Fires in vehicles have been happening for a very long time. However, some of the major incidents like the recent bus fire near Hyderabad forces us to think that with rapid technological advancements what could be done for risk mitigation and to ensure that such tragedies are minimised and completely eliminated.
It was in 2005 that the SP Technical Research Institute in the city of Borås in Sweden set one fully-built passenger bus on fire at its research lab to test the efficacy and functionality of fire safety in buses and coaches. The test was carried out on behalf of the Swedish Road Administration and Norwegian Public Roads Administration.
This test resulted in many interesting findings and technology interventions to improve fire safety for buses.
Today, if we take a closer look at passenger and goods transportation, on almost all fronts, India has progressed well in terms of infrastructure, road network, technologies, knowledge and awareness, world class travel experience, greater comfort level, reduced travel time, intelligent transport system, etc. The Automotive Mission Plan (AMP-2016) was formulated with long-term objectives in terms of higher revenue generation, GDP contribution and employment generation leading to tremendous contribution from the Indian automotive sector to economic development, overall growth and, most important, sustainable mobility.
With liberalisation and major investments, India can boast of having the second largest road network with around 3.3 million km road length carrying almost 85 per cent of passenger traffic. Around 80,000 km of National Highway with world class road infrastructure has led to higher average road speed from the earlier range of 15-20 kmph. Today on certain stretches, buses could even cross 100 kmph speed!
When you travel at such a high speed on good roads, in line with the NHAI standards, various design, construction, technical and safety parameters are also in place to ensure seamless safety on highways during travel.
When it comes to vehicular technologies, world class OEMs like Volvo, Scania and Mercedes and now Tata Motors and Ashok Leyland have introduced new generation passenger buses in the market. The average torque and horsepower output has increased almost 2-2.5 times for 2-axled 16.2 tonnes GVW buses.
These drivelines with extremely high level of reliability started offering much higher 
average travel speed and completely new experience for travellers in India. The high technical requirements were built into vehicles to meet and exceed CMVR values for emission, safety, performance, etc. In fact, the Bus Body Code is also an initiative in the same direction.
Finally, to handle and mange such a mobility situation, drivers are also trained not only to operate the new generation machines with different transmission systems, electronic controls, etc., but even get trained to handle any emergency situation in case of an accident, fire, etc.
Another technical aspect is CNG fuel widely used in New Delhi and a few other cities which would require great care and attention for fire safety on roads.
Besides all these infrastructure, technologies and training interventions, fire safety is an important aspect of road travel in today’s situation, requiring greater public attention and higher priority.
SP Technical Research Institute of Sweden started focusing on fire safety since 2005 with fire analysis and risk assessment of vehicles in the country. Its research initiatives brought out numerous reasons for the ignition of buses and coaches which could be heat, vibrations, material fatigue, malfunctioning, inadequate maintenance, faulty electrical systems, etc.
As per research findings, fire in most of buses and coaches starts from the engine compartment or surrounding areas. Fires can also start in the electrical / electronic systems and wheel houses with rim and tyres. With extensive research, SP Technical Research Institute has gained significant insight and experience in testing of electrical wire harness, cables, hoses and other components which could be the source of fire hazard.
The fire risk, being quite complicated, depends on multiple factors, including design, functionality, properties. In fact, the Institute, after studying the weak points and vulnerable areas, has embarked on Working on general safety provisions of buses at UN ECE, Geneva.
In vehicle safety, fire risk assessment entails consideration of both the hazard of fire, including 
ignition risk, fire performance of materials, heat transportation, in and around hot spots in the vehicles. Similarly, based on research findings that the engine compartment could be a critical area, all Swedish insurance companies have made it mandatory for all buses and coaches to be fitted with an approved fire suppression system in the engine compartment. Since implementation of this system, there has been no total loss due to bus fires so far.
The study also revealed some more interesting findings like internal materials used in the buses and coaches. Interior materials are tested as per the ISO standards which indicate the flame spread, smoke generation, analysis of toxic gases, and finally the very important aspect related to heat evolution from burning seats.
The absorbent materials are tested and measured for heat release rate and smoke evolution. Also, barrier structures also ensure that the fire spread is minimised or prevented from one part to the other part of buses. The key parameters and properties that are evaluated are integrity, insulation performance and smoke resistance.
Fuel tanks are also tested for fire hazards material of construction, leakage bursting characteristics, etc. Fuel hoses, filters, etc., are also tested to verify their retention function and fuel-tightness. Airbags and seat belts tensioners are also tested to meet fragmentation properties.
The full-scale tests show that once flames reach the passenger space, flashover will occur within a moment. Current requirements for interior materials (UNECE Regulation 118) only require them to pass a simple horizontal spread of flame test (FMVSS 302). This is clearly insufficient, as even materials with poor fire performance can be approved.
The fire safety requirements for other means of mass transportation such as trains, passenger ships and airplanes are considerably 
more stringent. The latest computer mumerical fire simulation using the CFD analysis predicts heat and gas evolution as well as sources of ignition. Thermal properties of textile materials, composites at high temperature and pressure, polymer materials, etc., also provide deeper insight.
Standards for suppression systems, a new approach
Extensive research, investigations and testing indicate that some of the effective measures could be engine compartment fire suppression system, alternate interior materials, flame propagation retardation and shielding of hot surfaces. In the absence of an international standard for evaluating fire suppression systems, SP has developed a test standard that can be used when specifying requirements for their efficacy and function. This work has been carried out on behalf of the National Road Authority in Sweden.
The objectives of this project have been to create a safer environment for passengers and bus drivers worldwide, reduce loss of property, and to design a standard that will evaluate the fire-fighting performance of different fire suppression systems in a well-defined, objective and comparable way.
