Please find below a collection of terms that are commonly used in entertainment rigging. You will find these terms in most rigging related classes, documentation, standards, and in One Shot Trainings. Please note that these definitions were collected from various sources for your convenience and are all cited via APA format. Any uncited definition is original content or common slang.
Abrasion: loss of material due to wear. (Entertainment Services and Technology Association, 2012)
Acoustical reflector panel: A reflective panel hung in the auditorium, generally above the audience, that is used to direct sound into desired zones. Often decorative in nature. (Hall & Sickels, 2016)
Alabama deck chain: Slang, meaning to attach multiple shackles together to make a fine adjustment in a bridle when a proper STAC chain is unavailable.
Allowable load: maximum static equivalent load that can be safely imposed on truss / tower in addition to the self-weight. (Entertainment Services and Technology Association, 2012)
Anchorage: A secure point of attachment to which the wire rope ladder is connected. (Entertainment Services and Technology Association, 2018)
Arbor guide: See Guide.
Arbor Stop: See Crash bar
Arbor pit: An opening in the stage that extends below the stage floor to allow extended travel of counterweight arbors. (Entertainment Services and Technology Association, 2016)
Austrian Curtain: A curtain that is raised (opened) with brailed lifting lines and is sewn with both vertical and horizontal thickness. (Hall & Sickels, 2016)
Batten: A pipe, tube, or other singular structural shape that is secured to the lift lines for the purpose of connecting loads to the counterweight system. (Entertainment Services and Technology Association, 2016)
Batten clamp (pipe clamp): A piece of rigging hardware, usually of some rigid material, that wraps or clasps a batten, providing for the attachment of a lift line or other lifting media. (Entertainment Services and Technology Association, 2016)
Beam: A Structural member (usually horizontal in a building structure) that resists bending. (Hall & Sickels, 2016)
Beam clamp: A Device from which a load is hung, attached to the flange of a steel beam without altering the beam in any way. (Hall & Sickels, 2016)
Belaying pin: A pin inserted into a pin rail hole, used for securing or controlling rope lift lines or spot lines. (Entertainment Services and Technology Association, 2016)
Bi-parting drape: A curtain that opens from the center to either side. (Hall & Sickels, 2016)
Block: An assembly of one or more sheaves in a housing designed to support one or more lines and allow a change of direction. (Entertainment Services and Technology Association, 2016)
Border curtain: A curtain used to define the top limit of the stage and to mask or hide lights and unused scenery and curtains. (Hall & Sickels, 2016)
Brail Curtain: A curtain that is raised (opened) with brailed lifting lines and is sewn with both vertical and horizontal thickness. (Hall & Sickels, 2016)
Brail Lines: Lifting lines that pass through a row of rings sewn to the back of a curtain and attached at the curtain bottom. The Curtain folds up when the lines are pulled. (Hall & Sickels, 2016)
Breaking strength: The load at which failure will occur in a component. (Entertainment Services and Technology Association, 2016)
Bridle: Any suspension configuration in which a lift line is divided into 2 or more tension load path elements angled downward from the lift line termination and connected to the batten. (Entertainment Services and Technology Association, 2016)
Cable Clip: A device to mechanically fasten cables, consisting of bolts, nuts, and pads that bear against the cable to prevent crushing and slippage. (Hall & Sickels, 2016)
Cable dog: Slang, see Haven grip.
Capstan winch: A winch, usually portable, with an un-grooved drum designed to assist in moving heavy loads. An operator wraps a rope around the drum and pulls to tighten the rope on the drum. Friction causes the rope to travel with the rotating drum. (Hall & Sickels, 2016)
Certified rigger: A rigger who has passed the “Entertainment Technician Certification Program” (ETCP) exam and is recognized as competent to do rigging for a period of time. This certification is based on both experience and a written exam. Regular re-certification is required. (Hall & Sickels, 2016)
Catwalk: A Steel Structure over the stage, the audience area, or both, used by stage personnel to access lighting, rigging, or other stage equipment. (Glerum, 2007)
Characteristic load: The maximum force applied to a component of a hoist system resulting from normal intended operating conditions while the system is at rest or in motion. This includes the apportioned fractions of the working load limit (WLL), self-weight including that due to load carrying devices and lifting media, and the forces due to inertia in normal use. (Entertainment Services and Technology Association, 2020)
Clew: A device, typically a flat steel or aluminum plate with multiple holes, used to connect several lift lines into a single line. (Entertainment Services and Technology Association, 2016)
Cloud: See Acoustical reflector panel.
