NISTIR 7406

Vehicle Fire Suppression Research Needs

Anthony Hamins

NISTIR 7406

ii

U.S. Department of Commerce 

Carlos M. Gutierrez, Secretary 

Technology Administration 

Robert Cresanti, Under Secretary of Commerce for Technology 

National Institute of Standards and Technology 

 William Jeffrey, Director

March 2007

Vehicle Fire Suppression

Research Needs

Anthony Hamins

Vehicle Fire Suppression Research Needs

Anthony Hamins

Fire Research Division 

Building and Fire Research Laboratory 
Vehicle Fire Suppression Research Needs 

Submitted to 

Motor Vehicle Fire Research Institute (MVFRI) 

1334 Pendleton Court 

Charlottesville, Virginia 22901 

March 1, 2004

Revised: March, 14 2007 

Abstract 

This report identifies research needs in automotive fire protection. The work focuses on 

the problem of post-collision vehicle fires. Recent fire suppression research is cited with 

special attention given to results cited in the scientific literature as well as relevant 

reviewed manufacturer information. The report is broken into several sections that 

include background information on the post-collision vehicle fire problem, a summary of 

previous suppression research in vehicles, recent fire suppression research, in general, 

and specific suggestions for further post-collision vehicle fire suppression research that is 

needed. The results of a workshop on “Fire Suppression Research Needs” that took place 

during the 2005 SAE World Congress is described. Several Appendices reproduce 

pertinent information, regarding suppression technologies for vehicle fire applications, 

which were obtained on the internet and in this sense act as an archive. 

iii
Table of Contents 

 Abstract ..................................................................................... iii 

1. Background ................................................................................... 1 

2. Current and Previous Fire Suppression Research .................................... 3 

2.1 The Search for Halon Replacements and Alternatives ............................. 3 

2.1.1 The Halon Replacement Program ......................................... 3 

2.1.2 The Next Generation Fire Suppression Program (NGP) ................ 4 

2.1.3 Conferences and Workshops on Fire Suppression Research ............ 4 

2.1.4 Aircraft and Automobile Fire Protection ................................... 5 

2.2 Commercially Available Fire Suppression Technology ........................... 6 

2.3 Technology Assessment for Vehicle Fire Protection ................................. 7 

2.4 Ford Fire Suppression Research for Post-Rear-Impact fires in the Crown Victoria 

Police Interceptor ....................................................................... 8 

2.5 Other Recent Fire Suppression Experiments......................................... 10 

2.6 Powder Panels ........................................................................... 11 

2.6.1 Operation .......................................................................... 11 

2.6.2 Previous Vehicle Fire Testing Using Powder Panels ........................ 12 

3. Ideas for Vehicle Fire Protection Research Directions ................................... 13 

3.1 The Character of Post-Collision Fires .............................................. .. 13 

3.2 Workshop on Vehicle Fire Suppression............................................... 16 

3.3 Development of Standardized Fire Suppression Test Protocols .................. 17 

3.4 Fire Suppression Systems ............................................................ 19 

3.4.1 Powder Panels .................................................................... 20 

3.4.2 Foams .............................................................................. 20 

3.4.2.1 Foam Freeze Protection ............................................. 21 

3.4.3 Solid Propellant Generators and Their Hybrids ............................... 22 

3.4.4 Other Suppressants ................................................................ 22 

3.5 Other Issues ......... ..................................................................... 23 

3.5.1 Economic Survey ................................................................. 23 

3.5.2 Firewall on Demand............................................................... 23 

3.5.3 Crashworthiness .................................................................... 23 

3.5.4 Computer Fire Models............................................................. 23 

3.5.5 Passive Fire Protection ............................................................ 24 

4. Summary and Recommendations............................................................. 24 

5. References ....................................................................................... 25 

Appendix A. Naples Daily News article on the suppression system on Ford’s Crown 

Victoria Police Interceptor, August 7, 2003 .................................................. 27 

Appendix B. Ford Motor Co. Information on Fire Suppression,........................... 29 

iv
Appendix C. Ford Motor Co. News Release of July 28, 2006 ............................ 32 

Appendix D. Information on Ford’s Automatic Fire Suppression System ............... 34 

Appendix E. Summary of Workshop on Research Needs for Suppression of 

Vehicle Fires ................................................................................... 42 

v
Vehicle Fire Suppression Research Needs*

 

This report identifies research needs in automotive fire protection with an emphasis on 

fire suppression. The report focuses on the problem of post-collision vehicle fires and is 

broken into several sections including background information on the post-collision 

vehicle fire problem, a summary of previous suppression research in vehicles and recent 

fire suppression research in general. Recent fire suppression research is cited with special 

attention given to results in the open scientific literature as well as relevant manufacturer 

supplied information. Specific suggestions for further post-collision vehicle fire 

suppression research are made. The last section lists cited references. A number of 

appendices are also included. The first four reproduce information found on the internet, 

are also included. The last one summarizes the results of a workshop on automobile fire 

suppression. 

1. Background 

Fires in vehicles that are not involved in a collision can be costly in terms of repairs, but 

are not typically a concern in terms of life safety. In a post-collision vehicle fire, 

however, egress from a vehicle may be impossible and therefore the fire can be the most 

significant event leading to a fatality. In cases involving a post-collision vehicle fire, the 

presence of an effective fire suppression system would be highly beneficial in reducing 

fatalities. 

The post-collision vehicle fire problem is unique. Consideration of the details of the fire 

scenario is important in the search for possible solutions. A post-crash vehicle fire, 

unlike many other fire scenarios, is characterized by several problems that combine to 

create a complex and challenging situation for active fire protection. Each of these 

challenges restricts the range of possible fire suppression options. They include the 

following: 

• The post-collision vehicle fire problem is not well documented. In particular, early 

fire time lines have not been adequately researched, so that there is little information 

regarding the initial fuel (motor oil, gasoline, transmission fluid, power steering fluid, 

etc.), its relative location, spatial distribution, and volume. The best available study is 

 

*

 This report was financed by the Motor Vehicle Fire Research Institute (MVFRI) to assist in the 

identification of research needs in automotive fire protection. The National Institute of Standards 

and Technology (NIST) is applying its expertise in fire science to this program because of the 

potentially high impact of this program on vehicle fire safety in the United States. In analyzing 

data available in the literature, certain vehicles, equipment, instruments, or materials are 

identified in this report in order to specify the experimental procedure adequately. In no case does 

such identification imply recommendation or endorsement by the National Institute of Standards 

and Technology, nor does it imply that the fire safety of a particular vehicle is superior or inferior 

to any other. In addition, certain trade names and company products are mentioned in the text to 

specify adequately the experimental procedure and equipment used or to identify types of 

currently available commercial products. In no case does such identification imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that 

the products are necessarily the best available for the purpose. 

1
that of Scheibe et al., [2001], which contains 35 case studies. It may be the best 

documentation in the literature of ignition source and first fuel. 

• The geometry of every vehicle make and model differs, which can influence ignition, 

fire spread and growth. 

• Post-crash vehicle fires differ from fires in intact vehicles, as the geometric 

configuration may be modified by the collision in ways that cannot be precisely 

defined beforehand. 

• Suppression system placement is restricted by limitations associated with vehicle 

function and crash survivability. 

• Practical considerations limit the mass and volume of an on-board suppression 

system. 

• Ambient factors such as temperature, wind, and incline of the road may impact 

suppression system performance. 

• Vehicle fires occur in a compartment that is partially open to the environment, which 

can lead to suppressant loss. 

• The particular crash scenario will govern the rate and relative location of fuel leakage, 

and these details will influence the severity of the fire and the probability of

successful fire suppression. 

• A high-speed vehicle crash can lead to vehicle movement tens of meters from the 

location of the collision, over a period of several seconds. Once the vehicle is 

stationary, a trail of fuel may extend beyond the vehicle footprint, due to fuel leakage 

during vehicle movement and/or due to the incline of the road surface. 

• Depending on the collision scenario, it is also possible that a pool fire could be 

situated around the footprint of a vehicle tire. A tire would create a large flow 

obstacle for a stream of suppressant, making suppression more challenging. 

• The time of initiation of a fire after a collision can vary. A fire can begin immediately 

after a collision or several minutes later as was observed in a front-end barrier crash 

that was conducted as part of the DOT/GM Agreement [Jensen et al., 1999]. In that 

event, an energized, collision-damaged, thermoplastic battery case was observed to be

the initial fuel source. 

There are several modes of post collision vehicle fires, including frontal collision 

underhood fires, rear collision fuel-fed fires, and rollover fires. Front collision 

underbody fuel-fed fires also occur. Rollovers fires are more frequent then fires in rear 

collisions and about half as frequent as fires in frontal collisions. About half of the 

rollovers have other collisions prior to the rollover which adds to the complexity of the 

scenario. Most rollover fires occur with the vehicle on its side or roof. Consequently, 

vehicle orientation needs to be considered in a fire suppression system. 

For simplicity, this report focuses on frontal collision underhood fires and rear collision 

fuel-fed fires, Some differences between these configurations are evident: 

• there is less distance traveled after frontal collisions. 

• fuel trails may be less important in frontal collisions. 

• underhood fluids may play an important role in fires after a frontal collision. 

• many more and different ignition sources play a possible role in underhood fires. 

2
Understanding the differences between these two types of post-collision fires is important 

in trying to develop practical and effective mitigation strategies. Rear end fuel-fed fires 

can be characterized as unconfined, that is the fire is not contained in a closed 

compartment. Underhood fires, on the other hand, occur in a compartment that is only

partially open to the environment. Suppression in the open is more challenging as 

suppressant unless deliberately directed, will not flow towards the fire source. 

2. Current and Previous Fire Suppression Research 

To appreciate the range of possible solutions that may address the automobile fire

suppression problem, it is instructive to understand applicable technology developments 

and recent fire suppression research efforts in related applications as well as research 

specifically focused on vehicle fire protection. 

2.1 The Search for Halon Replacements and Alternatives 

Fire suppression research has been conducted over the last one-hundred years, but not 

with the level of support as provided by the recent search to find a suitable replacement 

for the fire suppression agent, halon 1301 (CF3Br). Over the last ten plus years, a global 

effort has been in place to find a halon replacement, whose manufacture was halted due 

to its deleterious effects on stratospheric ozone. In the U.S., much of the work was 

sponsored by the Department of Defense (DoD), which has conducted fire suppression 

research primarily to protect the integrity of various types of weapon systems and 

focused mainly on aircraft fire suppression. The research on halon alternatives has 

revitalized fire suppression research, illuminating many new concepts for fire suppression 

applications. 

The Halon Replacement Program for Aviation and the Next Generation Program (NGP) 

focused mainly on aircraft fire suppression. Research on halon alternatives has 

revitalized fire suppression research, illuminating many new concepts for fire suppression 

applications. 

The research conducted through the NGP and Halon Replacement programs and that 

presented at the Halon Options Technical Working Conference (HOTWC) provide 

valuable information relevant to the vehicle fire problem. The lessons learned through 

the DoD work provide a basis for developing strategies to address vehicle fire protection. 

Indeed, much has been learned through both the successes and the failures of the DoD 

sponsored projects As many of the same challenges and issues are common to the aircraft 

and vehicle fire suppression problems. 

2.1.1 The Halon Replacement Program 

The DoD, in conjunction with the U.S. Federal Aviation Administration (FAA), and the 

aviation industry, sponsored the Halon Replacement Program for Aviation which 

provided support for a large number of fire suppression related projects. The work 

involved the selection of one chemical from a large list of possible replacement agents for 

halon 1301. 

3
The Halon Replacement Program attempted to evaluate many fire suppression chemicals 

for selection as a halon replacement, until a better long-term solution could be found. The 

Program also supported research to determine the most significant factors, which would 

impact the quantity of an agent required to suppress a fire. A major outcome of the 

program was the development of knowledge to specify engineering criteria for 

suppression system design. This allowed system designers to estimate the amount of 

agent needed to provide equivalent aircraft protection as was afforded by halon 1301. 

2.1.2 The Next Generation Program 

As a follow-up program, the Next Generation Fire Suppression Technology Program

(NGP) was sponsored by the Strategic Environmental Research and Development 

Program (SERDP), and under the auspices of the U.S. Department of Defense (DoD), 

Department of Energy (DoE), and Environmental Protection Agency (EPA). The goal of 

the NGP was to develop and demonstrate, by 2005, technology for economically feasible, 

environmentally acceptable and user-safe processes, techniques, and fluids that meet the 

operational requirements currently satisfied by halon 1301 systems. Originally, the 

Program addressed aircraft, ships, land combat vehicles and critical mission support 

facilities. Whereas fire suppression in these DoD applications differs in many respects 

from the automobile fire suppression problem, there are also similarities. 

The topics covered by NGP have included new flame suppression chemistry, the 

development of suppressant screening tests focused on aircraft applications, new and 

improved aerosol suppressants, improved suppressant delivery, viability of new 

suppressant technologies, and improved fuel tank inertion. Recent studies in flame 

suppression chemistry have investigated low boiling point compounds, the effectiveness 

of fluoroalkyl phosphorus compounds, and agent stability during long-term storage. 

Research on improved suppressants has investigated solid propellant fire extinguishers, 

the dispersion of suppressants at low temperature, suppressant dynamics, enhanced 

powder panels, mechanisms of unwanted accelerated burning, enhanced extinguishment 

using intumescent coatings, suppressant concentration measurements, analysis of the 

world of useful chemicals, identification of possible alternative suppressants, a suite of 

screening tests and guidance for their use, methods for determining and comparing the 

total life-cycle costs of new fire suppression technologies, and identification of 

diagnostics needed to characterize the outcome of fire tests. A number of these 

investigations have bearing on the vehicle fire suppression problem and are discussed 

below. 

2.1.3 Conferences and Workshops on Fire Suppression Research 

Industry, academic institutions, and international organizations have conducted fire 

suppression research, beyond the Halon Replacement Program and the NGP Program. 

Much of the most important recent fire suppression research is documented in the 

proceedings of the Halon Options Technical Working Conference [HOTWC, 1991-

2006], an annual conference that was dedicated to applied fire suppression research. 

Since 1991, conference papers have addressed a variety of relevant topics, including 

4
advanced chemicals and agents, total flood applications, passive fire suppression, 

suppressant mixtures, water mists and sprays, and non-halon alternatives. Other national 

and international conferences and workshops on combustion and fire research have 

included papers on fire suppression, although there have been few studies that directly 

address vehicle fire suppression research1

. Some of these conferences have had entire 

sessions devoted to fire suppression research, but the emphasis has usually been on 

structural or residential applications, typically involving water sprinklers or water mist. 

