Firefighters around the world mourn the loss of Paul Grimwood - UK pioneer in fire gas cooling

The fire service community around the world mourns the passing of Paul Grimwood, a legendary author and instructor whose contributions to fire safety, firefighting tactics, and firefighter education have left a huge mark on the profession. 

Dr Paul Grimwood passed away at the age of 71, reportedly after a short period of illness on Wednesday September 25, 2024.  

The news of Dr Grimwood's passing has led to an outpouring of tributes from fire professionals and volunteer firefighters from around the world. 

Paul Grimwood´s pioneering work, especially in fire gas cooling and compartment fire tactics, transformed firefighting, and his teachings live on in every fire department that has adopted his methods. 

CTIF's former president Tore Eriksson was one of Paul Grimwood's early inspirations, along with other Swedish pioneers in the field, such as Krister Giselson and Mats Rosander.

Grimwood, known for his groundbreaking work in fire behaviour and firefighting strategies, leaves behind a legacy that will continue to shape fire services for generations to come.

Photo Credit: Private photos of Paul Grimwood in 2015, from his Facebook account. 

Renowned author and lecturer

Paul Grimwood is perhaps best known for his numerous books and articles, which have become foundational texts for fire services across the globe. His writing helped bring clarity to the complexities of fire dynamics and provided innovative solutions for dealing with dangerous fire scenarios. 

Among his most notable works is *“Fog Attack”*, published in 1992, which introduced revolutionary ideas about fire attack strategies to an international audience, after being inspired by Swedish pioneers Krister Giselson and Mats Rosander. 

In his book, Grimwood advocated for the use of water fog and mist to control fire gases, a method that significantly reduces the risk of backdrafts and flashovers. His concepts were met with initial resistance but eventually became widely accepted, fundamentally altering how firefighters approach interior firefighting. The book is still considered essential reading for firefighters and instructors today.

Another key work was *“3D Firefighting: Training, Techniques, and Tactics”* (2005), co-authored with other prominent fire professionals. This book further expanded on the concepts of gas cooling, fire behavior compartmentalization, and safe approaches to modern firefighting. Grimwood's focus on three-dimensional firefighting not only improved tactical approaches but also saved countless firefighter lives by reducing exposure to dangerous fire conditions.

Grimwood's *“Euro Firefighter”* series also became essential resources for firefighters, with the first book released in 2008. These works documented his experiences and innovations throughout Europe, offering insight into different firefighting techniques used across the continent. The Euro Firefighter series emphasized international cooperation and learning, making Grimwood a respected figure not only in the UK but globally.

From Sweden to the UK - and to the World

Paul Grimwood’s introduction to fire gas cooling techniques came during the 1980s, through his keen interest in international firefighting methods and his commitment to improving firefighter safety. At the time, fire services in Sweden were developing innovative approaches to firefighting, particularly focusing on the dangers of fire gases and flashovers. 

Swedish fire researchers and firefighters had been pioneering new strategies, such as water mist or fog nozzles, to control fire gases in confined spaces, reducing the risk of explosive fire events like flashovers and backdrafts.

Grimwood, already an experienced firefighter and officer in the UK, recognized the potential of these techniques to revolutionize fire attack strategies. Intrigued by the success of Swedish methods, he traveled to Sweden and immersed himself in their research and practical applications. He studied the work of Swedish firefighting experts who were pushing the boundaries of fire behaviour science, particularly around compartment fires and the management of superheated gases that lead to dangerous phenomena.

As early Swedish pioneers in fire gas cooling, Krister Giselson and Mats Rosander, along with other Swedish firefighting professionals, had been working on ways to manage fire gases in compartment fires, focusing on reducing the risk of flashover and backdrafts, which were significant dangers to firefighters in enclosed spaces. 

The Swedish Model of Interior Offensive Firefighting

Their development of the fog nozzle technique and fire gas cooling strategies caught Grimwood's attention as he sought new methods to improve firefighting safety in the UK.

Paul Grimwood's relationship with Swedish firefighters Krister Giselson and Mats Rosander was one of professional collaboration and mutual respect. Both Giselson and Rosander were instrumental in developing and advancing firefighting techniques in Sweden, particularly in the areas of fire gas cooling, compartment fire behaviour, and the use of water mist for firefighting. Their pioneering work helped shape modern firefighting tactics, and they became influential figures in the global fire community.

Grimwood, who was deeply interested in improving firefighting safety and tactics, encountered Giselson and Rosander during his exploration of fire gas cooling techniques in Sweden. Both Giselson and Rosander were heavily involved in the research and practical application of advanced firefighting techniques during the 1980s and 1990s, and their work in Sweden inspired Grimwood’s own research and subsequent writings on the topic.

