Advanced Rigging
Introduction
Rigging is the one department where a mistake is not recoverable. A bad audio decision sounds wrong. A bad rigging decision arrives on people, from above, with no warning, and nothing about the rest of the show matters afterwards.
Advanced rigging is what happens past the basics: bridles rather than dead hangs, shared points, loads the house plot does not cover, structures that need an engineer, and a crew of riggers working to one person's plan.
This book is about that work and about the person responsible for it. It teaches the numbers, the geometry, the documents and the judgement, and it is honest that the only way to become a rigger is on a rigging crew, under people who already are.
This Book Cannot Make You a Rigger
Nothing here qualifies anybody to rig. Rigging is learned by doing it under supervision, for years, and the recognised certifications in this industry require substantial documented professional experience before you may even sit the exam.
What a book can do is give you the vocabulary, the arithmetic and the shape of the responsibility, so that the time you spend on a rigging crew teaches you faster, and so that everybody else on a show floor understands what the riggers above them are actually doing.
How to Use This Book
Read it in order. The chapter on numbers underpins everything that follows, and the chapter on responsibility is the one to read twice. Every chapter ends with a reference table, a procedure, a failure table written symptom first, an exercise and a checklist.
Keep a notebook
Write down every point you hung, where it was, and what went on it. A rigging plot is a drawing of intent; your notebook is the record of what was actually flown, and when a venue asks next year what you put on that beam, it is the only honest answer available.
Write down the bridle legs — the two points, the dead hang you were trying to achieve, and the leg lengths you ended up with. Bridle angles change the load in each leg dramatically, and a bridle that worked at this venue is the starting point for the next one.
Write down the hoist unit numbers and what each one carried. A chain hoist that has lifted near its rating repeatedly is not the same machine as one that has not, and inspection intervals mean nothing without a use history.
A note on the words
A point is a pick is a hang is a motor, and which word is used tells you where the speaker learned the trade. Arena riggers say point; theatre riggers say hang; the person on the deck usually says motor, which properly means the hoist rather than the place it is attached.
Hitches have precise names worth keeping precise: a vertical hitch, a basket hitch and a choke hitch load the same sling to three different capacities, and a sling's rated capacity means nothing until you say which hitch. The design factors are fixed and worth memorising — 4:1 for alloy chain, 5:1 for wire rope, 5:1 for synthetic web and roundslings under ASME B30.9.
A note on safety
Everything in this book is about weight held in the air over people. There is no version of this work where a mistake is small: a rigging failure is a load arriving on the floor from height, through whatever is under it.
The number that most often gets skipped is the building's. Venue capacity — what the roof steel will actually carry, in total and at any one point — is set by the building, not by your hoists, and a plot that works structurally as a set of individual points can still overload the structure that holds all of them. Ask for the venue's rigging capacity in writing before the plot is finalised.
Rigging is one of the few AV disciplines with a real certification behind it. ETCP's Rigger-Arena and Rigger-Theatre exams exist because this knowledge is not something to be self-assessed. This book teaches the subject; it does not qualify you to hang anything.
Where this book sits
This book assumes you have read Rigging Fundamentals, or that you already know what is in it.
Experience counts instead. If you have time on rigging crews as ground crew or a down rigger, where you have built bridles under somebody's eye and seen plots turn into rigs, start here.
If none of that is true yet, read Rigging Fundamentals first.
What pairs with this
- Personal Fall Arrest Systems (PFAS) — Certification Prep — what keeps the person in the steel attached to it
Where it leads
These are not steps in an order. Take whichever one fits.
- Staging & Crew Chief — the deck under everything you are hanging above
- Touring Fundamentals — the same rig, city after city
What Advanced Rigging Is
The line between rigging awareness and rigging is not a sharp one, but it is real, and it is mostly about who carries the decision.
Complex rigging, led by senior certified riggers.
Beyond the fundamentals
Basic rigging is hanging a known load from a known point in a way somebody else has already designed: a fixture on a bar, a speaker on an approved flying frame, a truss on a house point that the venue's plot says will take it.
Advanced rigging starts where the answer is not already written down. The point you need is not where the steel is, so you bridle. The load is bigger than the plot allows in that position, so it has to be spread or moved. Two hoists share a span and will not share it equally. A production wants something the building was never designed for, and somebody has to say what is possible.
Each of those is a calculation, a document and a decision -- and the decision sits with a person, not with a rule.
The head rigger and qualification
The head rigger plans the rig, produces or checks the plot, decides the method, leads the crew on the day, inspects what has been built and signs it off before anything is loaded.
Almost none of that is climbing. A head rigger on an arena call spends the morning with a plot, a laser, a radio and a marker, and their most important work happened weeks earlier, sitting down with drawings.
Qualification for it comes from experience under supervision, recognised certification, and the trust of people who have seen you work. There is no shortcut, and the industry is small enough that everybody knows who is ready.
