This guideline deals with occupational health and safety related to the design and construction of mechanised scenery and automated systems, and their installation and use in performance venues, rehearsal venues and temporary rehearsal installations. It does not deal with worker safety in the scene shop or during the transport of the equipment.

The Design and Construction sections are not intended to be a comprehensive exploration of all the engineering aspects of mechanised scenery and automated systems. They identify many of the health and safety considerations to be incorporated into the design and construction process, and leave it to the employer to decide on how to address those needs.

To comply with legislative and regulatory requirements, the construction, design and complexity of the scenery may need the services of a professional engineer to ensure the scenery conforms to good engineering practice. This guideline does not attempt to define when that would be necessary – the decision should be made for each project early in its planning, and reference should always be made to the Occupational Health and Safety Act (OHSA) and applicable regulations.

This guideline is intended to apply in a cumulative fashion – for example, an item that is mechanised and automated should meet the requirements for both, as well as all general requirements.

The Construction Projects Regulation (O. Reg. 213/91) applies during the erection, alteration, repair, dismantling, installation, and structural maintenance of mechanized scenery and automated systems. The Regulation for Industrial Establishments (Regulation 851) applies while mechanized scenery and automated systems are in operation and use in rehearsal and performance venues. Employers, supervisors and workers, among others, have an obligation to know and comply with the regulations that apply to their workplace.

Reference should always be made, as appropriate, to the Scenery and Risk Assessment Guidelines set out in the Safety Guidelines for the Live Performance Industry in Ontario.

Electrical materials and equipment must always be installed and used in compliance with OHSA’s regulations, and should be installed and used in accordance with the Ontario Electrical Code. Reference should always be made, as appropriate, to the Electrical Guideline set out in the Safety Guidelines for the Live Performance Industry in Ontario.


Note: These definitions are provided for clarity and guidance only and, unless otherwise noted, are not definitions found under the OHSA or its regulations.

Core definitions

Mechanised scenery
Scenic element(s) whose movement or immobility is created by or through a mechanical system, regardless of the complexity of the system, or the power source.
Automated systems
Mechanised scenery where the power source is not manual, and:
  • scenic motion is directly controlled by an operator at all times (e.g. a chain hoist run from a pendant control), or
  • scenic motion is initiated by an operator, with subsequent control being assumed by a machine (e.g. an automated cue playback system).

General definitions

Appropriate personnel
Where the OHSA or Regulations impose a duty on a specific person “appropriate personnel” refers to that person. In other circumstances “appropriate person” may be another worker assigned and made accountable for the proper completion of a task or action (e.g. Technical Director, operator, performer, etc.)
The initial start-up and testing of the mechanised or automated scenery by a competent person, including setting and testing of limits, and calibration of positioning devices, culminating in the running of the scenery through its full range of motion.
Control system
A component, or system of components functioning as a unit, which is activated, either manually or automatically, to establish, manage and maintain those devices actually performing the movement of the scenic piece. Components may include operating controls and displays, operator interface, PLCs, control valves, sensors, warning devices, relief valves, motor drives, and all related cables.
Dry tech
A rehearsal or testing session wherein portions (or all) of the technical operation of a show (lighting, sound, automation, etc.) are reviewed and executed to ensure proper and reliable function of all elements. Dry tech rehearsals do not involve performers, except to the extent required for a sequence (such as a scene change, etc.) to be properly executed.
“The practice of professional engineering” means any act of planning, designing, composing, evaluating, advising, reporting, directing or supervising wherein the safeguarding of life, health, property or the public welfare is concerned and that requires the application of engineering principles and concerns the safeguarding of life, health, property, economic interests, the public welfare or the environment, or the managing of any such act.” [Professional Engineer’s Act R.S.O. 1990, Chapter P.28 section 1]
A system designed to limit or avoid injury, damage or hazard to someone or something in an emergency.
Fail safe
A system or control designed to ensure that, if some mechanised or automated scenic element does fail, everything possible will be done to minimize hazardous outcomes from that failure. As an example, it may be safer in some circumstances for a moving element to come to a controlled stop, rather than a sudden stop. Implementation of a fail safe protocol is highly device-specific.
Hazard range
The area inside which injury from a scenic element is possible.
Hydraulic system
A device that is operated by a pressurized liquid.
Any mechanical device that transmits or modifies energy to perform or assist in the performance of tasks.
Manual power
Using human strength as the power source.
Manual control
Independent, un-programmed control of a mechanised element or system by an operator.
Motion envelope
A region describing the bounds of the full range of movement of a scenic element.
A person who is charged with the responsibility of operating a system. An Operator should be a competent person as defined in the OHSA.
Power source
The origin of energy used to create motion, such as electrical energy, hydraulic pressure, pneumatic pressure, or human strength.
Pneumatic system
A device that is operated by pressurized gas, such as air or CO2.
Prime mover
The initial source of motive power, including manual power.
Soft stop
A non-emergency stop, with gradual deceleration, initiated by the operator.

