Becoming a driver/operator can be a fairly intimidating step in one’s career. No matter how much training and/or experience you had as a firefighter, the pressure of being the one responsible for the safety of an attack crew causes some to question what they know is right.
Over the past few years, I have discussed the following question numerous times with driver/operators of varying experience levels. I am going to share the question, and my answer/opinion, with you. Please feel free to share your thoughts.
The question is…
When pumping an attack line, should the operator pump what they are supposed to have by the numbers (length, size, flow, friction loss) or give them enough to start with (so as not to “beat up” the crew) and rely on radio communications to adjust?
My answer/opinion is…
Give them what the numbers say they are supposed to have. It is the pump operator’s job to make sure that the attack crew has what they are supposed to have because…
- The safety and trust of the attack crew rests with their confidence in the operator to get them the water they need, when they need it.
- Radios are usually the weakest link in the fireground communications process and are unreliable for numerous reasons.
- Line size, length and nozzle selection is based on the numbers
- Neither the attack officer nor the IC can determine the effectiveness of the attack if they are not putting the CORRECT gpm on the fire to begin with.
- Any reductions in flow could/should indicate a kink in the line, burst or damaged section, or mechanical problem with the pump. It should never be a result of operator error.
Though noble is theory, the most common reasoning I’ve heard behind lower pressures initially is to make it easier on the attack crew. However, there is a fundamental breakdown with this theory. If the nozzle firefighter cannot handle the nozzle, it may be due to lack of training, improper nozzle positioning (i.e. pistol grips), lack of adequate backup on the line or any combination of these.
Though it’s drivers who usually bring up the question of attack line pressure, the issue is really brought about by firefighters who express concern about nozzle pressure (having too much). I stand by my opinion and would encourage crews to practice nozzle tactic training, especially the teamwork between the nozzle and backup firefighters. Most fires are controlled with the first attack line. There is also a cliche that “as the first line goes, so goes the fire.” With that being said, let’s get it right the first time and take the fight to the fire.
Below are a few links to give you some training ideas.
Thanks and Be SAFE
Video from Brotherhood Instructors- Engine Company Ops
Article/Post from Traditions Training- “Play Like You Practice…”
Also on SAFE Firefighter …
- Tips for Advancing the Attack Line – August 5, 2010
- Influential Fire Report- Firefighters Trapped at the HoJo – April 26, 2010
- Size Doesn’t Matter – November 1, 2009
- Understaffed Truck Work: Search – July 12, 2009
agree with you. We have trained with our hoselines, standardized the pressures, and labeled each discharge on the pump panels. The nozzleman always has the option to gate down the nozzle momentarily while waiting for radio acknowledgement to lower the pressure. Besides, when was the last time that someone was holding a nozzle and getting what looked like a good stream and asked for MORE pressure? A good looking stream from an automatic nozzle may only flow half of rated volume.
What is your opinion on low pressure nozzles? We currently switched from 100gpm to 50gpm dropping our PDP from 160 to about 90. This has caused us significant kinking and handling problems when pumping by the numbers. The justification to the lower gpm nozzle was less nozzle reaction, but with the 50psi nozzles flowing 150gpm inlieu of 100gpm, the nozzle reaction is infact neglegible, therefore officers have told there pump operators to pump 130PDP on 200′ 1.75″ so the pressure in the line stops kinking while advancing it.
If you are beating up your crews why not consider going to smooth bore nozzles…you can delivery the same amount of water with a dramatic decrease of Nozzle pressure…..
There are a number of ways to determine proper pump pressure. When I started out as a firefighter we were told that if you needed a little more pressure, motion with your thumb up would get you 5 psi more, and it worked provided you had eye contact with the Engineer. One day the Ol’ Gus forgot to set the relief valve and did a bad changeover from tank to hydrant, a behavior he was known for. I remember using a familar finger signal when I caught his attention and it wasn’t a thumbs up!
I agree with you but would add that the nozzle person can really make the setting of the PDP (proper discharge pressure) more effective by bleeding the line for 10-15 seconds after calling for water so the D/O can actually set the proper pressure. Typically the nozzle person quickly bleeds the line then gets to the fire and opens the nozzzle with a weak stream and screams at the operator for more water!!
OK, let’s think about the physics of this. Water puts out the fire, pressure delivers the water. In my experience the nozzle reaction from automatic delivering 125 gpm to straight tip is almost the same. It’s like gun experts arguing over which kicks more the .357 or the .45. The 357 actually has a higher recoil,(slightly)however most claim the .45 “kicks” more. Nozzle reaction is the weight of the water. Most automatics use the pressure to help shape the stream. I agree lower pressures make hose advancement harder with kinks more likely. The best answer is TRAINING!
