Smooth Bore Tips, The Next Generation

Smooth Bore Tips,

The Next Generation

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When it comes to water delivery on the fireground, I think it’s safe to say that the fire service has come a long way. My knowledge of history in regards to this topic goes back to the use of buckets in bucket brigades. I can’t imagine what was done before then. We have since seen the coming of fire hose and water delivery appliances called nozzles, producing major improvements in our capabilities. I am pretty sure that the smooth bore nozzle was the first nozzle design used and we are still using it successfully today.

 

Rules governing the use of smooth bore nozzles have been in place without change for at least the last 60 years, and possibly even longer. I think it’s time for a change.

 

SMOOTH BORE NOZZLE DEFINITION

The smooth bore nozzle is a fire stream producing device (nozzle) consisting of a nozzle valve and a pipe like extension that forms the fire stream used in conjunction with handline and master stream operations to deliver water in the form of an effective firefighting straight stream. The flow rating of the smooth bore tip is based on the diameter of the tip as well as the nozzle pressure.

 

HANDLINE OPERATIONS USING SMOOTH BORE TIPS

The following chart shows the most commonly used handline smooth bore tips with their corresponding flow and pressure ratings

7/8″ tip 159 GPM 50 psi NP

15/16” tip 185 GPM 50 psi NP

1”tip 210 GPM 50 psi NP

1-1/8” tip 265 GPM 50 psi NP

1-1/4” tip 325 GPM 50 psi NP

 

The following five rules on smooth bore tip handline operations are from the current fire stream management book by IFSTA .

#1-The maximum handline flow is 300-350 GPM. They claim that flows higher than this will create an unmanageable handline.

#2-The nozzle pressure for a smooth bore tip on a handline is 50 psi. If need be the nozzle pressure can be increased to 65 psi. Pressures higher than this will create an unmanageable handline as well as a broken, non-productive stream.

#3-The diameter of the smooth bore tip shall be no larger than half the diameter of the hose.

 

Let’s talk about the first three rules. The following chart shows various nozzle combinations and their capabilities as they relate to handline operations. The chart is divided into sections of flows ranging from 250 GPM to 500 GPM. It shows the nozzle (smooth bore or combination), nozzle pressure (NP), and nozzle reaction (NR).

 

HANDLINE NOZZLE REACTION CHART

250 GPM

15/16” tip@90 NP = 124 NR

1″ tip @ 72 NP = 113 NR

1-1/8″ tip @ 50 NP = 99 NR

combination @ 100 NP = 126 NR

300 GPM

1” tip @100 NP = 157 NR

1-1/8” tip @ 64 NP = 127 NR

combination nozzle @ 100 NP = 152 NR

325 GPM

1” tip @ 120 NP = 188 NR

1-1/8” tip @ 75 NP = 149 NR

1-1/4” tip @ 50 NP = 123 NR

combination nozzle @ 100 NP = 164 NR

350 GPM

1-1/8″ tip @ 87 NP = 173 NR

1-1/4″ tip @ 57 NP = 140 NR

combination nozzle @ 100 NP = 177 NR 400 GPM

1-1/8″ tip @ 115 NP = 229 NR

1-1/4″ tip @ 80 NP = 196 NR

1-3/8″ tip @ 50 NP = 148 NR

combination nozzle @ 100 NP = 202 NR

433 GPM

1-3/8” tip @ 59.5 NP = 177 NR

500 GPM

1-3/8″ tip @ 80 NP = 237 NR

1-1/2″ tip @ 56 NP = 198 NR

combination nozzle @ 100 NP = 253 NR


Now let’s analyze the chart. All combination nozzles listed up to the flow of 350 GPM are recognized by IFSTA as mentioned earlier.

 

250 GPM – combination nozzle – 126 NR

300 GPM – combination nozzle – 152 NR

325 GPM – combination nozzle – 164 NR

350 GPM – combination nozzle – 177 NR

 

The next list shows smooth bore nozzle pressure and flow combinations that according to IFSTA are unmanageable due to the nozzle pressure being too high. Every single one of these tips has an equal or lower nozzle reaction than the highest mentioned combination nozzle reaction that is sanctioned by IFSTA and yet it is said that they are more difficult to handle and. and not recommended.

 

250 GPM – 15/16” tip @ 90 NP – 124 NR

 

250 GPM – 1” tip @ 72 NP – 113 NR

300 GPM – 1” tip @ 100 NP – 157 NR

 

325 GPM – 1-1/8” tip @ 75 NP – 149 NR

433 GPM – 1-3/8” tip @ 59.5 NP – 177 NR

 

Nozzle reaction is nozzle reaction. It is the force measured in pounds opposite of the stream direction. As long as the combination nozzle is in the straight stream mode, there is no difference.

 

NOZZLE PRESSURE AS IT RELATES TO STREAM PERFORMANCE AND MANAGEABILITY

According to the books, an over-pressurized stream will lose its pipe like appearance and begin feathering on the edges causing a loss in reach and water volume.

The first question that comes to mind about nozzle pressures in smooth bore tips is why, again according to the books, does a handline stream begin breaking up at nozzle pressures higher than the 50 to 65 psi range while a master stream can be pumped up to 80 psi? There should not be any difference. Example, a 400 GPM flow is an accepted stream from a master stream appliance. It is produced from a 1-1/4″ tip at an 80 psi nozzle pressure. The stream quality is good and the reach is sufficient. Why then, can’t the same tip and nozzle pressure produce a sufficient stream on a handline? Does that make sense to you?

Flow tests have proven that 80 psi handline nozzle pressures do work just as good as they do on master streams. In fact, nozzle pressures reaching 120 psi and higher have proven to be very effective on handlines with the proper nozzle handling techniques. These higher pressure streams not only give a higher flow, they also increase the velocity and the reach of the stream significantly.

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High flow handline stream resembling the quality of a master stream.