Grimwood learned extensively from Giselson, Rosander, and their Swedish colleagues, adopting and refining their techniques to suit firefighting conditions in the UK. He incorporated their ideas into his own firefighting practices and teachings, which he detailed in his seminal book, “Fog Attack”, published in 1992. 

The relationship between Grimwood and these Swedish pioneers was built on shared knowledge and the common goal of enhancing firefighter safety through innovative fire behaviour research.

Though Grimwood, Giselson, and Rosander operated in different countries, their collaboration helped bridge the gap between Swedish and British firefighting tactics. 

Grimwood’s promotion of fire gas cooling and compartment firefighting techniques on the international stage was a testament to the profound influence that Giselson and Rosander had on his work. In turn, Grimwood helped spread their ideas to a wider global audience, cementing their importance in the evolution of modern firefighting strategies.

By learning directly from Swedish instructors and participating in hands-on training, Grimwood adopted and refined the practice of fire gas cooling, using high-pressure water sprays to rapidly reduce the temperature of fire gases. He then began to test and apply these tactics back in the UK, further developing them in a way that suited the different building structures and firefighting conditions there.

Grimwood’s landmark 1992 book, “Fog Attack”, was a direct result of this exposure to Swedish firefighting techniques. He effectively translated the principles of fire gas cooling into a context that could be applied across fire services worldwide. 

This was one of the first major efforts to bring Sweden's innovative firefighting methods to the attention of the broader international firefighting community. 

Through his work, Grimwood helped popularize fire gas cooling, which today remains a cornerstone of modern firefighting, particularly in interior fire attack scenarios.

CTIF Connections through Tore Eriksson - an early student of Giselson & Rosander

Tore Eriksson, a former fire instructor from Sweden, (as well as CTIF´s President between 2012 - 2020) further developed and refined these techniques in his work, particularly focusing on the practical application of fire gas cooling as a safer and more efficient method for interior firefighting. 

Paul Grimwood met Tore Eriksson early during his Swedish research, and Eriksson was one of the flashover instructors Grimwood met at the Sandö Fire College, and who inspired him to bring these techniques and theories to the UK. 

Flashover is a critical and dangerous phase in compartment fires, where all combustible materials in an area ignite almost simultaneously due to intense heat. Understanding and controlling this phenomenon are essential for firefighter safety, and Eriksson's training programs focused on equipping firefighters with the knowledge and techniques to recognize and prevent flashovers.

 Tore Eriksson’s relationships with fellow Swedish firefighters and researchers, Krister Giselsson and Mats Rosander, therefor played a significant role in refining and disseminating fire gas cooling techniques to the world, beginning with Paul Grimwood. 

Eriksson's research and field experience helped systematize the approach, ensuring that fire departments could apply these techniques in a structured manner. His work in Sweden with the Swedish Rescue Services Agency helped propagate these methods across Europe.

Tore Eriksson played a pivotal role in introducing and developing flashover training programs in Spain. His expertise in fire behavior and his pioneering work in fire gas cooling techniques were instrumental in shaping these training initiatives.

Both Eriksson and Grimwood worked in parallel, with Grimwood introducing and advocating for concepts of fire gas cooling, while Eriksson was enhancing, refining, and practically implementing those ideas within Swedish firefighting protocols. Their contributions were complementary, leading to a broader acceptance and use of fire gas cooling techniques globally. Together, they are considered key figures in advancing the science and tactics of fire gas management in interior firefighting operations.

In Spain, during the 90s and the early 2000s, Tore Eriksson collaborated with local fire services to set up realistic flashover training scenarios, often using purpose-built containers, specialized training structures or even burning in abandoned villages slated for deconstruction. These controlled environments allowed firefighters to experience the intense heat, smoke, and rapid-fire development associated with flashover conditions while practicing techniques like fire gas cooling and tactical ventilation. 

Eriksson emphasized the importance of controlling fire gases with pulsed water fog applications to manage heat and smoke, thereby delaying or preventing flashover.

His approach to flashover training also stressed the importance of safety and decision-making under pressure. He helped firefighters understand how to recognize the early warning signs of flashover, such as rollover (the ignition of fire gases overhead) and rapidly rising temperatures, and how to use these insights to protect themselves and manage fire development.

Tore Eriksson's work in Spain was highly influential in raising the technical proficiency and safety standards of firefighters dealing with interior firefighting operations, particularly in challenging compartment fire scenarios. His contributions to flashover training in Spain have had a lasting impact on the country’s firefighting methods, enhancing both firefighter safety and operational effectiveness.

Text By Björn Ulfsson / CTIF