Where AV meets it
Most AV crew are not riggers and do not intend to be. They still need this book's vocabulary, because their gear is what hangs: line arrays, LED walls, projectors, cameras on wires, lighting truss, scenic.
The questions that come back to an AV department are always the same: how heavy is it, where exactly does it hang, what are the pick points, how does the weight change when the array is curved, and what is the dynamic load when the thing moves. Being able to answer precisely, in writing, makes you easy to rig for; being vague makes you the reason the call runs late.
Basic against advanced
The difference is who carries the decision.
| Basic rigging | Advanced rigging | |
|---|---|---|
| The point | Already exists and is approved | Has to be reached, shared or created |
| The load | Known and within the plot | Calculated, and sometimes outside it |
| The method | Standard and prescribed | Designed for this rig |
| The paperwork | The house plot | A plot, and sometimes an engineer |
| The decision | Somebody else's, already made | Yours, with your name on it |
What the AV department must be able to say
Precisely, in writing, before the call.
| Question | Bad answer | Good answer |
|---|---|---|
| How heavy? | "About a tonne?" | A figure from the manufacturer's data |
| Where does it hang? | "Above the stage" | Dimensioned from a datum on the plot |
| What are the pick points? | "The frame" | Named points from the rigging drawing |
| Does the weight move? | "Not really" | Static, or a stated dynamic case |
How to do it
- Ask whether the point already exists and is approved for that load.
- Ask whether the load is known from data rather than estimated.
- Ask whether the method is prescribed or being designed on site.
- If any answer is the second one, a qualified rigger owns it.
- Put what your department knows in writing before the call.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| A rigging question answered by a lighting tech | The line between basic and advanced not recognised | Hand it to the head rigger; say you do not know |
| The rig call stalls waiting for weights | AV could not say what its gear weighs | Manufacturer data, in writing, before the day |
| A point invented on site | The needed position had no steel above it | That is a bridle and a calculation, not a guess |
Practice it
On your own gear.
- You can say whether a point already exists and is approved.
- You can say whether the load is known or estimated.
- You know who the head rigger is and what they decide.
- Your department's weights and pick points are in writing.
- You know this book does not make you a rigger.
The Numbers a Rigger Works In
Three numbers and one piece of geometry explain most of what a rigger does. Everything else is application.
Working load limit, breaking strength and design factor
Breaking strength is the load at which a component fails in a test. Working load limit is the most it may carry in service. Design factor is the ratio between them -- the margin.
The sling standard, ASME B30.9, sets minimums by type: alloy steel chain slings have a design factor of at least four, and wire rope slings, synthetic web slings and polyester roundslings at least five. So a roundsling rated at one tonne is built to break somewhere around five.
That margin is not capacity you are allowed to use. It absorbs wear, shock, heat, chemical damage, bad angles, ageing and the parts of reality nobody predicted. A rigger works to the working load limit and treats the rest as the reason everybody goes home.
Sling angle, and why a shallow bridle doubles the load
This is the arithmetic worth knowing by heart. When a load hangs from two legs, each leg carries more than its share of the weight as soon as the legs are not vertical, because part of the tension is pulling sideways rather than up.
The relationship is the sine of the angle from horizontal. At ninety degrees -- straight up -- the leg carries its share exactly. At sixty degrees it carries about fifteen per cent more. At forty-five, about forty per cent more. At thirty degrees, twice its share.
Two consequences follow. A shallow bridle multiplies the load in the legs and in the points, sometimes past what either is rated for, while the weight hanging underneath has not changed at all. And the sideways component pulls the two points toward each other, which is a load the structure may not have been designed for.
The D over d ratio and what bends a sling
A sling bent around something small loses capacity. The rule of thumb is the D over d ratio: the diameter of the object the sling bends around, divided by the diameter of the sling's body. The tighter the bend, the more the outside fibres or wires are stretched relative to the inside, and the lower the effective strength.
In practice this is why riggers use softeners and corner protection on truss and steel edges, why a choked sling is de-rated, and why wrapping a roundsling tightly around a sharp corner is not the neat solution it looks like.
Shared points and load distribution
Two points holding one beam do not necessarily carry half each. Distribution depends on where the load sits between them, how stiff the spanning member is, and whether both legs are the same length and tension.
A stiff truss on three or more points is statically indeterminate -- the arithmetic cannot say exactly what each point carries, and small differences in leg length can move a great deal of load. That is one of the places where the answer stops being arithmetic and becomes an engineer's.
