If you have Class A foam capabilities why wouldn't you use it initially when attacking a structure fire? For a room, or multiple rooms and contents fire it can be a real plus. I doubt I would use it on a fully involved structure.
We have a foam tank hooked up to a pre connect on our county structure engine/heavy rescue. We have to hook up the suction tube on the city engine. We train once in a while on foam, but rarely use it. Some of us have been researching the use of foam more and from we have read it is good for initial attack and mop up. It seems to us that anything that makes our job easier and what we do more effective makes good sense.
Since foam concentrate is expensive we use it judiciously, mostly for mop up on structures that are difficult to overhaul. We haven't had the luxury of using foam for initial attack.
Wildland fires... All the time.
Structure fires... on the initial attack for a quicker knockdown, and sometimes during overhaul.
Most everything we use Class A on, is set at .5% as a wetting agent, not to blanket an area like is done with CAFS.
I agree with Don, (yes, sometimes I do) that I wouldn't waste it on a fully involved structure.
Maybe you should sit down and relax...admitting you agreed with me may show some signs of some sort of psychotic episode!! :)
I agree with your explanation of when to use it. We like it for initial attack because it extends the waters effectiveness while a water supply is being established. For overhaul we aerate it and bump the percentage up a bit and will "Paint" the rafters or trusses, or other structural members to ensure extinguishment of any fire or smoldering remaining.
We don't see it as expensive to use when you figure in if you make a hard hit with that foam on the initial line and knock that fire down quicker. It may eliminate that long drawn out battle and the need to run tanker shuttles for hours. To me that is a cost savings.
In my department it is SOP to use foam 3% at all motor vehicle collisions with entrapment, we feel it greatly improves life safety should we encounter flammable vapors, because of the cost we avoid using it for structural situations.
We run a CAFS engine as our first out for fires. We also have proportioned Class A foam on our second out engine. Foam, regardless of CAFS/Proportioned is great for initial knock down from the exterior or interior. It does a great job at suppressing the fire. The trick with foam is knowing how to use it and, having it set right. Thick shaving cream CAFS foam is not what you aggressively attack fires with. CAFS for aggressive interior attack should look like soapy water, very small bubbles that dissipate rapidly. CAFS/Proportioned foam is good from 1 3/4" hoseline and down. If you are pulling the 2 1/2" run straight water, BIG fire = BIG water (not foam)...
We don't use anything but the class A foam. It is used any structure or vehicle fire. The key is where to apply it and how. Normal control only requires about .1% to provide effective assist to attack lines. If you have hydrocarbons, then just bump your concentration to .3% and then point down or on a wall behind and let the foam build and roll onto the fire. For fully involved structure, we use ti to stop/slow progression while other non foam attack lines are used to cool. We look at it as cheap insurance to reduce fire damage and manage overall loss. A very watched item by the insurance industry these days.
We use it depending on the officer and when we actually have the foam. One of our officers who has been in the fire service longer then most of us have been alive has started using normal dish soap to cut the costs of the foam as it works in alot of the same ways that the foam concentrate does in breaking up the surface tension of the water especially for wildland applications
I would use caution utillizing dish soap. Certain brands of soap are hard on pump packings. My department utillized dish soap several years ago, before we reallized it as the cause of packing failures. Again some brands are worse than others when it comes to an environmental issues because of the phosphate level. We used a certain brand of soap that starts with a "D" to wash down oil spills at crashes. Until we were warned by a representative from Polution Control that we were in fact polluting the ground because it wasn't bio-degradable.
ya the only kind we have used was the biodegradable stuff, mainly the type that you mentioned but made for rv's