Smooth Bore Tips, The Next Generation

Smooth Bore Tips,

The Next Generation

 him

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.

 10

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.

.

 

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.


       

   


 

Big Paulie the Monster Handline

Big Paulie,

The Monster Handline

him

 

 

The 2-1/2″ handline has always be known for its high flows.  In fact there are many different flows that are being successfully used by fire departments nationwide with this big line. With that being said, what I am about to tell you in this article is going to amaze you. The focus is going to be on a new nozzle concept called the Big Paulie which has a maximum flow of 500 GPM and is used on a. 2-1/2″ handline.

 

No it’s not a large caliper stream being delivered from a master stream appliance. It’s a nontraditional handline nozzle used for a heavy attack from a stationary position. A 500 GPM stream is a substantial amount of water very capable of getting the big hit on a large fire just as you would expect from a standard 2-1/2″ handline flow. The reason 500 GPM was chosen is two-fold. The 500 GPM handline evolution is at maximum flow in regards to what firefighters can handle. Flow tests have proven that two firefighters can safely and efficiently deploy a 500 GPM handline using the techniques that will be presented in this article. Flows higher than this are more difficult to handle and not recommended as handline operations.

 

Also, 500 GPM is the maximum allowed flow from the engine company tank to pump plumbing according to minimum requirements of NFPA apparatus specifications. A very large majority of apparatus fall under this spec. A larger flow can be designed into the plumbing, but it has to be specified at construction.

 

Can and should a 500 GPM attack be initiated from tank water? Under the right conditions, you bet! When we start working from a booster tank we automatically go into the conserving water mode. Too often we conserve too much water to a point where the water is ineffective. Example, with a 500-gallon booster tank, let’s say we are going to deploy two 1-3/4” handlines flowing 125 GPM each to for exposure protection instead of attacking the fire which is a mobile home. We are doing this because the water supply has not been established yet. This is done until a water supply is established or we run out of water. Firefighters usually keep the nozzles wide open for exposure protection, which uses the limited water supply fast. The end result of this is that exposure protection may be successful, but only until they run out of water.

 

I have a theory. If given a choice on whether to protect exposures or initiate a fire attack from booster tank water, I evaluate the fire volume. If an immediate knockdown is possible using no more than half a tank at a 500 GPM flow rate (based on a worst-case scenario 500-gallon booster tank) I will go for the attack, immediately eliminating the fire that is creating the exposure threat. It’s a done deal. When considering a fire attack from a booster tank, don’t think of the 500 GPM flow as moving 500 gallons of water. Instead think of it as gallons per second (GPS). A 500 GPM stream flows 8.3 GPS. There is a real good chance that the fire can be knocked down in 10-20 seconds. How much water have we used from our 500-gallon booster tank? Do the math. A 20 second 500 GPM blast will move a total of 166 gallons of water.

 

Again based on a 500-gallon booster tank capacity as worst-case scenario, an attack should be no more than 30 seconds. If the fire is not starting to lay down for you, shut down and regroup until a water supply can be established.

Blitz AttackBlitz Attack4Blitz Attack3Blitz Attack7

Sixteen second knockdown using the Big Paulie

 

          The Big Paulie handline consists of four parts assembled together to make up the nozzle.  They are:

*The nozzle valve made by Task Force Tips.  It has a 2″ waterway specifically designed for large flows.

 

*A long 2-1/2″ stream shaper made by Task Force Tips  designed to reduce the turbulence going into the smooth bore  tip as  well as to provide leverage for the firefighter directing  the stream.

 

*The stream directing handle which is placed between the stream  shaper and the smooth bore tip.  This handle makes it easier for the firefighter to direct the stream as well as moving the while not                             flowing.

 

*The nozzle itself which is a 1-3/8″  or 1-1/2″ smooth bore tip 9″ in length capable of a flow of 500 GPM at 80 or 55 psi nozzle pressure respectively.

.100_0065

NOZZLE HANDLING TECHNIQUES

The nozzle handling technique for the Big Paulie high flow handline is simple and is a modified version of a technique that has been used for decades. Just have a seat.  That’s right, it’s nothing more than sitting on a 2-1/2″ line with the loop with two modifications.  First, the loop is not needed. Numerous flow tests have proven that the loop really doesn’t provide that much more stability. However if you choose to make a loop that is entirely acceptable. Second, a minimum of two firefighters are required to sit on the line because of the nozzle reaction. The firefighter at the nozzle sits directly on the hose about 2-1/2 to 3 feet from the nozzle. The entire handline stays on the ground except for the last three feet that the firefighter is handling. The hose on the ground is important with this concept because the ground actually absorbs most of the nozzle reaction. Again, I have found that looping the hose at this point makes little difference on how well the nozzle reaction is absorbed. Furthermore, in a quick attack/minimum manpower situation setting the loop up takes time away from the initial quick hit especially if the line is already charged. . The second, or backup, firefighter sits directly on the hose behind the firefighter on the nozzle. 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.

bp1

The back-up person on a Big Paulie high flow handline sits on the hose to help support the nozzle man.