In addition, there are many international journals that address fire and combustion 

research, and include contributions on fire suppression research2

. A review, however, 

shows that the journals do not contain research papers that address fire suppression in 

vehicles. The exceptions to this is a recent SAE Conference, in which a number of papers 

on vehicle fire suppression research were highlighted3

. 

2.1.4 Aircraft and Automobile Fire Protection 

There are many issues that are common to vehicle fires and fire scenarios that are of 

concern to the DoD and FAA. The Halon Replacement and the Next Generation 

Programs addressed some of these issues. A major focus of these Programs was aircraft 

fire protection. Fire suppression systems on-board aircraft are designed to protect the 

engine nacelle, the dry bay, cargo areas, and in a number of cases, the aircraft auxiliary 

power unit and the on-board lavatory. 

The engine nacelle is a ventilated compartment encasing the aircraft engine. The space 

contains electronic and plumbing lines that carry fuel and hydraulic fluids. Suppressant 

mass requirements are driven to a large extent by the presence of hot surfaces that have 

been shown to cause re-ignition of a fuel leak. In a sense, an aircraft nacelle is similar to 

the underhood vehicle engine compartment, except that a vehicle engine compartment is 

partially open to the environment, which makes active fire suppression very challenging. 

It should also be noted that ventilation flows in the two volumes are very different. Both 

flows are very complex and have significant impact on fire suppression strategies. 

Dry bay fire protection is a concern for military aircraft encountering incoming ballistic 

rounds that can lead to a complex set of fast-occurring events involving the presence of 

fuel splashing and hot shrapnel, leading to a deflagration, shock wave formation, and 

possible over-pressurization of the dry bay compartment. 

 

1 International Aircraft Fire and Cabin Safety Research Conference, Atlantic City, NJ; Proceedings of the 

Interflam Conference, Edinburgh, Scotland; Proceedings of the International Symposia on Fire safety 

Science, International Association of Fire Safety Science (IAFSS), (1985 to present); Proceedings of the

Combustion Institute (1928-present); Proceedings of the International Conference on Fire Research and 

Engineering, Society of Fire Protection Engineers, 1995-current; Proceedings of the First International 

Conference on Fire Suppression Research, Stockholm, Sweden, 1992; Proceedings of the International 

Microgravity Combustion Workshop, Cleveland, Ohio. 2

 Combustion and Flame, Combustion Theory Modeling, Fire Safety Journal, Combustion Science 

Technology, Journal of Applied Fire Science, Journal of Fire Protection Engineering, NFPA Journal,

Progress in Energy and Combustion Science, and the Society of Fire Protection Engineers (SFPE) Journal. 3

 Session C on Fire Suppression, B-27 Forum, Society of Automotive Engineers World Congress, Detroit, 

MI, April 13, 2005 (see Dierker et al., 2005; Santrock and Hodges, 2005;. 

5
Some similarities of vehicle fires and the fire scenarios of concern to the DoD and FAA 

include the following: 

• Egress is not possible in many fire scenarios 

• Fires typically involve hydrocarbon based fuels 

• Catastrophic fire events may initiate rapidly and threaten life safety within a couple of

minutes 

• Fires occur in compartments that are partially open to the environment or are 

cluttered by machinery and parts 

• Fire scenarios vary depending on many factors 

• The presence of hot surfaces play a role including the potential for re-ignition 

• Agent toxicity, environmental impact, stability during long-term storage, 

compatibility with storage container materials, corrosion, cold weather storage, 

system maintenance requirements, are a concern.

• Suppression system effectiveness and reliability

Some major differences between vehicle fires and the fire scenarios of concern to the 

DoD and FAA include the following: 

• The basic automotive fuel (i.e., gasoline) is more volatile than common DoD fuels 

(i.e., jet fuel or diesel). 

• Diesel or jet fuel tanks can have an explosive vapor mixture in the tank; gasoline 

tanks do not as they are too rich (greater than the upper flammability limit, at least at 

ambient (20 o

C). 

• New model vehicles are loaded with thermoplastics, whereas many DoD applications 

do not have thermoplastics in the initial fire zone.

• The quantity of fuel in most DOD applications is typically much larger. 

• The automotive fire scenarios do not involve protection of compartments such as an 

aircraft dry bay or ventilated compartments such as a typical aircraft engine nacelle. 

In this sense, the geometric configuration of the automotive fire problem is not 

similar to most aircraft scenarios. 

For the dry bay scenario, very fast suppressant release is required for protection. The 

main similarities between the dry bay fire scenario and a rear-end collision and 

subsequent fuel-fed fire are the rate at which the event transpires and the occurrence of 

fuel atomization or fuel splashing in the presence of ignition sources at multiple spatial 

locations. The main difference between the scenarios is that the dry bay is a closed 

compartment, whereas an underbody fuel fed fire is only partially enclosed. This 

difference has significant implications in terms of fire suppression strategies and 

suppressant mass requirements. 

Fire suppression systems for aircraft are highly specialized. Once a suppression system is 

designed for a particular engine nacelle type, experimental verification is required to 

demonstrate suppressant distribution in an attempt to certify the fire protection system

performance. The design of effective vehicle fire suppression systems will require a high 

level of sophistication in engineering design and experimental demonstration. This is 

exemplified by the complexity of the recent work by Ford Motor Co. to provide an 

underbody fire suppression system as an option on its Crown Victoria police vehicle for 

6
the 2005 model year [Dierker, 2005; Ford, 2006]. The Ford suppression system is 

discussed in some detail in Section 2.4 below. 

The research conducted through the NGP and Halon Replacement programs and that 

presented at the HOTWC provide valuable information relevant to the vehicle fire 

problem. The lessons learned through the DoD work provide a basis for developing 

strategies to address vehicle fire protection. Indeed, much has been learned through both 

the successes and the failures of the DoD sponsored projects As many of the same

challenges and issues are common to the aircraft and vehicle fire suppression problems. 

 

2.2 Commercially Available Fire Suppression Technologies for Vehicles

It may be possible to borrow or modify current suppression technology to effectively 

address the vehicle fire problem. Commercial suppression systems are available for fire 

protection in trains, boats, mining equipment, military equipment, and aircraft. The U. S. 

Army, for example, uses automatic fire suppression systems in the engine compartments 

of armored vehicles [Bolt et al., 1997]. Some types of vehicles have been fitted with 

commercially available active suppression systems. These include buses, trucks, heavy 

equipment, and specialized vehicles such as racecars [e.g., Hodges, 1995]. In racing 

applications, both the passenger and the engine compartments may be protected using 

manual and/or automatic suppressant delivery systems. 

There has been some reported work on suppression systems for civilian automobile 

applications. Lim et al [1997] report that a German automobile manufacturer has 

developed an automatic fire suppression system for the engine compartment of its 

passenger cars. Lim et al. [1997] also report that an automatic fire suppression system has 

been developed for the engine compartment of passenger automobiles in the U.K. using 

halon alternatives. There has been no confirmation of this information and there is no 

evidence on the internet to suggest that vehicles are being manufactured with on-board 

suppression systems in Europe or anywhere else. In 2004, Ford Motor Co. announced 

that it will produce a hybrid foam/solid propellant gas generator fire suppression system 

as an option on its 2005 Crown Victoria Police Interceptor line of vehicles [Ford, 2004a]. 

Fire Panel has been selling a powder panel as an aftermarket addition for protection of 

fuel tanks of automobiles in the event of a rear-end collision [Fire Panel, 2006]. 

Comprehensive independent testing of the effectiveness of these on-board suppression 

systems has not been reported. 

2.3 Technology Assessment for Vehicle Fire Protection 

Bennett [1998] with participation by Santrock and Kononen of General Motors and 

Hamins of NIST conducted a comprehensive survey and assessment of available 

technologies that could be applied to the vehicle fire protection problem. The study 

included a literature search and a survey, which was sent to several hundred 

manufacturers of fire mitigation technologies. A rating process, based on expert 

judgment, was created to evaluate the relative merits of the different technologies for 

possible motor vehicle applications. A portion of the survey addressed fire suppression 

technologies and strategies. 

7
The survey was sent to approximately 300 companies who offered technologies that 

might improve the fire safety of passenger vehicles. The technologies could be used 

either off the shelf or with modifications. Foreign companies with special products were 

also considered. The set of requested information was reduced to the minimum necessary 

to assess the potential impact of a technology’s use in automobile applications. It was 

understood that many of the manufacturers may not have portions of the detailed data that 

were requested, and in fact, significant portions of many survey forms were not 

completed. Evaluation of the data was then performed based on engineering judgment. A 

listing of the detailed survey results is given in Bennett [1998]. A total of 38 companies 

returned surveys. Forty products were considered active systems (including 11 detector 

products), 12 were passive systems, and 11 were fire resistant materials. 

The relative merits of active fire suppression systems, passive fire protection systems and 

fire resistant materials were considered for possible motor vehicle fire safety applications. 

Active fire suppression systems that were evaluated included clean agents, dry chemicals, 

water mist, aqueous film forming foam (AFFF), gas generators using pure gas and 

hybrids that dispense clean agents and dry chemicals, pyrotechnic aerosol systems, 

tubular fire extinguishing systems and explosion suppression systems. The report 

described the various technologies and assessed the potential of the product to improve 

post-collision automotive fire safety. The rating protocol was based on engineering 

judgment and without the benefit of crash test data or field testing. The rating system

considered the various technology types in terms of required weight, reliability, 

crashworthiness, re-ignition protection, toxicity, cost, safety, and availability. The rating 

system made no distinction among highly variable vehicle designs, but did separately 

consider engine compartment fires and underbody fuel-fed fires. The results were broken 

into three categories: those with the highest potential as vehicle fire suppression systems 

and those with lower or moderate potential as vehicle fire suppression systems. 

The highest evaluation ratings went to aerosol extinguishers, conventional powder 

extinguishers systems, conventional water mist systems, conventional water based foam

systems, and gas generator/hybrid systems for the engine compartment fires. For the 

rear-end collision and underbody fuel-fed fires, ratings of most of the suppression 

systems were also grouped into three categories and the ratings were similar to the results 

for the engine compartment. 

It should also be noted that passive fire protection systems such as self-sealing fluid lines, 

enhanced crashworthiness of the fuel tank, and fluid shut-off devices were rated highly.

2.4 Ford Fire Suppression Research for post-rear-impact fires in the Crown 

Victoria Police Vehicle 

As part of its Police Officer Safety Action Plan, Ford Motor Co. announced in 2003 that it 

was actively evaluating fire suppression technologies to defend against ruptured fuel 

tanks and subsequent underbody fuel fed fires [Ford, 2003a]. The work was in apparent 

response to concern regarding fires due to fatalities associated with a number of highspeed rear-end impacts in parked Crown Victoria police vehicles. Between 1983 and 

8
2003, there were fourteen documented cases of officers who died in vehicles when the 

fuel tank caught fire after a rear end collision [Porretto, 2003; see Appendix A]. 

To address this issue, Ford recently announced that its engineers tested eight fire 

suppression systems. Part of the testing involved fires in moving vehicles. The test 

protocol was designed to simulate the movement experienced by a stationary vehicle 

following a 75 mph rear impact. Typically, such a case results in 30 m to 70 m (100 ft to 

200 ft) of movement of the struck vehicle. Ford reported that their test protocol 

guaranteed both a fuel leak and ignition of the fuel. A rough description of the Ford 

testing protocol was recently released on their website [Ford, 2006], and is reproduced in 

its entirety in Appendix D of this report. 

 

Among its findings, Ford listed the following as significant conclusions reached during 

the testing [Ford, 2003c]: 

• Fuel leaks that begin near the point-of-impact may leave a 75-to-200-foot fuel trail to 

the point-of-rest of the vehicle. 

• Ignition of this fuel trail can occur when the deformed vehicles scrape the road 

surface and create sparks while passing through or along the fuel trail. 

• An ignited fuel trail can initiate a fire at the vehicle's final point-of-rest if there is 

continuing leakage of a sufficient amount of fuel at the point-of-rest. 

• The fire is not intense at the passenger compartment until the vehicle is stationary, 

and unless there is a continuing leak at the point-of-rest. 

• Challenges associated with packaging the fire suppression substance and system, 

while still allowing the vehicle to function effectively as a police vehicle, necessarily 

limit the quantity of the available fire suppression substance. 

• The optimal time for deploying the limited amount of the fire suppression substance 

is near the point-of-rest, which can be seconds after and more than 200 feet beyond 

the point-of-impact. 

• Wind, ground surface and road grade are factors in fire propagation. 

• No vehicle fire suppression system can extinguish a fire fed by large quantities of

gasoline. 

• Liquid fire suppressants combined with surfactants performed better than foams or 

powders due, in part, to the ability of that substance to spread – like gasoline – 

beyond the direct reach of the deployment nozzles and to cover the gasoline. This 

combined substance more effectively reduced the risk of a re-ignition at the point-ofrest of the vehicle when the fire is not completely extinguished at, for example, the 

fuel trail or on the protected/outboard side of the rear wheels. 

Ford began offering fire-suppression technology as an option on its 2005 model Crown 

Victoria Police Interceptor vehicle. This is a watershed event in terms of fire safety for 

vehicles in the United States. After a broad preliminary research effort, Ford selected 

Aerojet, an aerospace and defense company based in Sacramento, California, to jointly 

pursue further development of the fire suppression technology for the police vehicle 

application. Aerojet's technology uses a pyrotechnic gas generator to deploy a 

combination liquid fire suppressant and surfactant. The pyrotechnic system is similar to 

9
an air-bag deployment system, but in this application it is used to release fire suppression 

chemicals [Dierker, 2005; Ford, 2006]. Ford reported that a surfactant was used, because 

it reduces the surface tension of the liquid fire suppressant, thereby enabling the liquid to 

spread more quickly and completely. Ford uses advanced electronics modules to measure 

post-impact vehicle movement and to determine the optimal time for deployment of the 

fire suppression system. Ford has not offered suppression system retrofit for older 

models, maintaining that the sophisticated electronics required for crash-activated and 

delayed deployment prohibit offering an after-market product. In May 2003, Ford and 

Aerojet reported that they planned to conduct about 30 fire suppression tests to learn 

more about the effect of varying fuel quantity, fuel spill rates, re-ignition, discharge 

timing and shadow (fire behind the rear-wheel) effects. 