Now don’t get me wrong, I feel that there is a place for the 40 to 65 psi nozzle pressures. If penetration and reach are not a factor in the stream application a low pressure might be all that is needed. This can allow for higher flows for interior attack lines.


REACH TEST

              TFT AUTO 100 PSI NBP      150 GPM    90′ REACH

              15/16″ TIP 50 PSI NP        185 GPM    84′ REACH

              1-1/8″ TIP 40 PSI NP        240 GPM    84′ REACH

              VIND. H.   30 PSI NBP       250 GPM    90′ REACH

 

DOES A LOW NOZZLE PRESSURE CAUSE THE HOSE LINE TO KINK?

One common issue about low nozzle pressures with smooth bore tips is the fact that the hose kinks more easily.  This has been common knowledge in the fire industry for years, especially in high-rise fires.  Kirk Allen, President of First Strike Technologies, has done a series of flow tests that disproves the low nozzle pressure / hose kinking theory in certain cases.  Following series of flow tests are designed to prove this concept.

KINK TEST WITH 1-3/4″ HOSE

       TFT AUTO 100 PSI NBP      150 GPM    KINKED 105 GPM

       1″ TIP      45 PSI NP        200 GPM    KINKED 170 GPM

       1-1/8″ TIP 40 PSI NP        240 GPM    KINKED 220 GPM

       VIND. H.   30 PSI NBP       250 GPM    KINKED 225 GPM

 


NOZZLE HANDLING TECHNIQUES

I think it’s safe to say that the nozzle handling techniques used for interior attack low flow handlines is working well. There are two nozzle handling techniques for high flow 1-3/4″ and 2-1/2″ handlines. The first one requires the firefighter at the nozzle to sit directly on the hose about 2-1/2 to 3 feet from the nozzle. The entire handline stays on the ground. The hose on the ground is important with this concept because the ground actually absorbs most of the nozzle reaction. I have found that looping the hose at this point makes no difference on how well the nozzle reaction is absorbed. Furthermore, in a quick attack/minimum manpower situation with the line already charged, setting the loop up takes time away from the initial quick hit.

 

For the higher nozzle reaction lines two firefighters should be used. The firefighter at the nozzle uses the same techniques as mentioned above. The second, or backup, firefighter sits directly on the hose behind the firefighter on the nozzle. The backup firefighter can use a hose strap secured to the hose for assurance, but in all honesty this will be more of a mental assurance than anything else. It is extremely important that both firefighters keep all their weight on the hose while flowing water to keep the nozzle reaction at a minimum. It is also equally important for the firefighter at the nozzle to keep one hand on the bale of the nozzle at all times in case it needs to be gated down to be manageable or shut down completely.

 

The second technique for handling a high flow handline utilizes a kneeling technique. The firefighter drops to both knees straddling the line perpendicular (facing it) with the hose going under the rear leg and over the front leg. This technique works the best for an advancing line because it is a position the firefighter can get into and out of quickly during the advancing. Again for the higher nozzle reaction lines two firefighters should be used.

 smooth-bore

Standing up creates a lot of work, just have a seat.

The back-up person on a high flow handline can either stand or sit on the hose to help support the nozzle man.

The straddle method hose handling technique.

No matter which technique is used, there could be a slight tendency for the hose to kink right behind the nozzle due to the nozzle reaction, especially in the

1-3/4” and 2”hose. Again I say this is a slight tendency. Being aware of this, countering the kink with proper technique is all that is needed to rectify the problem.

 

High flows using 1-3/4” and 2” hose can cause kinking at the nozzle due to the nozzle reaction. The firefighter can easily correct the kink by pushing against it.

 

Another method for dealing with the nozzle reaction problem is to use a short section of 2-1/2″ hose(five feet) at the end of the line just behind the nozzle.  the size of the 2-1/2″ will absorb the reaction better thus doing away with the kink.

 

 

The 2-1/2” playpipe with smooth bore stacked tips has been and continues to be a popular high flow handle nozzle. As previously mentioned, the tip sizes and their respective flows according to the traditional books are 1” @ 50 psi NP flowing 210 GPM, 1-1/8” @ 50 psi NP flowing 265 GPM and 1-1/4” @ 50 psi NP flowing 325 GPM. Now let’s see what we can get from these tips at higher nozzle pressures.

 

1” tip @72 psi NP = 250 GPM

@100 psi NP = 300 GPM

@120 psi NP = 325 GPM

 

1-1/8” tip @ 64 psi NP = 300 GPM

@ 75 psi NP = 325 GPM

@ 87 psi NP = 350 GPM

@ 115 psi NP = 400 GPM

 

1-1/4” tip @ 57 psi NP = 350 GPM

@ 80 psi NP = 400 GPM

 

To simplify the calculation for the PDP for a 2-1/2” handline nozzle utilizing the commonly used triple stacked smooth bore tips (1”, 1-1/8”, and 1-1/4”tips), here is an example of what can be done. Determine the maximum flow for the 2-1/2” handline evolution based on the largest tip, which is the 1-1/4” tip. The PDP should reflect that flow. This same PDP should be used for the 1-1/8” and 1” tips as well. It’s that simple. One PDP is good for all three tips. Below is an example of the flows that can be delivered from the three tips in the triple stack tips. The PDP used for these flows is based on the 1-1/4” tip flowing 325 GPM.

Tip Size    Flow

1-1/4”      325 GPM

1-1/8”      295 GPM

1”           260GPM

 

The triple stacked tips (1”, 1-1/8”, and 1-1/4”) on a 2-1/2” or 3” handline can provide a variety of flows using nozzle pressures higher than 50 psi.  The only thing that is required is to think out of the box.

In regards to rule #3, I am not sure why the tip diameter can be no larger than half the size of the diameter of the hose. The IFSTA offers no explanation for this. Many departments have been successful with nozzle/hose combinations that break this rule. In fact the FDNY is well known for their highly successful interior attack handline which is the 15/16” tip using 1-3/4” hose. I have had success with 1”, 1-1/8”, and 1-1/4” tips using 1-3/4” hose as well.