 

If you decide that the 500 GPM flow from a 1-3/8″ which has a nozzle pressure of 80 psi and a nozzle reaction of 237 lbs. is too much, a 1-1/2″ tip at 55 psi nozzle pressure with a nozzle reaction of 194 lbs. will also flow 500 GPM with a lot less effort. The trade off will be less reach but definitely enough to hit most targets.

 

There is also an entire range of 2-1/2″ flows that can be used with the Big Paulie nozzle that are under 500 GPM that can be extremely effective. The following list shows some tips with their corresponding nozzle pressures and flows from 210 GPM up to 500 GPM.

1”tip         210 GPM    50 psi NP

1-1/8”tip    265GPM     50 psi NP

1-1/4” tip   325 GPM    50 psi NP

 

1″ tip        300 GPM    100 psi NP

              300 GPM    100 psi NP

              325 GPM    120 psi NP

 

1-1/8″ tip   300 GPM    64 psi NP

              325 GPM    75 psi NP

              350 GPM    87 psi NP

 

1-1/4″ tip   350 GPM    57 psi NP

              400 GPM    80 psi NP

 

1-3/8″ tip   400 GPM    50 psi NP

              500 GPM    80 psi NP

 

1-1/2” tip   500 GPM    55 psi NP

 


 

bp1

500 GPM with a 1-3/8″ tip at 80 psi nozzle pressure

This article has been based on being progressive, keeping an open mind and continuous evaluation of equipment and techniques.  Most of what you have read will not be found in the standard fire stream books in circulation today.  Does that mean that this is not an acceptable way to deliver high flows through the 2-1/2″ handline?  In my opinion, it does not.  At no time do any of the above mentioned flows, nozzle combinations, nozzle pressures and techniques go against what the manufacturers say their equipment can do.  If you like what you have read, don’t implement it tomorrow, practice, practice, practice.  Feeling comfortable and confident is the key to success.

Big Knockdown Using the Little Guy With the Big Punch

Big Knockdowns Using The

Little Guy With the Big Punch

 

I think we are all aware of what the 2-1/2” handline can do for us in regards to big flow however we also understand the difficulties that might be encountered in its deploying. This is not to say that the 2-1/2” handline should be discouraged from its use because of the difficulties. Probably the most difficult part of using the big line is moving it while charged even when water is not being flowed. It’s a heavy line. When the 2 ½’s are used on large fires there is normally plenty of firefighters available to maneuver it. But what about the first-in company faced with a large volume of fire that needs to be suppressed with a large volume of water especially with the first line out? Most engines are set up with a pre-connected 2-1/2” handline for this reason. The pre-connected line makes deployment with minimum manpower (more than likely the crew of the first engine) much easier. But again, the one thing that pre-connected 2-1/2” line does not offer is maneuverability of the line after it has been charged and with the first-in scenario with minimum manpower it becomes even more difficult.

This article is going to offer an alternative to the pre-connected 2 ½“ handline that will make it really easy for one firefighter to maneuver after it has been charged. The handline I am talking about is the 1-3/4”.

When 1-3/4” was introduced to the fire service many years ago one of the big sales pitches that was presented to the firefighters was that it was going to be able to produce flows equal to the 2 ½ inch lines and be much easier to handle. Believe it or not a lot of departments believed this pitch and actually got rid of their 2 ½“ hose. They soon realized that achieving 250 GPM from the 1-3/4” handline was not possible the big majority of the time. There were several reasons for this. The required pump discharge pressures were easily over 200 psi and sometimes reaching 250 PSI which made firefighters hesitant to use. Since they already had nozzles on their 1-3/4” handlines that had the ability to flow 250 GPM, it was automatically assumed that they could use the same nozzle. The problem they wound up having was for the most part these were rated at a 100 psi nozzle pressure. This basically made the 250 GPM flow not obtainable. One other thing that was realized was that the nozzle reaction flowing 250 GPM with the small diameter 1-3/4” hose created severe kinking at the nozzle because of the nozzle reaction. With all this being said basically the 1-3/4” hose was not used in the high flow 2-1/2” mode.

