Tanker fires and foam....

[explr985]

When I rode on E-6 the other day, we had a fully involved tanker fire ( 3,000 gal. ) and we were told to use foam. Well I got up on top and handed down 5 gallons, driver hooked up eductor and attempted to flow foam and nothing happened. We had pump at 200-250 PSI, and enductor was open. I'm not sure how old foam was but we think it had set up from not being replaced. Has anyone else had a problem with this? I'm just wondering. It was a good fire, I'm the only explorer that has had a tanker fire. Was kinda ironic though, when we left I was reading FireEngineering Magazine on LP gas and tanker fires. Come back at 1:00 in the morning and find that open, kinda weird. The only thing bad that happened was that Truck 2 beat us there, but it was E-6 3rd due district. Happened at I-40 at U.S. 52.

[July36]

Sounds to me like it mightve been a problem in the eductor itself or the pickup tube(the tube that goes into the container).You may wanna check for any pinhole leaks in the eductor hose and also check for clogging.Another thing that comes to mind is the eductor pickup settings may not have been right which means if the foam is rated at .06 % then the "pickup" setting must also be at .06% or "matched" OR the eductor GPM wasnt matched with the fire hose GPM. You must remember that when using foam,the GPM in the eductor and the GPM that youre running thru the hose MUST be matched...meaning if you are running 250 GPM at the nozzle...then the eductor must also be rated for 250 GPM.But no...it has nothing to do with the foam being old becuase whether the foam is old or not it will still have its "flowing qualities"...it will just be very low on "expansion".Also....how far from the nozzle are you running the eductor?...how many feet behind the nozzle?....The reason I ask is because some eductors are or was designed for adding inline within a certain amount of feet(no more than 150 or 250 ft BEHIND the nozzle).
Also...is this eductor the inline type(meaning does it run thru the pump like a CAD unit or is it the type that you just hook up behind a nozzle and has the pickup tube?

Be Safe and good luck

Donna C
Fire Chief
Bridge Canyon VFD

http://cms.firehouse.com/dept/SeligmanAZ

[distchief60b]

July26 has some valid points....

A very important one is the fact that your equipment must be compatible and your foam must also be compatible.

Now....here are some more thoughts. I will disagree with July26 (respectfully chief) that there was not a problem with the foam. First, how old was it? You said you handed it down from the top. Well, storing the foam outside like that in different weather environments will affect the foam. The heat and cold will impact it's abilities to maintain it's qualities. Read the label on the can relating to storage requirements. Also, if the foam was AFFF-ATC and it had been opened and the top not put back securely, the effectiveness of the foam is compromised. Additionally, if you had used some foam out of the can (assuming it was AFFF-ATC) and then re-sealed the can with it being partially full the following will occur. As you drive around and the foam sloshes in the partly full can the polymers begin to seperate and the a polymeric membrane will form on the top. This is what gives you the extinguishing and vapor suppressiopn capabilities and when you draw from the can in this case all you get is liquid and there will be sludge left in the can. National Foam's "GOLD" 1% x 3% AFFF-ATC is thick like that and will give you the idea it is "bad" if you do not understand how foam works. The same happens when you carry AFFF-ATC in your on board tanks if you do not keep them full and if they are not vented properly. In most cases the shelf life on foam is unlimited when stored properly.

Additionally, your eductor may have been stopped up. If you use foam and do not flush/clean your equipment, it often gets gummed up and the little ball in the venturi of the eductor will get stuck, rendering your equipment useless. Equipment should be flushed and then cleaned in hot soapy water and then rinsed after use.

Now....some questions?
#1 What type of foam was it?
#2 Was it 1% x 3%,3% x 3%, 1% x 6%?
#3 What percentage were you using on the eductor?
#4 What GPM was your nozzle and were you using an aspirator, fog or straight Stream?
#5 What GPM was your eductor?
#6 Was the screen still in the bottom of the pick-up tube? (a lot of foam experts suggest you remove it to enhance capabilities)
#7 How long was your hose line? (limited to 200 feet from eductor unless you are using some manufacturer's low pressure nozzles)
#8 Why did you go to 250PSI?.....Requirement is 200PS to eductor
#9 You were getting no foam at all? or was it just ineffective?
#10 MOST IMPORTANTLY>>>>When was last time your department trained on foam?