 

Now let’s go back to the old rules #4 and 5 for smooth bore tips used with handlines

 

#4-The books say when operating a smooth bore handline the ball valve must be fully open to produce the best quality stream. A partially opened valve will create turbulence in the waterway totally breaking up the stream. It’s fully opened or don’t open it at all. This rule is correct in regards to getting maximum flow and it should always try to be practiced.  However if the nozzle needs to be gated down for safety, I have found that most smooth bore tip nozzle combinations can be gated down to almost half way reducing the nozzle reaction enough to maintain safe control of the nozzle while still providing a working stream. Will the stream be pretty? Probably not. The key is getting the wet stuff on the red stuff. Does the stream have the reach and is it hitting the target? This is what we should be looking for. You need to evaluate the stream based on performance, not appearance. Firefighters tend to do the opposite.

The following flow tests are designed to show 1-3/4” handline nozzle capabilities. The first series of tests will show how far an interior attack nozzle can be gated down and still provide a working stream. The streams were analyzed at a point when either it reached a minimum of 25’, had a flow of 100 GPM or broke up becoming inefficient, whichever came first.

             

              MAXIMUM FLOW FULLY OPENED         IN GATED POSITION

 

15/16” S.B.                     185 GPM                               145 GPM

 

1” SB                            210 GPM                               170 GPM

 

The next series of flow tests shows high flow handlines first in a maximum flow operation with the bale of the nozzle fully opened and then gated down to a point where the stream had a minimum reach of 50’, reached a flow of 250 GPM or start breaking up becoming inefficient, whichever came first.

 

              MAXIMUM FLOW FULLY OPENED         IN GATED POSITION

1” SB                     300 GPM                               265 GPM

 

1-1/8” SB                350 GPM                               280 GPM

                            400 GPM                               322 GPM

 

1-1/4” SB                400 GPM                               305 GPM

                           500 GPM                               365 GPM

 

It should be noted that a 1-1/2” stream shaper can be used with the handline/smooth bore tip combination to clean up the stream much as master stream shaper is used. It should be placed between the nozzle valve and the tip.. The small shaper has also provided improvement to nozzles using the slug tip which is built into the nozzle valve. For this application placing the shaper between the hose and the nozzle works best.

 

#5-The size of the waterway in the ball valve should be larger than the tip size. If the waterway is smaller than the tip size it will act as the tip itself thus creating turbulence as it enters into the larger tip size. This will produce a broken stream. This rule is accurate.

MASTER STREAM OPERATIONS USING SMOOTH BORE TIPS

 

Here is a basic definition of a master stream. A master stream is a heavy caliber stream delivered through a master stream water delivery appliance. A master stream is used when flows surpass 350 GPM becoming too difficult to be delivered from a handline operation due to nozzle reaction. The stream that a master stream operation produces is high in flow and usually in the form of a straight stream using a smooth bore tip or some type of combination nozzle.

 

There are three types of master stream operations, the fixed master stream, the portable master stream and the elevated master stream. The following information about master stream smooth bore tips can be found in most fire stream management books in circulation today. It’s information that needs to be understood to establish a base to operate from.

 

The most common set of smooth bore tips that come with a master stream is what is known as the stacked tips. The stacked tips gets its name because it consists of four tips connected into one stack, which is then attached to the master stream appliance. The tip sizes and the corresponding flows are based on an 80 PSI NP.

 

1-3/8” – 502 GPM

1-1/2” – 598 GPM

1-3/4” – 814 GPM

2” –     1063 GPM

 

For master stream appliances capable of flows higher than 1000 GPM the following tip sizes with 80 PSI nozzle pressures will apply. Again these are the most common.

 

2-1/4” 1345 GPM

2-1/2” 1661 GPM

2-3/4” 2010 GPM

 

It should be noted that the standard rule on smooth bore tip nozzle pressures used with master stream operations is to use a nozzle pressure of

80 PSI. Nozzle pressures higher than this will create a broken and insufficient stream, as well as an unstable operation in the elevated and portable modes according to most fire stream books. Nozzle pressures up to 100 psi can only be used with fixed master stream operations. We will show how smooth bore tips can be taken to a much higher level producing high pressure streams that were never thought possible while remaining safe and efficient in all modes of operation.

 

HIGH PRESSURE MASTER STREAM OPERATIONS

USING SMOOTH BORE TIPS

 

The purpose of high pressure smooth bore tip operations used in conjunction with a master stream is to provide the required GPM to extinguish the fire problem with a high velocity stream that improves the reach and penetration capabilities of the fire fighting stream itself while still maintaining efficient stream performance.

The maximum allowed nozzle pressure for this type of operation is based on the following rules

1. Maximum allowed inlet pressure to the master stream appliance. The three most common manufacturers of the master stream appliance for the municipal fire service are; Task Force Tips, Akron Brass and Elkhart Brass. Listed below are the specs for each of the three brands of these appliances in the fixed mode.

 

Task Force Tips 200 PSI inlet pressure 1250 GPM 631 NR 2000 GPM 1010 NR

Akron Brass 200 PSI inlet pressure 1250 GPM 631 NR 2000GPM 1010 NR

Elkhart Brass 200 PSI inlet pressure 1250 GPM 631 NR 2000GPM 1010 NR

 

I think you will find that most of the other master stream manufactures require the same 200 psi inlet pressure as well. Always make sure the inlet pressure is never exceeded when performing high pressure operations.

2. Maximum allowed flow for the master stream appliance.

3. Maximum allowed nozzle reaction for the master stream appliance. This is based on a 100 psi combination nozzle at the rated flow of the appliance. For example a 1250 GPM master stream appliance using a 100 psi combination nozzle flowing 1250 GPM has a nozzle reaction of 631 LBS.

