co₂ Monitoring in Theatres – Starlight Express
Behind the Scenes at Starlight Express: CO₂ Monitoring in Action
This week, we visited Troubadour Wembley Park Theatre, home to Andrew Lloyd Webber’s Starlight Express, to learn more about their experience using the Analox Ax60+ CO₂ detection system.
When audiences take their seats for Starlight Express, they see speed, spectacle, and technical brilliance. What they do not see is the safety infrastructure working quietly behind the scenes.
Our visit provided an opportunity to understand why CO₂ monitoring was required, how the system was installed, and how it helps support both stage production and hospitality operations throughout the venue.
It also highlighted an important and often overlooked aspect of theatre safety: the management of carbon dioxide (CO₂) in performance and hospitality environments.
Understanding CO₂ Monitoring in Theatre Environments
In theatre environments, CO₂ monitoring uses fixed gas detection systems to continuously measure carbon dioxide levels across performance spaces, technical areas, and hospitality zones. These systems provide early warning if CO₂ concentrations begin to rise, allowing venue teams to respond quickly and maintain safe conditions for performers, crew, contractors, and staff.
In venues where dry ice effects, beverage dispensing systems, or other compressed CO₂ applications are used, continuous monitoring is not simply a precaution, it is a critical safety measure.
By providing real-time gas detection and immediate alarm notification, CO₂ monitoring helps ensure that potentially hazardous conditions are identified before they pose a risk to people or disrupt venue operations.
Why CO₂ Monitoring Is Essential in Theatres Using Dry Ice and Stage Effects
Where Is CO₂ Used in Modern Theatres?
Modern theatre productions increasingly rely on CO₂ for a variety of operational and creative applications, including:
- Dry ice low-lying fog effects
- Atmospheric stage environments
- Special effects systems
- CO₂ cylinder storage
- Beverage dispensing systems in bars and restaurants
While CO₂ is non-flammable, it can present a serious safety risk if released into enclosed or low-level areas.
Because carbon dioxide is colorless, odorless, and heavier than air, it can accumulate in locations such as:
- Substage voids
- Orchestra pits
- Track systems
- Technical wells
- Cellars and storage rooms
Without appropriate monitoring, elevated CO₂ levels can develop unnoticed, creating potentially hazardous conditions for performers, technicians, hospitality staff, and contractors working within the venue.
Elevated CO₂ concentrations can cause dizziness, disorientation, and, in extreme cases, loss of consciousness.
In immersive productions such as Starlight Express, where staging incorporates low-level performance areas and complex technical spaces, understanding how gases behave within the environment is essential.
A fixed CO₂ detection system is therefore more than a best-practice recommendation, it is a critical safety control measure, helping ensure that potentially hazardous conditions are identified early and managed effectively.
A Structured Approach to CO₂ Safety at Troubadour Wembley Park
During our behind-the-scenes tour, we saw how the Analox Ax60+ system has been carefully integrated into the theatre’s safety infrastructure.
Sensors are positioned in key low-level areas, where CO₂ would naturally accumulate in the event of a leak. A clearly displayed site plan identifies each monitoring zone, enabling staff to quickly locate and respond to any alarm activation.
The Ax60+ provides continuous, real-time CO₂ monitoring throughout the venue, supported by clear audible and visual alarms. Defined response procedures are in place should gas levels rise, giving the technical team immediate awareness and control.
The system operates quietly in the background:
- It is not intrusive.
- It does not disrupt the creative process.
- It provides confidence that performers, crew, and staff are protected.
What stood out most during our visit was that safety is not treated as a reaction to risk—it has been designed into the operation from the outset.
Behind the Scenes of Starlight Express
Before the show began, we were given an insightful tour of the theatre’s technical spaces. Seeing the sensor installations, alarm units, and documented safety procedures firsthand highlighted the professionalism and strong safety culture embedded throughout the venue.
We were then fortunate enough to experience Starlight Express itself, a spectacular production that showcases the precision, coordination, and technical excellence of modern theatre.
What the audience sees is impressive.
What they do not see is equally important.
Behind the scenes, systems such as the Analox Ax60+ operate continuously, helping to maintain safe conditions for performers, crew, and venue staff without disrupting the production.
Effective CO₂ monitoring enables theatres to safely use modern stage effects and hospitality systems while protecting people, supporting operations, and preserving the performance experience.
At Starlight Express, it was clear that safety and creativity work hand in hand, and that the best safety systems are often the ones the audience never notices.