Compensating system: A component of the counterweight system that automatically adjusts to counterbalance the weight of the lift lines as it shifts between the load side and counterweight side of the head block during operation. (Entertainment Services and Technology Association, 2016)
Competent person: A person who is capable of identifying existing and predictable hazards in the workplace, and who is authorized to take prompt corrective measures to eliminate them. (Entertainment Services and Technology Association, 2016)
consumables: items that require regular replacement with use. (Entertainment Services and Technology Association, 2012)
Counterweights: Cast iron, steel, or lead weights placed on the arbor to balance the load on the batten. (Glerum, 2007)
Counterweight arbor (counterweight carriage): A guided, movable rigid carriage assembly used to hold counterweights and to counterbalance a load. (Entertainment Services and Technology Association, 2016)
CPL (center point load): a concentrated load that is applied at the midspan. (Entertainment Services and Technology Association, 2012)
Crash bar: A horizontal member, usually attached near the top and bottom of the T-bars, that limits the travel of the arbors. (Glerum, 2007)
Crosby: Slang, see Cable clip.
Curtain: Any fabric panel that is hung as part of a scene or to mask unwanted views. (Hall & Sickels, 2016)
Curtain Track: A formed or extruded shape that contains moving carriers and supports drapery. They often have a cord or other means to open and close the drapes. (Hall & Sickels, 2016)
Dead haul: Pulling a load that is not counterbalanced. (Hall & Sickels, 2016)
Dead hung: Directly fixed to the structure or attached at a fixed elevation using chain, rods, or cable. (Hall & Sickels, 2016)
Dead load: The permanent or non-removable part of a system load (i.e. the weight of a batten versus the load hung from it). (Hall & Sickels, 2016)
Deck Chain: A piece of large chain that is designed for making small adjustments in a bridle. Historically it was deck chain used on a ship to attach the anchor to the ship, but these days we use chain specifically made for entertainment industry.
Defect: Any characteristic or condition that tends to weaken or reduce the strength of the tool, object, or structure of which it is a part. (Entertainment Services and Technology Association, 2018)
Design factor: A ratio of the design load to the breaking strength of a material or component. (Entertainment Services and Technology Association, 2016)
Design load: The maximum anticipated load that will govern design parameters. (Entertainment Services and Technology Association, 2016)
Double reeve (double purchase): A system using compound reeving of the lift lines and operating line, designed to allow full-height batten travel distance with half the arbor travel distance, but with the requirement that the arbor to be loaded to twice the mass of the batten load. (Entertainment Services and Technology Association, 2016)
Down-Stage: Towards the audience.
Drop curtain: A curtain that is painted or constructed in a manner that makes it a part of the scenic environment. (Hall & Sickels, 2016)
Drum Hoist: A hoist with a drum for wrapping cable as it is taken up. One end of the drum is typically supported by a bearing while the other end is connected to the output shaft of the gear box. (Hall & Sickels, 2016)
Dynamic loading: forces caused by the acceleration or deceleration of an object. (Entertainment Services and Technology Association, 2012)
Eye: A loop formed in the end of a wire rope for the purpose of connecting the wire rope to something else. (Entertainment Services and Technology Association, 2018)
Fall Arrest System: A device that engages to halt a person or other load that has exceeded a predetermined speed, indicating a falling condition. (Hall & Sickels, 2016)
Fiber rope: A rope made of natural or synthetic fibers that are twisted. braided or woven together to create a rope. This is the kind of rope you would tie knots with.
Fid: A tapered pin (usually wood) used in opening the strands of a rope. (Glerum, 2007)
Fleet angle: The angle between the centerline of a rope as it enters or exits a sheave groove, and the plane defined by the centerline (pitch) circle of that groove. (Entertainment Services and Technology Association, 2016)
Fire Curtain: a nonflammable curtain immediately behind the proscenium, contained in the smoke pocket, used to protect the audience from possible smoke and fire originating from the stage area. (Glerum, 2007)
Floor block: See Tension block.
Fly: To move scenery or similar devices vertically on the stage. (Glerum, 2007)
Fly gallery: A raised platform attached to the wall where the fly system can be operated without taking up space on stage level.
Fly house: The space between the stage and the grid where the battens reside and move along the vertical axis.
Fly loft: the space above the grid and below the roof.
Fly system: A system of ropes, blocks, counterweights, and related devices within a theatre that enables the stage crew to fly loads quickly, quietly, and safely.
Foot Block: See Tension block.
