Thread: Strategy and Tactics

1. Strategy and Tactics

Does anyone know who or what says anything about pulling a back or second handline? I'm just looking for the NFPA code or any help would be great...

2. Nfpa 1710

NFPA 1710 states that you need to be capable of flowing 300 gallons per minute for an interior attack. So unless your going in with a 2 1/2 line with a big tip, your going to need to stretch two 1 3/4 hose lines.

3. Pitt8Truck is right - NFPA 1710 states a requirement for ...

Establishment of an effective water flow application rate of 1140 L/min (300 gpm) from two hand-lines, each of which shall have a minimum of 380 L/min (100 gpm). Each attack and backup line shall be operated by a minimum of two individuals to effectively and safely maintain the line.
The NFA flow-rate formula is also designed for accommodating an attack line with a back-up line - A/3 = gpm

Example -

20 x 30ft fire involvement = 600ft2 / 3 = 200 gpm
which is two lines (attack and back-up) at 100gpm minimum (not one line at 200gpm)

4. Originally Posted by Batt18
The NFA flow-rate formula is also designed for accommodating an attack line with a back-up line - A/3 = gpm
Where did you dream that up?

Neither the Iowa or NFA formula address the number of lines used to attack a fire. They both determine necessary fire flow, that is it.

If you calculate that you need 200 gpm and you can do it with one line, so be it.

Chief
Has
Arrived
On
Scene

5. Originally Posted by MemphisE34a
Where did you dream that up?

Neither the Iowa or NFA formula address the number of lines used to attack a fire. They both determine necessary fire flow, that is it.

If you calculate that you need 200 gpm and you can do it with one line, so be it.
No dreams Robert ... That is how the National Fire Academy arrived at the A/3=gpm formula on their PIC course (Preparing for Incident Command) review some years back. The notion was that several lines are better than one single line and this flow-rate formula includes those delivered by the attack line/s and the back-up hose-line/s.

6. Originally Posted by Batt18
No dreams Robert ... That is how the National Fire Academy arrived at the A/3=gpm formula on their PIC course (Preparing for Incident Command) review some years back. The notion was that several lines are better than one single line and this flow-rate formula includes those delivered by the attack line/s and the back-up hose-line/s.
I have never seen or heard it taught that way. Any chance of siting a source or reference online. I googled it and not a single article I have found so far mentions backup lines.

7. Originally Posted by MemphisE34a
I have never seen or heard it taught that way. Any chance of siting a source or reference online. I googled it and not a single article I have found so far mentions backup lines.
The NFA fire flow formula is not means tested but I do consider it one of the most accurate methods of estimating needed fire flow, either for on-scene requirements or for pre-planning. The IOWA method is totally irrelevant unless you are utilizing indirect water-fog tactics.

The NFA formula was derived by asking experienced fire officers on NFA courses to take into account their own size-ups for hose-line and flow requirements in a range of case scenarios for different types of occupancy.

The guidance given to them included the need for back-up and additional hose-lines. It was suggested that good firefighting tactics will include support hose-lines as such and the flow-rate formula was developed around such an approach. It was not meant to provide a flow-rate from a single hose-line and acknowledged that additional lines were generally laid in, during the first few minutes, to surround the fire and support interior crews. The NFA formula is based on these very principles.

Think about Vince Dunn's well published estimate that suggests one 300gpm line will handle up to 2,500sq.ft of fire .... Chief Dunn was an experienced fire officer and he knew how much fire could be swallowed up by any given flow-rate. If you calculate the NFA flow (NFF) for 2,500sq.ft it equates to 833gpm. But if you calculate the NFA formula as one line for fire attack and one line for back-up, then you get closer to the truth! Vince Dunn's 300gpm line if supported by a 300gpm back-up line comes much closer to to the NFA formula.

The originators of the NFA formula purposely built in a safety factor to account for the fact that several hose-lines may be needed and also that when the building is ventilated, the rate of burn may increase. In effect, more water than is actually necessary is calculated.

I have some articles that are old and will need scanning. E-mail me and I'll try to get something to you.

8. When I was at the NFA last year, the instructors emphasized several times that the NFA A/3 formula was designed for calculating needed flows for Aggressive Interior Attack.

The instructors said that different flow rates were needed for different control styles. For example, if you are going defensive on a single family dwelling with no exposure issues and no life/safety risks, your needed fire flow could be calculated as zero

9. When I asked this question. It was to answer a group talk we have been having at the station. No one knows why we pull a back up line. Just that we do it because we ahve been taught that way for so time. If I remember right it has to be the same size or bigger and equal or greater length. So we just was wondering where it came from...

10. 300gpm

We have Inch and 3/4 lines that flow 300GPM problem solved?