The Ford fire suppression test program is unique and any information released to the 

public bears careful consideration. The lessons learned from Ford’s research program are 

extremely important as they represent an extensive set of reported research results. Any 

vehicle fire suppression system must function under real-world conditions. A 

comprehensive on-board suppression system must be crashworthy, and must address fuel 

trails, and vehicle travel after collision impact. The Ford system used a strategy to 

address these concerns. Some amount of information on the test protocol is available, but 

unfortunately it is not in the form of written reports. Some information is available 

through what can only be termed as adversarial communication involving Ford Motor 

Co. and Fire Panel Inc., a company whose product was tested during the Ford Fire 

Suppression Test Program. From documentation on the Fire Panel and Ford websites 

[Fire Panel, 2006; Ford, 2006], some amount of information regarding the details of the 

test protocol can be ascertained. In particular, a report to Fire Panel by Hughes 

Associates [2003] quotes a deposition taken from Joseph B. Dierker, a Ford Employee 

and technical leader of the Ford fire suppression project team, regarding the test protocol. 

Description of the suppression test protocol is quite detailed and offers an understanding 

of the experimental procedure used by Ford. For the design of future fire suppression 

testing, it would be useful to have complete documentation of the Ford Fire Suppression 

Test Program. Detailed reports of the experimental findings would foster the 

development of post-collision fire suppression systems that would benefit the public. 

2.5 Other Recent Fire Suppression Experiments 

NIST recently performed a series of experiments on the effectiveness of fire suppressants 

in simulated post-collision engine compartment and underbody fires. General Motors 

financed the research pursuant to an agreement between GM and the Department of 

Transportation. NIST tested both traditional and emerging active fire suppressants. These 

included dry powders, inert suppressants, compressed liquefied halogenated compounds, 

and a number of prototype suppression concepts such as tubular suppression systems, 

solid propellant generators, and aerosol generators. A number of experimental approaches 

were investigated to appraise the feasibility of fire suppression using the representative 

suppressants. 

Hamins [2000] investigated the effectiveness of fire suppressants as an intervention 

strategy in simulated post-collision vehicle fires. General Motors Corp. financed the 

10
study pursuant to an agreement between General Motors and the United States 

Department of Transportation. A number of experimental protocols were developed to 

appraise the feasibility of extinguishing fires using common and emerging types of 

suppressants. Several experimental configurations were investigated including both fullscale and reduced-scale engine compartment and underbody fires. Several fire 

suppressants were selected for testing. These included dry powders, clean suppressants, 

and a number of prototype devices. The report describes the experimental results with an 

emphasis on the relative performance of the suppressants and the influence of various 

parameters associated with the vehicle itself (e.g., geometry) or the suppressant (e.g., 

delivery rate). Experiments were performed using both laboratory test devices and a static 

uncrashed mid-size passenger vehicle. Long fuel trails extending beyond the confines of 

the vehicle and environmental factors such as wind were considered. The results showed 

that it is highly improbable that an on-board fire suppression system will be able to 

extinguish all engine compartment and underbody fires. Many suppressant types were 

found to be impractical for post-collision engine compartment applications. Of the 

systems tested, solid propellant gas generators (SPGG) were the most effective. 

Subsequent suppression testing using SPGG was performed by Santrock and Hodges 

[2002] in a crash test and in three static tests in previously crashed vehicles. SPGG 

suppression was unsuccessful in the moving crash test with a fire burning power steering 

fluid ignited on a hot manifold. In the static vehicles tests, the SPGG extinguished the 

fires, but with fluid continuing to leak onto an energized hot surface, re-ignition was 

observed. 

Full-scale underbody experiments by Hamins [2000] showed that suppression of a 

(333 mL volume) gasoline pool fire was achieved with less than 300 g of ABC and BC 

powder suppressants when the fuel was located under the vehicle footprint for low wind 

conditions. If a fuel puddle in an underbody fire extended beyond the vehicle footprint 

and if moderate to high winds were present, then the powder suppression system failed to 

reliably extinguish the fire. 

Santrock and Hodges [2005] report on a prototype fire suppression system installed in 

full-scale vehicle crash tests and static vehicle fire tests. The system consisted of two 

Solid Propellant Gas Generators and two optical detectors installed on the hood bottom of 

the test vehicle. A vehicle crash test and a series of static vehicle fire tests were

performed to determine the effectiveness of this prototype fire suppression systems in 

extinguishing fires in the engine compartment of a crashed vehicle. The results indicate 

that dynamic factors in a crash such as vehicle crush, vehicle movement, wind, and 

reignition of fuel after release and dispersal of agent (reflash) can substantially reduce the 

effectiveness of an automatic fire suppression system in extinguishing a post-crash fire. 

2.6 Powder Panels 

2.6.1 Operation 

Powder panels are a particularly intriguing passive fire protection system. The NGP (see 

Section 2.2.1) recently supported an investigation on the effectiveness of powder panels 

for fire suppression. Powder panels were first developed and used by the British Royal 

Aircraft Establishment [Cyphers et al., 2003]. The panels are relatively simple devices 

composed of molded thermoplastic that contains a fire suppressant powder. A variety of 

11
fire suppressants have been tested as the active agent in powder panels including 

Monnex, KDKI, Al2O3, Al2O3 with KI, Al2O3 with SiO2, Purple K, potassium

bicarbonate, and 10% acetate in water [Cyphers, 2003]. 

Powder panels have been applied to the lining of aircraft dry bays to provide passive, 

lightweight, fire protection against ballistic impact. Dry bay areas are zones in military 

aircraft that store fuel. The panels are strategically positioned such that they are stationed 

directly in front of vulnerable fuel storage containers. When a projectile penetrates the 

panel, the agent from the panel is released to inert the space vulnerable to a fuel spill and 

fire. Cyphers et al. [2003] conducted a survey on the use of powder panels. Cyphers 

reported that the use of powder panels in dry bay protection of rotary wing aircraft has 

been established, for example, in the Navy UH-1Y Huey and AH-1W Super Cobra 

aircraft. In addition, the V-22 Osprey Tiltrotor aircraft uses powder panels extensively. 

Powder panels have been examined widely for military combat land vehicles, such as 

tanks and armored personnel carriers. 

Cyphers [2003] conducted a series of reduced-scale experiments to investigate a number 

of enhanced performance concepts for application of powder panels. Cyphers [2003] has 

attempted to create a “reactive” powder panel that adds energy to enhance delivery 

effectiveness of the powder. Preliminary tests of the enhanced powder panel design have 

been encouraging. As part of the NGP program, research continues to examine means for 

effecting greater powder release, better dispersion of powder, longer powder suspension 

in the air to prevent the possible ignition of a fire for longer periods of time, and panel 

durability. Ongoing optimization test variables include panel materials, and thicknesses, 

powder loading (density of powder inserted into a given panel size), rib design, and the 

assembly process. Preliminary tests have shown that the innovations in powder panel 

design yields improved performance over traditional powder panel designs [Cyphers et 

al., 2003]. Fire Panel has made this technology commercially available for fuel tank 

vehicle fire protection [Fire Panel, 2006]. 

2.6.2 Previous Vehicle Fire Testing using a Powder Panel 

Bennett [2005] describes the Fire Panel technology as designed to prevent post-collision 

vehicle fires. The Fire Panel consists of ABC dry powder (mono-ammonium phosphate) 

encased in a custom molded thermoplastic assembly [Bennett, 2005; Hughes Associates, 

2003]. Fire Panel was recently tested by Ford during its Crown Victoria Fire Suppression 

Testing program. Some details of the test procedure are available (as mentioned in 

Section 2.4 above) in the form of a letter from Hughes Associates, a consulting firm hired 

by Fire Panel Inc. The letter quotes from a deposition taken from Joseph Dierker, an 

employee with Ford Motor Co., who led the recent Ford fire suppression testing [Hughes 

Associates, 2003]. 

The Fire Panel assembly was attached to the outer surface of the fuel tank. Upon 

collision, the fire panel is designed to shatter and release its powder into the air, thereby 

preventing flame propagation through a gasoline vapor/ air mixture, which may be 

present after a rear-end vehicle impact. The design attempts to inert the zone about the 

panel as it crushes and releases its powder, thereby preventing ignition and flame 

12
propagation in the region where sufficient powder concentrations are present. After 

evaluating and performing one test on this technology, Ford [2003c] concluded that the 

Fire Panel is not effective. Ford’s web site stated that: 

• Fire Panel releases its fire suppressant powder at the point-of-impact. Little or no 

powder is released at the critical time and place of the point-of-rest of the vehicle. 

• The technology offers little or no protection against fires occurring at the vehicle's 

point-of-rest; if the fuel trail is ignited or any other ignition source is present after 

the time and place of impact, the Fire Panel technology provides little or no 

benefit. 

• The powder distribution can be adversely affected by wind and other weather 

conditions. 

• Moisture and road debris trapped between the 6 mm (1⁄4") gap between the Fire 

Panel and the fuel tank could cause degradation of the steel fuel tank. Either of 

these concerns could lead to significant out-of-warranty maintenance problems, 

and potentially degrade fuel system safety. 

The Fire Panel website attempts to refute each of the Ford conclusions [Fire Panel, 2006]. 

It will be interesting to follow the effectiveness of these fire protection systems as 

information on their performances in actual fire incidents become available. 

3. Ideas for Vehicle Fire Protection Research Directions 

This Section presents ideas on automotive fire suppression research needs. While an 

infinite number of research approaches are possible, to limit the many possible research 

directions to those that may be most fruitful, a number of prioritized ideas are proposed. 

Some underlying assumptions and simplifying premises are first presented. 

• For life safety, a fire protection system must function post-collision and must provide 

on the order of 10 min to 30 min of protection for vehicle passengers to be effectual. 

The suppression system must provide protection almost immediately as fire may enter 

the passenger cab within minutes depending on the fire scenario. 

• Fire protection systems are not essential to save lives and serious injuries in noncollision situations. However, a non-crash underhood fire protection system may be 

justified based on the reduction of property damage, and may also lead to a reduction 

of injuries during crashes that result in fires. The exact time needed is related to time 

needed for emergency response by authorities. The time required for rescue 

represents a threshold for effectiveness of a fire protection system. Systems that are 

less successful are less deserving of development. 

• The simpler the fire protection system, the better. This is particularly important when 

considering system reliability. Systems that rely on the use of multiple pieces of 

hardware pose a higher risk in terms of malfunction. For example, suppression 

systems that require distinct detection and activation hardware are more complicated 

than those that are bundled into one system. In the same manner, systems that 

13
passively activate by design are not dependent on the signal from a detector, which 

have been observed to fail in recent crash tests [Santrock and Hodges, 2002]. 

• Previous research and experience in automotive fire safety should be closely 

examined. Lessons learned should be exploited and the open literature should be 

closely scrutinized. 

• Any vehicle fire suppression system must be crashworthy. Field testing of any 

proposed system must be conducted under realistic conditions. 

• A suppressant should be delivered soon after ignition occurs, or possibly even before 

ignition. Once a fire spreads and grows, it is more difficult to extinguish, simply 

because the suppressant must act to inert larger volumes as well as surfaces that may 

be heated to higher temperatures. 

The following is a list of suppression research ideas and may be considered a starting 

point for the continued development of a vehicle fire suppression research program. 

3.1 The Character of Post-Collision Fires 

An engine compartment contains combustible substances including gasoline, hydraulic 

fluids, windshield washer fluid, anti-freeze, engine and brake oils, rubber, thermoplastics, 

and possibly magnesium. Several ignition sources may be present in a post-collision 

vehicle including friction sparks generated during the collision, hot surfaces (e.g., exhaust 

manifold or catalytic converter) to which flammable fluids (e.g., gasoline, windshield 

washer fluid) or combustible fluids (e.g., motor oil, transmission fluid) might be exposed, 

or shorted wires that could generate electrical sparks [Jung et al., 1997]. It should be 

noted that flammable liquids have flashpoint temperatures between 32 o

C and 60 oC, 

while combustible liquids have flashpoint temperatures above 60 o

C. Understanding the 

early moments of a post-collision vehicle fire, that is, the initial interaction of ignition

sources and combustible materials, would be helpful in developing appropriate fire 

suppression strategies and test protocols. A clear understanding of the identity of initial 

fuel sources, ignition sources, and early fire time-lines would provide a realistic basis for 

formulating appropriate fire intervention strategies. Some work in this regard has been 

reported [Ragland and Hsia, 1998]. 

High quality data is needed to allow researchers to focus on solutions to the vehicle fire 

problem. Without statistically meaningful information, the development of fire 

suppression strategies may be misdirected. Informed with verified information on fire 

ignition sources and mechanisms, researchers would be able to focus on actual rather than 

hypothetical fire scenarios. Detailed information may be useful in developing fire 

suppression and fire protection strategies for vehicles. It may be possible, for example, to 

provide local protection for particularly vulnerable components. This may involve 

strategies to prevent ignition or achieve early suppression of the first item ignited in 

post-collision fires. Accurate information on the first item ignited in a fire would be of 

value. 

14
Some data are available from post-collision fire investigations, although it is very limited 

[Scheibe et al., 2001]. This work involved case studies of post-collision fires in vehicles. 

The data point to a wide range of fluid types that may have been the first item ignited 

such as transmission fluid, gasoline, motor oil, washer fluid, etc. The estimated time to

ignition after collision was typically less than 5 min, but this may be biased by eyewitness reports from people who were often not cognizant of a fire until it became visible 

and therefore quite large. Some very useful information on fire initiation and propagation 

is also available through the GM/DOT funded studies in the late 1990’s and early 2000’s, 

which investigated the detailed fire initiation and propagation in a large number of 

(about 11) vehicle crash and burn experiments [e.g., Jenson and Santrock, 1997; 1998; 

1999; Santrock, 2001]. These experiments are extremely comprehensive in terms of 

instrumentation and analysis. The GM/DoT “Fire Initiation and Propagation Tests” are 

summarized by Digges and Stephenson [2006] and are described in 19 reports available 

at the DOT/GM website (http://dms.dot.gov/search/searchFormSimple.cfm) under 

Docket # 3588. 

More needs to be learned about fire initiation. Instrumented collision experiments would 

be very useful, but it is unlikely that such a program would occur because of the large 

amount of funding that would be needed. Another approach would involve searching 

data that is public, for example, through United States Department of Transportation 

(DOT) National Highway Traffic Safety Administration (NHTSA) sponsored crash test 

data or through accident reports such as the NHTSA Fatality Accidents Reporting 

Systems (FARS) or NASS (National Accident Sampling System), or other databases. The 

quality of the information is not clear in this regard. A study by Freidman used the FARS 

database and data from several states to estimate fire rates in collisions [Friedman et al., 

2003; Friedman, 2005]. The data is limited to Police Accident Reports (PAR) and has 

very little detail about fires – certainly nothing on ignition source or first fuel ignited. 

The information in NASS is somewhat better, but is still very limited and the sample size 

in NASS is small. 