100_0357

      High flows using 1-3/4” hose can cause kinking at the nozzle due to the nozzle reaction.

Well that was then and this is now. Let’s see how the 1-3/4” hose can be used for that initial pre-connected big hit line by the first-in engine company safely and efficiently. It’s important to understand the intention of this article is not to persuade fire departments to get rid of their   2- ½ “ hose. This is only meant as an alternative for the pre-connected 2-1/2.

This article is going to talk about two different types of 1-3/4” hose that can be used for this scenario. The first is the standard 1-3/4” that actually measures out to be 1-3/4”in diameter. The second one is a 1-3/4” line that is sold by several manufacturers with the claim of being able to get higher flows. This 1-3/4” is actually oversized and measures out to approximately   1-7/8 Why it’s not sold as 1- 7/8″ hose I do not know. However I can tell you that the difference in flows between the standard 1-3/4” and the 1-7/8” hose is tremendous.

100_0344

On the left is standard 1-3/4” and on the right is the oversized 1-3/4”

Standard 1-3/4”Hose

The goal for a maximum flow on standard 1-3/4” hose is going to be 250 GPM. This is going to be based on a 200’ line. Let’s address the issues that firefighters were faced with years ago when they originally tried to flow 250 GPM through their 1-3/4” hose and make improvements.

The first thing I’d like to address is the pump discharge pressure. There are ways to lower the required pump discharge pressure but we are still going to be looking at pressures close to  200 psi. Is this something to be concerned about? I say no and here’s the reason why. It’s important to understand what today’s fire hose is rated at in regards to maximum pressures. Most attack hose used in the fire service today has high pressure ratings. For example the burst pressure is 1200 psi. The annual service test pressure can be tested up to 400 psi. By the way I do recommend testing it at 400 psi because this will give us a wide safety margin from the test pressure to the operating pressure of no higher than 250 psi NFPA used to say that the maximum operating pressure shall be 10% less than the annual service test pressure which would make the standard 1-3/4” hose have an operating pressure of 360 psi. They have since changed their wording to state that the attack hose should be able to have at least a 275 psi operating pressure is still higher than what we will pump our lines for this operation.

The 250 GPM flow on the 1-3/4”line is going to require the use of a 2 ½“ discharge to be an efficient line. The plumbing in the traditional crossways for pre-connected 1-3/4” lines is just too small.

Now let’s address the nozzle itself. We need to get away from the 100 PSI nozzles in order to keep the pump discharge pressure as low as possible. A 50 psi smooth bore nozzle or a combination nozzle rated at 50 psi works well for this operation. If you’re using a smoothbore nozzle the inch and 1/8 tip is the standard for the 250 GPM flow (it’s actually 265 GPM but we’ve always rounded it off to 250). Combination nozzles can be rated at 250 GPM also with a 50 psi nozzle pressure rating.

There’s a real simple fix for addressing the severe nozzle reaction kinking in the hose just behind the nozzle. A short section 2 ½ inch hose connected to the end of the 1-3/4” and then to the nozzle totally eliminates all nozzle reaction kinking simply because it’s a larger hose. A 5 foot section works well for this however it is possible to go to 10 feet and still have the lightweight capabilities of the small diameter hose. Remember this line is set up to be a big hit line so the short section of 2-1/2” should be an issue. If we chose to take this line interior I still don’t think the 2 ½ would hinder hose advancement.

A short section of 2-1/2” at the end of the line takes away the kinking caused by nozzle reaction.

100_0071

 

 

As far as nozzle handling techniques are concerned the only thing that has really changed, and it has changed for the better, is that advancing a charged line has become a lot easier. Take a look at a scenario where a one person evolution is used for deploying a pre-connected big flow line. There’s a real good chance that a first-in unit would actually use just one person to deploy even a 2-1/2” line. Pulling the line from the hose bed has become easier simply because of the weight of hose. Nozzle handling with one firefighter will most likely be done from a stationary position simply because if you’re attacking a large volume of fire you’re going to have to knock it down first before advancing in. With this being said using some type of technique where the firefighter’s bodyweight is on top of the hose pushing to the ground makes it very easy to handle the nozzle reaction that a 250 GPM flow will produce.