I still pull Big Hose for big fire but I have seen some fires brought to their knees with the small diamiter hose & Taskforce Tips...We have Task Force tips on our 2.5" hose also....

I have been told I am old school, but I like Big hose for big fire....

11. Originally Posted by Tiller98250

I have been told I am old school, but I like Big hose for big fire....
If that's old school, then who the F*** is teaching school?

I'd say you're experienced and their naive at best, and sadly dangerous at worst.

12. Originally Posted by Batt18
The NFA formula was derived by asking experienced fire officers on NFA courses to take into account their own size-ups for hose-line and flow requirements in a range of case scenarios for different types of occupancy.

The guidance given to them included the need for back-up and additional hose-lines. It was suggested that good firefighting tactics will include support hose-lines as such and the flow-rate formula was developed around such an approach. It was not meant to provide a flow-rate from a single hose-line and acknowledged that additional lines were generally laid in, during the first few minutes, to surround the fire and support interior crews. The NFA formula is based on these very principles.
I guess that is where I either have a misunderstanding or where we disagree. To me there is a difference bewteen laying additional attack lines to fight the fire and a back up line. IMO, a back up line is one that is charged in case something goes wrong with the first one OR one that is laid to the same location as the first because the first one is not putting the fire out. Another line to another location is not a back up line, it is another attack line - at least to me.

For example, if the NFA formula called for 250 gpm, it would make no difference in the overall outcome if two 1 3/4" lines were laid both flowing 125gpm or a single 1 3/4" or 2 1/2" flowing 250 gpm.

Oh and by the way, you can email me by clicking on the Yahoo icon under my avatar.

13. Call me old school too. They're great for preplanning, but forget about fancy formulas and calculations for simple fireground decisions like this. If you're pulling one line, always pull a second. If you have the manpower and room to work it, go with a bigger line than the attack line. It doesn't need to be any more complicated than that for actual on the spot practice. Good old common sense firefighting...

One thing that is good to look into as far as formulas go: Make sure your operating procedures emphasize rapid establishment of a water supply (not at the expense of unduly delaying some sort of an attack and other operations going of course). Pulling an 1 3/4" and a 2" or 2 1/2" with 500 gal. in the tank and no water supply, or an insufficient one isn't great. Make sure you'll be able to flow enough on your initial attack to support at least these two lines for the early stages of suppression efforts. If you can't guarantee that with current SOGs, change the SOGs. Get all this first and then worry about the NFPA standard. This should be common practice.

Don't get me wrong, I'm all for working out the math on this sort of thing, but this is really a simple question with simple answers. Disclaimer: Forgive me if I misunderstood the nature of the question.

14. I like the 1 3/4"= single-family residential and 2 1/2" = Commercial Building rule of thumb.

15. Originally Posted by mtngael
Call me old school too. They're great for preplanning, but forget about fancy formulas and calculations for simple fireground decisions like this. If you're pulling one line, always pull a second. If you have the manpower and room to work it, go with a bigger line than the attack line. It doesn't need to be any more complicated than that for actual on the spot practice. Good old common sense firefighting...

One thing that is good to look into as far as formulas go. Make sure you're operating procedures emphasize rapid establishment of a water supply (not at the expense of unduly delaying some sort of an attack and other operations going of course). Pulling an 1 3/4" and a 2" or 2 1/2" with 500 gal. in the tank and no water supply, or an insufficient one isn't great. Make sure you'll be able to flow enough on your initial attack to support at least these two lines for the early stages of suppression efforts. If you can't guarantee that with current SOGs, change the SOGs. Get all this first and then worry about the NFPA standard. This should be common practice.

Don't get me wrong, I'm all for working out the math on this sort of thing, but this is really a simple question with simple answers. Disclaimer: Forgive me if I misunderstood the nature of the question.
Good post! The original request was simply asking for references to the 'pulling of back-up lines'. These have been cited and the above post puts the practical aspects into perspective. Formulas are really for pre-planning but with time and experience, they will also assist you in estimating flow requirements simply by looking at any particular level of fire involvement. For those without extensive experience of assessing a hose-stream's fire-fighting capability, a background knowledge of such formulas is very useful.

16. Originally Posted by MemphisE34a
I guess that is where I either have a misunderstanding or where we disagree. To me there is a difference bewteen laying additional attack lines to fight the fire and a back up line. IMO, a back up line is one that is charged in case something goes wrong with the first one OR one that is laid to the same location as the first because the first one is not putting the fire out. Another line to another location is not a back up line, it is another attack line - at least to me.

For example, if the NFA formula called for 250 gpm, it would make no difference in the overall outcome if two 1 3/4" lines were laid both flowing 125gpm or a single 1 3/4" or 2 1/2" flowing 250 gpm.