Vehicle manufacturers do crash testing on a regular basis. They crash test their vehicles 

and the vehicles of their competitors. During testing, however, Stoddart solvent, a low 

volatility hydrocarbon, typically replaces gasoline and the engine may not be running 

during the tests. In addition, the battery may be disconnected and many underhood fluids 

drained. In part, this is done to avoid a fire, which can lead to significant financial costs 

associated with fire fighting and possible losses. Contamination of the crash test facility – 

many of which are indoors and issues of worker safety may also be concerns. An 

instrumented crash test dummy, for example, contains sophisticated instrumentation and 

is extremely expensive. On the other hand, if crash tests were conducted with real 

gasoline, the engine running, battery connected, and all fluids full, then all crash tests 

become fire tests (in addition to the primary purpose of the test, which may involve 

airbag testing or rollover). This would greatly increase the knowledge base regarding the 

mechanisms of fire initiation in collision induced fires. 

 

While little information is known about which fuel is the first ignited in engine 

compartment fires, it is fairly certain that the culprit in rear-end collisions typically is 

15
automotive fuel. Although fires associated with rear-end collisions are often attributed to 

underbody fuel fed fires, the nature of these fires is not well documented. Relatively 

little reliable quantitative information is available regarding leak rates, the size of a fuel 

trail, or the possible presence of fuel sprays. Although leak testing based on the Federal 

Motor Vehicle Safety Standard (FMVSS) 301 Fuel Integrity Test is routine, the test 

specifies the speed and configuration of various crash types. After the crash test, a 

rollover test is required. The vehicle is placed in a fixture and rotated about its 

longitudinal axis. In this test, there is no attempt to measure any fluid leakage other than 

motor fuel. Consequently, there is no data on the leakage of other fluids that may be 

responsible for engine compartment fires. Measurement of all fluid leakage in this test 

would increase the incentive to prevent all leakage in rollovers. It would increase 

knowledge about possible causes of vehicle fires and the requirements for suppression 

systems for underhood fires. The character of fluid leakage in a vehicle requires an 

improved understanding as this information could play a role in the design of 

experiments addressing the post-collision fire problem and ultimately possible solutions 

to the problem. 

If a fire occurs and a suppressant is successfully deployed, there is a finite chance of reignition under certain conditions. Many conditions may affect the probability of reignition. This is essentially a heat transfer problem that involves cooling by the 

suppressant competing with the conditions that may lead to re-ignition including the 

temperature of a hot surface and its size and mass, the rate, temperature, and type of fluid 

that is impinging on that surface, and the flow rate and the temperature of the air near the 

hot surface. There are no comprehensive studies to date that assess the probability of reignition for post-collision engine compartment fire scenarios. Santrock [2001] reports 

detailed measurements on the ignition of underhood fluids on a hot metal surface. 

Unfortunately, that report does not include information on the actual temperatures of 

components in the engine compartment. To be meaningful, such measurements should be 

conducted with vehicle running with a load; idling is not enough. Information on the 

underhood temperatures in several types of vehicles is described by Fournier [2004]. 

Temperature information on used older model vehicles, not necessarily maintained to 

specification would also be of interest. It would also be useful to measure how quickly 

the surfaces cool after the engine has stopped, which would provide an estimate on the 

time of vulnerability to ignition, as well as possible re-ignition after suppressant delivery.

3.2 Workshop on Vehicle Fire Suppression 

It is suggested that a workshop identifying and prioritizing fire suppression research ideas 

be convened. The workshop would endeavor to develop a consensus on the ideas and 

direction for new research in automobile fire safety. There is no documentation of such a 

workshop having taken place in the recent past. Much has been learned over the last 

decade in fire suppression research. A workshop should capitalize on that experience and 

more specifically, from vehicle fire suppression testing. Experience suggests that experts 

from all over the country would attend and actively participate in such a workshop 

[Grosshandler, 2002; Walton et al., 1999a; 1999b]. The outcome of the workshop could 

form the basis for consensus on the prioritization of future research in this area. 

16
A brain-storming session bringing experts with a variety of backgrounds together to 

discuss research needs in vehicle fire suppression and fire safety may lead to new 

directions or confirm ideas that have been previously expressed. It would be 

advantageous to invite experts with a range of backgrounds including both applied and 

fundamental suppression research and those from academia, industry, and government to 

discuss productive directions in fire suppression research. 

The format for such a workshop might include presentation of a limited amount of 

background information defining the scope and magnitude of the vehicle fire problem

and research to date. One session of the proposed workshop could address the issue of 

standard test methods (see Section 3.3 below). Currently, there are no accepted standard 

test methods to evaluate vehicle fire suppression technologies. The development of a 

sanctioned or consensus test method would presumably foster critical thinking in the 

identification of vehicle fire problems and provide a basis in the search for effective fire 

suppression technologies. The current practice of using of ad-hoc test methods will likely 

retard public acceptance of positive results in the development of suppression systems 

and impede advancement in the field. 

An expected outcome for such a workshop would be a panoply of ideas on future 

directions in fire suppression and vehicle fire protection. While not all of the ideas can be 

expected to be constructive, it is likely that a significant number of ideas will be useful. 

The job of a workshop coordinator would be to encourage the prioritization of ideas 

based on scientific and engineering judgment of the participants. This type of workshop 

could probably be organized in three to four months and would require a modest 

investment of funds, but would yield confidence that best thinking was used before 

significant research investments were made.4

3.3 Development of Standardized Fire Suppression Test Protocols 

No standard apparatus exists for evaluating the effectiveness of a suppressant in 

extinguishing post-collision vehicle fires. Detailed experimental test protocols for engine 

compartment and underbody suppression systems are needed to assist fire suppression 

researchers to address peculiarities of the automotive fire problem. The development of 

standardized test(s) or at least guidelines in the development of such tests would be 

useful, providing a common basis for evaluating the effectiveness of alternative fire 

suppression systems. 

A suppression protocol can be designed such that suppression is extremely easy to 

achieve or nearly impossible to achieve, The key to the design of a test protocol is that 

the scenario is representative of the actual fire problem. This does not mean that the 

scenario should be “worst case,” particularly if the worst case is very rare. If statistics 

and details associated with the post-collision vehicle fire problem are inadequately 

understood, then the development of a perfectly representative suppression test protocol 

is impossible. It is possible, however, to develop protocols and test suppression systems 

 

4

 A brief Workshop on Fire Suppression Research Needs was held on the morning of Wednesday, April

13th 2005 at the SAE World Congress in Detroit, following paper presentations at Session C on Fire 

Suppression of the B-27 Forum. Appendix E of this report summarizes the discussion at the Workshop.

17
based on incomplete information and engineering judgment in order to advance the 

understanding of safety systems. 

There have been a number of experimental investigations looking at the effectiveness of

vehicle fire suppression systems in both moving and static vehicles. Experimental 

protocols were developed. The apparatus in each of the experimental configurations 

included a fire zone and a suppressant delivery system. They are discussed in some detail 

below. 

Hamins [2000] developed a number of experimental protocols to appraise the feasibility 

of fire suppression using a static uncrashed vehicle. A number of experiments were 

conducted to test the importance of operating conditions on suppressant effectiveness in 

the simulated vehicle fires. These included geometrical factors and suppressant delivery 

parameters. Long fuel trails extending beyond the confines of the vehicle and 

environmental factors such as wind were considered. The test protocols used actual fullscale non-running older-model vehicles in a static mode. Experiments focused on two 

configurations: underbody fuel-fed fires near the fuel tank and an engine compartment 

fire in which the fuel was dripping and pooling under the vehicle creating a threedimensional fire. For the engine compartment fire scenario, portions of the vehicle, such 

as the engine compartment including component surfaces were pre-heated by the test fire. 

The hood was bent or crumpled to create gaps on either side of the hood, simulating a 

post-collision situation. For the fuel tank fire scenario, a “fuel drip” was located on the 

fuel tank towards the middle of the vehicle rather than its rear. For the engine 

compartment scenario, a continuously energized hot surface was not present, so the 

possibility of “re-light” after suppression was not fully considered. The likelihood of relight in an actual situation would depend on many factors specific to the collision, the 

fire, and the suppression system. The experiments were relatively inexpensive by design. 

Both configurations used gasoline to fuel the fire. This set of experiments provided a 

basis for screening the effectiveness of various suppression technologies. In conjunction 

with the test protocols described below, it could form the basis for the development of a 

standard suppression test protocol. 

Santrock and Hodges [2002] developed experimental fire suppression test protocols for 

moving and static vehicles. The experimental procedure for the moving vehicle 

suppression test repeated the protocol from a frontal crash test of a sedan that led to a fire 

[Jensen and Santrock, 1999; Santrock and Hodges, 2002]. No supplementary fire 

ignition mechanism was added to the vehicle. On-board detectors were used to 

discharge solid propellant gas generators (SPGG) mounted in the engine compartment. 

The experimental configurations and procedure are outlined in Jensen and Santrock 

[1999]. Subsequently, Santrock and Hodges [2002] repeated that test and replicated the 

fire event, which was attributed to power steering fluid as inferred by gas 

chromatographic, mass spectrometric (GC/MS) analysis. The ability to plan and repeat a 

crash/fire experiment should be a key element of any standard test protocol. 

Ford developed a different approach, using moving vehicles. Their tests focused on the 

suppression of underbody fuel fed fires [Dierker, 2005; Ford, 2003c; 2006]. To evaluate 

18
the effectiveness of fire suppressants, Ford used both a fuel leak and an ignition device to 

assure that a fire occurred. The igniter was halted a finite time after ignition was assured. 

The duration of the ignition event is an important parameter, which may differentially 

affect the suppression effectiveness of some agents more than others, and has 

implications in terms of the possibility of fuel re-ignition or re-light. 

Gunderson and DiMarzo [2004] tested the effectiveness of an underhood foam fire 

suppression system on a number of static, older-model vehicles. The vehicle was in an 

upright position except for one simulated rollover test in which the vehicle was on its 

head. Shallow metal trays, etiher rectangular or circular in shape and approximately 

0.3 m diameter in size we refilled with 14 mm of gasoline and placed on the ground 

below the center of the engine compartment or on top of engine components near the

battery location (towards the front of the vehicle). In the case of the rollover, the tray 

was placed on the hood, directly below the engine. The initiation of the suppressant foam

release was concurrent with the ignition of the fire. In the open, enough gasoline was

used to create about 5 min of burning, and the size of the gasoline was estimated as 80 

kW. In one control test, the foam suppressant was not deployed and the fire size 

continued to grow until the entire engine compartment appeared to be enveloped in

flames. The surface of the burning fuel in these tests was two-dimensional, which is

rather simplistic considering the complex geometry of vehicle engine compartments. In 

addition, Hot surfaces were not created in this scenario, so re-light (or re-ignition) was 

not addressed by this test protocol. 

An appropriate screening protocol should include critical features of the vehicle fire 

problem. Several levels of standardized testing may make the most sense, with the first 

level of screening involving stationary vehicles and a second level of testing involving 

moving vehicles. A standardized test ought to be full-scale rather than reduced scale. 

Although full-scale experimentation is typically far more expensive than laboratory-scale 

experiments, it is not clear that a reduced-scale device would be appropriate for the 

variety of length and time scales involved in the vehicle fire suppression problem. The 

development of a reduced-scale apparatus must demonstrate the relationship between its 

results and the full-scale problem. In this sense, full–scale testing may be more practical 

than reduced –scale testing combined with scale modeling as cars are cheap and probably 

much cheaper than making a suitable scale model. For the post-collision fire problem,

the apparatus would need to represent the panoply of post-collision conditions including 

the effects of a moving vehicle, a partially crushed vehicle geometry, a warm engine 

compartment and adverse weather conditions including possibly strong winds. 

The issue of re-ignition must be addressed in the development of a standardized test 

protocol. Since so little is known about the heat transfer processes associated with the 

multitude of possible suppression and re-ignition scenarios, it is conservative to assume 

that re-ignition will occur unless an agent does a significant amount of cooling or if an 

agent physically separates the fuel, air, and ignition source for a significant amount of 

time. 

19
The idea of using moving/colliding vehicles to create a standardized test is an expensive 

proposition. Use of stationary vehicles for initial testing will reduce costs. Yet, the use of 

moving vehicles is important to capture real-world conditions that may play a defining 

role in the physics of the scenario. Ventilation in the engine compartments of a moving 

vehicle is different than in stationary situations and will undoubtedly affect suppressant 

performance. Ventilation will also be different if the engine is running with the radiator 

fan blowing. A possible fire suppression strategy may be to delay suppressant release 

until a vehicle has come to rest and the fan has been turned off. Ventilation effects may 

then be insignificant. Of course, this is not possible for all suppressant types. Powder 

panels, for example, are initiated by the crush of the accident itself, so testing of powder 

panels must be conducted in a vehicle collision scenario. 

 

The idea of performing a suppression test on a vehicle that is running and under load is 

also an important consideration. The effects of a hot engine compartment and hot 

components may impact the flow behavior and effectiveness of an agent. For example, 

water based agents such as foam may vaporize. The temperature distribution within the 

engine compartment will create natural ventilation that will impact the flow field. Jensen 

and Santrock [1999] modified a number of vehicles to enable the motor to run during 

crash tests. They emptied fuel from the fuel tank and added a small gasoline reservoir 

and auxiliary fuel pump. Many of these crashed vehicles were subsequently burned as 

part of the General Motors crash and burn experiments [Wichman, 2003; Jensen and 

Santrock, 1999]. 

Assuring that a fire occurs during vehicle movement is a key part of the development of 

an experimental protocol. This has proven to be a contentious issue and must be 

meticulously addressed [Ford, 2004c; Fire Panel, 2004]. The attributes and relative 

effectiveness of powder panels is unclear at this time. In the case of the Ford/Fire Panel 

testing described in Section 2.6.2 above, disagreements about the effectiveness of the 

technology has led to a debate on the appropriate test protocol. 

It would be desirable that the design of an experimental apparatus and protocol be 

developed through a consensus process involving multiple parties representing a variety 

of perspectives. It would also be useful to understand the details of previous research by 

Ford, General Motors, and others who have conducted crash/burn/suppression 

experiments. In this manner, the final design would be more likely to have merit and be 

accepted by vehicle manufacturers. This topic could be a key component of a Workshop 

(see above) on fire suppression. 

While a static tests may be preferred, because it is cheaper, easier, and more repeatable, 

fluid flow effects associated with a moving vehicle may need consideration, particularly 

for some systems like the powder panel, in which suppressant delivery is directly linked 

to the collision. In other cases, dynamic testing may be needed to validate a static test 

method.

