Bus Fire Fighting Information

[rv_safetyman]

Well, I thought I would start a thread that had some bus realated content.

On the old board, Glen Hanson posted about being broken down in the Denver area.  His alt. caught fire and he was left stranded.  The thread evolved into a couple of posts that discussed fire fighting capablility.  Since I had written an article for Bus Conversion Magazine, I thought I should reply.

I hope that the content of that reply might help others on this new board

The following is my reply:

Glen, I am also glad to hear that at least you are safe and have some direction.

Gumpy had flagged several Denver area folks right after you made your original post.  I felt helpless, as we are still on the road on our maiden voyage (currently in Shoshone CA).

I would like to comment on your comment about fire extinguishers.  A couple of years ago, I wrote an article for Bus Conversion Magazine on the subject of bus fires and fire suppression systems.  One of the main themes in the article was that not all fire extinguishers are "created equal".  Dry powder units, which we all have, are not very effective and can wreak havoc with some of the metals in our buses.  There are much better fire suppression systems.  You can find the article on our website listed below.

Also, mounted fire suppression systems were mentioned.  Right now, mechanically activated racing systems are about all that are available.  These are usually quite expensive.  We are currently working on a prototype that will use our large Cold Fire extinguisher and have the option to have it electronically or mechanically activated.

There is one system that spreads plastic tubing in the engine compartment and has it charged with fire suppression material.  The thought is that the fire will melt the plastic tubing and deliver the fire suppression material to the area of the fire.  That system is also quite expensive.  The same thing can be done with our large (2.5 gallon) unit and simply mount tubing to the head and mechanically lock the hand valve into the open position.   

I got to add another bus fire photo to my collection during this trip.  In New Mexico, I could see a plume of smoke on the horizon.  As I neared the fire, it was obvious that it was a commercial bus.  The fire fighters were still putting the fire out when I took my pictures.  My guess is that it was an engine fire, but the bus was totally involved and it was hard to tell exactly what happened.

[rv_safetyman]

I forgot that with this great new software, I can post a picture.  So here is the picture I took in NM.

[plyonsMC9]

Scary stuff. 

I followed & read up on the link re: notification systems.  Once we are notified of the hazard, won't we then still have to put out the fire with a fire suppressent with a chemical which "... can wreak havoc with some of the metals in our buses."  Or, did I miss anything with regard to better, kinder fire extinguishers?  Of course, I realize it's better to not lose the bus and still have the chemical issues.     Just don't want to miss any news on better extinguishers.

Regards, Phil

[rv_safetyman]

Hi Phil

I am trying to tread lightly so that I don't do "advertising", but rather try to give basic information and let folks who are interested go to our website/articles and learn more.

To answer your question, everyone in the fire suppression business agrees on one thing, dry powder extinguishers are the "pits".  They don't have much fire fighting capability, they create a terrible mess that is almost impossible to clean up (especially on the interior of the bus), can be highly corrosive (not allowed anywhere near air planes), and can cake up because of constant bouncing in highway use.  There are some great alternatives and I list them in my article. 

If you have the March 2004 issue, you can read the article, or you can download it as a PDF for the website listed below.

Please do not throw me off the board for blatent advertising

[rv_safetyman]

Well, I think I will try to kill two birds with one keyboard.  This is a test to see if the direct link to my Bus Fire article works.  It will also let folks get the information without having to poke around on our website

http://www.rvsafetysystems.com/Updated%20fire%20article.pdf

[plyonsMC9]

Works for me - Linux / Firefox browser.  - thx!! 

Regards, Phil

[NCbob]

Interesting information there, Jim.  In terms of volume, could you guestimate what it would take to extinguish an engine compartment
fire on one of our busses?  In my situation, with a Detroit 8V71, as one of the guys said, "My engine doesn't leak oil....it sweats Horsepower".  Mine sweats a bit more than I'd like it to...and add the mess in the blower vanes...it appears that there's a bodacious amount of flammables in there no matter how hard I try to keep it clean.  Can we actually carry enough to extinguish a full blown engine fire?

Now that I look back over what I've written I find the thought of it quite depressing!

NCbob

[rv_safetyman]

Hi NCbob

Without question, the new technology fire extinguishers would easily put out a large engine fire -- it you catch it before the whole bus is involved.

The product I sell is Cold Fire and it is used almost exclusively in the racing industry for on-board systems.  I have followed the technology since it was first introduced to NHRA perhaps 15 years ago.  I have witnessed some horrendous fires that were extinguished by this material. 

Even though I was very familiar with the product, I can't sell something that I don't test and verify.  I worked with a fire department training center and we put three large car tires in a large "burn tub".  We put at least a couple of gallons of gasoline and diesel fuel mix in with the tires.  I let the tires get quite involved and then used our 2.5 gallon hand held extinguisher to very quickly put out the fire.  That was fun, but we had a bunch of liquid left in the extinguisher.  To make a long story a bit shorter, we put the tires out three times with one extinguisher.  The last time, I let the tires burn for several minutes to make sure they were really cooking.

The material works very well on fuel fires as well as general combustibles.  All of this and a very enviornmentally friendly material to boot.

Bottom line, it will do the job if the fire has not totally engulfed the coach.