Mechanised scenery and automated systems


Design and construction

Appropriate personnel should:

  • Complete a risk assessment on the system.
  • Conduct load calculations with due regard to the load capabilities of the components (see section 31 of O. Reg. 213/91)
  • In the case of manually-operated scenery, ensure movement and control of a scenic element are within the physical capabilities of the intended operator(s).
  • Ensure hardware and other technology is appropriate and adequate for the intended use.
  • Ensure all structural components are designed with appropriate factors of safety.
  • Ensure proper guarding of operating controls that might be activated unintentionally (see section 28(b) of Regulation 851)
  • Ensure proper guarding of moving parts that might pose a hazard (see sections 24-34 of Regulation 851).
  • Ensure adequate clearance between any moving scenic element, or any item or person carried by the moving scenic element, and any other element or structure.
  • Ensure all controls systems are designed as fail safe.
  • Incorporate an E-stop system consistent with the Regulation for Industrial Establishments, for systems not relying on manual power.
  • Ensure automatically controlled scenic elements with overlapping motion envelopes are interlocked to prevent collision.
  • Provide documentation on equipment capability, operation instructions and safety warnings, including identifying hazards (see subsection 25(2)(d) of OHSA).
  • Ensure all key components are easily accessible for inspection and maintenance.
  • Ensure loading or usage limits for the scenic elements are clearly identified on the scenic elements (see section 31 of O. Reg. 213/91).
  • Establish a plan for response and recovery in the event of breakdown of any mechanised element.
  • Conduct commissioning of the whole system prior to any dry tech testing. No persons should be close to any part of the system unless actually involved in the testing and calibration of the system.
  • Conduct operator (crew) training (see subsection 25(2)(a) of OHSA).
  • Conduct full dry-tech testing of the system under expected loads and operating conditions.

General operation

Appropriate personnel should:

  • Ensure that all workers know and understand the hazard range area and never enter the hazard range without taking precautions to protect their health and safety (see subsection 25(2)(d) of the OHSA). If performers are required to activate any system, then they are also operators and need to be trained to that level. Understudies and alternate crew must also be trained to the same level (see subsection 25(2)(a) of the OHSA).
  • Establish a communication system and chain of command.
  • Ensure that soft-stops are used in all non-emergency situations to avoid damage to equipment or personnel.
  • Ensure that changes to procedures, positioning, blocking or sequences are made and tested by an authorized competent person.
  • Ensure that the operator is made aware when there is to be any deviation from agreed-upon procedures, positioning, blocking or sequences (see subsection 25(2)(a) of OHSA).
  • Ensure that affected components are re-commissioned upon reinstallation, where mechanized scenery is disassembled or uninstalled between uses, such as in repertory theatre.

Rehearsal operation

Appropriate personnel should:

  • Conduct sufficient tech rehearsal to ensure predictable and safe operation of the mechanised elements.
  • Conduct sufficient rehearsal to ensure the safety of all persons required to be within hazard range of the elements in motion. Enough time should be given to ensure that they are familiar with the operation of the element, and comfortable with the safety precautions in place (see subsections 25(2)(a) and 25(2)(d) of OHSA).
  • Establish clear rules for use of E-stop system.
  • Rehearse use of and recovery from E-stop activation.
  • Ensure additional rehearsal is held to establish familiarity and comfort with the new sequence, where non-trivial changes are made to any sequence (see subsection 25(2)(a) of OHSA).

In-show operation

Appropriate personnel should:

  • Conduct pre-show testing of each system to confirm safe operation of all elements, including checks of fluid levels and operating pressures as appropriate.
  • Confirm that all guards and hazard markings are in place.
  • Check for loss of fluid and/or loss of operating pressure as part of operation monitoring.
  • Ensure every E-stop functions.
  • Monitor machinery in operation for any signs of malfunction.
  • Operate equipment safely and with an eye toward unexpected occurrences.
  • Ensure camera view of the element, with infrared equipment being used as necessary, if the stage layout or dim lighting precludes clear operator or “spotter” view of the element in motion.