20
3.4 Fire Suppression Systems 

A finite number of fire suppressant types exist. These are discussed in Hamins [2000] and 

Bennett [1998]. Suppressant types include both traditional and emerging fire suppressants 

such as dry powders, clean suppressants, compressed liquefied halogenated compounds, 

water based foams, and water mist; and prototype devices such as powder panels, solid 

propellant generators and their hybrids, aerosol generators, as well as tubular 

extinguishers. There are many variations in each type of suppressant in terms of exact 

chemical type, thermophysical behavior, suppression effectiveness, engineering 

adaptability, and storage concerns. Some of these suppressant types are unlikely to 

provide post-collision vehicle fire protection [Hamins, 2000], whereas others may do so. 

Very little agent mass is needed to extinguish a fire if it is delivered such that it 

encompasses a fuel source. Re-ignition protection, however, is also a concern for both 

underbody and engine compartment fires. In an underbody fire, a burning fuel trail poses 

the possibility of re-igniting a suppressed fuel puddle. In an engine compartment, reignition may occur due to a hot ignition source such as a battery or an electrically 

generated spark or arc. An agent that cools a hot surface, isolates the fuel from the 

ignition source, or isolates ambient air from the fuel and ignition source could afford 

protection in these cases. 

To improve distribution of a suppressant, judicious engineering coupled with 

experimentation is needed. To provide re-ignition protection, a suitable suppressant must 

be selected. The following agents are suppression candidates that warrant further testing. 

3.4.1 Powder Panels 

The advantage of a passive system such as a powder panel rests in its simplicity. Fire 

protection systems comprised of several components (such as a suppression system that 

requires active detection) risks failure at each link in the system. While the powder panel 

tested by Ford may or may not have weaknesses, further testing of enhanced powder 

panel designs may be beneficial. The results of Cyphers and coworkers [2003] suggest 

that enhanced powder panel designs can improve powder distribution (see Section 2.6 

above) and possibly suppression effectiveness. 

There are a series of experiments that would be useful to consider to fully test this 

technology for vehicle fire suppression. It would be useful to test the effect of particle 

size distribution, powder type, powder amount, and enhanced powder designs on 

suppression effectiveness for fuel tank protection in conjunction with rear-end collision 

scenarios. A key component of the success of this technology will be inerting the ignition 

or suppressing a fire associated with a gasoline trail extending beyond the vehicle 

footprint. 

Experiments by Hamins [2000] suggest that demonstration of this technology in engine 

compartment fire scenarios has a low probability of success. This is because the engine 

compartment scenario demands that agents be propelled to all corners and behind all 

engine components to provide comprehensive protection. Traditional powder panels do

not provide momentum to propel the powder. Also, since the entire compartment needs 

21
protection, the panels would need to encase the entire compartment. A crash or thermally 

actuated panel may be useful for suppressing fires that occur just below the hood of an 

engine compartment. In fact, an after-market product named FirePanel uses the powder 

panel technology, and claims to have found a commercial niche in racing cars and police 

cruisers. 

3.4.2 Foams 

It would be useful to test the effectiveness of high expansion foams to defend against 

both engine compartment fires and underbody fuel fed fires. Some work is currently 

underway in this area by di Marzo (engine compartment) and Aerojet/Ford Motor Co. 

(underbody fuel tank protection). Previous work in this area was reported by Lim et al., 

[1997] who used a foam expansion ratio of 62 to extinguish engine compartment fires in 

uncrashed vehicles. Di Marzo suggests that this expansion ratio is too low [Gunderson 

and DiMarzo [2004]. A limited number of tests by DiMarzo are encouraging and have 

demonstrated the potential for foam as a suppressant of small flames, and certainly as a 

method to significantly reduce the risk of delayed underhood ignition. Ultimately, this 

technology remains to be proven in experiments that combine vehicle collisions and fires. 

Some details of the Aerojet/Ford approach to fuel tank protection have been made public 

[Dierker, 2005; Ford, 2006], and a two suppressant approach has been implemented. The 

primary suppressant (SPGG) is used to knock-down the fire and a secondary suppressant 

(foam) is used to prevents re-ignition, possibly by a gasoline trail. The foam expansion 

ratio in this arrangement would have a bearing on the results. Detailed information on 

these effects would be helpful in suppression system design. 

 

Di Marzo [2004] proposes using N2 to drive foam expansion, whereas it has been 

announced that Aerojet is using solid propellant generators in their apparatus [Ford, 

2006]. This suggests that the foam is being driven by the SPPG effluent - composed 

mainly of N2, CO2, and H2O. Di Marzo used a high expansion ratio foam with a volume 

expansion factor of nearly 200, in which the foam is essentially stable and a liquid water 

solution does not leak from the foam [Gunderson and DiMarzo, 2004]. The experiments 

of DiMarzo show that the foam system is capable of suppressing some types of fires in 

the engine compartment. Further work may be able to show that it is effective for 

suppression of ignition. In this sense, the results of this study lay the groundwork for 

further studies on under-hood fire suppression by foam. 

It may also be useful to consider driving the foam expansion with gases other than 

nitrogen. There are many gaseous suppressants that are more effective on a volumetric 

basis than gaseous nitrogen. The more effective the suppressant, the higher the 

probability that fire suppression will be achieved. Although many agents are as effective 

as nitrogen on a mass basis, a more important criterion is effectiveness on a volumetric 

basis. Candidate agents must meet certain requirements as outlined in the report, such as 

Reynolds number, partial pressure and agent compatibility with tubing, fittings, etc. 

Agents that might be considered include CO2 or the low boiling point (Tboil < 40 o

C) 

fluorinated agents such as CF4, CF3H, and C2HF5, which are significantly more effective 

fire suppressants than nitrogen on a volumetric basis. For example, CO2 and C2HF5

22
require 23 % and 9 % by volume (respectively) in the air stream to extinguish heptane 

cup burner flames as compared to 32 % by volume for N2. Cold weather considerations 

may limit the use of higher molecular weight compounds such as C2F6 and C2HF5, 

although they might be considered an option in warmer climates. 

It should be noted that the combustion of fluorinated compounds leads to the formation of 

HF, which is toxic. If it is determined that the suppression effectiveness of fluorinated

driven foams are more effective than inert compounds (N2 or CO2) for the engine 

compartment fire scenario, then measurements of HF in the passenger compartment 

during suppression would be necessary. 

A further consideration is the use of high expansion foam to mitigate an underbody fuel 

fed fire. The use of a more effective agent than gaseous nitrogen would be useful in this 

case (see above). Protection may be afforded by rapidly filling the entire underbody 

footprint with a thick blanket of foam, which would effectively choke off the ambient air. 

Rapid delivery of the foam may be advantageous, depending on the rate of the gasoline 

leak. In this regard more than one release point for the foam may be beneficial. DiMarzo 

suggests that future work should include more tests on a wider variety of fires that start 

within the engine compartment, and try to extend the system to protect against pool fires 

that originate below the engine compartment [Gunderson and DiMarzo, 2004]. 

3.4.2.1 Foam Freeze protection 

The viability of foam is limited by freeze protection. This is a significant issue that needs 

to be addressed. Addition of anti-freeze to foam may decrease the foam expansion ratio 

and may cause other significant penalties in terms of materials compatibility, suppression 

effectiveness, or other issues. Foam concentrate/water solutions (with anti-freeze) have 

been found to be limited to volume expansions of ≈3 to 30 [Madrzykowski, 1999]. The 

expansion ratio is important because in a simplified sense, the larger the expansion, the 

larger the volume that can be filled for a given mass of foam. A comprehensive search

for foam freeze protection by a research chemist may be of value. 

Another approach would be to consider active heating of the foam solution under 

freezing conditions, perhaps electrically or by use of a heat exchanger, taking advantage 

of heat from the engine or the exhaust system. The effects of heating and temperature 

cycling on foam behavior and storage life would need investigation if this approach is 

considered. 

3.4.3 Solid Propellant Generators and Their Hybrids 

The use of hybrid technology with solid propellant generators offers an intriguing 

approach to the vehicle fire problem. The hybrid approach utilizes the effluent of the 

solid propellant generator to propel a suppressant, such as a compressed liquid or foam. 

Ford selected Aerojet’s approach based on demonstration of their technology in 

suppressing an underbody fuel fed fire. It may be useful to test the Aerojet [Ford, 2006] 

approach on engine compartment fires. The primary suppressant (SPGG) would knock 

down the fire and a secondary suppressant (foam) would prevent re-ignition. Such an 

approach is the basis of the Ford system. 

23
 

3.4.4 Other Suppressants 

The problem with most other fire protection systems (clean agents, halogenated 

compounds, powders, water mist, tubular extinguishers, etc.) is their failure to address 

protection from re-ignition by a gasoline trail in the case of the underbody fuel fed fire or 

hot surface re-ignition in the case of the engine compartment fire. 

In an engine compartment, water mist could have some cooling effect on hot surfaces and 

lower the likelihood of re-ignition, but many parameters would play a role and there is 

little guarantee of success. The same is true for ABC powder, which interacts with 

burning materials to form a hard non-combustible coating. ABC powder (NH4H2PO4,

mono-ammonium phosphate) is unique among the powders. When in contact with a hot 

surface it reacts to form cross-linked polyphosphoric acid [Camino et al., 1994], a glassy 

impenetrable substance that can smother a smoldering fire and create a layer of insulation 

over a hot surface, which can diminish the likelihood of re-ignition. Other powders can 

also be expected to affect smoldering fires and prevent hot surface ignition, but mainly 

through physical processes rather than through a combination of chemical and physical 

processes. The success of these agents in preventing re-ignition will depend on may 

parameters including the hot surface temperature and the amount of powder that covers it. 

Like water mist, powders could lower the likelihood of re-ignition, but many parameters 

play a role and there is no guarantee of success. 

3.5 Other Issues 

3.5.1 Economic Survey 

An economic study/survey to define consumer willingness to pay for on-board fire 

protection suppression systems would be useful to gauge. Demand from risk-averse 

consumers has driven expanded application of air bags in vehicles, such as in the use of 

side impact bags. A survey of consumers informed on the costs and benefits on the use 

of on-board fire suppression systems would inform vehicle manufacturers to the 

economic and marketing advantages in offering enhanced safety options. Decreased risk 

of fire injury and fatality must be weighed against decreased gas mileage, increased 

initial purchase costs, and maintenance issues. 

It may also be possible to justify the expense of enhanced fire safety on vehicles based on 

possible reduction of cost to society. Property damage (vehicle and structures) due to 

vehicle fire is estimated to be over $1 B [Ahrens, 2005]. The cost to the community in 

terms of use of the fire service for non-collision fires should also be considered. Public 

fire departments responded to an estimated 297,000 vehicle fires in the United States 

during 2004, almost 19 % of the total number of reported fires. These fires caused an 

estimated 550 civilian deaths and 1,500 civilian injuries [Ahrens, 2005]. 

3.5.2 Firewall on Demand 

Research supported through the NGP has pioneered the novel approach of using strategic 

placement of an intumescent material to reduce the cross-sectional area of the engine 

nacelle in an aircraft in the event of a fire. This approach creates an “instant firewall” and 

24
allows achieving required concentrations with smaller amounts of suppressant. 

Intumescent materials, however, can take tens of seconds to expand [Hamins, 1998] 

and may fail. This is because typical intumescent materials are one-dimensional in their 

expansion and any holes in these materials fail to close during this process. However, 

holes in the firewall are just one pathway into the passenger compartment. Another 

common pathway is flames breaking through the windshield and molten flaming 

thermoplastic dripping and igniting materials within the passenger compartment. 

Consideration of other approaches to creating barriers should be considered. This may 

include the use of non-flammable lightweight materials that drop down from a vehicle 

body panel to the ground, forming a barrier that serves to confine subsequent release of a 

suppressant and prevent air entrainment to the underbody, for example. Another option 

that has been proposed is a non-flammable hood insulation that would detach under heat 

and subsequently fall, blanketing the engine compartment and smothering a fire. There 

has been no documented independent testing to demonstrate the effectiveness of this 

technology. Fournier and Bayne report on the flammability of some 20 underhood 

insulation blankets using the cone calorimeter [2006]. 

3.5.3 Crashworthiness 

Much research remains to determine the crashworthiness and placement strategies 

associated with fire suppression hardware in post-crash vehicle applications. Some

amount of empirical crash testing must be conducted to assure survivability and 

functionality. 

3.5.4 Computer fire models

Despite a modest investment, results from the NGP program suggests that computational 

fluid dynamic simulations of fire suppression are not sufficiently developed to assist in 

the design of fire suppression systems for vehicle applications. The extension of 

computer fire models to vehicle fire scenarios is a long term project that may require a 

decade of investment to reap reward. Some modeling has been reported by Barnett 

[Wittasek, 1997]. Additional research is needed to develop effective suppression 

modeling tools. 

3.5.5 Passive Fire Protection 

Passive fire protection systems such as self-sealing fluid lines, enhanced crashworthiness 

of the fuel tank, and fluid shut-off devices are a viable strategy for post-collision fire 

protection that has not been fully investigated. Some recent research on a passive fire 

protection technology has been conducted by Ford. Ford tested an aftermarket fuel tank 

bladder and made their results public [Ford Motor Co., 2004b]. Fuel tank bladders are 

flexible liners that are intended to reduce the risk of fuel leakage after a collision. Ford 

tested the bladder with a foam insert, which prevented the liner from collapsing when the 

tank was not filled with fuel. Ford reported that bladders are required on some race 

circuits. 

Ford evaluated the bladder tank technology offered in the aftermarket by "Fuel Safe" to 

Ford's internal fuel system test protocol, which is composed of a battery of 73 different 

25
tests. Testing was completed in June 2003 on 50 samples. A summary of important 

results from the Fuel Safe bladder tank testing is posted on the Ford web site [Ford, 

2004b]. In summary, Ford expressed concern on the quality, durability and maintenance 

associated with the handmade bladder tanks that they tested. Issues included 

disintegration of the foam and conditions of engine “fuels starve” under certain 

conditions. Ford concluded that fuel bladders have never been successfully used in a 

mass-production, high-mileage or severe duty-cycle vehicle application and that as of 

now, the Fuel Safe fuel tank bladder does not meet Ford’s fuel tank testing requirements. 

Preventing post-collision fuel and underhood fluid leaks avoids the need for active fire 

suppression. It is a strategy that appears to have merit. Indeed, fuel tank protection may 

be the most practical approach to address the post collision underbody fuel fed fire 

scenario. Further research in this area may be warranted. 

4. Summary and Recommendations 

Much has been learned over the last decade in fire suppression research and more 

recently from vehicle fire suppression testing. This report attempts to summarize this 

research and to identify future research needs for automotive fire protection. This report 

on vehicle fire suppression research needs was not written with any particular dollar 

amount or timeline in mind. Nor does it propose one particular technology or line of 

research over another as the solution to the automotive fire suppression problem. Instead, 

the report proposes a series of interrelated activities, which could contribute to the 

development of an integrated program on automotive fire suppression research. 