4. Maximum allowed operating pressure for the discharge hose supplying the master stream appliance when applicable. This applies to elevated stream operations using a non-quint truck company and portable master stream operations.

5. Stream angle capabilities for the appliance/apparatus combination. In order to provide the required pressure for the high pressure operation the pump operator needs to understand the limitations mentioned above and throttle up accordingly. Flow tests will determine what the maximum pressure can be, again based on the above mentioned criteria. A pump chart should than be designed showing all possible pump operations that can be used. The pump operator should plan on throttling up to the maximum allowed pre determined pressure unless something stops him. Does this mean that every time a deck gun operation is placed into service the pump discharge pressure needs to be maxed out? No. The pre determined pump discharge pressure is the number that the pump operator will try to reach unless something stops him.

 

Some of the things that may stop the operation from going to maximum pressure are:

1-run out of water

2-run out of throttle

3-run out of RPMs

4-the stream accomplishes its goal

5-other rules set by the department

6-orders from the company officer

HIGH FLOW/ HIGH VELOCITY OPERATIONS

The following smooth bore tip sizes with their corresponding nozzle pressure and flows have successfully produced high velocity/high flow streams using a master stream. The maximum nozzle reaction for a 1250 GPM appliance is 631 LBS and for a 2000 GPM appliance, 1010 LBS.

 

1-3/8″ tip @ 175 psi NP = 743 GPM 519 NR

1-1/2” tip @ 150 PSI NP = 817 GPM 530 NR

1-3/4” tip @ 120 PSI NP = 996 GPM 577 NR

1-3/4” tip @ 150 PSI NP = 1114 GPM 721 NR

 

2” tip @ 100 PSI NP = 1189 GPM 628 NR

2” tip @ 110 PSI NP = 1250 GPM 691 NR

2” tip @ 120 PSI NP = 1303 GPM 754 NR

2” tip @ 140 PSI NP = 1407 GPM 879 NR

2” tip @ 150 PSI NP = 1455 GPM 942 NR

2” tip @ 160 PSI NP = 1500 GPM 1005 NR

 

It should be noted that the 2” tip at 160 PSI NP produced a stream with a footprint reaching 360 feet.

 

LOW FLOW/HIGH VELOCITY OPERATIONS

Picture a large fire that has totally consumed the structure ending up with a large pile of burning rubble left to be overhauled? This is where the digging power of a high velocity stream can really have a positive effect. The following smooth bore tip sizes and corresponding nozzle pressures and flows have been successfully used in this type of operation. One point to remember is that the goal in this type of operation is to produce velocity, not high flows.

 

1-1/8” tip up to 180 PSI NP = 504 GPM

 

1-1/4” tip up to 180 PSI NP = 623 GPM

 

1-3/8” tip up to 180 PSI NP = 754 GPM

 

This deck gun is using a 1-1/4” smooth bore tip flowing 623 GPM at 180 PSI NP.

 

Working a brush fire from a fixed master stream appliance is a heck of a lot easier than pulling hose. When possible, a fixed master stream can make very large sweeps in burn areas with the above mentioned high pressure stream operations. In fact, the

1-1/8” tip application will more than likely be the tip of choice for this operation.


These same three also apply to portable master streams and elevated master streams.  However, with elevated master streams you have to follow the guidelines for flowing water at specific angles.  This information is always found on a placard on the turntable console.

 


 

2000 GPM APPLIANCE AND WATERWAY ON AN ELEVATED PLATFORM WITH A 2″ TIP

165 NP     1527 GPM         220′ REACH       1005 NR

   

 

BLITZ ATTACK OPERATIONS

NFPA requirements for tank to pump flow delivery capabilities state that a minimum of 500 GPM shall be delivered. Unless a department has specified their apparatus to deliver more, this is the flow rate capability they will have. A very high percentage of fire apparatus have the 500 GPM maximum flow capability. Two popular tip applications for a 500 GPM Blitz attack are the 1-1/4” tip @ 115 PSI NP which delivers a flow of 495 GPM and the 1-1/8” tip @ 180 PSI NP flowing just at 500 GPM. These high nozzle pressures produce hard-hitting streams capable of penetrating deep into the fire which could very well be needed in an offensive Blitz attack operation

 

DEVELOPING THE REQUIRED PUMP DISCHARGE PRESSURE FOR THE PORTABLE MONITOR

The following information is based on any size discharge hose used as either a single line or Siamese lines.

 

Just as with the fixed master stream operation, the portable monitor can deliver several different flows with each potentially having a different pump discharge pressure. It is not practical to list all of them on the pump chart The only pressure that needs to be listed is the numbers for the maximum flow operation with the most common being 1250 GPM with a combination nozzle at 100 psi NP. Adhere to the specific manufacturer’s ratings on what the highest flow in the portable mode should be. The manufacturer should also be able to tell what the friction loss in the appliance is, at the high flow. Add the appliance friction loss and the nozzle pressure together and note it on the chart. The number for the nozzle pressure should be based on the highest nozzle pressure used in the department’s arsenal. Here is an example. If a department uses smooth bore tips rated at 80 PSI and a 100 PSI combination nozzle for their portable monitor operation, the pump chart should reflect the higher 100 PSI figure in the formula listing on the pump chart. The friction loss per 50 or 100 feet of the hose evolution being used (whichever works best) should also be noted. Remember the friction loss is based on the highest flow the departments operations allow for. Determine how much hose is being used in the evolution and add up the friction loss plus the numbers from the appliance and nozzle pressure and to develop the pump discharge pressure. Example, a portable monitor is flowing 1000 GPM through an automatic nozzle with a 300 foot 5” discharge line. Add 15 for the appliance friction loss, 100 for the nozzle pressure based on the fact that the highest nozzle pressure used is 100 PSI, and 5 PSI per 100 feet of 5” hose (15 PSI for the 300 feet) bringing the sum to 130 PSI.