The three numbers
Confused constantly, and the difference matters.
| Number | Means | Used for |
|---|---|---|
| Breaking strength | Where it fails in a test | Nothing in service |
| Working load limit | The most it may carry in use | Every decision |
| Design factor | The ratio between them | The margin you do not spend |
Minimum design factors by sling type
From ASME B30.9, the sling standard; manufacturers may publish higher.
| Sling | Minimum design factor |
|---|---|
| Alloy steel chain | 4 |
| Wire rope | 5 |
| Synthetic web | 5 |
| Polyester roundsling | 5 |
Sling angle against leg tension
The leg's share of the load, divided by the sine of the angle.
| Angle from horizontal | Each leg carries | Meaning |
|---|---|---|
| 90 degrees | 1.00 x its share | A dead hang |
| 60 degrees | about 1.15 x | Comfortable bridle territory |
| 45 degrees | about 1.41 x | Getting expensive |
| 30 degrees | 2.00 x | Double, and pulling the points together |
How to do it
- Establish the total load, from data rather than memory.
- Establish each leg's share from the geometry of the apex.
- Measure or calculate each leg's angle from horizontal.
- Divide each leg's share by the sine of its angle to get the tension.
- Compare that tension to the working load limit of the sling, the hardware and the point.
- Check the horizontal pull the bridle applies to both points.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| A point overloaded by a load well within its rating | A shallow bridle multiplying the leg tension | Steeper legs, or a different point |
| Hardware failing below its marked figure | Design factor treated as spare capacity | Work to the working load limit, not the margin |
| A sling cut at a truss corner | Tight bend and no softener | Corner protection; respect the D over d ratio |
| Three points sharing very unequally | A stiff span and unequal leg lengths | That is an engineer's calculation, not a rigger's estimate |
Practice it
On paper, with a calculator.
- The load comes from published data, not memory.
- Leg tensions were calculated from the actual angles.
- Every component is inside its working load limit.
- Bends have softeners and de-rating is accounted for.
- Anything statically indeterminate has gone to an engineer.
Complex Rigs & Calculations
What the arithmetic is actually for: reaching a point that does not exist, and knowing what the rig does to the building.
Complex systems and the engineering behind them.
Complex rigs and systems
A complex rig is one where the geometry does the work. Bridles reach positions with no steel above them. Spanning sets carry a point between two others. Dead hangs, deviations, trolleys and multi-leg arrangements all exist to put a hook exactly where the production needs it and nowhere else.
Add motors and the rig becomes dynamic: things move, loads transfer, and a truss that is perfectly balanced at trim may not be while it is being lifted unevenly. Add automation, performer flying or anything over an audience and you are in a category with its own rules, its own standards and its own specialists.
Rigging calculations
The everyday calculations are few and repeated: total load and where its centre of gravity sits; each point's share; leg tension from angle; the horizontal component at each point; the capacity of the point, the hardware and the sling; and the de-rating from any bend or choke.
Riggers do this with a calculator, an app, a plot and a habit of writing it down. Written down matters: the next person needs to see the numbers, and so does anybody asking afterwards why something was safe.
And some calculations are deliberately not done on site. Statically indeterminate rigs, structures being asked to do something new, and anything with a dynamic case go to an engineer with the time and the tools to do them properly.
Bridles, and how a point ends up where it is not
A two-leg bridle takes two existing points and creates a third hanging between them. Where that apex ends up depends on the lengths of the two legs and the distance between the points, and the arithmetic to place it precisely is the core skill of arena rigging.
Two things go wrong in practice. The legs end up shallower than anybody intended, because the points were further apart than the plot suggested, and the tension climbs. And the bridle pulls the two points toward each other, applying a horizontal load to steel that was designed to be pushed down rather than sideways.
Both are reasons that a bridle is planned rather than improvised, and that measurements come from the building rather than from the drawing alone.
Hardware, and what each piece is rated for
Every item in the load path has a rating and an identity: shackles stamped with size and working load, slings tagged with capacity and identification, steel with published limits, hoists rated and serviced, beam clamps and trolleys rated for a particular flange.
The weakest item in the path is the capacity of the whole path, and an unmarked item has no capacity at all as far as a rigger is concerned. Mixing hardware from unknown sources into a load path is the same error as mixing staging systems, with worse consequences.
Screw pin shackles want their pins secured where there is any chance of rotation; safety-bolt shackles exist for long-term or unattended loads. Use hardware the way its maker intends, and never side-load a shackle that was not designed for it.
Inspection, tagging and removal from service
Rigging gear is inspected before use, inspected formally and recorded at intervals, and removed from service the moment there is doubt. Cuts, abrasion, heat and chemical damage, broken stitching, distorted or cracked hardware, damaged or missing tags, and anything that has taken a shock load.
Removal from service means the item cannot come back by accident: tagged, separated, and destroyed if condemned. The same rule as fall protection, and for the same reason.
An item with no tag, no identification and no history is not cheap gear. It is unknown gear, which in a load path over people is the same as no gear at all.