Grid: A steel framework above the stage area that is used to support the rigging system; short for gridiron. (Glerum, 2007)
Guide: A device or assembly of devices that connect a counterweight arbor or tension block to the guide rails in order to control the path of its travel. (Entertainment Services and Technology Association, 2016)
Guide rails: A means of guiding the counterweight arbor throughout its travel in the vertical plane, but which also limits horizontal or twisting motions of the arbor. Typical examples are T- or J- shaped members. (Entertainment Services and Technology Association, 2016)
Guide system: Components and assemblies used to vertically guide a counterweight arbor, including components attached to the arbor specifically for such purpose. (Entertainment Services and Technology Association, 2016)
Guillotine: A curtain that runs the width of the proscenium. (Hall & Sickels, 2016)
Hand line: See Operating line.
Hand winch: See Manually operated hoist.
Haven grip: A light, compact cable pulling jaw grip designed for use with steel rope.
Hoist system: See Line set.
Head block: The stationary block assembly above and closest to the counterweight arbor or pin rail. The head block permits lift lines to change direction. In some counterweight systems, the head block is also grooved to allow the operating line to change direction by 180 degrees. (Entertainment Services and Technology Association, 2016)
Hemp system: See Rope and sandbag system
Idler assembly: An assembly of sheaves and a housing, used to support only the self-weight of the lifting media reeved through it. Idler blocks are used for the same purpose as sag bars except that idlers provide a reduced coefficient of friction. (Entertainment Services and Technology Association, 2016)
Index strip: A device located at the front of a locking rail to hold line set identification labels. (Hall & Sickels, 2016)
Installer: The person or organization that is responsible for the installation of the rigging equipment. (Entertainment Services and Technology Association, 2016)
Klein tool: Slang, see Haven grip.
Knuckle: Slang, meaning four shackles held together by a fifth.
Lattice track: A wall-mounted guide system, usually for a single arbor, in which the guide rails are located at opposing sides of the arbor assembly, rather than on one side only. (Entertainment Services and Technology Association, 2016)
Leg Curtain: A curtain used to define the side limit of the stage and to mask or hide actors, lights, and unused scenery in the offstage area (wings). (Hall & Sickels, 2016)
Lift line: Any fiber or wire rope reeved through block(s) and attached to a load. Lift lines operate singly, as spot lines, or in “sets” of several lift lines working together to support a load. (Entertainment Services and Technology Association, 2016)
Limits of use: the parameters under which the system is designed to operate (e.g. working load limit, speed of movement, duty cycle, environmental conditions, user skill level, availability of maintenance). (Entertainment Services and Technology Association, 2020)
Line set: A system of multiple lift lines, operated together to raise, lower, or suspend a load; all of the mechanical, component subsystems required for supporting, positioning, and operating those lift lines as a system. (Entertainment Services and Technology Association, 2016)
Line Shaft Winch: Winch with a series of cable drums connected to a gearbox by a common shaft. (Hall & Sickels, 2016)
Load securing device: a mechanical device that prevents unintentional movement in the hoist system. (Entertainment Services and Technology Association, 2020)
Load Suspension system: The battens, blocks, counterbalancing and tension load path, components used to suspend and counterbalance the load. (Entertainment Services and Technology Association, 2016)
Loading bridge (Loading gallery): A load-bearing, elevated personnel access and work area, located to permit counterweight loading and unloading at the arbor. (Entertainment Services and Technology Association, 2016)
Locking collar: A device placed on a counterweight arbor rod to reduce unintended vertical movement of counterweights on the arbor. (Entertainment Services and Technology Association, 2016)
Locking rail: A structural railing that supports the rope locks. (Entertainment Services and Technology Association, 2016)
Loft block: An overhead block through which one or more lift lines pass before being attached to the batten. A loft block typically permits the change of lift line direction in the vertical plane. (Entertainment Services and Technology Association, 2016)
Manually operated hoist: A hoist primarily intended and designed to be hand-operated. (Entertainment Services and Technology Association, 2020)
Marlinespike: A Metal version of a fid.
Masking: A set of curtains or scenic elements used to define the visual limits of a performance area. (Hall & Sickels, 2016)
Motorized Fly System: A Fly system that uses electric motors to raise and lower battens.
Mouse: Securing a hook, turnbuckle, shackle, or other rigging device to ensure that it can not unintentionally open.
Mule block: A supplementary block located between the head and loft blocks, designed for the specific purpose of changing the direction of lift line travel. (Entertainment Services and Technology Association, 2016)
Mule winch: See Capstan winch.