 

When using smooth bore nozzles, the maximum flow pump discharge pressure listed on the pump chart will work with any size tip from 2” down to 1” and still provide for a safe and efficient operation. Yes the rated flow at the standard smooth bore nozzle pressure (80 PSI) will probably be surpassed. However it will do this while keeping within the required inlet pressure of the appliance (200 psi) and the maximum allowed flow and nozzle reaction. Here’s an example. The pump chart lists a pressure of 115 PSI plus 5 PSI per 100 feet of 5” for a portable master stream supplied by 5” LDH flowing 1000 GPM. The 115 PSI represents the appliance friction loss of 15 and the nozzle pressure for the automatic nozzle, which is 100 PSI. Now, for whatever reason, the automatic nozzle is being replaced with the with the 1-3/8” tip. The pump discharge pressure for the 1-3/8” tip at its rating of 500 GPM has a friction loss of

2 PSI for the 5” hose. But since the pump discharge pressure will remain at the high flow pressure, the excess pressure in the hose (3 PSI per 100 feet) will be added to the nozzle pressure creating a slightly elevated flow. A picture tells a thousand words so do the flow tests and take a nozzle pressure reading.

 

 

Pump to the largest tip

Based on a 2″ tip flowing 1060 GPM @ 80 psi NP.

                                                        

                     1-38″ tip   589 GPM    110 psi NP

                     1-1/2″ tip  634 PGM    90 psi NP

                     1-3/4″ tip  814 GPM    80 psi NP

                     2″ tip       1060 GPM  80 psi NP        

IN CLOSING

The information presented in this text is based on being progressive, keeping an open mind, and continuous evaluation of equipment and techniques. Much of the information presented will not be found in IFSTA. Does that mean that this is not an acceptable way to use smooth bore nozzles on the fire ground? In my opinion, it does not. At no time do any of the above mentioned flows, nozzle combinations, nozzle pressures, hose evolutions, and techniques go against what the manufacturers say their equipment can do. If you like what you have read, don’t implement it today, instead practice, practice, practice. Feeling comfortable and confident is the key to success. Once that is accomplished implementation will be easy.

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The Big Hit Offensive Concept

DSC00027The Big Hit Offensive Concept

 

I have been wanting to write about this for a long time now and wanted to keep it as basic as possible. I was talking with my wife trying to come up with an opening statement that would be basic and have enough information as possible to explain what I’m trying to say. So here’s what I asked her. When we go out in our RV a lot of times we set up a camp fire and sometimes when we are ready to call it for the night the fire is still burning so we like to put it out instead of letting it burn unattended. So here’s a question I asked my wife. If you have a choice of putting out this fire which is in about a 4 foot diameter enclosure with a squirt gun or a garden hose, what would you choose and why? Her answer was simple. I would choose the garden hose because it would put the fire out a lot faster.

 

I like to look at YouTube videos of large fires not just for the entertainment factor but for educational purposes. Again I asked my wife to watch one of these videos with me which showed a three-story wood framed residential complex, I’m guessing 50 by a 100 with the whole front of the structure well involved. Now understand that I was not present at this fire so I’m not going to really call this a critique of this fire departments operations. That would not be fair. Instead I am going to use it as a learning tool. The first line out on this large fire was 1-3/4” hand line which went to the exposure. The second line out was a 2 ½” hand line with the triple stack smooth bore tip combination with the entire stack still attached to it. In other words they were using the 1” tip and if it was being pumped correctly they were getting 210 GPM. Because my wife and I have been married 35 years now and I have been teaching this stuff for the same amount of time she is semi-versed in what my concepts and theories are all about. So I asked her is there anything else that they could be doing that might put this fire out faster and save the exposure? She said without any hesitation why don’t they fire up the deck gun and blast the shit out of it?

 

The concept of using large flow streams to put out fires is actually pretty simple and for that matter as far as firefighting goes also pretty safe for the firefighters. You’ve all heard statement ‘you have to match the GPM’s to the BTUs”. I go one step further and say that you have to overwhelm the BTUs with the GPM. I’d like to make a quick list for reasons why fire departments do not practice the overwhelming blast concept.

 

1. Firefighters do not understand their equipment and capabilities

2. Firefighters don’t understand the fire science of overwhelming BTUs with GPM’s

3. Lack of training.

4. Lack of understanding of water delivery not just from the discharge side of the pump but also in regards to water supply.

5. Firefighters tend to do what they have always done.

6. It’s not fun.

 

If your department is one of these that lacks insufficient water delivery for large fires I’m sure you can probably relate to some of these and maybe others that I have not talked about. The bottom line is we need to start thinking and practicing these big hits on certain fires to do a better job in controlling and finally extinguishing the fire.

Here is my theory on exposure protection. If there is an exposure problem with first in companies there is a decision to make. Do I protect the exposures with water application or do I knock down the problem that is creating the exposure, the fire? If you think that a direct attack on the fire can knock down the fire in seconds to a point where it is not hot enough to create the exposure then go for it. If not then the direct application of water on the exposure is warranted. If you choose to hit the exposure creator than knock the snot out of it. Hit it with everything you possibly can with in your limitations.

I’d like to talk about two different topics from my above-mentioned list that will greatly improve the knockdown capabilities of large fires. Usually when I discuss water delivery I always start with the water supply however in this section I want to start with required streams and then talk about developing the required water supply to feed the streams. The reason for this is simple. A lot of times bigger tips or larger flows are not used simply because they do not have the water to support them, or at least they think they don’t.

Deploying A 500 GPM Blitz Attack From Tank Water

This section is going to focus on fire attack on an exposure threatening fire based on a limited water supply, more commonly known as a blitz attack operation. It will be a worst case scenario being a 500 gallon booster tank and will be using 500 GPM for the flow rate for maximum knockdown power..