Extending CO₂ Detection to Theatre Bars and Hospitality Areas
Like many modern theatres, Troubadour Wembley Park is more than a performance venue. It also operates licensed bars and hospitality areas that rely on compressed CO₂ for beverage dispensing systems.
In these environments, CO₂ is typically stored in cylinders located within enclosed cellar or back-of-house areas. If a leak were to occur, carbon dioxide could accumulate rapidly at low level, particularly in confined spaces where staff may be working alone.
The same Analox Ax60+ CO₂ detection system used to support stage and technical safety also helps protect:
- Beverage cellars
- Gas cylinder storage rooms
- Back-of-house hospitality areas
This versatility allows a single monitoring platform to support both theatre production environments and hospitality operations, helping reduce risk and maintain safe working conditions across the entire venue.
What Is the Analox Ax60+ CO₂ Detection System?
The Analox Ax60+
The Analox Ax60+ is a fixed gas detection system designed to continuously monitor carbon dioxide (CO₂) levels in enclosed, confined, or low-level environments where gas accumulation may occur.
Trusted across a wide range of industries, the Ax60+ helps provide early warning of elevated CO₂ levels through continuous monitoring and clear alarm notification.
Applications Include:
- Theatres and live performance venues
- Hospitality and beverage cellars
- Industrial facilities
- Laboratories
- Food and beverage production sites
With scalable monitoring capabilities, configurable alarms, and support for multiple sensors, the Ax60+ provides a flexible solution for organizations looking to improve safety and protect personnel in CO₂-risk environments.
Key Features
- Accurate NDIR CO₂ sensing technology
- Continuous fixed gas monitoring
- Clear audible and visual alarm indication
- Wall-mounted display and control units
- Expandable multi-sensor capability
- Designed for environments where low-level CO₂ accumulation may occur
The Ax60+ provides early warning of rising CO₂ concentrations, helping organizations protect personnel, reduce risk, and support workplace safety compliance.
Installation Delivered by Production Ltd.
The Ax60+ system was installed by Production Ltd., a specialist contractor with extensive experience delivering technical safety systems within live theatre environments.
Working in partnership with Analox, Production Ltd. implemented a structured installation plan, positioning sensors in key low-level areas where CO₂ would naturally accumulate. This ensured effective coverage and reliable gas detection throughout the venue.
Through close collaboration, Production Ltd. and Analox delivered a solution tailored to the theatre’s unique layout and operational requirements, combining proven CO₂ detection technology with expert installation, commissioning, and integration support.
The result is a monitoring system that operates seamlessly alongside the venue’s production and hospitality activities, helping maintain safe working conditions without impacting day-to-day operations.
Is Your Theatre or Venue Protected?
FAQs About Gas Detection in Theaters
Why is CO₂ monitoring required in theaters?
Theatres that use dry ice effects, fog systems, or compressed CO₂ cylinders can experience carbon dioxide buildup in low-level or enclosed areas. Fixed CO₂ detection systems provide early warning of rising gas concentrations, helping protect performers, crew, contractors, and venue staff.
Where should CO₂ sensors be installed in a theater?
CO₂ sensors should be installed at low level in areas where carbon dioxide is most likely to accumulate, including:
- Substage areas
- Orchestra pits
- Track systems
- Technical wells
- Cellars and storage rooms
- Other enclosed or poorly ventilated spaces
Do theatre bars and restaurants need CO₂ detection?
Yes. Beverage dispensing systems commonly use compressed CO₂, often stored in cellar environments. If a leak occurs, CO₂ can accumulate quickly at low level, making fixed gas monitoring an important safety measure for hospitality staff and contractors.
What is the best CO₂ detection system for theaters?
A fixed, multi-sensor monitoring system such as the Analox Ax60+ is well suited to theatre environments. It provides continuous CO₂ monitoring, clear audible and visual alarms, and scalable coverage for complex venue layouts spanning both production and hospitality areas.
Find out more about how the Ax60+ can help you to keep your people and your business safe.
Key Takeaway
If you are storing or using carbon dioxide, a dedicated CO₂ detector should be considered an essential part of your safety strategy. Analox offers a range of fixed and portable CO₂ monitoring solutions designed to suit a wide variety of applications and risk environments.
Whether you operate a theatre, hospitality venue, brewery, laboratory, or industrial facility, effective gas monitoring helps provide early warning of hazardous conditions and supports the protection of personnel.
If you need advice on selecting the right solution for your application, get in touch with the Analox team. We’ll be happy to help you identify the most suitable gas detection system for your requirements.