Data from NHTSA’s Fatality Accidents Reporting Systems (FARS) shows that since 

1990, there has been a significant reduction in rear-end fires from fuel leakage [Digges, 

2007]. Among other reasons, this may be due to the implementation and improved 

effectiveness of a number of technologies that prevent crash-induced fuel leakage from 

severed lines connected to the fuel tank [Digges and Stephenson, 2007]. This suggests 

that the implementation of vehicle fire suppression systems may be most beneficial for 

underhood fires, particularly in frontal and rollover crashes. Past work has emphasized 

suppression of engine compartment fires and underbody fuel fed fires. Future research 

should also consider post-collision suppression of vehicle fires after rollover, as the fire 

risk in rollover is 2 times that in frontal crashes [Digges, 2007]. Underhood fires may 

rise in frequency as the amount of thermoplastic increases underhood, while the number 

of fatalities in rollovers has increased over the last two decades [Digges, 2007]. 

Through work with the automotive industry, it is clear that there is a tremendous amount 

of information in the field of fire safety that is proprietary. While this may be true in 

many endeavors undertaken by industry, the nature of safety related information is 

qualitatively different. Cooperation among industry leaders in this regard would promote 

accelerated development of technologies to improve life safety associated with mitigation 

of post-collision vehicle fires. 

The implementation of an effective light inexpensive on-board fire suppression system

would be a significant step in reducing fire fatalities, injuries, and property losses. One 

26
major impediment to vehicle fire safety is the lack of standards in this area. The only 

related existing requirement, the 1968 Federal Motor Vehicle Safety Standard (FMVSS) 

301 Fuel Integrity Test for vehicles has not adequately addressed the post-collision 

vehicle fire problem as fire losses associated with vehicles are significant. The 

implementation of a standard performance test that directly addresses post-collision 

vehicle fires would allow the market to respond to this national problem, and allow the 

public to have confidence that a commercially-available technology is effective. 

27
5. References 

Ahrens, M., “U.S. Vehicle Fire Trends and Problems,” National Fire Protection 

Association, Quincy, MA, August 2005; Report available at http://www.NFPA.org. 

Bennett, JM, “Survey of Fire Intervention Technologies for Their Potential Application 

in Motor Vehicles,” Report NHTSA 98-3588-31, 1998; available at http://dms.dot.gov

docket 3588, report 31. 

Bennett, JM, “Principles, Testing and In-Field Experience for the Fire Panel Fuel Tank 

Protection Device,” Paper 2005-01-1790, SAE 2005 World Congress, Detroit, April 13, 

2005. 

Bolt, W., Herud, C., and Treanor, T., “Halon Replacement Program for Combat Vehicles, 

A Status Report,” Proceedings of the Halon Options Technical Working Conference, 

Alberquerque, NM, May 1997. 

Camino, G., Luda, M.P., and Costa, L., “Developments in Intumescent Fire-Retardant 

Systems,” Chapter 6 in Fire and Polymers II (ed.: G.L. Nelson), ACS Symposium Series 

599, American Chemical Society, Washington D.C., 1995. 

Cyphers, D.C., Frederick, S.A., Haas, J.P., Enhanced Powder Panels, Proceedings of

HOTWC-2002 12th Halon Options Technical Working Conference, Albuquerque, NM, 

April 20 – May 2, 2002 (R.G. Gann and P.A. Reneke, Eds.) NIST Special Pub. 984, June 

2002. 

Dierker, J.B., Thompson, R.H., and Wierenga, P.H., Development of Ford Fire 

Suppression System, SAE World Congress, Fire Suppression Session (B-27 Forum),

Paper 2005-01-1791, April 2005. 

Digges, K.H., A Research Program to Improve Impact Related Fire Safety, 20th 

International Technical Conference on the Enhanced Safety of Vehicles (ESV), to appear, 

June 2007, Lyon, France.

Digges, K.H., and Stephenson, R.R., “Summary of Recent Research in Crash-Induced 

Vehicle Fire Safety,” Paper 2006-01-0551, SAE World Congress, Detroit, MI, April 

2006. 

Digges, K.H., and Stephenson, R.R., “Recent MVFRI Research in Crash-Induced 

Vehicle Fire Safety,” Paper 2007-01-0880, SAE World Congress, Detroit, MI, 2007. 

Fire Panel Vehicular Fire Protection Systems, http://www.firepanelllc.com/frameset1.html, 

2006. 

Ford Motor Co., website on the Crown Victoria Police Vehicle, http://www.CVPI.com, 

2004a. 

28
Ford Motor Co., Fuel Safe Bladder Tank Test Status, 

http://www.cvpi.com/bladder_tank_test.htm, 2004b. 

Ford Motor Co., Fire Suppression, http://www.cvpi.com/fire_suppression.htm, 2004c; 

reproduced in Appendix B. 

Ford Motor Co. Automatic Fire Suppression System (60S), CVPI/Ford website 

(https://www.fleet.ford.com/showroom/CVPI/FireSuppression.asp) 2006; see Appendix 

D. 

Fournier, E., “Under Hood Temperature Measurements of Four Vehicles,” Report No.: 

R04-13 b, Biokinetics and Associates Ltd., Ottawa, Canada, September 2004, Final 

Report for the Motor Vehicle Fire Research Institute, available at: http://www.mvfri.org/. 

Fournier, E. and Bayne, T., “Flammability of Underhood Insulation Materials,” SAE 

World Congress, Paper 2006-01-1011, Detroit, MI, April 2006.

Friedman, K., Kenney, T., Holloway, E, “Impact Induced Fires and Fuel Leakage: 

Statistical Analysis of FARS and State Data Files (1978-Present),” Friedman Research 

Corporation, October 2003, Available at http://www.mvfri.org/Contracts/friedman.html

Friedman, K., “Impact Induced Fires: Statistical Analysis of FARS and State Data Files 

(1978-2001); Paper 2005-01-01421, SAE World Congress, Detroit, MI, April 2005. 

Grosshandler, W. L. (Ed.), “Fire Resistance Determination and Performance Prediction 

Research Needs Workshop,” NISTIR 6890, Sept. 2002. 

Gunderson, J. and di Marzo, M., “Nitrogen Fire Suppression System for Automobile 

Under-hood Post-collision Fire Protection,” Fire Protection Engineering Department, 

University of Maryland, College Park, MD, Nov. 2004, Final Report for the Motor 

Vehicle Fire Research Institute, available at: http://www.mvfri.org/. 

Hamins, A., "Evaluation of Intumescent Body Panel Coatings in Simulated Post-Accident 

Vehicle Fires," August 1998, Docket # NHTSA-1998-3588-24, National Institute of 

Standards and Technology, Gaithersburg, MD. 

Hamins, A., “Evaluation of Active Suppression in Simulated Post-Collision Vehicle 

Fires,” NISTIR 6379, National Institute of Standards and Technology, Gaithersburg, MD, 

November 2000; also available as Report NHSTA 98-3588-132, 2000 at 

http://dms.dot.gov docket 3588, report 132; or http://www.mvfri.org/Library/b-04.html 

Halon Options Technical Working Conference (HOTWC). Albuquerque, NM, 1991-2003 

29
Hodges, S.E. and Simpson, G.D., “Effective Technologies for Fire Sensing and 

Suppression on Transit Vehicles,” American Public Transportation Association (APTA) 

Bus Operations and Technology Conference, May 1995. 

Hughes Associates, Inc., “Review of Ford Motor Company’s Test of Fire Panel in a 

Simulated Rear Collision Scenario,” Prepared for FIRE Panel Vehicular Fire Protection 

Systems, July 31, 2003. http://www.firepanelllc.com/pdfs/Review of Ford Motor Company -

FIRE Panel Test.pdf

Jensen, J.L. and Santrock, J., Evaluation of Motor Vehicle Fire Initiation and 

Propagation Vehicle Crash and Fire Propagation Test Program, NHTSA-98-3588-38; 

1999; also available at http://dms.dot.gov docket 3588, report 38, or at 

http://www.mvfri.org/Library/b-03.html

Jenson, Jack L., and Santrock, Jeffrey, "Evaluation of Motor Vehicle Fire Initiation and 

Propagation Part 1: Vehicle Crash and Fire Propagation Test Program," General Motors 

Corporation (July 1997); available at http://dms.dot.gov docket 3588, report 38, or at 

http://www.mvfri.org/Library/b-03.html

Jenson, Jack L., and Santrock, Jeffrey, "Evaluation of Motor Vehicle Fire Initiation and 

Propagation Part 2: Crash Tests on a Passenger Van," (September 1998) Docket # 

NHTSA-1998-3588-30, General Motors Corporation. available at http://dms.dot.gov

docket 3588, report 38, or at http://www.mvfri.org/Library/b-03.html

Lim, Sung-Mook, Jung, Ki-Chang, Kang, Young-Goo, Kim, Hong, “A Study on the 

Assessment of the Performance of the Automatic Fire Suppression System Using the 

HCC-227ea Liquefied-Gas Filled AFFF Fire Extinguisher,” International Symposium on 

Fire Science and Technology, 1997, p. 590. 

Madrzykowski, D., NIST, Personal Communication, 1999. 

Porreto, J., Naples Daily News, Naples, FL., August 7, 2003; reproduced in Appendix A. 

Ragland, C.L. and Hsia, H.-S., “A Case Study of 214 Fatal Crashes Involving Fire,” 

Paper Number 9X-S4-O-08, The Sixteenth International Technical Conference on the 

Enhanced Safety of Vehicles, Windsor, June 1998. 

Santrock, J. and Hodges, S.E., Project B.14 - Demonstration of Enhanced Fire Safety 

Technology – Fire Suppression Systems, Part 2A: Evaluation of Fire Suppression 

Systems in a Full Scale Vehicle Fire Test and Static Vehicle Fire Tests. NHTSA-98-

3588-202; 2002; also available at http://dms.dot.gov docket 3588, report 202; or 

http://www.mvfri.org/Library/b-14.html 

Santrock, J., "Evaluation of Motor Vehicle Fire Initiation and Propagation Part 3: 

Propagation of an Engine Compartment Fire in a 1996 Van Passenger," (August 2001) 

Docket # NHTSA-1998-3588-119, General Motors Corporation. http://dms.dot.gov

docket 3588, report 38, or at http://www.mvfri.org/Library/b-03.html

30
Santrock, J., and Hodges, S., “Evaluation of Automatic Fire Suppression Systems in Full 

Scale Vehicle Fire Tests and Static Vehicle Fire Tests,” Paper 2005-01-1788, SAE 2005 

World Congress, Detroit, April 13, 2005. 

Scheibe, R.R., Shields, L.E., Angelos, T., “Field Investigation of motor vehicle collision 

fires,” NHTSA-98-3588-164, 2001; also available at http://dms.dot.gov docket 3588, 

report 164; or http://www.mvfri.org/Library/b-02.html

Walton, W.D., Bryner, N., and Jason, N.H., “Fire Research Needs Workshop 

Proceedings,” Emmitsburg, MD October 20, 1999, NISTIR 6539, 1999a. 

Walton, W.D., Bryner, N., Madrzykowski, D. Lawson, J.R., Jason, N.H. (Eds.), “Fire 

Service Needs Workshop Proceedings,” San Antonio, TX October 13-15, 1999, NISTIR 

6538, 1999b. 

Wichman, I., Prog. Energy Combust. Sci., 29, 247-199, 2003 

Wittasek, Nathan B., Pehrson, Richard D., and Barnett, J.R., "Computational Fluid 

Dynamics Modelling of Post-Crash Vehicle Fires," (May 1997) Docket # NHTSA-1998-

3588-209, General Motors Corporation. 

31
Appendices 

The appendices contain information that is cited in the body of this report. Information is 

typically taken from sites on the Internet. This appendices document the information by 

providing a complete citation and by reproducing it here. This is important, because 

information posted on the Internet is typically not archived, nor is it permanent. It is, 

however, useful in tracking the development and commercialization of fire suppression 

technology. 

Appendix A 

 

Naples Daily News, Naples Florida, Thursday, August 7, 2003. 

Ford to offer fire-suppression equipment on Crown Victoria police cars 

By JOHN PORRETTO, Associated Press 

TRAVERSE CITY, Mich. — Ford Motor Co. said Wednesday it will begin offering 

fire-suppression technology on its Crown Victoria police cars, which have been linked to 

numerous deaths in rear-end collisions that caused gas-tank explosions. Ford 

spokeswoman Carolyn Brown confirmed the new equipment would be used but said 

details were being withheld until a news conference Thursday in New York. At an 

automotive seminar Wednesday in this resort city, Ford president and chief operating 

officer Nick Scheele declined to discuss the new technology. About the Crown Victoria, 

Scheele told reporters, "It's a very safe vehicle, but it's got some very difficult usage 

conditions." Police unions and some political leaders have complained about the safety 

record of the Crown Victoria Police Interceptor, which is used by about 85 percent of all 

police departments. Since 1983, 14 officers have died in crashes when their Crown 

Victoria's gas tank caught fire after being hit from behind. In the past several years, the 

cars have been the subject of numerous lawsuits and a federal investigation. 

Although Ford denies the cars are dangerous, about a year ago the company initiated a 

program of retrofitting older models with plastic shields designed to better protect the gas 

tanks. It is unclear if Ford will install the new fire-suppression technology in Crown 

Victorias sold to the public. The National Highway Traffic Safety Administration has 

said the car meets current federal standards that require a vehicle to withstand a rear crash 

at 30 miles per hour without leaking fuel. The agency also said the vehicle did not leak 

fuel during a test at 50 miles per hour, which the agency has proposed to be the new 

standard. Ford shares rose 13 cents to close at $10.65 in trading Wednesday on the New 

York Stock Exchange. 

32
Appendix B 

(Ford Motor Co., Fire Suppression, http://www.cvpi.com/fire_suppression.htm, 

2004c.) 

Fire Suppression

Ford is actively evaluating fire suppression technologies. Current fire suppression 

systems remain unproven for a mass-produced, high-mileage vehicle. Existing racecar 

systems are not adaptable because they require the driver to deploy the fire suppression

system (driver's are typically incapacitated following rear crashes severe enough to 

produce a fuel leak) and involve a fire suppressant material that may not be appropriate in 

the police vehicle application because it is not breathable. 