Appropriate personnel should:

  • Ensure maintenance (see subsection 25(1)(b) of the OHSA) and inspections are done by an authorised competent person.
  • Establish a maintenance schedule, with a method of logging the maintenance work done.
  • Conduct maintenance according to the schedule, and more frequently when any observed behaviour of the system warrants it.
  • Pay particular attention to components that might be subject to wear or damage from outside sources.
  • Ensure maintenance includes checks for wear to hoses and cables.
  • Lock out and immobilise mechanised elements for maintenance activities where any operation of the element would pose a hazard. Immobilization of elements for maintenance must include lockout procedures consistent with sections 42 and 74-76 of the Regulation for Industrial Establishments.

Load out and decommissioning

  • All temporary mechanical or automation elements should be fully uninstalled at load-out.
  • Where temporary installations are retained as permanent, their suitability should be fully reassessed for all likely uses over an indefinite life span.
  • Scenic elements must be reviewed after every change in design or use, and before use, to ensure that changes in use have not resulted in loads or operational requirements exceeding those originally anticipated and allowed for at the time of construction and installation.

Automation control systems

Design and construction

Appropriate personnel should:

  • Design control systems for simplicity and reliability in operation, and durability in repeated use.

Appropriate personnel shall:

  • Incorporate an E-stop system into control systems (see section 27 of Regulation 851).
  • Incorporate a sufficient number of motion tracking components into control systems to ensure predictability and repeatability of motion.
  • Incorporate a sufficient number of limit-sensing and feedback components into control systems to ensure that motion overrun, operation beyond anticipated parameters, or unexpected load immediately disables motion.
  • Incorporate a manual control option into control systems to easily permit single-element movement, outside the cue sequence, in case of emergency or for maintenance. The manual controls shall be clearly labelled, and easy to understand and use. Operators shall know and understand how to use the controls (see subsection 25(2)(a) of the OHSA).

In-show operation

Appropriate personnel should:

  • Conduct pre-show testing of any motion sequences where equipment malfunction could result in a collision of elements.


Appropriate personnel should:

  • Ensure operational changes are made only by an authorised competent person, and communicated to all operators.
  • Ensure that software upgrades are avoided if possible during the run of a show. If software must be upgraded, test the system thoroughly through all motion sequences before use in performance and ensure all operators and workers are re-trained on the new functions, motions or other changes (see subsection 25(2)(a) of the OHSA).

Design and use of an E-stop system

A properly designed and implemented E-stop system provides the operator with an emergency means to quickly and safely stop scenery from moving. The goal of an E-stop system is the avoidance or limitation of hazard and harm in an emergency – it is not a guarding system, nor is it a substitute for guarding or for other risk reduction choices. It is also not intended as an alternative for non-emergency soft stop use. Follow manufacturer’s recommendations for use of the E-stop to temporarily disable system activation, where appropriate.

The following guidelines are adapted from and are consistent with CSA Z432-04 and the Regulation for Industrial Establishments.

Design and construction

  • The actuator(s) for the E-stop System shall be single-action, conspicuously and clearly identifiable, clearly visible, and within easy reach of the operator and/or spotter(s) at all times (see section 27 of Regulation 851).
  • Activating the E-stop system shall stop scenery motion as quickly as possible without creating additional hazards. If this is not possible or the risk cannot be adequately reduced, an emergency stop function may not be the best solution and other solutions should be sought.
  • The E-stop process (immediate removal of power [CSA Z432-04: Category 0], or controlled stop followed by removal of power [CSA Z432-04: Category 1]) shall be determined through risk assessment.
  • The E-stop system shall trigger or permit the triggering of certain limited movements to respond to an emergency.
  • Resetting the E-stop system should permit motion to be restarted once all safety criteria are met, but should not automatically restart motion.

Call toll-free

Call 1-877-202-0008 anytime to report critical injuries, fatalities or work refusals. For general inquiries about workplace health and safety and to report potentially unsafe work conditions, call 8:30 a.m. – 5 p.m., Monday to Friday. In an emergency, always call 911 immediately.

More information

Performance Industry
Ministry of Labour

Health and Safety Ontario (health and safety association)

Workplace Safety & Insurance Board

Canadian Standards Association (CSA) standards referenced in occupational health and safety legislation

This resource does not replace the Occupational Health and Safety Act (OHSA) and its regulations and should not be used as or considered legal advice. Health and safety inspectors apply and enforce these laws based on the facts they find in the workplace.