting capacities. It is essential to know chain weights and motor weights to calculate your lifts. On the page, you can find the official maintenance manual for Lodestar series motors. Study this to get a really in-depth look at chain hoists, their parts, and troubleshooting. You will know much more than the average rigger. Most of the info you need to pay attention to for the tests purposes are the lifting capacities, electrical/control properties, and knowing that chain motors are rated 25% under their actual capacity to account for the small shock load produced by the initial inertia of lifting/lowering. Also note that Lodestars are rated in metric tons. Make sure to check out all the different models CM offers too. ProStars are popular for their light weight and silent operation, and are rated from 300-1000lbs, differing from the metric rated Lodestars. Make sure to note this difference when you look at the label on the butt of the motor housing.

    Beam Clamps:

    You will use beam clamps whenever beam clearance is too low to use traditional 5’ wire rope slings and still achieve trim height. Note that beam clamps of large capacities will not allow you to attach to steel too small to take the load it is rated for. In other words, if your rig is going into a building with 2” angle trussing (typical in small ballrooms and venues), you won’t be able to rig your show with your 1 ton beam clamps. Better hope your points are rated for less than a half ton!

    About