The everyday calculations
Few, repeated, and written down.
| Calculation | Answers | Goes wrong when |
|---|---|---|
| Total load and centre of gravity | What is hanging, and where | Weights estimated |
| Share per point | What each point carries | Assumed to be equal |
| Leg tension from angle | What the sling actually sees | Angles shallower than planned |
| Horizontal component | What the bridle pulls sideways | Nobody checks the steel for it |
| De-rating from bends | The sling's real capacity | Choked or bent tight with no softener |
The load path
The weakest item is the capacity of the whole thing.
| Item | Carries its rating how | Unacceptable |
|---|---|---|
| Structure or house point | Venue plot and engineering | Unapproved steel |
| Beam clamp or trolley | Rated for a flange size | Wrong flange, wrong rating |
| Shackle | Stamped size and working load | Unmarked, or side-loaded |
| Sling | Tagged capacity and identification | No tag, unknown history |
| Hoist | Rated, serviced, with records | No service record |
How to do it
- Measure the real point positions in the building, not just the plot.
- Calculate the leg lengths that put the apex where it is needed.
- Calculate the tension in each leg from its angle.
- Check the horizontal pull each point will see.
- Confirm every item in the load path is rated, marked and inspected.
- Write the numbers on the plot so the next person can see them.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| The apex is not where the plot says | Point positions taken from the drawing alone | Measure the building; drawings age |
| Legs shallower than planned | Points further apart than expected | Recalculate; do not accept the angle you get |
| An unmarked shackle in a load path | Gear of unknown origin in the box | Unmarked is uncapacitated; take it out |
| A sling still in use after a shock load | No removal-from-service discipline | Tag, separate, destroy if condemned |
Practice it
With a plot and a tape.
- Loads come from data and the centre of gravity is known.
- Point shares, leg tensions and horizontal components are calculated.
- Every item in the load path is rated, marked and inspected.
- Bends and chokes are accounted for with de-rating and softeners.
- The numbers are written on the plot.
The Building and Its Limits
Everything a rigger hangs ends up in somebody else's structure, and that structure has an owner, a drawing and a limit.
Reading a venue rigging plot
A venue rigging plot is the document that says where the steel is, what each point or beam will carry, where the no-hang zones are, and what the house rules require. Arenas, theatres and convention centres publish them, and they vary enormously in quality and age.
Read it before the production drawing is finalised, not after. Most rigging arguments on a load-in are the result of a plot nobody consulted until the trucks arrived.
And treat the plot as a starting point rather than gospel. Steel gets modified, services get installed under beams, and a capacity from 1994 may have been revised. The house rigger knows what the plot does not say.
What the building will actually carry
A point's capacity is an engineering property of the structure, not a judgement a visiting rigger gets to make. This venue capacity comes from the building's own engineering, and it comes with conditions: a maximum per point, a maximum per beam or per bay, a total for the roof, and often limits on horizontal loads.
That last one matters because bridles pull sideways. A beam happy to carry a tonne straight down may not be designed for several hundred kilograms pulling along its length.
When a production needs more than the building allows, the answer is not to spread the difference quietly. It is to redesign the rig, reduce the load, or get the venue's engineer to say what is possible in writing.
Who approves a point
On most sites the venue's house rigger or technical manager approves what may be hung and where, working to the venue's engineering. On a build with a structural contractor there will be an engineer of record for the temporary structures.
For a visiting head rigger, the job is to know who those people are, to bring them a plot they can check rather than a surprise, and to accept a no when it comes.
When the answer needs an engineer
Certain things go to an engineer as a matter of course: loads beyond the published capacities; statically indeterminate rigs; anything applying significant horizontal load to a structure; new or unusual configurations; anything over an audience; performer flying; and any structure being asked to do something it was not designed for.
Knowing that list is not an admission of weakness. It is the competence: the difference between a rigger and a hazard is largely the ability to recognise the edge of what can be worked out on site.
What a rigging plot tells you
And what it does not.
| On the plot | Means | Check anyway |
|---|---|---|
| Point positions | Where steel is available | Measure the real thing |
| Capacity per point | The engineered limit | Whether it was revised |
| Per beam or per bay limits | Totals, not just points | How your rig adds up |
| No-hang zones | Services, ducts, weak steel | Recent installations |
| House rules | Hardware, secondaries, who climbs | Ask the house rigger |
Straight to an engineer
Not a weakness; the competence itself.
| Situation | Why |
|---|---|
| Beyond published capacity | The limit is engineering, not judgement |
| Statically indeterminate | The arithmetic cannot answer it |
| Significant horizontal load | Structures resist sideways poorly |
| Over an audience | Its own standards and specialists |
| Performer flying | A separate discipline entirely |
| A structure doing something new | Nobody has calculated this case |
How to do it
- Get the venue's current rigging plot before the design is fixed.
- Identify the house rigger or technical manager and talk to them early.
- Lay the production's points over the plot and total the loads per beam and per bay.
- Identify every bridle's horizontal component and check it against the venue's limits.
- Send anything unusual or beyond capacity to an engineer, in writing.