The most common initial hose deployment that most departments use when they are facing a threatening fire on tank water is to pull a small hand line, more than likely a 1-3/4”, which is used to protect exposures. The flow will usually range from 100 GPM to about 150 GPM. The reasoning behind this move besides protecting exposures is to conserve water until a water supply can be established. At 150 GPM a 500 gallon booster tank will last a little over three minutes. This might be enough time to get the uninterrupted water supply if the first in company laid the supply line, but at best it will probably be close. With a lot of departments going straight in on tank water and calling for the second due to lay a line you are really pushing your luck. Well what if the second due is delayed or doesn’t bring in the line? Now you are really in trouble because the fire that has caused the exposure problem is still causing the problem and there is no more water.

Yes, water puts out fire. The rate of extinguishment is based on the flow rate (GPM) of the water delivered onto the fire. Throughout the years there have been articles published talking about scientific statistics in regards to water and its abilities to put out fire in hopes of improving the process. Terms such as BTU’s, rate of application, fire growth rate, big drops, little drops, and so on. All of these somewhat scientific terms are probably right on, but what do they really teach us or tell us about what needs to be done about the application itself? It’s really simple. Put enough water on the fire to put it out as quickly as possible. When we make our attack we don’t think about all of this techno stuff. Our goal is to apply water at a high enough flow rate to do away with the fire problem as quick as possible or to at least slow it down.

With that being said, I would like to offer my perspective of what needs to be done to have a successful outcome. Are you ready, here it goes. If the company officer thinks it’s possible, don’t screw around with putting water on the exposure, just blast the fire!!! You heard it right. Put enough water on the fire based on the situation at hand to achieve at least a knockdown as quick as possible. A good definition of a knockdown on a fire for the blitz attack scenario is to hit the fire with an overwhelming amount of water to change the state of the fire from a fierce out of control and spreading situation to a more docile, non-exposure threatening state that will allow firefighters to regroup and get the proper lines in place to accomplish extinguishment.. It’s kind of like a one two punch. This tactic, if sized up and done correctly will have a real good chance of achieving a knockdown on a fire in seconds. This means the exposure will only be exposed for seconds instead of minutes. It’s entirely possible to get a five second knockdown with the correct weapon and ammunition (flow rate) of choice.  .This holds true for the smallest of fires to the largest where an initial attack can be successfully done.

Based on using a limited water supply I think the application time for a blitz attack should be no more than 30 seconds. This goal, as tough as it may sound, has a good chance of being accomplished with the right flow rate. Always try to flow a maximum amount even if you think it’s an over kill. If you do indeed flow more water than the fire requires the only thing that will happen is that the fire will go out quicker.

When it comes to the proper tactics of water delivery itself there are several things to consider based on the situation at hand. They are water supply, amount of water needed (flow rate), water delivery system, manpower, and hose handling techniques if applicable.

No matter what method of attack is going to be used, you have to have the water to do it. Engine company booster tank operations need to be more precise in this type of operation because there is probably going to be only one chance at an attempt to get the fire. One big question that comes up when the fire is creating exposures is, with a limited water supply do we protect exposures or conduct fire attack. The best way to protect an exposure is to eliminate the exposure creator, the fire problem. A thorough size-up can determine whether or not hitting the fire first will accomplish an immediate knockdown. This is where real world experience with water volume versus fire volume (GPM VS BTU’s) comes into play. With that being said, what about the company officer that doesn’t have that experience yet?

The National Fire Academy (NFA) has developed a formula (LENGTH X WIDTH /3) that accurately calculates the required flow for a structure based on dimensions and fire involvement. Can it be used at the time of the fire? Obviously it is possible however, in my opinion, difficult at best due to the extreme situation at hand, the fire.  However, this formula can be used as a training tool to determine the types of structures, based on size, in your area that could fall into the category of being 500 GPM blitz attack candidates.

The first thing to know with this type of operation is how much water is available and at what flow rate (GPM). Most booster tank to pump plumbing designs only allow a maximum of 500 GPM to be delivered from the tank to the pump. This is the NFPA minimum standard and most departments go with it when designing their engines. So should 500 GPM be used as the flow rate? Obviously the company officer will make the choice based on the fire volume. For now let’s say that 500 GPM will be the required flow.

If you are going to attempt a 500 GPM blitz attack from a 500 gallon booster tank the stars must be aligned. First make sure the fire is a 500 GPM fire or less. Again this is based on being able to get a knockdown within 30 seconds. These fires could include garage fires, mobile home fires, fully involved houses under 2000 square feet, commercial properties basically the size of a convenience store, and so on. And I will say it again, you are only trying for a knock down.

It’s important to realize that flowing 500 GPM doesn’t mean you will use 500 gallons of water. 500 GPM is the rate of flow. Think of the flow rate as it relates to using up the water supply as gallons per second because the knockdown needs to be accomplished in 30 seconds or less. 500 GPM is 8.3 gallons per second. The following sequence of photos shows a well involved 2 story residential structure that was hit with a 500 GPM stream that got a knockdown in 16 seconds. The total amount of water used was 132 gallons from a 500 gallon booster tank.garygodBlitz Attack3Blitz Attack7