Operating line: The line that an operator pulls to move, position or hold a counterbalanced load. (Entertainment Services and Technology Association, 2016)
Operating system: Components and assemblies used to move, position and hold the counterbalanced load. (Entertainment Services and Technology Association, 2016)
Out-of-balance condition: A condition where the weight of the batten load differs from the weight of its associated counterweight equipment by more than 23 kg (50 lbs). (Entertainment Services and Technology Association, 2016)
Outrigger batten: A batten mounted in a fixed position parallel to the locking rail, and intended to protect counterweight equipment from unintended contact with non-rigging system elements. (Entertainment Services and Technology Association, 2016)
Peak load: The maximum force applied to a component of a hoist system, while the system is at rest or in motion, resulting from abnormal conditions or irregular operation. (Entertainment Services and Technology Association, 2020)
Permanent deformation: Any permanent measurable change in the shape of the object, or any measurable slippage in the connection between two objects after the load has been released. (Entertainment Services and Technology Association, 2018)
Pickle: Slang, the device for local control device of a chain motor.
Pile-on drum: drum in which the individual lifting media are confined in separate winding chambers so that the lifting media winds in concentric layers. (Entertainment Services and Technology Association, 2020)
Pin rail: A rigidly mounted railing, and its associated supports, with holes designed to accept belaying pins, used to tie off rope and sandbag rigging lines. It transfers unbalanced system loads to the building structure. (Entertainment Services and Technology Association, 2016)
Pipe: See Batten.
Pipe clamp: See Batten Clamp.
Pitch diameter: The diameter of a sheave measured to the centerline of the rope for which it is designed. (Entertainment Services and Technology Association, 2016)
Porkchop: Slang, see Haven grip.
Proscenium: The wall between the stage and the audience containing the proscenium arch. (Glerum, 2007)
Purchase Line: See Operating line.
Qualified person: A person who by possession of a recognized degree or certificate of professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work. (Entertainment Services and Technology Association, 2016)
Reeve: To pass a rope over the sheaves in a block or a system of blocks. (Entertainment Services and Technology Association, 2016)
Reverse bend: A condition where a rope is reeved in opposing directions, over two or more sheaves, within two lays of the rope strands. (Entertainment Services and Technology Association, 2016)
Rigging: The general term describing systems used to raise, lower, or move the stage equipment overhead. (Glerum, 2007)
Risk: combination of the probability of occurrence of harm and the severity of that harm. (Entertainment Services and Technology Association, 2020)
Risk assessment (RA): the process of identifying, evaluating, and quantifying the potentially hazardous conditions, severity, and probability of occurrence of harm. (Entertainment Services and Technology Association, 2020)
Risk reduction (RR): mitigation of risk created by hazardous conditions. (Entertainment Services and Technology Association, 2020)
Rope binder: A metal bracket that pinches both the front and the back purchase line together and bends them over multiple angles creating friction to hold an out of balance system in place while the counterweights are being adjusted.
Rope and sandbag system: A type of counterweight system that uses natural or synthetic rope, instead of wire rope, for the lift lines, and uses sandbags as the counterweight method. (Entertainment Services and Technology Association, 2016)
Rope lock: A positioning device, located on the locking rail that holds an operating line of a balanced counterweight set and prevents unintended movement. (Entertainment Services and Technology Association, 2016)
Run Away: Theatre jargon which indicates an out of balance batten that is out of the operator’s control. (Hall & Sickels, 2016)
Sag bar: A linear structural element or other assembly used to support the self-weight of one or more lift lines. A sag bar is used for the same purpose as an idler assembly. (Entertainment Services and Technology Association, 2016)
Sandbag: Fabric bag filled with sand, and used with rope rigging to counterbalance a load. (Entertainment Services and Technology Association, 2016)
Scrim: A curtain from a semi-transparent material that looks solid when lit from the audience side and becomes almost invisible when back lit. (Hall & Sickels, 2016)
Shackle: A U-shaped device with holes at each end to accommodate a pin or bolt; used to connect a rope, cable, or chain to another device or hanging point. (Hall & Sickels, 2016)
Sheave: A grooved wheel in a block or pulley. (Glerum, 2007)
Single reeve (single purchase): A system of rigging employing weights, blocks and lines to hold or move a load of similar weight, using a 1:1 mechanical advantage for counterweight and batten load. (Entertainment Services and Technology Association, 2016)
Snub Line: A short piece of rope used to tie down a handline to prevent movement. (Hall & Sickels, 2016)
span: the distance between support points. (Entertainment Services and Technology Association, 2012)
Spot block: A block designed to function as either a head block or loft block in temporary applications, and is also designed to be easily repositioned. (Entertainment Services and Technology Association, 2016)
Spot line: A single line, used in conjunction with one or more spot blocks to support a load. (Entertainment Services and Technology Association, 2016)
Spreader plate: Plate that is installed between counterweight arbor rods to keep the rods from spreading during rapid travel or impact, preventing counterweights from falling out of the arbor. (Entertainment Services and Technology Association, 2016)
Stage house: see Fly house.
