Hey everyone. I am an Engine Man through and through, and I am glad to be in this group but we need to start some discussion here!!
I have been reading articles and talking a lot about the Positive Pressure Ventillation/Positive Pressure Attack concept. I am an old school firefighter...grab the hose, stretch it to the seat of the fire, and as the hose team opens up the ventilation team pops windows and cuts holes. If everyone does their jobs than it does an efficient job of extinguishing the fire. Now you have the PPV concept...Thats all fine and good but from what I understood you need total control of ALL openings to control the air flow and the direction of ventilation. If any other opening is made than the fire will be "Pushed" towords this new opening, and I dont know about you guys/gals, but If Im the poor SOB caught between this new opening and the rapidly spreading fire, It will turn my day bad in a hurry. Im just not impressed with this tactic. Whats everyone elses views on this topic?
I was tought go in hit the ceiling with a fog pattern,then kick ash on the seat of the fire using a circular motion and the sweep from side to side.As far as venting goes cut the 4by4 holes in the roof to vent the fire,smoke.And pop the windows if you need to.I seen a newer method on the discovery channel the other night its called 3D fire fighting.you go in hit the ceiling with a fog pattern using small quick spurts of water.This is designed to disipate the smoke.And it also helps to vent the fire.You do this for a few mi utes and then go for the throat of the fire.
Thats just the indirect attack though, isnt it? You hit the ceiling with fog and the steam blankets the seat of the fire smothering it. Thats an effective tactic also, used to cool the fire down so you can reach the seat and put her to bed. What show did you see the firefighting stuff on?
The way I understand it, this technique doesn't work as well in the U.S. as it does in Europe because of building construction. Most fires, at least in the UK, are contents only without structural involvement because the structure is cement (courtesy of the Nazi urban renewal program in 1941).
There's also a special nozzle that allows pencilling without beating the hell out of the pump.
Back to PPV. I've been told that it requires constant training to prevent the situation you described. You can't run the company through it once a year and then do it successfully. On the other hand, I've never done it, so I don't know anything about it.
Here we go again.. lol .. Not to take away anything from either side of da fence.. But lets look at a couple of things 1st, Building construction... There is a bit of differance between a New England balloon frame 3 or 4 decker, ( or any balloon frame) and say, a south florida "Compartment" or concrete construction , or as was mentioned many of the "euro dwellings" ... Obviously.. PPV is sworn by as the be all end all , but this depends on yourresponse area too.. Setting up PPV in a balloon frame is asking to aid in neighborhood redevelopment agencies in my neck of the woods... But in a vault like set up, would definately allow closer access....
also For "us" the use of smooth bore nozzles Kick ash, while if you were attacking a fire in an "vault" chances are you would do more and safer for you if you use an indirect method, if not the Navy method of using fog /steam to extinguish compartment fires. In certain situations one works better then the other and thats why we use / have access tomultiple methods of attack. Its not much differant, then foam nozzle methods of delivery, it depnds on what the situation is thats in front of your face.. do you lob it in? or deflect the foam in? or does the situation/require you to just flow and overtake it in? Ventilation is an important tool, and means of doing the task, vary because of construction, conditions, and other "stuff" .. PPV just like mechanical , hydralic, Horizontal , and vertical ventilation are just some of the ways to best accomlish the task at hand, and that is containment and extinguishment...
Like you guys have stated, I am old school, I've done outside vent operations, been on enough rooves and even trapped on a few, I've also stretched into the seat of the fire Once or twice (lol) in 32 years of doing this stuff
I have seen "other local departments" jump on the PPV train because "they read PPV was the end all be all, saving lives and roof dangers" and watched them all burn down various buildings,,, I have been an advocate for many years now ,of IF the FD "intervention" costs many lost man hours and more damage (ultimately) then if NOTHING had been done ie: loosing exposures, when if the fire was left to just free burn.. without potential exposure loss... lol then why are we out there for 16 hours??? lol
anyway, PPV does have its place. and as long as that place ISN'T on my job then all is good.. :)