The new standard SP method published in 2012 describes a new means of testing and validating the fire suppression performance of different suppression systems in a repeatable and reproducible way. An engine compartment mock-up was built where the impact of various parameters was examined.
It should be noted that real bus engine compartments differ quite substantially from one another depending on the type of the vehicle and the manufacturer. However, the aim was to design an enclosure with “typical” bus engine compartment characteristics (enclosure size, hot surfaces, obstructions, ventilation and openings) rather than a replica of a specific engine type.
A broad reference group, including more than 80 companies such as bus manufacturers and operators, transport authorities, insurance companies, fire investigators and suppression system manufacturers, have given valuable feedback for the development of the test method. More than 450 pre-tests have been performed involving 10 fire suppression system manufacturers and several types of suppression agents.
P-mark, a voluntary certification / quality mark
The main objective of the research leading up to the standard development has been the promulgation of this standard at the UN ECE Working Group on General Safety Provisions (GRSG) in Geneva. SP will submit a proposal, through the Swedish Transport Agency, for amendment of the UN ECE Regulation 107 at the GRSG meeting during Spring 2014. If this is adopted, then installation of fire suppression systems in engine compartments will be mandatory for all single-deck, double-deck, rigid or articulated vehicle of category M2 or M3. This is on the assumption that the member-State is one of the contracting parties that have signed and agreed to the UNECE Vehicle Regulations – 1958 Agreement.
In parallel, SP has established a voluntary certification/quality mark for the industry – the P-mark – according to SPCR 183 (SP Certification Rules) in view of the fact that progress through GRSG can be protracted. To obtain a P-mark in accordance with SPCR 183, the fire suppression system will need to fulfill the requirements in SP method 4912 in which the capability of the system to extinguish different types of fires is evaluated. In addition, the components included in the system are tested for harsh environments such as vibration and corrosion. A risk assessment at installation is also required in order to identify fire hazards and dangers. It would be documented as to how each particular hazard is handled.
The benefits from fire suppression systems are many. You will allow safe escape for the most vulnerable passengers, i.e., disabled and older people as well as school children, effect much get reduction in loss of lives, buses and societal costs, secure business continuity, and enhance general goodwill.
By adopting the P-mark the industry can be assured that the systems maintain a good level of quality and safety (www.sp.se/safebus).
Fire safety activities around the world
Israel: Of late, there have been a lot of bus fires in Israel. A statement from Fire Chief Shahar Ayalon issued a couple of months back threatened to close down the Egged transportation co-operative if fire suppression systems are not installed in buses. Further, on March 11, the Israeli Ministry of Transportation, Road Safety and Infrastructure announced that the Ministry had decided to make fire extinguishing systems compulsory on all buses. Israel is thus the first country in the world that will legislate on installation of fire suppression systems on buses.
Israel is now developing a new standard. SP met with the Steering Committee for this project in June and presented the P-mark with the intention to make Israel simply adopt the P-mark rather than to “invent the wheel once more”. Discussions are in progress.
Australia: There are almost 70 bus fires every year in Australia, according to The Australian Bus Industry Confederation (BIC). Three major fires on buses were fuelled by compressed natural gas in the past four months. This led to the Transport Workers Union in West Australia threatening to strike unless Perth’s 550-strong gas bus fleet was taken off the road at the beginning of the year.
Following this, acting Transport Minister Kim Hames said on March 26 that AUD 1.4 million would be spent on improving fire suppression equipment on buses. BIC has also started developing a Bus Industry Advisory on Bus Fire Mitigation. The main objective is to reduce or mitigate the risk of fire and, should a fire occur, what steps need to be taken to minimize the risks. The Bus Fire Mitigation will be based around maintenance and fire suppressant options and procedures for vehicle evacuations.
Representation has been made to the Federal Government and other departments regarding the need to ensure reasonable changes in vehicle design to reduce fire risk and control spread of fire.
The SP technical team met with the Steering Committee for this project in July and presented the P-mark. Hopefully the P-mark will be adopted in the Bus Fire Mitigation document. Discussions are still in progress.
USA: On September 23, 2005, there was a major bus fire in Wilmer, TX, where 23 nursing home passengers were fatally injured. After this, the Volpe National Transportation Systems Center carried out a study for the Federal Motor Carrier Safety Administration (FMCSA). The objective was to gather and analyze information regarding the causes, frequency and severity of motorcoach fires that are caused by mechanical or electrical failure. Based on this study the US Department of Transportation issued a Motorcoach Safety Action plan. In this plan the National Highway Traffic Safety Administration (NHTSA) identified upgrading motorcoach fire safety requirements as a priority safety area, and as part of this to evaluate the need for a Federal Motor Vehicle Safety Standard that would require installation of fire detection and suppression systems on motorcoaches.
In 2008 NHTSA initiated a two-year fire safety research program with the National Institute of Standards and Technology (NIST). Its objectives were to better understand wheel well fires, their spread into the passenger compartment and tenability of the passenger compartment due to such fires as well as and countermeasures and detection systems.
In 2012 NHTSA once more issued a Motor Coach Fire Safety Research Solicitation in which it was specifically pointed out that more research specific to fire detection, fire suppression and test procedure development was needed. This project was awarded to Southwest Research Institute in San Antonio, TX.
Finally, buses and coaches with engine fire extinguishing systems, more than one door for entry-exit, trained driver / conductor and specially selected interior materials could not only minimize fire risk but facilitate quick evacuation of buses and coaches in the event of any unfortunate fire hazards.
Though a lot of studies analyses and results are now available on a continuous basis, it is worthwhile setting up an expert committee to go deeper into this issue and come out with recommendations and a road map for introduction of fire safety measures similar to fuel emission.