- Take the approved plot to site and measure the building against it.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| A production plot that will not fit the building | Designed before the venue plot was read | Venue plot first, always |
| Points within limits but the beam is overloaded | Per-point checked, per-beam totals not | Total by beam and by bay as well |
| A venue refusing a rig on the day | A surprise rather than a checked plot | Bring the house rigger in early |
| A bridle pulling a beam sideways | Horizontal component never calculated | Calculate it and check it against the venue's limit |
Practice it
For a venue you work in.
- The current venue plot was read before the rig was designed.
- Loads total within per-point, per-beam and overall limits.
- Horizontal loads from bridles have been checked.
- The house rigger has seen and approved the plot.
- Anything unusual went to an engineer in writing.
Theatre and Arena Are Different Trades
The industry certifies arena riggers and theatre riggers separately, and the reason is that the two jobs share arithmetic and almost nothing else.
What an arena rig is
An arena rig hangs a show from a building's roof steel for two days. Everything is temporary: points are made where the production needs them, usually with bridles, and the whole rig comes down the same night.
The skills are the ones in the previous chapters -- plots, bridles, capacities, hoists -- carried out quickly, at height, by a crew that has often never worked together before, in a building the head rigger may be seeing for the first time.
What a theatre rig is
A theatre is the opposite: a permanent system, engineered into the building, that the production borrows. A counterweight fly system has line sets running over head blocks to an arbor loaded with counterweight, a purchase line, a rope lock at the lock rail, and a loading gallery where weight is added and removed.
Its hazards are its own. An unbalanced set is the classic: a batten flown out with the scenery removed but the counterweight still on the arbor, or the reverse, which turns a rope into something that will run away with a person attached to it. Loading and unloading weight happens in a defined order for exactly that reason.
Many houses now mix counterweight sets with motorised hoists and automation, which means a theatre rigger has to understand both and the interactions between them.
Why the certifications are separate
The vocabulary of a fly floor -- arbor, purchase line, head block, lock rail, loading gallery, spot line -- does not appear in an arena, and the arithmetic of bridling into roof steel does not appear in a theatre. The judgement each one needs is built on different daily practice.
So somebody excellent in one is a beginner in the other, and the industry says so plainly by certifying the two disciplines separately. Recognising which building you are in, and which of the two you actually know, is part of the competence.
Dynamic loads and things that move
Both trades share one modern problem: loads that move. A static load is a number. A load being lifted unevenly, accelerated, stopped suddenly, or swung transfers far more than its weight into part of the rig, and a shock load can multiply it.
That is why loads are lifted in stages and checked, why hoists are not raced, why a snatched lift is a fault rather than a style, and why automation and performer flying are separate disciplines with their own standards and specialists.
If something in the rig moves during the show, say so at the planning stage. A dynamic case belongs to an engineer, not to an estimate made at the controller.
Arena against theatre
Shared arithmetic, different trades.
| Arena | Theatre | |
|---|---|---|
| The system | Temporary, made for this show | Permanent, engineered into the building |
| The points | Bridled into roof steel | Line sets already in place |
| The lifting | Chain hoists | Counterweight sets, hoists, automation |
| The classic hazard | Overloaded point or shallow bridle | An unbalanced set running away |
| The vocabulary | Points, bridles, spans | Arbors, purchase lines, lock rails |
| Certification | Rigger - Arena | Rigger - Theatre |
The fly system, part by part
The words a theatre call uses constantly.
| Part | What it does |
|---|---|
| Batten | The pipe the scenery or lighting hangs from |
| Line set | The whole assembly of lines, blocks and arbor for one batten |
| Head block | The multi-sheave block at the top that turns the lines |
| Arbor | The carriage that holds the counterweight |
| Purchase line | The rope the operator pulls |
| Rope lock | The lock at the rail that holds a balanced set |
| Loading gallery | Where counterweight is added and removed |
How to do it
- Establish whether it is a counterweight house, a motorised house or both.
- Find the house rigger or technical manager and ask for the house rules.
- Ask which sets are available and what each is rated for.
- Never move weight or fly a set without the house's agreement.
- Say plainly if this is not the discipline you are experienced in.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| A set runs away on the rail | Weight removed from the batten with the arbor still loaded | Load and unload in the defined order, with the house |
| An arena rigger improvising on a fly floor | Rigging treated as one trade | They are separately certified for a reason |
| A rig damaged by a snatched lift | Dynamic loading nobody accounted for | Lift in stages, smoothly; dynamic cases go to an engineer |
Practice it
In a theatre and in an arena.
- You know whether the house is counterweight, motorised or both.
- You know the house rules and who owns the system.
- You can name the parts of what you are being asked to operate.
- Nothing that moves during the show was estimated rather than engineered.
- You have said plainly which discipline your experience is in.
Leading the Rig
A rigging call is a crew working to one person's plan, above everybody else's heads, with a schedule attached.
Planning, directing, and signing off complex rigs.
