Putting Out the Fire
Story and Photography by Richard Newton
This is equipment you never want to use. Most of the time when you buy a part it’s to make your car faster, or easier, to drive. When you buy a fire extinguisher, or a fire suppression system, you’re buying something that hopefully will never get used.
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| This might meet the rules but that's about all it's good for. |
Once you accept the fact you’re really afraid of being burned in your car the type of fire system is very simple. While a small fire extinguisher may very well meet the rules it’s simply not a real answer.
Think about this for a minute. The purpose of fire fighting equipment is to save the driver from injury. If you have a fire and the only thing available is a 2-pound handheld fire extinguisher you’ve got a big problem. First, you’re going to have to exit the car and then reach back in for the fire extinguisher. At the very least you’re going to be climbing out of the car with a fire extinguisher cradled your arms. Try that in your garage sometime and see how well it works.
Think about this for a minute. The purpose of fire fighting equipment is to save the driver from injury. If you have a fire and the only thing available is a 2-pound handheld fire extinguisher you’ve got a big problem. First, you’re going to have to exit the car and then reach back in for the fire extinguisher. At the very least you’re going to be climbing out of the car with a fire extinguisher cradled your arms. Try that in your garage sometime and see how well it works.
Even worse is that you have no experience at fighting a fire. You don’t have a clue about where to point the extinguisher. Should you open the hood? Or, should you leave the hood down in the case of an engine fire? If you don’t know the answer then you have no business fighting a fire.
Now having said all that you might want to listen to what Phil Bagley at Klub Sport has to say about small fire extinguishers. “There could very well be a small electrical fire where it really isn’t necessary to activate the large system.” This makes sense. Notice though that Phil doesn’t say the little extinguisher should be used to replace the fire suppression system. It’s in addition to the real system.
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| This is the nozzle for the fire system. |
The cost of a fire suppression is often mentioned as an issue. I don’t’ believe it. I see a huge number of $3,000 driver’s suits at most vintage races. If a driver can spend that much money on a driving suit why are they only spending $35 on a fire extinguisher? Ok, I know why. No one can see your really cool fire system.
With a fire suppression system you simply hit a button (or pull on a cable) to activate the system. You can activate the system as you’re climbing out of your car. Even better if something has happened to you the safety workers can activate the fire system.
We also have automatic systems that activate with a temperature-sensing switch. These are great for the fuel cell area. It you have a fire in your fuel cell area chances are you won’t see it right away. By the time you actually see flames coming out of the fuel cell area it’s way too late. A temperature sensing system solves that problem.
One great feature of a fire suppression system is that you can actually fight the fire at its source. The "at the source" theory on plumbing a car involves concentrating the discharge where the fire starts. The idea is that concentrating the spray in the engine compartment and around the fuel cell will minimize if not eliminate the fire. I’ve seen a system with two automatic nozzles, one on the fuel cell and one in the engine compartment. There was a separate bottle with a pull cable to flood the driver's compartment.
Three Choices
The first decision is which chemical you’re going to use in your fire suppression system. Every single car owner and crew chief I spoke with (and I spoke to dozens) said they were quite happy with Halon. On the other hand every single manufacturer I spoke with suggested that people get rid of their Halon systems and use one of the newer chemicals. Interesting.
In addition to the traditional Halon fire suppression system two chemicals that have emerged as Halon replacements. That means that we have three choices.
- Traditional Halon System
- FE-36 Fire System
- AFFF Fire System
Neither FE-36 nor AFFF are a simple drop-in replacement for your old Halon system. Both require modificationto the piping systems and nozzles. If you make the switch away from Halon it’s easiest to just buy a brand new system.Halon 1211 and 1301: These Halon systems were first used in settings in where people wanted to avoid damage to expensive electronic components. A few years back there was a tremendous amount of fear that Halon would simply go out of existence since it’s an ozone-depleting chemical. That doesn’t appear to be the case at this point though. It seems we have more than enough Halon stored away for several decades.
Halon is stored as a liquid under pressure and discharged as a combination of liquid and gas that flows around obstructions to smother the flame and cool the fire to reduce re-ignition. Halon does not require any cleanup under normal circumstances. Halon systems are still accepted by many race-sanctioning bodies but keep in mind that you won’t be able to recertify the system once you hit the expiration date.