The following chart is going to show flow tests that were done with a 200 foot 1-3/4” line using a 1 1/8 “ smooth bore tip at 50 pounds nozzle pressure and the combination nozzle rated at 250 GPM with a 50 pound nozzle pressure.

GPM              NOZZLE         NP      FL        PDP

250                  1-1/8”             45        70        185

250                FIXED GAL.        50        70        190

There is another way to bring down the pump discharge pressure if 190 psi is a little high for you. Theoretically on the 200 foot line most if not all the maneuvering after it has been charged will be done at the last 100 feet. With this being the case if you wanted to build this line with 100 feet of 2 ½” from the discharge out and have 100 feet of 1-3/4” line at the working end, this will lower the pump discharge pressure to 135 psi.

 

1-3/4” Oversized Hose

The 1-3/4” hose with the oversized diameter, 1-7/8”, has the ability to flow up to 325 GPM on a 200 foot line. Yes you heard it right. 325 GPM is at the high end of most 2-1/2” handlines. This particular hose has a burst pressure of 1500 psi with an annual service test pressure of 500 psi. According to the previous NFPA standard the maximum operating pressure for this hose can be as high as 450 PSI. Based on the 325 GPM flow on a 200 foot line the pump discharge pressure is 205 psi. This type of hose is very kink resistant however it still requires the short piece of 2 ½ at the end of the line to negate the kinking from the nozzle reaction of these high flows. If you want a lower pump discharge pressure by replacing the first hundred feet of 1-3/4” with 100 feet of 2 ½, pressure will be lowered to 140 PSI. The chart below shows the specs on the 200 foot line using this hose.

 

 

GPM              TIP SIZE         NP      NR      FL        PDP

250                 1-1/8″           45       99       50       145

275                 1-1/8″           55       109     56       180

300                 1-1/8″           65       129     62       200

328                 1-1/4″           50       123     76       205

 

I know the basis for this article calls for the replacement of the 2 ½ “ pre-connect however there’s nothing that says you can have both lines especially with flow capabilities of the 2 ½” line reaching 500 GPM using the single inlet mini monitors that have proven themselves over the last few years. In fact there’s even some that have been getting 500 GPM flows on specific types of handline nozzles with a lot of success.

In closing

This article has been based on being progressive, keeping an open mind and continuous evaluation of equipment and techniques.  Most of what you have read will not be found in the standard fire stream books in circulation today.  Does that mean that this is not an acceptable way to deliver high flows through 1-3/4” handlines?  In my opinion, it does not.  At no time do any of the above mentioned flows, nozzle combinations, and nozzle pressures go against what the manufacturers say their equipment can or cannot do.  If you like what you have read, don’t implement it tomorrow – train, train, train,.  Feeling comfortable and confident is the key to success.

 

 

What Size Handline Should Be Used In a Highrise Fire?

What Size Handline Should Be Used In A Highrise Fire?

The purpose of this document is to provide information that will help firefighters in making a decision on what size handline is to be deployed in a highrise fire.

There are four basic components for a high-rise handline operation. They are the hose, the nozzle, a 2.5 x 2.5 gated wye, and a in-line pressure gauge.

HOSE AND NOZZLE

Choosing the proper hose and nozzle combination needs to be based on delivering the required flow for fire attack using low system operating pressures. The reason for this is simple. High-rise fire protection systems are limited in operating pressures because of elevation, friction loss in plumbing, pressure reducing devices, and probably the most concerning issue, system pressures. established by NFPA, which is the codes that high-rise fire protection systems are designed from.

 

There are two basic sets of standards that have been put in place by NFPA that can effect water delivery. The first standard was in place until 1993 and the second standard which is still in place started on 1993. Please note that structures with the Pre 93 standards were not required to upgrade to the Post 93 standards.

 

PRE 1993 The minimum requirement for water delivery is 500 GPM at 65 psi standpipe residual pressure at the highest standpipe in the system. The pressure restricting device has a minimum allowed residual pressure at the standpipe outlet at of 100 psi and a maximum of 175 psi. The pressure reducing valve has a maximum static pressure of 175 psi at the standpipe outlet.

 

POST 1993 The current code requires the same 500 GPM flow but the minimum residual pressure was increased to 100 psi. The pressure restricting device pressure setting of 100 psi is not required and the pressure reducing valve static pressure setting remains at 175 psi.

 

NFPA also requires a minimum flow of 150 GPM on attack lines. It makes no difference whether the fire attack is taking place in a single-story structure or a multi-story structure.