Having run a pumper for 15-20 years with a small rural volunteer department, we pretty much standardized 110-120 PDP on our 150′-200′ attack lines. If the nozzleman wants more or less he either hand signals (if visually in contact or radios if inside). I stress in training that the pump operator should maintain contact with his crews and devote ALL of his attention to THEM as it only takes a few seconds for them to get into trouble. We keep the Relief Valve at about 150#’s to keep down surges that would cause the crews problems.
I am a driver on an engine. That is my position and what I get paid to do.
First of all, I agree with safefirefighter. Give them the correct pressure.
To answer Collin’s comment, if you are using low pressure or high pressure nozzles it doesn’t matter. Give them the correct pressure for the application and equipment.
All that being said, I have been an “engineer” exclusively for around 6 years and have been driving off and on (including pumping) for the past 10.
If we pull up and it is a common attack with common lines pulled I am golden. I know the pressures right off the bat. This includes 1 3/4″ and 2 1/2″ 200 foot attack lines with fog or solid nozzles that we carry. Beyond that I move into my knowledge and can come up with pretty decent approximations.
For instance if we have a wyed line or siamesed line, I might have to go back to the old paper and pencil to get the exact. However, I will get them going with what I estimate is the proper pressure right off the bat.
As for setting the pressure prior to waterflow: That is something you have to know what you are doing. Sure, some might set the pressure and never look back. A good operator will set the pressure, realize when water is flowing and adjust accordingly.
Great discussion!
I think one needs to be realistic with what pressures one tries to flow. A chief training officer told me one time that we went to 1 3/4 lines to increase the gpm we could deliver with attack lines. I agree with this, however he also told us that to get maximum gpm out of a 200′ preconnect we needed to pump it at over 200psi pdp. Although this may be true, at that psi, the attack team is trying to move a pipe. Gpm doesn’t do you any good if you can’t put it on the fire. If you are marginal on the gpm you are delivering, use larger or multiple lines or both. Keep your pressures at a point to where attack crews can manuver the line and actually attack the fire.
I am a firm believer in firefighter nozzle control. I also believe that a line should be pumped to the required needs flows and the dudes at the nozzle be responsible for the application. With the proper training nozle control of even higher then standard pressures can be handled. On ther hand if you try to take it easy on the nozzle people you may wind up not giving them enough water putting them into a bad situation.In reply to the comment about automatics being decieving as to how much water they are flowing because of the pretty streams they make at low flows I have this answer. If you had a 15/16″ tip that was under flowed and you were on an interior attack with poor to no visibility, how would you know if the stream was flowing enough?. The nozzle reaction wouuld be a good indicator. You know what it feels like to flow your standard attack line flow. And would be able to feel a underpowered stream. Well an auto is no different. Under flowed lines can be felt with autos just as with any other type nozzle.The nice thing about autos is that if a line is overpumped it can be gated down without distrupting the stream.
If you are utilizing Task Force Tips then you can supply them with 200lbs of pressure and the attack crew can control nozzle reaction. They do this by the detents designed into the nozzle. They can open it half way if that is comfortable. They have more GPM if they need it.
Hey Fire Critic,
Thanks for the feedback. FYI… 3″ wyed down to 1 3/4″… your FL is 2# per 100′ @ 150 gpm and 9# per 100′ @ 300 gpm. It’s a popular tactic with us so I sat down and figured it out one day. Thanks again!
Hey Chief,
Thanks for the tip. You’re right about how quickly we typically bleed the line… it definitely requires the D/O to pay attention. Another tip is to straddle the line and CRACK the nozzle after you call for water (while putting on your mask). It pushes the air out as it comes to the nozzle which could also accomplish what you were suggesting. Thanks again.
Matt
Hey Paul,
That’s a good point. There has been a resurgence of the smooth bores as well as the growing popularity of low pressure fogs (see Colin’s comment below). Thanks for the feedback.
Matt
Hey Colin,
Good to hear from you and thanks for the comments. I think that the advantage of reduced pressures is that the nozzle firefighter may not need the backup firefighter checking his prostate. That being said, the backup firefighter (or officer) can hang back on the line a little and help manage kinks as the line advances through the building. Also, my opinion is that the triple stack doesn’t lend itself to a nice, straight, kink free line stretch. By it’s design, it drops into a pile of kinks. With low pressure nozzles (fog or smooth bore) the stretch may be the most important factor to reducing the kinks. Sorry for the long reply and thanks again.