As part of the Police Officer Safety Action Plan, Ford tested eight fire suppression 

systems. Part of our testing involved fire-involved moving vehicles. Following a 75 mph 

rear impact, the struck vehicle typically moves 100' –200', and our test protocol was 

designed to simulate such movement. Testing the competing technologies in a movingvehicle environment was important to our evaluation of the competing systems' rearworld performance. Our test protocol guaranteed both a fuel leak and ignition of the fuel 

so as to properly evaluate the fire suppressant technologies – many fuel leaks do not

result in ignition, so a test of a fire suppressant system is invalid if an ignition source is 

not present. Significant conclusions reached during the testing include the following: 

Fuel leaks that begin near the point-of-impact may leave a 75-to-200-foot fuel trail to the 

point-of-rest of the vehicle. 

Ignition of this fuel trail can occur when the deformed vehicles scrape the road surface 

and create sparks while passing through or along the fuel trail. Other ignition sources 

may be present after the time and point-of-impact. The ignited fuel trail can trace forward 

to the vehicle at its point-of-rest, which may be 50-, 100- or 200-feet from the point-ofimpact. An ignited fuel trail can initiate a fire at the vehicle's point-of-rest if there is 

continuing leakage of a sufficient amount of fuel at the point-of-rest. The fire is not 

intense at the passenger compartment until the vehicle is stationary, and unless there is a 

continuing leak at the point-of-rest. Challenges associated with packaging the fire 

suppression substance and system, while still allowing the vehicle to function effectively 

as a police vehicle, necessarily limit the quantity of the available fire suppression 

substance. The optimal time for deploying the limited amount of the fire suppression 

substance is near the point-of-rest, which can be seconds after and more than 200 feet 

beyond the point-of-impact. Wind, ground surface and road grade are factors in fire 

propagation. No vehicle fire suppression system can extinguish a fire fed by large 

quantities of gasoline. 

In our testing for the vehicle application, liquid fire suppressants combined with 

surfactants performed better than foams or powders due, in part, to the ability of that 

substance to spread – like gasoline – beyond the direct reach of the deployment nozzles 

and to cover the gasoline. This combined substance more effectively reduced the risk of a 

33
re-ignition at the point-of-rest of the vehicle when the fire is not completely extinguished 

at, for example, the fuel trail or on the protected/outboard side of the rear wheels. 

Fire Suppression Technology—Next Steps

As part of Ford's commitment to law enforcement to advance the state of the fire in fire 

suppression technology, Ford is taking the following steps: Ford has selected Aerojet as 

the fire suppression vendor to jointly pursue further development of this technology for 

the police vehicle application. Aerojet's technology uses a pyrotechnic gas generator to 

deploy a combination liquid fire suppressant and surfactant. A surfactant is used because 

it reduces the surface tension of the liquid fire suppressant, thereby enabling the liquid to 

spread more quickly and completely. 

This technology was initially developed and tested for use in the interior of U.S. military 

armored personnel vehicles. The external application on the CVPI requires further 

development of this promising technology. Ford will likely use advanced electronics

modules to measure post-impact vehicle movement and to determine the optimal time for 

deployment of the fire suppression system. As explained above, it is important that the 

limited quantity of fire suppressant material be deployed at or near the point-of-rest of the 

vehicle rather than only at the point-of-impact. The sophisticated electronics required for 

crash-activated and delayed deployment prohibit offering an after-market product. 

In May 2003, Ford and Aerojet will conduct about 30 fire suppression tests on a CVPI to 

learn more about the effect of varying fuel quantity, fuel spill rates, re-ignition, discharge 

timing and shadow (fire behind the rear-wheel) effects. Beginning in June 2003, Ford 

and Aerojet will focus on integrated product development and design validation of the 

CVPI fire suppression system. While Ford and Aerojet will conclude a substantial 

portion of the design and development work by year-end 2003, it is premature to predict 

suitability of this technology to the CVPI application, let alone estimate pricing or timing. 

Ford will update the police community through our website, www.CVPI.com, as progress 

warrants. 

Fire Suppression Technology—Fire Panel

In September 2002, plaintiffs' lawyers held a press conference announcing that the Fire 

Panel product successfully prevented ignition in a crash test. Because the fuel tank in that 

test was not full and ignition was not guaranteed, Ford does not believe that that test had 

engineering validity. Regardless, F.I.R.E. Panel subsequently approached Ford seeking 

an evaluation of its "Fire Panel" product. Ford evaluated the Fire Panel product 

consistently with its evaluation of the other fire suppression products. 

Fire Panel is essentially a fire suppressant powder that is stored in a plastic casing taped 

to the fore side of the fuel tank. The plastic casing is intended to shatter, and thereby 

release its powder, in a high-speed rear impact when the fuel tank is pushed into the rear 

axle. After evaluating and testing this technology, Ford offers the following conclusions: 

Fire Panel releases its fire suppressant powder at the point-of-impact. Little or no powder 

is released at the critical time and place of the point-of-rest of the vehicle. 

34
The technology offers little or no protection against fires occurring at the vehicle's pointof-rest; if the fuel trail is ignited or any other ignition source is present after the time and 

place of impact, the Fire Panel technology provides little or no benefit. 

The powder distribution can be adversely affected by wind and other weather conditions. 

Because the Fire Panel product insulates and is attached to the fuel tank, it may increase 

the temperature of the fuel and cause performance, durability and maintenance concerns. 

Moisture and road debris trapped between the 1⁄4" gap between the Fire Panel and the fuel 

tank could cause degradation of the steel fuel tank. Either of these concerns could lead to 

significant out-of-warranty maintenance problems, and potentially degrade fuel system 

safety. 

The Fire Panel design did not adequately address mounting and fastener robustness. 

During one test, the entire Fire Panel actually detached from the vehicle upon impact and 

thereby failed to deploy its fire suppressant powder. Due to the inadequate mounting 

methods, the large plastic panel could also detach from the vehicle during normal driving, 

potentially creating a road hazard for other motorists. For these and other reasons, Ford

does not support the Fire Panel aftermarket product offered to police fleets. 

35
Appendix C 

Ford Motor Company News Release 

Available on the Ford website:

(http://www.aerojet.com/program/news/nr_080703fd_ford_introduces_industry_first_polic

e_vehicle_tech.htm?program_ID=64) on July 28, 2006.

FORD INTRODUCES INDUSTRY-FIRST POLICE VEHICLE TECHNOLOGY 

NEW YORK, NY, August 7, 2003 - Ford Motor Company and New York State Senator 

Nicholas Spano today announced an important step to protect police officers. During the 

2005 model year, Ford plans to offer a fire suppression system as a factory option on 

Crown Victoria Police Interceptors. This is an automotive industry first. The 

announcement today is part of a holistic approach by Ford and the law enforcement 

community to reduce the risk of fire-related injuries to police officers from high-speed, 

high-energy rear crashes. 

In recent months, Ford and representative members of the law enforcement community 

formed a Blue Ribbon Panel and Technical Task Force to reduce the risks faced by police 

officers in highway stops. Law enforcement personnel, independent experts, component 

suppliers and Ford personnel worked in a number of areas, including improving 

communications with a dedicated website – www.cvpi.com. The initial results, including 

the Upgrade Kit designed to shield the Crown Victoria Police Interceptor's fuel tank from

vehicle components, were announced and published on the website for broad and quick 

dissemination. Ford also has developed a Trunk PackTM to allow police officers to locate 

police equipment more safely. In addition, Ford engineers have worked with members of 

the law enforcement community to evaluate alternative traffic stop procedures in a 

manner that reduces the officer's exposure to danger. Ford also is encouraging state 

legislators to pass "move-over" laws in their states to protect officers in their line of duty. 

"Today's announcement is further evidence of Ford's commitment to police officer 

safety," said Sue Cischke, Ford Motor Company vice president, Environmental and 

Safety Engineering. "We have already advanced the safety of the Crown Victoria Police 

Interceptor well beyond governmental regulations or industry practice. However, until 

we, as a society, eliminate high-speed accidents, we will never eliminate the risk of fire. 

The potential of a fuel leak, while rare, is part of the risk of every high-speed accident. 

Therefore, we believe the actions we are taking to introduce fire suppression technology 

will help save lives." 

Ford is developing a fire suppression system with Aerojet, a supplier for the United 

States military with the technology initially developed and tested for use in the interior of 

U.S. military armored personnel vehicles. The system uses advanced electronics and onboard sensors to measure post-impact vehicle movement to determine the optimal time 

for deployment of the fire suppression material. The system will be integrated into the 

CVPI's structure and electrical architecture. Ford and Aerojet conducted joint testing of 

many different fire suppression formulas and dispersal methods. Ford and Aerojet will 

continue to validate the effectiveness and reliability of fire suppression in an automotive 

application. "This is a monumental day for law enforcement across the country," Senator 

Spano said. "Ford deserves credit for their commitment to creating this technology. It 

36
represents a major first step in reducing fuel tank fires that have unfortunately taken the 

lives of officers across the country." 

Additionally, the National Highway Traffic Safety Administration is joining with the 

International Association of Chiefs of Police to look at broader issues of police officer 

safety. Four members of the original "Blue Ribbon Panel" will participate in the 

IACP/NHTSA Joint Panel. They will focus on three areas initially: police procedures, 

police equipment and enhancing the safety of vehicles traveling on the nation's highways. 

Information from the Joint Panel will be available on the www.cvpi.com website. 

37
Appendix D 

This appendix contains information released by Ford on the Automatic Fire 

Suppression System (60S), which was an optional package on their 2006 model Crown 

Victoria Police Interceptor. This information was obtained from the CVPI/Ford website 

on July 28, 2006. (https://www.fleet.ford.com/showroom/CVPI/FireSuppression.asp; 

Fire Suppression 

The Ford Fire Suppression System 

is designed to reduce the risk of 

injury in high-energy rear impacts by

deploying chemicals designed to

suppress the spread of fire or 

potentially extinguish a fire. By doing 

so, it provides more time for 

occupants to either escape from a 

crashed vehicle or be removed from 

the vehicle by outside persons. 

 

 Ford offers the Fire Suppression System as a factory option. The 

FSS is an automotive industry first.

Development testing showed that the best time for deploying the limited amount of fire suppression

substance is near the point of-rest, which can be seconds after, and more than 200 feet beyond, the point of 

impact. It also showed that liquid fire suppressants, combined with surfactants, performed better than foams 

or powders due, in part, to the ability of these substances to stay with the fuel source and to spread, like 

gasoline, beyond the direct reach of the deployment nozzles and to cover the gasoline. 

The Ford system uses advanced electronics and on-board sensors to measure

post-impact vehicle movement to determine the optimal time for deployment of 

the fire suppression material. The system is integrated into the Police 

Interceptor’s structure and electrical architecture. 

Robust Test Procedure 

The Ford Fire Suppression system was tested in 75 mph rear impact collisions in 

which gasoline and ignition were artificially provided. 

Test Protocol 

A consistent, repeatable test protocol is required for testing in order to properly 

evaluate the system and any changes that are made during the development 

phase. 

System Sketch – Total Vehicle 

38
The system consists of: 

• Two stainless steel 

containers that hold the fire 

suppressant material and 

gas generators used to 

pressurize and deploy the 

suppressant material. 

• Two manifold assemblies, 

each with two deployable 

nozzles, which spray fire

suppressant down onto the 

ground. 

 

• An additional manifold, mounted high with two fixed nozzles, which sprays fire suppressant material

up and into the body. 

• The electronic control module (located under the rear seat). The module contains the rear crash 

sensor, the processing computer, and a large electrical capacitor for backup system power in case 

vehicle electrical power is lost. 

• Two redundant wiring harnesses run between the control module and the gas generators. Each 

harness is armored to protect during a high-energy crash. The redundancy allows one to be 

damaged without impacting functionality of the system. 

• The Manual Activation Switch is located on the headliner between the sun visors. 

How the System Works 

In the event of a very high speed, high-energy rear impact, a system of crash 

sensors and high speed electronic processors determines that the system needs 

to deploy. The system delays deployment until the ABS wheel sensors indicate 

the wheels have slowed and the vehicle is coming to rest. 

If the vehicle speed sensors have been so damaged in the accident that they are 

unable to command deployment, a back-up timer will deploy the system six 

seconds after impact. 

The fire suppression materials are stored in an unpressurized liquid state. When 

the deploy signal is given, two gas generators, similar to the gas generators used 

in airbags, generate high pressure gas. Suppressant and surfactant materials are 

then emitted through a system of manifolds and nozzles to suppress the fire. 

Surfactant reduces the surface tension of the liquid fire suppressant enabling the 

liquid to spread more quickly and completely. 

The system deploys: 

• Automatically when a high-speed, high energy impact occurs at the rear of the vehicle 

39
• Manually when other situations require fire suppression 

None of the materials used in the Fire Suppression System are hazardous. 

System Illustrations 

Manual Activation Switch 

There is a covered manual activation switch mounted in a console on the 

headliner between the visors that can be used by vehicle occupants to manually 

deploy the system. 

Retrofits

The system cannot be retrofitted for two reasons: 

• The system is integrated with the vehicle’s computer and a high-speed vehicle data bus that is new

for the 2005 model year. This precludes retrofits onto pre-2005 model year vehicles. 

• Modifications to the vehicle frame were required to support the additional weight at the mounting 

locations. Only vehicles built at the factory will have the frame modifications required to support the 

additional weight. 

Fire Suppression Test Video (broadband connection highly recommended due 

to large file size) 

This video is of a Fire Suppression System test conducted in March 2004. The 

system was activated by a fixed time trigger, not cessation of vehicle motion. 

There was no leak of fuel from the vehicle and no punctures of the fuel tank. Fuel 

for the fire, as well as the ignition source, were deliberately introduced as 

described in the Robust Test Procedure section. 

• 75 mph 

• 50% offset left 

• 200 oz. fuel 

• Fixed time trigger 

• No punctures of the fuel tank 

• Fuel and ignition source introduced by separate systems 

• Fire suppressed automatically by onboard system 

System Limitations

• The system has been designed and tested to withstand a 75 mph 50% offset rear impact by a 

Taurus-sized vehicle 

o In some crashes, including very high-energy crashes, the fire suppression system could 

be so damaged by the crash forces that it cannot deploy. 

o Like any vehicle component, the Fire Suppression System may not withstand some

crashes. 

• The Ford Fire Suppression System was tested and designed under controlled conditions involving 

the artificial deployment of 200 ounces of gasoline. 

o In some accidents, including those involving more fuel, the Ford Fire Suppression System

40
may not be effective in controlling the fire. 

• No vehicle can completely eliminate the risk of fires. 

• You should not consider the vehicle “fire proof” because it is equipped with a Fire Suppression

System. 

• Like the Upgrade Kit, the Trunk Pack, and the Trunk Packing Considerations, Ford is offering the 

Fire Suppression System to reduce the risk of fires. 

Test Protocol

A consistent, repeatable test protocol is required for 

testing in order to properly evaluate the system and any 

changes that are made during the development phase. 