Stage-Left: When you are standing on the stage and you are looking at the audience, your left is stage-left.
Stage-Right: When you are standing on the stage and you are looking at the audience, your right is stage-right.
Static load: The maximum force applied to a component of a hoist system resulting from normal intended operating conditions while the system is at rest. This includes the apportioned fractions of the working load limit (WLL) and self-weight, including that due to load carrying devices and lifting media. (Entertainment Services and Technology Association, 2020)
Static equivalent load: a static load whose magnitude equals the peak force reached by a dynamically applied load. (Entertainment Services and Technology Association, 2012)
Tag line: A line attached to a load to assist in controlling it’s movement. (Hall & Sickels, 2016)
Tandem block: A block that consists of a series of single or multiple groove sheaves, each mounted on a separate shaft. (Entertainment Services and Technology Association, 2016)
Teaser: See Border curtain.
Tension block: A block designed to remove slack from an operating line, preventing it from twisting in its travel, and from rubbing against wire ropes, structural framing, and adjoining equipment. (Entertainment Services and Technology Association, 2016)
Tension load path: The path of tension-only load that follows the axis of the rope or wire rope lift lines, including all connections and terminations along this path. The single reeve system tension load path includes all connections between the arbor and the batten. The double reeve system tension load path includes all connections between the head block and the batten. The rope and sandbag system tension load path includes all connections between the pin rail and the batten. (Entertainment Services and Technology Association, 2016)
Thimble: A grooved fitting around which a rope is bent to form an eye. It supports and protects the rope to prevent kinking and wear. (Entertainment Services and Technology Association, 2016)
Trim: (1) a load is “in trim” when the equipment load equals the counterbalancing weight. (2) A set or element is trimmed when it has been placed in the desired position within the performance area. (Hall & Sickels, 2016)
Trim chain: A length of chain and fittings used to connect a lift line to a batten (or other load) and adjust its level relative to the other lift lines along the batten. (Entertainment Services and Technology Association, 2016)
Trim clamp: A device with spring-loaded cams that allows several ropes to be held together and operated as a group. (Entertainment Services and Technology Association, 2016)
Tread diameter: The diameter of a sheave measured at the bottom of its groove. (Entertainment Services and Technology Association, 2016)
Tower: one or more modules assembled vertically to carry primarily axial load; usually square or triangular in cross section. (Entertainment Services and Technology Association, 2012)
Truss: one or more modules assembled to carry load over a distance, generally horizontal, and primarily acting in flexure. (Entertainment Services and Technology Association, 2012)
Truss batten: Pipes, tubes, or other structural shapes, in which main chord members are connected together with bracing members as a truss, and used in place of a pipe batten. (Entertainment Services and Technology Association, 2016)
UDL (uniform distributed load): a load that is evenly spread over the length of a truss or tower. (Entertainment Services and Technology Association, 2012)
Ultimate load carrying capacity: The maximum load an assembly may support without failure. (Entertainment Services and Technology Association, 2020)
Uncle Buddy: Slang, see Rope Binder.
Under hung: Hung from the bottom of a beam. (Hall & Sickels, 2016)
Upright: Resting on top of a beam or structure. (Hall & Sickels, 2016)
Up-Stage: Away from the audience.
Well: The Space between the beams on the grid over which the loft blocks and the working lines are placed to drop to the batten. (Glerum, 2007)
West coasting: Catching a curtain or other soft good in your arms, gathering it up vertically to use it’s own tie lines to bundle the curtain together for transportation.
Winch: A machine for pulling and holding equipment using rope or cable. (Hall & Sickels, 2016)
Wire guide: Tensioned wire ropes installed and used to guide the path of counterweight arbors or clews. Definition taken from (Entertainment Services and Technology Association, 2016)
Wire rope: Strands of one or more carbon or nickel steel wires wrapped in a helical fashion to form the finished product. (Entertainment Services and Technology Association, 2018)
Working line: see Lift line.
Working load limit (WLL): The maximum rated capacity of a component or system during normal operating conditions, as determined by the component manufacturer, or as determined by a qualified person for a specific application. (Entertainment Services and Technology Association, 2016)
Sources:
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