Planning and engineering the rig
The work that decides whether a rig goes well happens weeks earlier: collecting weights and pick points from every department, laying the production's points over the venue's plot, resolving the conflicts, calculating the bridles, sending anything unusual to an engineer, and producing a plot the crew can actually work from.
A good plot says what hangs where, what it weighs, which points are used, what each bridle's leg lengths are, what hardware is needed at each position, and what order it all goes up in. A bad plot says where things go and leaves the rest to the morning.
Bring the venue in early. A plot the house rigger has seen and agreed is worth more than a perfect drawing produced on the day.
Leading, inspecting, and signing off
On the day, the head rigger leads: briefing the crew on the plot, the sequence and the hazards; keeping the floor below clear; holding the pace; and making the decisions as reality differs from the drawing, which it always does.
Then the inspection. Before anything is loaded and before anybody works underneath, somebody walks the rig: every point, every bridle, every shackle pin, every hoist, every secondary. The check is done against the plot rather than from memory.
And then the sign-off, which is a person putting their name to the statement that this rig is safe to load. That signature is the whole subject of the next chapter.
Hoists, control and safe working practice
Chain hoists put the load where it needs to be and then hold it there. Which hoists, how they are controlled, whether they are being used in a way the standards allow for loads over people, and who is permitted to operate them are all part of the plan rather than decisions made at a controller.
The practical rules on a call are constant: nobody under a moving load; the person calling motors is the only person calling motors; loads are lifted in stages with the rig checked between them; and a hoist that behaves oddly stops the call rather than being nursed along.
Hoists have service records for the same reason slings have tags. An unserviced hoist over a crew is a decision somebody made, even if nobody said it out loud.
Secondary suspension and redundancy
Secondary suspension is the back-up that catches a load if the primary fails: safeties on fixtures, secondary steels on flown equipment, and redundant attachments where the standards or the venue require them.
Where it is required depends on the country, the venue, the production's own standards and what is underneath. What does not vary is the principle: over people, a single failure should not put anything on the floor.
A secondary with metres of slack is a shock-loading device rather than a safety, and a secondary attached to the same failing element as the primary is decoration. It is worth looking at every one and asking what exactly it would catch.
Up riggers, down riggers and the crew
An arena rig is a team with defined roles. Up riggers work in the steel, moving points and making attachments. Down riggers work on the floor, building bridles, measuring and marking positions, attaching loads and running lines. A head rigger runs the plot and the sequence, and the ground crew keeps the floor clear.
What makes it work is communication discipline: clear calls, confirmations, nobody talking over the person calling motors, and an agreed language for stopping. What makes it dangerous is silence and assumption.
What a working plot contains
Anything missing becomes a decision made at seven in the morning.
| On the plot | So that |
|---|---|
| What hangs where, dimensioned | Positions are measured, not judged |
| Weights per point | Capacities can be checked |
| Bridle leg lengths | The apex lands where it should |
| Hardware per position | The right steel goes up the first time |
| Sequence | The rig goes in an order that works |
| Venue approval | The house has already agreed |
The roles on a rigging call
Defined, and not interchangeable.
| Role | Works | Owns |
|---|---|---|
| Head rigger | The plot and the floor | The plan, the decisions, the sign-off |
| Up rigger | In the steel | Attachments at the point |
| Down rigger | On the floor | Bridles, measuring, attaching loads |
| Motor operator | At the controller | Only moving on the agreed call |
| Ground crew | The floor below | Keeping it clear of people |
How to do it
- Brief the crew on the plot, the sequence, the hazards and the stop call.
- Confirm who calls motors and that nobody else does.
- Mark and measure positions from the building before points go up.
- Build and check bridles on the floor before they are sent up.
- Lift in stages, checking the rig between them, with nobody underneath.
- Walk the whole rig against the plot before anything is loaded.
- Sign it off, and say out loud that it is signed off.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| Two people calling motors | No agreed single voice | One caller, agreed in the briefing |
| A load lifted over the crew | The floor not cleared or watched | Ground crew owns the floor; nobody underneath |
| A rig checked from memory | No plot in hand during the inspection | Walk it against the plot, point by point |
| A secondary that would catch nothing | Slack, or attached to the same failing element | Look at each one and ask what it catches |
Practice it
On your next rigging call, watching rather than working.
- The crew is briefed on plot, sequence, hazards and the stop call.
- One person calls motors and everybody knows who.
- The floor under the rig is owned and kept clear.
- Lifting happens in stages with checks between them.
- The whole rig is walked against the plot before it is loaded.
Responsibility & Qualification
The honest centre of this book. Rigging is the department where being nearly right is not a category.
The senior responsibility — and the certification it demands.
The weight of responsibility
Everything a rigger hangs is above people. Crew work under it all day, performers stand under it all night, and an audience sits under it afterwards. A failure does not degrade gracefully; it arrives suddenly, and it lands on somebody.