Oh and by the way, you can email me by clicking on the Yahoo icon under my avatar.
No I agree .... What you say here is not incorrect.

Its just that the theoretical foundation behind the NFA formula recognized that it is often necessary to lay in several lines instead of one, either for back-up or because two attack lines may, in some situations, be better than one. I have researched this formula for many years and compared it to several others. If you simply base it on a single attack line and fail to account for a back-up line as well then the formula estimates very high Needed Fire Flows, when compared to similar formulas or estimates. The original exercise given to NFA students to produce the fire-ground formula asked them to consider specific areas of fire involvement and then place hose-lines of various sizes, including back-up lines, into position to effectively deal with the fire. The floor areas were then divided by the needed flow-rates estimated by the students and a factor of 3 was commonly derived. This is how the formula evolved.

It was acknowledged that not all the hose-lines would be laid in immediately but that the aim would be to increase the lines as additional staff and apparatus arrived on-scene, so arriving at the needed flow to deal with the fire. If the calculated estimate was for 300gpm and a single 300gpm line went straight into action then so be it. However, if an additional line went in flowing another 300gpm then this was surplus to requirements, according to the NFF produced by the formula. If, on the other hand, a 150 gpm line went immediately into action and a second 150gpm back-up line was laid in some three minutes later (even if not flowed), that is all that is required to meet the flow demands.

Simply, the NFA formula provides a gpm figure that is needed to deal with a fire, in an area, whilst accounting for all tactical lines (whether flowed or not) in accordance with the way the US fire service were approaching fires in the 1980s. The notion was that if we needed an attack line as well as a back-up line, we should provide an adequate flow-rate to support both lines in an area of fire involvement based on sq.ft.

BTW Robert - I have tried to e-mail you at memphise3a@yahoo.com which is listed as you suggest, below your Avatar, but the e-mails bounce back?

17. Ahhhh. Sorry, thats supposed to be memphise34a@yahoo.com

I'll fix it. Thanks.

18. BATT18 and Memphis, I'm not sure I disagree with or 100% agree with either of you, but here's my understanding of the NFA formula:

The NFA LxW/3 plus 25% per exposure is a fire flow formula used to determine overall fire flow for the "current or arrival" conditions. On arrival you then know what type of water supply you'll have to establish, a single hydrant line up to multiple hydrants or water supply's from multiple locations. It will most often determine you need multiple lines to get the flow onto the fire. This also helps us determine how many companies need to be brought to the scene. It like any formula is subject to too many factors to be a silver bullet.

A single story of 30 x 40 with no exposures would require 400 gpm. If this were a restaurant with a large open space and the right fuel load, this clearly would indicate a large line (2.5"). But if this is a 30x40 house with multiple rooms (read compartments) chances are great that a single 1.75" line will be able to get the job done. Again, one cannot assume that given smoke conditions we'll be able to accurately predict the percent of involvement. If its got flames and smoke from all sides of the floor I figure 100% of the floor, and in fact unless it was fairly obvious that it was contained to a smaller compartment, 100% of that floor is a safe figure for the total fire flow.

Another point this thread brings up: I don't agree that two 1.75" lines flowing 150 gpm each have the same ability as one 2.5" line flowing 300 gpm. If the fire requires 300 gpm and the two small lines will easily lose most of their punch from the heat, vs. the single large stream that loses some but allows the center to reach deeper with more power. This is especially true with better ventilation as the steam conversion will have much less effect.

The original question of the back up line: as soon as possible regardless of what any formula says. As always musty be as capable if not more than the original attack line it's backing up. This may mean large or longer but always equal as a minimum.

19. Originally Posted by RFDACM02
The NFA LxW/3 plus 25% per exposure is a fire flow formula used to determine overall fire flow for the "current or arrival" conditions. On arrival you then know what type of water supply you'll have to establish, a single hydrant line up to multiple hydrants or water supply's from multiple locations. It will most often determine you need multiple lines to get the flow onto the fire. This also helps us determine how many companies need to be brought to the scene. It like any formula is subject to too many factors to be a silver bullet.

A single story of 30 x 40 with no exposures would require 400 gpm. If this were a restaurant with a large open space and the right fuel load, this clearly would indicate a large line (2.5"). But if this is a 30x40 house with multiple rooms (read compartments) chances are great that a single 1.75" line will be able to get the job done. Again, one cannot assume that given smoke conditions we'll be able to accurately predict the percent of involvement. If its got flames and smoke from all sides of the floor I figure 100% of the floor, and in fact unless it was fairly obvious that it was contained to a smaller compartment, 100% of that floor is a safe figure for the total fire flow.