Jeebs
BCGATTI I couldn’t agree more. As a 26 year volunteer I have been on all sides of the nozzles and hoses. I mainly drive/pump now and I have the full trust of the rest of the guys on the dept. TFT’s have greatly reduced the nozzle jump, although I start with 150 psi on our 1 1/2″ lines, but it also depends on how much hose is strung out and what we have for an incident. We serve a huge rural area and we get everything from sheds to barns to houses and lots of trailer houses. The biggest thing is to get the guys to trust the TFT’s and that takes TRAINING!!!!
Too Much Todo About Nothing. Kinks; they are in the line regardless of NP or PDP. Deploy the line correctly and you will reduce the kinks in a line. But everyone chases kinks, including the chief.Overcoming the BTU’s being produced with GPM’s delivered by trained firefighters through the correct size line,with the correct pressure for the nozzle used is what puts out fires. As for controling nozzle reaction on automatics by the “dents designed into the nozzle”, Give me a break! If you gate the nozzle down, you reduce the GPM’s being delivered. Not a good thing! The nozzle is either opened or closed when in an active firefight!Gate the nozzle during salvage and overhaul. As for the officers position on the line; beside or slightly in front of the nozzleman to direct the stream and LEAD the company. My opinions. Stay Safe, FTM-PTB
Being on the pipe for many years this has always been a hot topic. The simple solution is switch the attack crews and engineers up once in awhile so they all get a feel of what both sides are like. They then work much better together. Give me a 2 1/2 with about 120 PSI and I’m happy as a clam. I know they go hand in hand but I’m more concerned with volume not pressure.
BC, I respectively disagree with you on the gating down of the nozzle operation. I have done extensive flow tests on this topic and have proven that gating down a nozzle to reduce nozzle reaction can still produce a good flowing stream. Of course it depends on the initial flow that you are starting with. If you start with 100 gpm then of course gating down will not work but do you really need to gate down low flows in the first place? What about the FDNY 1-3/4″ flow of 185 GPM. This is a great flow for interior work and is definately set up for maximum flow. You know as well as I do that a 120 to 150 GPM flow also works well in most situations. With that being said if a 185 gpm flow had to be gated down for what ever reason and still provide a working stream, based on my flow testing , the flow would still be in the 120 to 150 gpm range. Gating down to me is better than getting the snot beat out of you and having to shut down in a fire fight. As I said in my prior post , nozzle traing is very important in having a sucessful operation.
Very good discussion. I have been in the fire service for around 18yrs and it is clear to me that the “numbers” are not necessarily correct. Friction loss charts are quite conservative so the best solution is to check the friction loss of your particular hose then the pump operator has real numbers to work with. Give the nozzle what they need from the start. Those of us that think combination nozzles are the only way need to try a smooth bore alongside flowing the same water. The smooth bore is going to be easier to handle but is not as versatile as the combination. They both have their place.
Good discussion here. Taking one good engine company ops class will open your eyes to these concepts. My personal opinion is this: leave the automatics on the front trash lines and give me a 15/16″ smooth bore on one preconnect and a 175 @ 75 fixed combo on the other. You now have the best of both worlds and can pump the lines the same to get the same flow from both nozzles. Oh, and the pistol grips can stay on the trash lines too. All they do for interior operations is promote poor hose handling technique. And we really have to get away from thinking the 2 1/2″ is a defensive line. Pump the lines for what the numbers say you need and train to handle and USE the pressure and flow on the other end. Most of the people I have seen complain of too high pump pressures are the ones with the worst form for hose handling.
Lou,
Great article to discuss. I’m with you, by the numbers. I will add a little something for a side note though. If the Engineer and Officer are comfortable with each other and have the same expectations regarding flow, I think a deviation from the book would be acceptable. I know as a Company Officer, my thoughts on water need/availability are part of my size up. If I plan on one GPM and get another, there is the possibilitynthat my attack will not go as expected. Train, train, train with your crews. Once everyone is on the same page, there should be very few suprises based on crew errors/miscommunications.
At my job our SOP’s has us to use the hand method where it has use to add 32 psi per 100 ft for a 1.75 hose to acheive 200 gpm. So on our crosslays we have 2 that are 200 ft & 1 thats 300 ft. No one on a hand line wants to wrestle with 196 or 164 psi. If you like those numbers please post a video of you trying to work with that! lol.