For all of the rear crash testing, the following protocol

was used: 

• 75 mph hit with a mid-size vehicle (Taurus) 

• 50% offset left - The 50% offset is so that only 

one frame rail is engaged (worst case analysis) 

• 200 oz. fuel 

• Solid rocket motor, burning for 2 – 3 seconds, to 

ensure fuel ignition. 

• No punctures to tank – fuel introduced by

separate system at a constant, known rate 

• Fire suppressed automatically by onboard 

system 

 

A major advantage of body-on-frame 

construction is the high gauge steel 

frame to absorb crash energy. A 

complete rear end crash would engage 

both frame rails, which would both 

absorb and split the crash load. Worst 

case would have only one rail engaged 

to absorb all of the crash energy. 

Manual Activation Switch

The Manual Activation Switch is located on 

the vehicle’s centerline, just rearward of the 

windshield, and between the sun visors. 

41
A clear plastic hinged cover protects the switch 

from accidental activation. It can be pushed or 

pulled open 

Pushing the red button deploys the Fire 

Suppression System (key must be on) 

The system can also be activated by a 20 lb. 

Force without opening the cover 

42
System Views

Below are various views of the Fire Suppression System. 

Major system components - rear of vehicle Tanks and nozzles 

Four lower nozzles are used in the deployment of the system. They are held in an elevated 

position so as not to decrease vehicle ground clearance until needed. They are covered with a 

protective cap until the system deploys. When the system deploys, the force of the gas 

generators deploys the nozzles, as shown in the diagram on the right, so that the fire suppressant 

material is spread below the vehicle. 

FSS Nozzles - Stowed FSS Nozzles - Deployed 

43
Robust Test Procedure

The Ford Fire Suppression 

system was tested in 75 mph 

rear impact collisions in 

which gasoline and an 

ignition were artificially 

provided. 

To effectively design and 

evaluate a fire suppression 

system, ignition sources and 

fuel must be present. Ford’s 

testing involved spraying 200 

ounces of fuel, under 

pressure (60 psi) up and 

under the vehicle to simulate 

fuel migration as seen in real 

world crashes. Ford tested

with 200 ounces of gasoline 

both because it was 

consistent with the leakage

experienced in some field 

and test vehicles, and 

because it was determined to 

be within the outer limits of

technology. A rocket motor 

with a burn time of two to 

three seconds was used to

reliably ignite the fuel. 

 

Above is a photograph of the test fuel cylinder (shown in red) used

to deliver fuel during the development testing. It delivered 200 

ounces of pressurized fuel to ensure fuel for a fire at repeatable 

delivery quantities. 

44
Appendix E 

Summary of Workshop on Research Needs for Suppression of Vehicle Fires 

A brief (about two hours in duration) Workshop on Fire Suppression Research Needs was 

held on the morning of Wednesday, April 13th 2005 at the SAE World Congress in 

Detroit, following paper presentations at Session C on Fire Suppression of the B-27 

Forum. This Appendix summarizes the results of the Workshop. 

Much has been learned over the last decade in fire suppression research and more 

recently from vehicle fire suppression testing. The panel discussion was intended to 

capitalize on that experience and to provide a forum to discuss the strategies, 

technologies, procedures, best practices and R&D that can significantly improve fire 

suppression effectiveness in vehicles. 

The Panel followed the Session on Fire Suppression by design. Four papers were 

presented at the session [Bennett, 2005; Dierker et al., 2005; DiMarzo and Gunderson, 

2005; Santrock and Hodges, 2005]. These papers formed the basis for the panel 

discussion as they underlined the state of the art in fire suppression research, 

development, and testing. Each of the four papers were unique and represented a 

significant contribution to the knowledge of vehicle fire suppression research. 

The goal of the panel discussion was to identify barriers that impede advancement in the 

application of fire suppression technologies to vehicle fires with emphasis on postcollision vehicle fires. In this regard, the Panel was invited to explore a number of 

general issues, including the following: 

• Review of new advances in vehicle fire suppression and continuing challenges 

• Recent developments in fire suppression technology in other applications 

• Identification of technological advances and further research that is needed to address 

the vehicle fire suppression problem

• Establishment of standard test protocols to characterize suppression system 

performance 

• The roles of industry, federal agencies and standards committees in establishing 

standard test methods 

• Special needs associated with alternative fueled vehicles 

• Opportunities for collaboration 

The panel included scientists and engineers with a diversity of expertise and background, 

which should stimulate lively discussion. Representatives from the automotive industry 

were invited to participate (Dr. Joeseph Dierker, Ford Motor Co., Dr. Jeffrey Santrock, 

General Motors), but they declined. Professor Marino DiMarzo (University of Maryland 

at College Park) was invited and planned to attend. Unfortunately, he became ill and did 

not attend. The list of panel participants included the following people: 

• Michael Bennett, Bennettech 

45
• Richard Gann, NIST 

• Steven Hodges, Kidde Dual Spectrum

• Leland Shields, Leland Shields Inc. 

• Archibald Tewarson, FM Global 

• Paul Wierenga, Aerojet 

• Anthony Hamins, NIST (Panel Moderator) 

The Panel included experts from the combustion fire suppression community as well as 

those currently doing research on vehicle fire suppression. The experience of the 

panelists represented about 150 collective years of knowledge in fire research and 

development. 

A list of ten discussion questions was submitted to the panelists several weeks before the 

commencement of the Workshop. The questions were designed to focus and promote 

discussion during the Workshop. The questions were the following: 

1. What additional research is needed, either fundamental or applied, that would 

accelerate implementation of fire suppression technologies? 

2. What phenomena need further understanding to accelerate the development of fire 

suppression technologies for post-collision vehicle applications?

3. Are there fire scenarios (ignition, materials, etc.) in post-collision vehicle fires that 

have not been adequately addressed by the suppression research to date?

4. What are the prospects for implementation of fire suppression technologies in the 

passenger or commercial vehicle marketplaces? Can this process be accelerated and 

streamlined? 

5. Would the development and institution of standard test methods for post-collision 

vehicle fires be useful in the development of suppression technologies? 

6. Is special research needed to address suppression in alternative fueled vehicles?

7. Where is funding for post-collision vehicle fire suppression research going to come

from in the future? 

8. How do fire scenarios involving post-collision passenger vehicles differ from fire 

scenarios involving buses, off-road, and military vehicles that carry fire suppression 

systems? 

9. Are there technical challenges that hamper further progress in the development of 

suppression technologies?

10. Comments on the papers presented at the Suppression Session. 

The Session was split into several parts. Each of the panelists was introduced. A brief 

“opening” statement was made by each panelist regarding the state of fire suppression of 

vehicle fires in general, and thoughts on the character of the papers presented during the 

Suppression Session. Opening statements were focused on general issues, rather than a 

recapitulation of the material that was presented during the paper presentations. There 

was no minimum suggested duration for the statement. The duration of the opening 

statements varied, with a minimum of a few sentences, and a maximum of several 

minutes. Participants were encouraged to consider preparing one or two PowerPoint 

slides for the opening statement, and two of the participants did so (Hodges and Shields). 

46
While many of the panelists focused their commentary on the papers that had just been 

presented as part of the Fire Suppression Session (B-27 Forum) that took place 

immediately preceding the Panel Discussion, others presented their unique perspective on 

other fire suppression issues. The participants discussed challenges and progress in the 

suppression field. Hodges presented the results from experiments examining the 

effectiveness of suppressants on fast combustion situations. Shields presented 

information related to the incidence of fire and collisions. Others highlighted the 

importance of flammability of materials that are found underhood. Response from the

audience indicated that they were interested in hearing the thoughts of the panelists on the 

challenges and progress in the field. 

• Tewarson asserted that both passive and active approaches to fire mitigation 

should be considered. He argues that passive system approaches were needed as a 

simple way to reduce injuries due to fire spread from a vehicle underhood to the 

passenger compartment. Tewarson felt that the time was ripe for further advances 

in reduction in fire losses with the progress demonstrated by the papers presented 

during the Fire Suppression Session, and that through a combination or synergy of 

work among the General Motors/DOT research program, the University of 

Maryland program, and the Ford program, substantial progress has been made. 

• Shields presented information on fire suppression from a fire investigator’s 

perspective. He emphasized practical considerations including the importance of 

maintenance issues when discussing the addition of on-board suppression 

systems. He asserted that in terms of practicality, testing must assure that 

unintended consequences are avoided. He was concerned about issues of 

visibility, toxicity, and service injuries. For example, if a powder system is used 

underhood, how would false discharge affect visibility? Shields asserted that 

sources of field data such as databases of collisions should be analyzed by 

multivariate techniques to look at important events that may lead to a fire. He felt 

that the reliability and accuracy of the databases should be evaluated. 

• Bennett discussed the evolution of air bag technologies and the willingness of the 

public to pay for enhanced safety features on vehicles. He argued that a wellcrafted market study needs to be undertaken to determine exactly how much the 

public is willing to pay for vehicle fire safety. Bennett went on to argue that if the 

amount invested in safety systems was proportional to the rate of injuries 

associated with fire, then spending on fire safety intervention would soar, and 

presumably losses would be reduced. 

• Wirenga cited his experience with military systems and how preliminary 

technology developments progress in fits and starts, initially costly, but more 

economical with time as engineering optimization has time to mature. 

• Gann suggested that many issues should be considered. Citing 30 years of fire 

statistics, he indicated that the number of fatalities had changed little over this 

period, and at the same time the number of miles driven and the number of roads 

had increased significantly. He suggested that the substitution or modification of 

flammable vehicle fluids and thermoplastic materials should be considered. He 

asked what fraction of the annual fire fatalities would be eliminated if underhood 

47
fluids were less flammable or made entirely non- flammable, or if flammable 

materials were substituted with materials with appreciably improved fire resistant 

behavior. 

• Hodges presented research results on heavy-duty vehicle fire protection, with 

emphasis on the US Army M1 Abrams tank. Video was presented of experiments 

examining the suppression of fuel explosions in an armored vehicle. An analogy 

between suppression in this system, transit buses, and automobiles was made. 

Hodges cited National Vital Statistics from 2002, and challenged the audience to 

address the practicality of working on fire related fatalities and injuries associated 

with vehicle collisions, from the perspective of automobile manufacturers. The 

point being that fire related losses represent only a small fraction of total 

collision-related losses. 

At the conclusion of the statements made by the Panelists, participation by the audience 

was encouraged. To promote discussion, the ten questions listed above were posed to the 

audience. 

The number of people in the audience was rather small and numbered no more than about 

20 at its peak. Yet, through their questions and comments during the discussion, it was 

clear that the audience members were highly knowledgeable about the vehicle fire 

problem. 

Bennett suggested that FARS statistics should be expanded to cover the full economic 

cost of vehicle fires, including injuries, lost work time, insurance costs, etc. He went on 

to argue that the fire safety community should work to quantify the lives saved through 

enactment of FMVSS 301. 

One audience member highlighted the problem of developing accurate statistics on the 

vehicle fire problem. The person suggested that death certificates should be precise and 

specify fire as the cause of death when that is the case. The person noted that vehicle 

deaths were second only to deaths by fire in homes; and that 2.9 % of deaths in vehicles 

involved fire. 

One person asked the audience to look beyond post-collision fires as the community 

attempts to better represent the magnitude of the vehicle fire problem. He stated that 

about 10 % of vehicles in a salvage yard were due to fire damage. This participant 

highlighted the need for some kind of standardized test for fire suppression. He 

challenged the community to better define the requirements of a standardized test, asking 

if DiMarzo’s 80 kW fire was an appropriate test or if Ford’s method that used 200 ounces 

of gasoline was suitable. Wierenga responded by saying that the method should depend 

on the vehicle type and make, and that a single pass/fail test would be unsatisfactory. 

Wierenga went on to say that the test should not favor one technology over another, but 

should be a fair test based on actual fire conditions. 

The moderator posed the question as to whether standardized tests should be static or 

dynamic. Hodges responded by recounting that the military does realistic testing, trying 

to simulate actual conditions, and going as far as using live ammunition in their 

suppression tests. Tewarson suggested that standardized tests may not be needed. 

Shields contended that a systematic research project should prioritize conditions linked 

48
with post-collision vehicle fires. The implication is that that information is needed to 

design realistic standardized tests. Gann stated that the fire protection community does 

conduct standardized testing. He suggested that an important consideration may be 

ventilation effects. 

Bennett made the comment that at least some testing must be dynamic, as some systems 

operate in response to a collision, such s self sealing fuel lines or powder panels. 

One person in the audience brought up fuel tank testing. There was little follow-on 

discussion. 

The question of the use of simulation in lieu of experiments was discussed. Tewarson 

felt that it is not possible to do accurate and complete fire suppression modeling, because 

it is too complex. Other suggested that coarse calculations may give guidance for system 

design, or at least in the design of effective and insightful experiments. Gann agreed that 

suppression modeling was not accurate at this time, but he suggested a pragmatic 

approach in which simplification of the flow field, the ventilation, and fuel sources may 

yield useful information in the design of suppression systems. 

One panelist challenged the community by suggesting that the financial benefits of fire 

safety systems should not be a focus for several reasons, including the decreasing rate of 

fire losses as safety as vehicles generally improve. 

Some amount of discussion addressed issues associated with changing the problem of the 

lack of research and development funding. One panelist argued that it may be possible to 

justify increased investment on fire safety systems based on savings in non-collision 

situations. Wierenga confirmed that automobile manufacturers are slowly recognizing the 

financial benefit of safety. Another panelist suggested that a full-blown economic study 

of the cost of vehicle fire losses to the economy be considered including the cost of 

injuries directly attributed to fires in vehicles. Others suggested that the financial benefits 

of the FMVSS 301 should be estimated. One member of the audience suggested that an 

argument for funding should consider the occurrence of non-crash fires, the long 

response time for emergency response in rural areas, that fires under bridges can cause 

extensive property damage, that fire create toxic pollutants and run-off, and that vehicle 

fire are a possible sources of forest fires. 

At the end of the session, the moderator performed a survey of the audience, seeking 

information on the number of people who represented the automobile industry in the 

audience. Not one person responded affirmatively. It is apparent that a great deal of 

education will be necessary to convince automobile manufacturers that R&D in fire 

safety is a good investment. 

In summary, the panel discussion addressed a number of important points. Yet, some

amount of focus was lost in the discussion, as the key questions (see numbered points 

above) were only partially addressed. This may have been related to the format of the 

Workshop, which was perhaps too brief (about two hours in duration) to delve in-depth 

into this relatively complex subject matter. From the discussion, it was clear, however, 

that many challenges, both technical and political remain, before fire losses associated 

with vehicles are to be significantly reduced. 

49