The successful deployment of the FOGTEC high-pressure water mist system in the Dwarka Tunnel in Delhi demonstrates what international standards and guidelines have stipulated for years: properly designed fire suppression systems contain fires, ensure safe escape and rescue conditions, and protect critical transport infrastructure.
When a car recently caught fire in the Dwarka Tunnel in Delhi, India, FOGTEC’s high-pressure water mist system did exactly what it was designed to do: it created a safe environment for tunnel users and protected the tunnel structure. The system was automatically triggered by the fire alarm system, extinguished the fire quickly and effectively, limited its spread and ensured safe conditions for motorists and emergency services.
The incident demonstrated that a professionally designed and installed fire suppression system, which not only takes the latest research findings into account but also complies with relevant standards such as the SOLIT2 guidelines, significantly increases safety levels in the tunnel in the event of an emergency and ensures that the infrastructure is restored to service more or less immediately.
The Dwarka Tunnel is a vital and heavily used link to Delhi Airport. Prolonged closures here would have led to enormous economic losses.
This successful deployment underlines an international trend: water-based fire suppression systems are increasingly becoming an integral part of modern tunnel safety concepts. This not only significantly enhances safety and availability but also substantially reduces investment in areas such as ventilation and structural fire protection. In recent years, numerous standards, guidelines and other publications have provided recommendations on this subject.
Today, water-based fire suppression systems are taken into account in many of the world’s leading documents on tunnel safety. Let’s take a look at the most important standards and guidelines:
NFPA 502, USA
NFPA 502 contains comprehensive recommendations on design objectives, system integration and performance requirements. Appendix E summarises the current state of research and documents the proven benefits of fixed fire-extinguishing systems for the protection of people and infrastructure. As an active member of the NFPA 502 Technical Committee for over 20 years, FOGTEC contributes directly to the ongoing development of this internationally recognised standard.
SOLIT² Guidelines, worldwide
The German SOLIT² guideline, which is supported by ITA-COSUF (the sub-group “International Tunnel Association”) and is referenced in NFPA 502, provides a comprehensive framework for fire testing, design, installation, operation and maintenance of fire suppression systems for tunnels. It also demonstrates how fixed fire-fighting systems can positively influence the overall tunnel safety strategy by partially or completely replacing other safety measures. The specific guidelines set out in the SOLIT2 guide have increasingly been incorporated into planning and tender documents in recent years.
RABT and EABT 80/100, Germany
In Germany, the RABT and EABT 80/100 recommend the provision of fixed fire-extinguishing systems for certain types of tunnels and design fire loads of 100 MW or more. These have been superseded by the RE ING, which adopts the same safety approach with regard to fire-fighting systems. Their ability to contain the spread of fire, support emergency response measures and minimise structural damage is recognised as part of the overall tunnel safety concept.
PIARC, worldwide
PIARC (World Road Association) has further strengthened its positive stance on fixed fire-fighting systems in recent years. Based on international experience, PIARC recognises fire-fighting systems as an effective risk-mitigation measure that improves user safety, extends the time available for evacuation and protects the tunnel infrastructure.
RVS 09.02.51, Austria
The Austrian guideline RVS 09.02.51 describes, amongst other things, further benefits of fire-fighting systems for tunnels, including the reduction of radiant heat, lower smoke generation and the potential to optimise other technical safety measures such as ventilation systems, distances between emergency exits and structural fire protection.
UPTUN, Europe
Similarly, the European UPTUN consortium has, as part of a joint research project based on extensive full-scale fire tests, drawn up technical guidelines defining minimum requirements and best practices for water-based fire suppression systems in tunnels.
Although national regulations still vary from country to country, the general direction within the international tunnelling industry is clear: worldwide, tunnelling authorities and infrastructure operators are increasingly relying on the aforementioned internationally recognised standards and technical guidelines when implementing fixed fire-fighting systems. This brief overview is also intended to provide guidance to those in countries where local standards and guidelines may not yet be available.
The successful deployment of the FOGTEC water mist system in the Dwarka Tunnel therefore confirms what international research, testing and standards have demonstrated for many years: well-designed high-pressure water mist systems effectively combat tunnel fires, improve personal safety and protect critical infrastructure.