If this does not help I suggest you contact Mr. Jim Cottrell of Cottrell & Associates ( [email protected] ) and get his advice. He is considered by most as an expert in the foam field and I am sure he will be happy to offer you information as a courtesy.

[Dalmatian90]

God, I hope this is someone pulling our legs...

3,000 gallon tanker, fully involved...let's setup the 5 gallon can of foam and eductor...anyone see a problem here?

[distchief60b]

Dalmation90....

You know..I had that in the back of my mind when I replied. I have learned (as I am sure to which you were eluding)...that in situations like this we have no where near the amount of foam required, even if we had an onboard tank. Bottom line in this case, it may have been better to let it burn and consume the fuel, melting down the outer shell as it did, leaving less mess for clean up. Protect exposures and step back!

[colfireman]

Tanker Fire hmmm.... set up major supply lines bring in our foam unit and then foam the "H" out of it...I agree that you can't do much with 1 5 gallon pail. You might want to call your nearest airport for the CFR truck.

[Rescue101]

Dal,you stole my thunder again.3000 gal. and a 5 gal bucket of foam?HeHe,going to take a bit more than that.With due respect to the Chief,I disagree on the shelf life of the concentrate.Up here in the north,freezing of class B concentrate can cause a breakdown which leaves the foam looking more like Jello than foam.Once there,it WILL NOT flow thru an eductor.I've seen similar conditions in unfrozen containers as they age.The old protein foam was as good a storing foam as there was,but nasty to work with.Grows grass well though.T.C.

[E229Lt]

#1 test your equipment often. Use up outdated foam for drills and tests. No outdated foam? Use colored water to test your pick-up tube and eductor. "O" rings on the eductor pick-up tube must remain well lubricated with some lithium grease.

#2 NEVER start a foam operation until you have more than enough foam on scene to mitigate the problem!

[SamsonFCDES]

When in doubt, batch mix.

[distchief60b]

Batch Mixing is only good for Class A.....I am assuming by Batch Mixing you mean pouring it into the tank?

[BB3939]

A lot of good advise and things to think about.
Cant say enough about keeping the eductor clean and flushing it after EVERY foam and foam type use.
Some other things to think about. Was the nozzel valve open the whole way...If you are using a 95 GPM eductor and the nozzel is only partially open chances are you are not flowing 95 gpm and the eductor will not suck foam concentrate. Was the incident up hill from your engine (eductor) causing back pressure?
Do you use multiple types of foam ... like AFFF-Standard, AFFF-Universal (for polar solvents-Alcohol resistive) and or Class A. If you have PREVIOUSLY acidentally mixed them and NOT cleaned the eductor system before changing foam types you may have gumed up the eductor system (and plumbing on your truck if it is an internal bypass type system).
There are so many things that could have happened...We just need more information to help you with your problem.
Like many have said before...If you only had a total of 5 gallons of foam for a 3000 gallon tanker...you probably should have saved your foam for a smaller incident.
I also suggest you contact Mr. Cottrell...he can be a big help. Perhaps he can do a foam class for your department...I have had many foam classes over the years...and he has a slightly different approach that makes things more memorable. GOOD LUCK

[SamsonFCDES]

Originally posted by captstanm1
Batch Mixing is only good for Class A.....I am assuming by Batch Mixing you mean pouring it into the tank?

Yes, dump direct into tank.

We have a wildland heavy unit which uses a batch mix (type A) CAF system.

We had a tanker truck fire two months ago. It was a crude oil hauler truck with a truck mounted 400 barrel tank and a 400 barrel pup trailer.

The type A CAFs had the fire out in under 10 minutes and under 850 gallon of water and 50 gallons of foam (what the truck capacity is).

[distchief60b]

Ok...Yes...Class A foam will in most cases suppress or aid in suppression of Flammable Liquids Fires. However, there is NO RATING for vapor suppression when it comes to Class A Foam. So...yep...you sure do extinguish the finre, but create a problem that you can not see.....VAPORS!!!

I was assuming that from the original post and from the description, we were dealing with Class B Foam. Not a good idea at all to begin to rely on class A for Class B Fires..... Not knocking CAF Systems,,,,but when you use Class A Foam for uses other than it is approved/designed, you are setting yourself up for a problem.