The 2.5 gallon extinguisher is a bit large, but the comfort you have knowing you have the ability to fight a big fire -- hopefully on some other persons vehicle

[JohnEd]

Gents,  I have always intended to install a sprinkler in the engine compartment and feed it water from freshwater holding.  My thought was to activate it with a "high temp" mechanical sensor and a manual valve.  I know that water won't put out an electrical fire and it will only get diesel and hydraulic fluid to below their flash point.  The upgrade stage I thought about was a chemical tank that added a flame suppressor to the water before it get sprayed.  I read about this many years ago and the article was about aircaft fire fighting.  Seems the trucks have two tanks aboard and mix the stuff as needed.  Problem back then was chemical expense and cleanup.  Delivery was dirt simple.  Anybody know how this system has evolved and what the costs/technology is?  I know that I am way out of my deapth here but if I were watering my lawn and a bus puled up and flames came out of the engine compartment, well the thing would get quickly as wet as I could make it and I don't think I stand out on this.  Having fun.

JohnEd:-\

[rv_safetyman]

Hi JohnEd.

Two issues with your project.  The first is that water would tend to spread the fire.  The oil/fuel would get on top of the water and the fire could spread.  The second issue is that a pump system could let you down if you had a power failure as a part of the fire.  It is relatively cheap to have a pressurized tank ready to dispense a good fire fighting material.  Since it is pressurized, it will alway be ready.

Now comes the question as to how you trigger it.  I have not found temperature sensitive heads that work with liquid and are in the temperature range that would survive in an engine compartment.  There are good racing heads that would have the temperature range that would work for us, but they are for Halon and that is not a good material for our application (too easy to replenish the oxygen)

So, give some thought to what I suggested earlier.  Take a good surfactant hand held extinguisher (like our 2.5 gallon unit), remove the spray hose, hook up some cheap plastic tubing (with a reasonable melting temperature -- say 300 degrees), plug the other end, snake it around the top of the engine compartment, and then lock the handle in the spray position.  For less than $200 you could have a great system just waiting for you to have a fire.

[Timnvt]

Jim, Thanks for posting information on this important topic.

I have a question regarding the cold fire extingishers.

Can RV or automotive type antifreeze be substituted for the water?

Thanks,  Tim.

[NJT5047]

May I ask what most often burns on a bus?  Any stats on cause?   
My MC9 has two fire sensors in the engine compartment...the wiring is functional, no way to tst the things otherwise...as far as I know. 
Having been involved with a fire department for some years, near a major trucking highway, I've never seen (Jims pix excepted) an engine related truck or bus fire...seen brakes and resulting tire fires.  Supression of tire fires is relatively straigtforward.  I'm interested in the engine fire potential.
I would assume that electrical fires are rare...and perhaps the result of somethng that has been modified??
Thsi is an interesting subject.   I just added a 300 amp fuse to my inverter 24VDC source.   Thought this should make potential problem safer.   This sort of thing is where I worry about fire.   
More on this later.    Seems something we should all know about. 
Cheers, JR

[gus]

JimEd,

My guess is that your system would help if it were designed to fog properly. This is based on my firefighting training in the Navy.

My second comment is to stress the importance of checking mufflers on DDs for holes. I found a hole the size of a quarter in the top of one of mine that was blowing directly underneath the bed and the attaching flange rusted through on the other. Either one could have caused a major fire.

I checked the mufflers based on a post by another busnut a while back and can't thank him enough for the idea. I don't remember his name but he saved my bacon.

[rv_safetyman]

Hi Tim.

Automotive antifreeze is considered flammable.  RV antifreeze can be flammable.   Not the kind of material you want in a fire extinguisher.

The RV stuff is propylene glycol.  As a exercise a couple of years ago I downloaded several different MSDS sheets for propylene glycol and they varied considerably in the flammability ratings.  Some said none, some said low and one flat out said it was flammable.  To be on the safe side, I do not recommend using any kind of commercial antifreeze.

What you want is potassium acetate.  On my web site I discuss the mixture needed to go as low as minus 70 degrees F.  Potassium acetate is a very harmless material and the food grade version is sometimes used in IV feeding to increase the level of potassium.  They use and industrial version for de-icing runways.

Good stuff, but a bit hard to find.  I had to buy it in 100 pound lots.  I list it for sale on my website.  It is a bit pricey.  It takes about 4 pounds to make 1 gallon of water good for about 20 below.  Thus the big extinguisher would require 10 pounds.  My price is $4 per pound plus shipping.  If you have a good chemical company in your area, they can order it for you and if you can find the industrial grade (I could only find the food grade), it should be even cheaper.

[rv_safetyman]

First, to all of the board, I am trying to make sure this does not read like some sort of advertisment.  I have done a lot of research in this area, and hope that my posts are taken in the spirit intended -- to give useful information.

NJT5047, engine fires are more prevelant than you might think.  Earlier in this thread, I posted a link to the article I wrote on bus/motorhome fires.  In the article  I cite the two links to two studies that were done in Finland on commercial buses.  Very interesting reading.

I wrote another article on the subject of alarm systems for buses/motorhomes:

http://www.rvsafetysystems.com/Alarm_Article.pdf

In that article I cite 5 years of statistics from the Oregon Fire Marshall's office (considered to be one of the better statistical databases).  Over the five years, 515 motorhome fires were recorded of which 214 fell into the category of "engine/wheel" area.

My Eagle also had what I call a passive fire detection system.  It was supposed to warn the driver of an engine fire.  However, like you, I had no way of knowing whether it worked or not.  Today all commercial buses are required to have a fire warning system in the engine compartment.  Conversely, no RVs are required to have any kind of similiar system.  As a result, I decided to design and manufacture an ACTIVE system that always lets you know it is active.  It is discussed in the alarm article.