That is why the culture of the trade is what it is: pedantic about numbers, slow to accept assurances, unembarrassed about saying no, and unforgiving about gear of unknown provenance. It is not conservatism for its own sake. It is the only workable response to a job where mistakes cannot be corrected afterwards.
For a head rigger, the responsibility is personal and it is documented. You sign a rig off. If something is wrong and you signed it, that is yours, and everybody in the industry understands that. Which is exactly why the answer to schedule pressure has to be a flat one: it goes up right, or it does not go up.
The other half of it is the crew. Riggers are responsible for people working at height and for everybody underneath, and a chief who tolerates a culture where nobody raises a concern has already made the important mistake.
Senior certification and experience
The recognised certification in this industry is ETCP, the Entertainment Technician Certification Program, run through ESTA. It certifies riggers in two disciplines -- Arena and Theatre -- alongside Entertainment Electrician and Portable Power Distribution Technician.
It is deliberately not an entry-level qualification. Candidates must be at least twenty-one and must document substantial professional experience before they may sit the exam. ETCP counts it in points: a candidate needs thirty, and entertainment rigging work earns one point for every hundred hours, so somebody qualifying on work alone has documented around three thousand hours. Internships, apprenticeships and degrees can make up part of the total. ETCP sets and revises these rules, so check the current requirements at etcp.esta.org before you plan around them. The exams themselves are written by working professionals to test the judgement of people who already rig. More than a thousand arena riggers have been certified in North America.
Certification proves knowledge and experience; it does not by itself make somebody a head rigger on a particular show, and it does not replace the venue's approval or the employer's authorisation. It is a floor, not a ceiling, and the people who hold it will be the first to say so.
What certification is not
- It is not a licence to rig anything anywhere.
- It does not replace the venue's approval of a point.
- It does not replace an engineer where an engineer is needed.
- It does not expire quietly -- it has to be renewed.
- It does not substitute for experience on the kind of rig in front of you.
Recertification exists because the standards, the equipment and the practice all move. Keeping it current is part of holding it.
Knowing the edge of your competence
The most valuable thing a rigger can say is that they do not know. Every serious incident in this trade has somewhere in it a person who was not sure and went ahead anyway, usually because it was late and somebody was waiting.
The professional response is to name the doubt, stop, and get the person or the calculation that resolves it: the house rigger, a more experienced colleague, the manufacturer's data, an engineer. Nobody in this industry has ever lost standing for that. The opposite happens.
What ETCP certification is
A recognised floor, earned with documented experience.
| Fact | Detail |
|---|---|
| Disciplines | Rigger - Arena, Rigger - Theatre, and the electrical certifications |
| Minimum age | 21 |
| Experience | 30 eligibility points; rigging work earns 1 point per 100 hours (about 3,000 hours on work alone). Check ETCP's current rules |
| The exam | Written by working professionals, testing judgement |
| Scale | Over a thousand arena riggers certified in North America |
| Renewal | Recertification is required to keep it |
What it does and does not replace
Useful to be able to say out loud.
| Replaces | Does not replace |
|---|---|
| Doubt about your baseline knowledge | The venue's approval of a point |
| An employer's uncertainty about hiring you | An engineer where one is needed |
| Some of the burden of proving experience | Experience on this kind of rig |
How to do it
- Say so, out loud, to the person running the call.
- Stop the part of the work that depends on the answer.
- Name precisely what you are unsure about.
- Get the person or document that resolves it -- house rigger, data, engineer.
- Record the answer on the plot so it is not re-litigated at midnight.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| A rig signed off by somebody who was unsure | Schedule pressure and a room full of people waiting | It goes up right or it does not go up |
| A crew that never raises concerns | A chief who reacted badly the first time | Thank the person who stops the call, visibly |
| A certification treated as authority over a venue | A card mistaken for approval | The house still approves the points |
| An expired certification in use | No recertification tracking | Diarise the renewal the day you pass |
Practice it
Honestly, about yourself.
- The person signing off is the person who checked it.
- Schedule pressure does not change what gets signed.
- Concerns raised by anybody are welcomed and acted on.
- Certification is current and understood as a floor, not authority.
- "I do not know" is a normal sentence on the call.
Advanced Rigging Awareness
What to keep, and the honest route into a trade that is learned on a rigging crew rather than in a book.
Understanding the senior craft and its path.
Advanced rigging understood
Carry a few things away. Working load limit is the number you work to; the design factor above it is the margin that absorbs everything nobody predicted, and it is not yours to spend.
Sling angle is the arithmetic that catches people: each leg's tension is its share divided by the sine of its angle from horizontal, which is double at thirty degrees, and the same geometry pulls the two points toward each other.
The building is somebody else's engineering. Read the venue plot, total by point and by beam, check the horizontal loads, and take anything unusual to an engineer. The load path is only as strong as its weakest marked item, and an unmarked item has no rating at all.
And the rig is signed off by a person. That signature is the subject of the trade: everything hangs over somebody.