FE-36 Systems: FE-36™ is DuPont's replacement for Halon. It has zero ozone depletion potential and lower toxicity than Halon with similar performance. It was designed to be used in computer and telecommunications areas. DuPont designed it to be used in a streaming application, which makes it perfect for engine compartments. FE-36 has been approved by SFI and SCCA.
FE-36 replaces Halon1211 as the agent of choice for applications where the system must be electrically nonconductive, environment-friendly, extremely low in toxicity and exceptionally effective. Unlike Halon FE-36 isn’t considered ozone depleting. It leaves no residue and is not thermal shocking. FireBottle uses FE-36 exclusively in their SFI-certified systems. They feel that it’s the best replacement for Halon.
One small disadvantage is that it takes almost twice as much FE-36 to do the same job as Halon. When compared to Halon, it takes between 1.5 and 1.8 times more FE-36 to be as effective as Halon.
This means that a 7.5 to 9-pound FE-36 system is needed to put out a fire that could have been extinguished by a 5-pound Halon system. What’s a little puzzling is how a sanctioning body can mandate either a 5-pound Halon or a 5-pound FE-36 system as a minimum requirement. Did anyone even read about this material? Come on guys.
FE-36 is gaining a huge share of the fire suppression market in the United States. This is because DuPont and NASCAR have worked together on these systems. These two giants have squeezed others out of the room.
AFFF Systems: AFFF stands for Aqueous Film Forming Foam. This is a water-based soapy solution that’s stored as a liquid and discharged as foam. The US Navy developed aqueous film-forming foam (AFFF) in the mid 1960s. This synthetic foam has a low viscosity and spreads rapidly across the surface of most hydrocarbon fuels. A water film forms beneath the foam, which cools the liquid fuel and stops the formation of flammable vapors.
The idea is to use AFFF to not only cool the area but also cut off the oxygen. AFFF is similar to Halon that it quenches the fire. The disadvantage of the AFFF systems is they’re heavier than either Halon or FE36 and the foam won’t spread out like Halon. The more serious problem is that AFFF leaves a mess both in the car and on the track.
The good part is that it cleans up with water. Because it’s water based you can just rinse the residue off with a water hose. It’s also accepted by most race sanctioning bodies including SCCA, FIA, and IMSA.
These AFFF systems are very popular in Europe and generally FIA approved. AFFF units need to be serviced every 2 years. This can be anywhere from $100 to $300, assuming no components will need to be replaced.
SFI and FIA Certification
The SFI Foundation, Inc. (SFI) is a non-profit organization created to issue and administer standards for automotive and racing equipment. They established a standard (SFI 17.1), which sets the requirements for fire suppression system design and hardware. They also monitor live fire testing scenarios in order to assure the systems actually suppress a fire.
SFI certification is most common in circle track racing. Part of that is because circle track cars are the most common form of racing in the United States and SFI is an American foundation. Also never discount the NASCAR influence. Most sports car racing in the United Sates looks to the FIA certification for guidance. AFFF is the most common material used in FIA approved systems.
Mounting Guidelines
If you’re driving a sedan or some form of passenger car it makes sense to mount the fire bottle in the passenger area of the car. That provides a little help with your weight distribution. Five or six pounds may not seem like a significant amount but it can make a difference where traction and balance are critical to maintaining speed and control of the car.
The extinguisher should always be mounted horizontally in the car. Also mount the bottle so that the gauge and label are visible. Tech inspectors like to verify the gauge readings and read the service information on the label.
When you run the lines on your fire system use more clamps than necessary. If the aluminum tubes move around too much they’ll crack from the vibration. NASCAR specifies steel tubing for this reason. Another alternative is to use braided stainless lines. They won’t get bent or crushed as you work around the car. It’s going to add a little more expense to this project but it adds a little more protection.
The basic theory for plumbing a racecar is to save the driver. Remember the primary goal is to protect the driver. This means you want a concentrated amount of material on the driver.