16 second knock down with the Big Paulie 500 GPM nozzle

The method of delivery can coincide with the manpower available to put it into play. There are two methods for implementing the big hit. The first is the fixed master stream AKA the deck gun. This is a one man job whether it is a manually operated appliance that requires the firefighter to be on top to work the appliance or it is remotely operated from the ground. It is important to know the exact pump discharge pressure for the deck gun in order to avoid cavitation of the pump by over pumping the device. In reality, even though the 500 GPM is the rule, most apparatus can deliver a little more. But the 500 GPM target flow should be kept. It is also important to not waste water in the application of the fire stream. Having the deck gun PDP obtained before the appliance is opened will help. One problem that could arise from doing this is opening the discharge under the required pressure if the discharge mechanism is the rod type of handle that works by pulling it out. NFPA requires a slow moving device to open and close the master stream valve which involves a wheel /gear type mechanism. This will alleviate the problem. The deck gun should be aimed at the target as much as possible again to help eliminate wasting water. Finally only use as much water as it takes to effect a knock down not an extinguishment. When an uninterrupted water supply is secured then the gun can be reopened to complete its job. There are two types of nozzles that can be used in a deck gun blitz attack, a combination nozzle (automatics are the most common) and smooth bore tips. Velocity and penetration can be crucial in an initial blitz attack to hit as deep into the fire problem as possible. This means that a high nozzle pressure should be used. Combination nozzles are usually rated at 100 psi but can go as high as 120 psi. The higher the better. The 1-3/8” smooth bore tip is rated to flow 500 GPM at 80 psi nozzle pressure. Using smaller size tips to get 500 GPM can also be accomplished without breaking the rules set by the manufacturers. For example the 1-1/4” tip flowing 500 GPM has a nozzle pressure of 115 psi and believe it or not the 1-1/8” tip can also flow 500 GPM at a whopping 175 psi nozzle pressure.11

A 1-1/4” tip flowing 500 GPM with a nozzle pressure of 115 psi.

Going back to the 30 second rule, if after flowing the chosen stream and it is decided that a knockdown doesn’t seem possible, don’t use any more water, shut it down and regroup.

Now let’s talk about hand lines. More than likely if a high flow hand line is to be used for a blitz attack, the firefighters will be in a stationary position. If this is the case and the situation will allow, don’t stand up with the line especially at the higher flows. It will beat you to death and possibly indirectly reduce the flow rate if the nozzle guy needs to gate it down to handle it. Instead just have a seat. It’s a proven fact that the firefighter’s weight sitting on the hose is extremely helpful in eliminating the nozzle reaction effects. If a 500 GPM attack line is to be used it will take two firefighter’s accumulated weight to hold down the nozzle reaction effects. If lower flows are delivered it may only require one. Training in whatever line you choose will help you decide what works best.

The 500 GPM line will need to be a 2-1/2”. Flow tests have proven that a 2-1/2” line can be up to 200′ long and provide the 500 GPM flow at around a 200 psi PDP. Of course the design of the discharge plumbing will dictate the actual pressure needed. The 1-3/8” tip at 80 psi NP, a 1-1/2” tip at 55 psi NP, and a 500 GPM combo nozzle at 80 psi NP, or 100 psi NP are all good nozzle combinations.13

 

The Big Paulie Blitz Attack Nozzle flows 500 GPM.

This same 500 GPM application can also be delivered through what I like to call the mini monitors. Basically the mini is a small version of a portable master stream light in weight and capable of a 500 GPM flow. It has a single inlet and can be supplied from a single 2-1/2” line.100_0057

500 GPM delivered from the Minis100_0511

HandlinesBig Paulie0001

Every apparatus should have at least one designated handline that can be used for a large flow operation whether it’s pre-connected or simply stored in the hose bed. It should have a nozzle that will flow a maximum amount of water based on equipment and policies of the department. Here’s a good example. A pre-connected 2-1/2” handline 200 feet long with the triple stack smooth bore tips which are all connected to the nozzle. I personally don’t believe in the triple stack tip because even though it gives the firefighter the opportunity to dial in the flow it seems to never happen. The entire stack is just about always left on the nozzle which means that the 1” tip is what is flowing and if it is pumped right the flow is 210 GPM. Let’s say that firefighter on the nozzle wants to go bigger and go to the 1 ¼” tip to get 328 GPM. In order to do this a different pump discharge pressure needs to be used. Now becomes a communication issue where the pump operator needs to know what size tip is being used on the nozzle to get the correct flow. A lot of times this can be a problem. Here is my recommendation. Keep one size nozzle in regards to its flow capabilities and nothing else. If its smoothbore tips keep the one tip on there that you would like to get the biggest flow from. So instead of keeping the triple stack tip on just have 1 ¼” tip. With this setup the firefighter will know what he is getting and the pump operator will know what to give him.100_0424

 

If you choose to go with a combination nozzle whether it’s an automatic or a fixed gallonage I suggest going to the maximum flow available from the nozzle. Most combination nozzles have a maximum flow ranging from 250 to 300 GPM. The key is to have one flow so there’s no confusion as to what will be delivered on the hand line. If it’s an automatic nozzle my suggestion would be to pump to the maximum flow that the nozzle is capable of. For example a 100 to 300 GPM automatic nozzle should be pumped as though it’s flowing 300 GPM. If for whatever reason the firefighter needs to gate down the nozzle than he can do that on his own without communication to the pump operator.

Big Paulie 500 GPM nozzle100_0065


 

Master Streamslvfd big water

Okay now it’s time to increase the size of the fire. Remember the fire that I described to you earlier in this section that I saw on YouTube that was a three-story apartment complex well involved in the front. Now were talking about streams of it least 1000 GPM, notice I said streams. Again, a study of YouTube fires that are multi-company operations with the big guns flowing reveals a high percentage of the time the entire stack of tips are left on the master stream appliance. In fact one of the videos I saw had audio with it and you can hear the order being given to use the 1 3/8”tip. Well if that tip is being pumped properly you can expect 500 GPM. The problem is that the fire is probably a 2000 GPM fire. The same decisions need to be made on whether to protect exposures or hit the fire however this time one large and more complicated decision needs to be made if you’re going to hit the fire with the proper flow. Where might you get the water from? The fire on YouTube was in a major city and was a major fire department meaning that apparatus and fire hydrants were plentiful. This department used 5” large diameter hose and grabbed the closest hydrants to the fire. I’m not sure why they used the 1-3/8” tip but a common reason for this is because they ran out of water even using large diameter hose. I have a famous little phrase that I like to use all the time which states “the waters out there you just have to go get it”. Most departments with large diameter hose again lay from the closest hydrants and when they develop water supply issues they give up. Word gets back to the IC that they out of water and IC says everybody gate down to where we get streams that will reach the fire and guess what the fire eventually goes out.