The path to advanced rigging
Start on the ground. Down rigging teaches the arithmetic, the hardware and the plot, and it is where the people who will eventually vouch for you can see you work.
Learn from riggers, by working for them. Ask to build bridles and have them checked. Ask why a point was chosen. Read the plot before the call and compare it to what actually happened.
Take the structured training that exists -- rigging schools, manufacturer courses, union and association training -- and then document your hours, because the recognised certification requires documented professional experience before you may sit it.
And be patient in a way that is unusual in this industry. Riggers are made slowly on purpose.
Practical sign-off
This book builds advanced-rigging AWARENESS only. The reader understands complex rigging, the head rigger's responsibility, and that real advanced rigging requires senior certification and deep experience. It does NOT qualify anyone — that requires accredited certification (e.g., ETCP) and years of qualified experience.
- Explained advanced rigging and the head rigger's role
- Understood complex rigs, calculations, and leading a rig at an awareness level
- Understood the profound safety responsibility involved
- Knows advanced rigging requires senior certification and deep experience
What to do on Monday
- Find the venue rigging plot for the room you work in most.
- Calculate the leg tensions for one bridle on your last show.
- Read the tag on one sling and one shackle properly.
- Ask the head rigger on your next call what they check before sign-off.
- Put your own department's weights and pick points in writing.
The last one is the most useful thing a non-rigger can do, and it makes you the department riggers want to work with.
Awareness against being a rigger
The gap is experience, supervised, over years.
| This book gives you | A rigging crew adds | Certification confirms |
|---|---|---|
| The vocabulary and the numbers | Doing it with real gear | That you know them |
| Sling angle and bridle geometry | Building them and being corrected | That you can calculate |
| What a plot contains | Working from and to plots | That you can read one |
| Where an engineer is needed | Seeing where seniors stop | Your judgement |
| Awareness | Competence | A recognised floor |
How to do it
- Get onto rigging calls as ground crew or a down rigger.
- Learn the hardware and the arithmetic properly, with somebody checking.
- Take structured training from schools, manufacturers or associations.
- Document your hours and the kinds of rigs you have worked on.
- Work toward recognised certification once the experience is there.
- Keep asking why a point was chosen, on every call.
What goes wrong
| Symptom | Likely cause | What to do |
|---|---|---|
| Somebody climbing before they can calculate | Up rigging treated as the glamorous part | The floor teaches the trade; the steel comes later |
| Hours worked but never documented | Nobody said it would matter | Keep a record from the first call |
| A book or a short course treated as qualification | Impatience with a slow trade | Riggers are made slowly on purpose |
Practice it
This week.
- You can explain working load limit, breaking strength and design factor.
- You can calculate leg tension from a sling angle.
- You know why a shallow bridle pulls its points together.
- You know what a venue plot contains and who approves a point.
- You can name the situations that go straight to an engineer.
- You know this book did not make you a rigger, and you know the route.
Glossary
| Apex | The point where the legs of a bridle meet and the load hangs. |
| Bridle | Two or more legs from existing points, creating a hanging point between them. |
| Breaking strength | The load at which a component fails in a test; never used in service. |
| Dead hang | A single vertical leg from a point straight down to the load. |
| Design factor | The ratio between breaking strength and working load limit -- the margin. |
| Down rigger | A rigger working on the floor, also called a ground rigger: bridles, measuring, marking and attaching. |
| D over d ratio | The diameter a sling bends around divided by the sling's own diameter; tight bends de-rate it. |
| ETCP | The Entertainment Technician Certification Program, which certifies Arena and Theatre riggers. |
| Head rigger | The person who plans the rig, leads the call, inspects it and signs it off. |
| Horizontal component | The sideways pull a bridle applies to its points, which structures resist poorly. |
| House rigger | The venue's own rigger, who knows the building and approves what may be hung. |
| Load path | Every item between the structure and the load; its weakest marked item is its capacity. |
| Rigging plot | The drawing of what hangs where, with weights, points, bridles and sequence. |
| Secondary suspension | The back-up attachment that catches a load if the primary fails. |
| Shackle | The rated connecting hardware between elements of a load path, stamped with its size and limit. |
| Sling angle | The angle a leg makes with the horizontal; leg tension is the share divided by its sine. |
| Softener | Protection placed between a sling and a sharp edge or tight corner. |
| Statically indeterminate | A rig whose point loads cannot be found by arithmetic alone; an engineer's problem. |
| Up rigger | A rigger working in the steel, moving points and making attachments. |
| Venue capacity | The engineered limit for a point, a beam, a bay or a roof. |
| Working load limit | The most a component may carry in service; the number a rigger works to. |
What the gear actually looks like
Every device named in this book, in one place. Recognition is the whole point of Chapter 4 — use this page to attach a picture to each name before you meet it on a dock at six in the morning.
Find the destination.
Work along the path between them.