Another point this thread brings up: I don't agree that two 1.75" lines flowing 150 gpm each have the same ability as one 2.5" line flowing 300 gpm. If the fire requires 300 gpm and the two small lines will easily lose most of their punch from the heat, vs. the single large stream that loses some but allows the center to reach deeper with more power. This is especially true with better ventilation as the steam conversion will have much less effect.
I agree pal. I guess I should clarify. As in your example above, I meant when the two smaller lines flowing the same amount were stretched to the same area and attacking the fire together. The combined gpms will be necessary to penetrate into the seat of the fire before evaporating.

20. Originally Posted by RFDACM02
BATT18 and Memphis, I'm not sure I disagree with or 100% agree with either of you, but here's my understanding of the NFA formula:

The NFA LxW/3 plus 25% per exposure is a fire flow formula used to determine overall fire flow for the "current or arrival" conditions. On arrival you then know what type of water supply you'll have to establish, a single hydrant line up to multiple hydrants or water supply's from multiple locations. It will most often determine you need multiple lines to get the flow onto the fire. This also helps us determine how many companies need to be brought to the scene. It like any formula is subject to too many factors to be a silver bullet.

A single story of 30 x 40 with no exposures would require 400 gpm. If this were a restaurant with a large open space and the right fuel load, this clearly would indicate a large line (2.5"). But if this is a 30x40 house with multiple rooms (read compartments) chances are great that a single 1.75" line will be able to get the job done. Again, one cannot assume that given smoke conditions we'll be able to accurately predict the percent of involvement. If its got flames and smoke from all sides of the floor I figure 100% of the floor, and in fact unless it was fairly obvious that it was contained to a smaller compartment, 100% of that floor is a safe figure for the total fire flow.

Another point this thread brings up: I don't agree that two 1.75" lines flowing 150 gpm each have the same ability as one 2.5" line flowing 300 gpm. If the fire requires 300 gpm and the two small lines will easily lose most of their punch from the heat, vs. the single large stream that loses some but allows the center to reach deeper with more power. This is especially true with better ventilation as the steam conversion will have much less effect.

The original question of the back up line: as soon as possible regardless of what any formula says. As always musty be as capable if not more than the original attack line it's backing up. This may mean large or longer but always equal as a minimum.
Yes I am in agreement with all you say too. The formula is certainly no silver bullet and is not cast in stone. As I stated earlier though, of all the formulas I have researched and used, it is the most practical as well as the most accurate.

The intention of the formula was, according to the program developers, to include the back-up hose-line/s in the calculated estimate of needed fire flow. Therefore with two attack lines flowing 150gpm and one back-up (not necessarily flowing its 150gpm) the fire-ground formula would be 1350sq.ft = 450gpm.

21. Originally Posted by Batt18
The intention of the formula was, according to the program developers, to include the back-up hose-line/s in the calculated estimate of needed fire flow. Therefore with two attack lines flowing 150gpm and one back-up (not necessarily flowing its 150gpm) the fire-ground formula would be 1350sq.ft = 450gpm.
I guess we're really all saying the same thing here. The formula attempts to account for the total supply needs of all lines vs. the initial attack line flow.

This is also the formula we use as it seems most accurate vs. adding other variable that are still questionable (fire loads). Though the end, most often it's big fire-big lines, small fire small lines and most often big lines for commercial buildings of any size.

22. Originally Posted by RFDACM02
Though the end, most often it's big fire-big lines, small fire small lines and most often big lines for commercial buildings of any size.
Absolutely!! I have never one time pulled up at any fire and actually taken the time to establish the numbers to plug into the formula to figure out what I am going to lay.

Ultimately, I gauge from experience that I can either get it with something smaller than a standard size hose line, a standard 1 3/4" lay, a larger lay, or utilize the deck gun. End of story.

23. Originally Posted by MemphisE34a
Absolutely!! I have never one time pulled up at any fire and actually taken the time to establish the numbers to plug into the formula to figure out what I am going to lay.

Ultimately, I gauge from experience that I can either get it with something smaller than a standard size hose line, a standard 1 3/4" lay, a larger lay, or utilize the deck gun. End of story.
I use a calculator and a range finder, a dry erase board with neon markers and an astrolabe.

24. Originally Posted by johnny46
I use a calculator and a range finder, a dry erase board with neon markers and an astrolabe.
Hope you have the safety vest on when doing that. And of course a helmet, in case you should fall down from the intense headache.

25. Originally Posted by nyckftbl
Hope you have the safety vest on when doing that. And of course a helmet, in case you should fall down from the intense headache.
The safety vest has an intrinsically safe LED set, a GPS locator and a safety line.

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