Experience has shown though that if the fire is onlyfought at the driver it will be bigger and more difficult to extinguish than if it were attacked where it started. Current thinking is to also attack the fire at its source. This means you want nozzles in both the fuel cell area in the engine compartment. Some firms though believe in focusing on the engine compartment and driver. They prefer to ignore the fuel cell since they feel no system is really capable of putting out fuel cell fire.
They feel that if you have a fuel cell fire there isn’t a system made that can put out that fire. This means we have to return to the basic goal of protecting the driver. These companies argue that another nozzle on the driver helps a lot more than a nozzle in the fuel cell area. Ask the company you buy the system from how they feel about nozzle placement.
You’re going to have to increase the size of the bottle when you add nozzles. FireBotle likes to use a separate small bottle just for the driver. Make sure you explain what you want when you talk to the folks that are selling you the system. Use their experience to build a good system.
Actuation Systems
Today's fire suppression systems are actuated in three main ways. First, there is the push/pull cable actuation. Most of these systems have a safety pin to prevent accidental set-offs. Once the pin is removed the knob is either pulled or pushed to set off the extinguisher. The advantage of the cable mount system is that they can be mounted anywhere that’s easy for the driver to reach. Make sure that you remove the safety pin before you go out on track.
Electrical activation systems are a little more complex than the traditional cable system. These electronic systems consist of a power pack, wiring, and usually 2 actuator buttons. It’s usually a lot easier to run the switches and route the wiring for an electrical setup compared to a cable activation system. Make sure that you deactivate the system at the end of each day to reduce the chances of accidental discharge. This is the same thing as putting the lock pin back in place with the mechanical system. While some drivers are paranoid that someone might accidentally push the activation button he chances of an accidental firing aren’t that great.
Electrical activation systems are a little more complex than the traditional cable system. These electronic systems consist of a power pack, wiring, and usually 2 actuator buttons. It’s usually a lot easier to run the switches and route the wiring for an electrical setup compared to a cable activation system. Make sure that you deactivate the system at the end of each day to reduce the chances of accidental discharge. This is the same thing as putting the lock pin back in place with the mechanical system. While some drivers are paranoid that someone might accidentally push the activation button he chances of an accidental firing aren’t that great. Another method of actuation is the automatic discharge nozzle. This nozzle eliminates the need for the driver to pull a cable. The automatic nozzle is set to discharge when its surroundings rise to a predetermined temperature. These temperatures can be specified and range from 135 to 500 degrees F. An automatic nozzle for a fuel cell is typically set at 286 degrees F while one for an engine compartment is set at 360 degrees F. These temperature settings are far above normal operating temperatures for the cockpit, engine compartment, and fuel cell area, but they are far below the temperature that a fire will generate.
If you decide to use a basic fire suppression system in your vintage racer you’ll spend around $400. You can get a high-end system with six to eight nozzles for not much over $1,000. Consider how much you spend on tires for the weekend. How much was your new driving suit?
Remember you’re going to get several years of use out of a fire suppression system. Or, should I say non-use. You need to consider what it might be like to drive a flaming racecar to the nearest corner station for help. Are you really confident that you can stop your car on track and put out a fire with a 2.0 lb. extinguisher? Wouldn’t it just be a lot easier to activate your fire suppression system and then run like hell? You already know the answer. Now go install the system.
The Rules
All cars must be equipped with a 2 lb., 10 BC (or Halon equivalent) fire extinguisher securely mounted with a metal bracket and metal strap, plastic is not acceptable. Hand held extinguishers should be within reach of the driver. An onboard fire system is strongly recommended.
All cars must be equipped with a dry chemical or Halon fire extinguisher of at least 2 pounds, securely mounted with a metal quick-release device, in the cockpit within reach of the driver. On-board fire suppression systems are highly recommended,
All race cars must be equipped with at least a 2 lb. dry chemical fire extinguisher, securely mounted in the cockpit of the car or an on-board manual or automatic fire suppression system. (On-board manual or automatic fire system is strongly recommended.)
A minimum of a 2.5-pound BC approved fire extinguisher is required. An on-board fire suppression system is strongly recommended. All extinguishers must be securely mounted within reach of the driver.
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