[SamsonFCDES]

Originally posted by captstanm1
Ok...Yes...Class A foam will in most cases suppress or aid in suppression of Flammable Liquids Fires. However, there is NO RATING for vapor suppression when it comes to Class A Foam. So...yep...you sure do extinguish the finre, but create a problem that you can not see.....VAPORS!!!

I was assuming that from the original post and from the description, we were dealing with Class B Foam. Not a good idea at all to begin to rely on class A for Class B Fires..... Not knocking CAF Systems,,,,but when you use Class A Foam for uses other than it is approved/designed, you are setting yourself up for a problem.

Good idea or not, it is a neccesity for us.

We are a rural (to the extream) Montana Vol fire department which is blessed not only with literaly thousands of square miles of pristeen nature, but also with a substantial pertolium industry in the form of the Williston Basin Oil Formation.

Our small budget is "burnt" up each and every year (since 88 till present) fighting wildfire which has gone far beyond disaster proportions. This has left us very short on equipment to combat other types of fire, such as chemical fires associated with the oil industry. We have applied to the Fire Act grant (got the 6 questions, fingers crossed and waiting patiently ) to help replace such essential gear as structural PPE, SCBAs, and to get our hands on a TIC which is great when you want to know how much of a given nasty liquid is still in a tank. We have been responding to these types of incidents with bunker gear that is 10-15 years old and well cooked. Our SCBAs are nearly suicidal. This is not because of lack of care, it is because of lack of funds. Hopefully that will soon change.

Which also brings up the vehicle issue. We have a 1000 GMP 1983 Peirce pumper truck with Class A foam and a 1985 International rescue/pumper with Class A foam. Those are our structure trucks, thats it. They are definatly not what is needed at a significant chemical fire.

What we do have and make the best of is wildland units, we have 14 brush trucks of varios types. Our most capable of these baja machines are the CAFs units. We have 2 for the county, a light and a Heavy. We are desperatly looking for more. These are the units that put out our chem fires (and in reality more then their fair share of wildfire). They are basicly the only ones that have a chance to control a chemical fire. We have also had good fortune at structure fires with them.

So, if you think that fighting chemical fires in 15 year old Bunker gear, SCBAs that like to leave you a bit short on air, and with wildland CAF brush trucks useing Class A foam is a bad idea...

I would tend to agree with you!

So it seems a FEMA/NFPA group of my peers would also.

Its not that we like to live dangerously, we just dont have much choice.

On the brite side, there is not a lot we havent tried/learned/perfected with class A compressed air foam.

[Dalmatian90]

Random Thoughts:

1) Class B foam simply isn't practical for most departments. The quantity you need to be effective, and the incredibly rare times most departments would see the proper situation, doesn't make it cost effective.

That said I know there's some departments using Class B in their CAFS systems, but I still like to see the environmental impact statements on that. Class B isn't the evilist thing in the world, but it's still many times worse than Class A, and at least in my state the State DEP has a real dislike of Class B foams.

2) Crude oil fires are a much different beast from Gasoline or even Kerosene/Diesel/No. 2 Fuel Oil fires. Crude generally is less volatile than refined fuels, and it tends to be thicker.

Heck, going down the refinement scale to industrial (No. 6?) fuel oil and naval fuel oils, there used to be tactics of simply using plain water to froth the oil up to smother itself. If I recall right, that same tactic could be used on crude. Of course today with foam much more readily available, that's the greatly preferred tactic.

3) The "vapor barrier" formed by AFFF or other film-forming foams depends on a relatively flat, unpenetrated surface. Heavy grass on the side of the road? Not going to have a film form properly. Just have a tank burning or fuel spilled on an airport tarmack? Yep, AFFF will form a film and suppress vapors that way.

I'm sure it varies from area to area, but most rural to suburban areas the usual advise is to let the fire burn, and protect exposures. If you have a special situation, like the fire is exposing steel of a bridge (and that could cause substantial disruption to a lot of people for a long time to replace that bridge), then having a good CAFS system you can use to knock down the fire and form a foam blanket that'll do a fair job of suppressing vapors is a good thing.

But even at that, you're gonna need to make sure you can keep re-supplying Class A foam to keep that Class A CAFS blanket in tact. Certainly an easier job than using 3% Class B through aspirating nozzles...but still a challenge if you have a large spill and a long ETA for cleanup crews.