 

Here’s what needs to be done. First of all if a master stream is going to be used for a sustained water delivery operation, in other words not a tank water blitz attack, the goal should be to supply the rating of the appliance. Most fixed mounted master stream appliances on engine companies are rated to flow 1250 GPM. This is not achievable with the 2” tip which is the largest in the stack because of appliance restrictions. A 1250 GPM master stream appliance has a maximum allowed inlet pressure to the device of 200 PSI, and based on the 1250 GPM flow with a 100 PSI nozzle pressure with a combination nozzle can only flow up to 631 pounds nozzle reaction. In my testing I have found that a 1250 appliance cannot reach 1250 with the 2” tip because of the nozzle reaction limitations. So with that being said either use a combination nozzle for 1250 GPM or set the goal for a fixed master stream with the 2” smooth bore tip for 1000 GPM.

 

Here is another example of a maximum flow operation from a single unit. The unit is a 2000 GPM elevated platform with a pump. Department SOP requires a 2000 GPM flow so here is the evolution that will produce it efficiently. The Quint gets the initial water supply with 5” hose from the closest hydrant. Unless the fire ground area is already being tapped by multiple hydrant use or if it’s known that the hydrant is weak, I don’t see a need to make this line a relay pump operation however it would not be wrong to set it up as one. Most hydrants cannot supply 2000 GPM but even if a hydrant can one of the issues that will encountered with this operation is an extremely high rpm from the engine on the Quint. What I recommend is to automatically lay a second 5” supply line back to a hydrant and set up for a relay/tandem pump operation which will bring in the extra water if needed and will assist the engine of the quint went by lowering its rpm’s because of the pressure being brought in from the relay.

This is a tandem pump operation. Notice the engine pumping in tandem 300 feet from the quint

2000 GPM streamP1000695

    

 

Three minis flowing 500 GPM each from the same  pumper 

With the right water supply this can be doubledBlitz Fire

Whether a high flow hand line or master stream is going to be placed into service it needs to hit the fire. I know you are thinking, what does this guy think we are stupid? What I mean is move the stream around to hit as much fire as you can from your location. So often t. I see that when a big stream is aimed into a fire it looks like a big drill trying to drill a hole. It doesn’t move. It almost seems like they are trying to fill the building up with water from that point.

 

 

 

Water Supply Evolutions2-3

When a multiple master stream operation is going to be put into service to fight a sustained fire obviously this means that you have to have the water supply to deliver this flow. If the water is not available from the closest hydrants from the initial supply line another engine needs to reverse out to a more distant hydrant that is hopefully on another loop and relay pump. This is all stuff we used to do all the time before large diameter hose. Big water meant putting pumps on hydrants to pump to the engines that were delivering the water. LDH has made a big change in water delivery however the real magic in the hose realistically is for small fires that allows hydrant pressure to deliver the required flow. When it comes to the big fires where multiple master streams are needed more than likely we need to go back to the olden days in regards to our operations and set up the relay pump operations to move the required water. The good thing is that large diameter hose used in the relay will really move a lot of water especially compared to dual 2 ½ or 3 inch lines used in the olden days. As a little side note it takes five 2-1/2” lines to equal one 5” line and four 3” lines to equal one 5” line.

The logic for the IC should be not to wait for a water supply issue to arise. Expect it. Be proactive and immediately start the resources to set up for large water supply evolutions. Designate companies to start the reverses to other hydrants and set up for relay pumping. If the extra water is uncertain at the time, don’t charge the supply lines, just charge the hookups to the hydrant. If it turns out that the water is not needed than an uncharged line will be a lot easier to pick up. By having the line laid it will only take a couple of minutes to charge. On the other hand if you wait to lay the line until the water is needed the time frame for water is now looking like at least 15 to 20 minutes. Be proactive.

An engine can lay a dry line and only charge it if needed. This is called being proactive.100_0457

 

So if you agree with the concepts I have discussed and how it can be implemented especially on large fires with multiple master streams working. I will tell you firsthand that freelancing is not an option for implementing the operation. . Can you imagine individual units trying to set up multi-company operations that require specific hydrants and specific hose lays. A water supply or water management officer or officers needs to be implemented into the command structure specifically to design the hose evolutions. The water supply officer takes his orders from the incident commander in regards to the required flow’s and appliances to be used and implements it with the required hose evolutions which includes apparatus.

Maximizing all the ports on the hydrant with LDH

Will allow this to happenP9210884DSC000183DeckGuns100_0122100_0057


 

 

 

 

 

This Is Great Stuff, But We Only Have Two Stations

This book has presented a lot of information on large flow water delivery involving multiple companies. I am well aware of the fact that a lot of departments are not capable of some of the evolutions presented in this book simply because they don’t have the apparatus and manpower. If mutual aid is available, even if it’s not right next door, I feel it is extremely important to figure out a way to use them more efficiently. There are several things that can be done. One crucial adjustment that can be made is to have an automatic dispatch that sends mutual aid units at the very moment the first in units are dispatched. Another thing that can be done is to form strike teams for water supply delivery only. These units upon arrival go right to work stretching supplemental supply lines to the units that are already at work.

 

Well what about the one or two station departments that unfortunately have no help coming? If this is the case a lot of tactical decisions need to be made on how to deploy whatever manpower and equipment they have for the emergency at hand. For example a decision may need to be made that stops all interior attacks and just deploys heavy streams to try to save the block. A real good example of this was used in the Los Angeles riots in 1992. As you know hundreds of major structure fires were burning in the City of Los Angeles at the same time, and even though they ran a statewide mutual aid response, many large commercial fires were handled by a couple of engines.

Here’s the bottom line. Where there is a will there is a way. It may not always turn out to be the best operation possible but you would be surprised what a well-tuned group of guys can do when they get in a pinch. It requires a lot of training.