Rigorous Testing Means Better Fire Suppression

Bus fires happen, and they happen frequently as can be confirmed by a quick search of the internet. These fires endanger lives, disrupt traffic often at key locations and times, and have a negative impact on the reputation of the operator. 

What is interesting though, is the fact that protected buses also catch fire – but those fires do not make the news. With the protection of a fire system on board, the fire is quickly and effectively dealt with – and from an outside view, the view of the incident is reduced to more of a mechanical failure (of which few take notice) versus a fire which carries with it all of the negative impacts mentioned.

Fire systems are more than just a check box on a spec sheet. The presence of the system can have a real impact on operator and rider safety as well as costs and financial impacts.


SPCR 4912 and Testing Standards

SPCR 4912 was the first testing designed specifically for the evaluation of fire systems on buses – testing them against a variety of different fire scenarios commonly found on buses – from small fires and little airflow, to large hot fires with high airflow, and even hidden fire, where the fire is located in a place where it is segmented away from the larger engine bay, largely shielded from the fire nozzles.

Testing of a system is conducted by authorized independent testing bodies who certify that the system is installed within the parameters established in 4912. The testing report can then used to apply for either a P Mark 183 certification, which was the initial and more rigorous standard, or the follow-on UNECE R107, which is now a requirement for buses in Europe.

The testing for buses has not changed since the development of the program, however, 4912 has been used as the basis for other standards, such as the P Mark 199 standard for heavy equipment.

What has changed, or really what has been added to the P Mark 183 certification, is a grading scale. 

Initially, a system was seen to pass if it received a score of 6 or higher on specific test elements of 4912. Essentially, this means that four scenarios could be a failure. For systems which passed all the testing, this seemed a little unrepresentative of the performance. Subsequently a grading system, much like has been used on schools for years on a A to F basis, was applied.

Reacton is an automatic fire system that, in buses, typically utilizes dry chemical powder (while Reacton has access to a variety of agents, the results of the 4912 testing – across multiple manufacturers and agent types – has demonstrated to us that powder is the overall most effective in a bus engine environment).  At the heart of our system is a pneumatic pressurized detection tube that is tolerant of the heat of the engine and also the dirt grime and the cleaning of the engine, but reacts quickly and accurately to a small but growing fire. While tubing is used commonly in bus engines, our system valve is uniquely designed so that if there is a small leak, it will not cause the system to false activate. While new to the U.S. market, Reacton is by no means a new system, with a 30-year pedigree in the protection of heavy equipment and mobile assets throughout Europe. It also has a variety of system add-ons to alert the driver or allow the, to activate the system.

We are proud that our systems achieved an A+ rating with all tests passed, but also humbly suggest that the scoring and performance be a key part of the system selection process. Many of the systems available today scored much lower.

Most importantly I would suggest following Europe’s lead, that safety should not be just an option. Beyond that, take the time to learn the options, the performance, and the long-term cost of ownership of the system… the initial price tag shouldn’t be the single selection factor.


Scott Starr is vice president of Americas for Reacton Fire Suppression. Visit www.reactonfire.com for more information.

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