 

Because of the above-mentioned pressure issues in fire protection systems most fire departments have opted to exclusively use 2 ½ “ handlines with smoothbore nozzles for all fire scenarios big and small. The true fact is that the 2 ½ “ handline will provide the most water every time. However along with the positive flow capabilities of this line there are also negative deployment and kinking issues that have to be dealt with because of the size of the hose itself.

 

The low standpipe residual pressures mentioned above have been misleading causing firefighters to to assume that smaller handlines such as

1-3/4” and 2” could not be used because of the higher friction loss these lines possess as compared to the 2-1/2”. Let’s analyze the true pressures that can be expected in a high-rise fire protection system.

 

Again, fire protection systems are based on a 500 GPM flow capability and after flowing 500 GPM the residual pressure will need to be either 65 psi, 100 psi, or 125 psi depending on when the system was built. The true fact is that if 500 GPM is not flowing, which it would not be with the initial handline deployment, the residual pressure will actually be higher. The following chart will illustrate this. Actual flow tests were conducted at the Binions Horseshoe Hotel using 1-3/4” 1.88”, 2”, and 2-1/2” hose all at 150’ in length. Here are the results.

 

Binions Horseshoe Hotel in Las Vegas.

This is a 500 GPM / 65 psi system.

FIRE PROTECTION SYSTEM STANDPIPE

RESIDUAL PRESSURE FLOW TESTS

                                                                                                                                     

                                                                                                                                  SRP    STANDPIPE RESIDUAL PRESSURE 

                                                                                                                                               GPM    GALLONS PER MINUTE

                                                                                                                                                    NP    NOZZLE PRESSURE

 

                                                                                                                                     SYSTEM SPECIFICATIONS     500 GPM @65 PSI SRP

                                                                                                     1.75”HOSE X 150’              SRP 100                    GPM 188       TIP 1”             NP 40

 1.88” HOSE X 150’             SRP 98                      GPM 210       TIP 1”            NP 50

 2” HOSE X 150’                   SRP 92                      GPM 222       TIP 1”            NP 56

 2.5” HOSE X 150’                SRP 88                      GPM 301       TIP 1-1/8”      NP 64

 

As you can see the standpipe residual pressures increased significantly and all flows exceeded the NFPA minimum handline flow of 150 GPM as well. The size of the hose in the high-rise pack should reflect the requirements of the fire and the system pressure.. The GPM needs to match the BTUs and the diameter of the hose needs to be able to overcome the system pressures. In order to have the luxury of an easy to deploy 1-3/4” or 2” handline, a 2 ½ “ hose pack needs to be brought into the structure as well just incase its use is warranted. .

 

Low-pressure nozzles are a must in a high-rise operation even with the higher residual pressures which were indicated in the chart. Remember system pressures are going to be low so lowering the nozzle pressure from the standard 100 psi to a much lower pressure in the range of 40 PSI to about 60 psi greatly improves water delivery capabilities.

 

The following chart shows examples of the Combat Ready 1-3/4” and 2-1/2” hose packs with their accompanying nozzles and their approximate flow capabilities in three different system pressures, 65 psi, 100 psi, and 125 psi.

 

1-3/4” x 150’ with a 15/16” smooth bore tip and a 185 GPM fixed gallonage combination nozzle @ 50 psi nozzle pressure

65 psi system           100 psi system         125 psi system

185 GPM                     191 GPM                   198 GPM

105 psi SRP              120 psi SRP              135 psi SRP

 

2-1/2” x 150’ with a 1-1/8” smooth bore tip and a 250 GPM fixed gallonage combination nozzle @ 50 psi nozzle pressure.(both were identical in flow)

65 psi system         100 psi system        125 psi system

300 GPM                330 GPM                 335 GPM

90 psi SRP             110 psi SRP              135 psi SRP

 

Not all standpipe outlets are user-friendly in regards to connecting hose and gated wye appliances to them. Because of this a short 15 foot section of either 2-1/2” or 3 “ hose should be used to connect the high-rise pack to the standpipe outlet.

 

GATED WYE

A 2-1/2” x 2-1/2” gated wye should be connected to the end of the short section of hose leading from the standpipe to allow two handlines to be connected from one standpipe outlet.

 

2-1/2” INLINE PRESSURE GAUGE

The 2-1/2” pressure gauge is connected between the gated wye and the short section of hose leading off the standpipe outlet.The purpose of the

in-line pressure gauge is twofold. Part of the high-rise deployment procedure requires a flow test of the hand line before commencing with the fire attack to determine if the required handline pressures can be met from the system which in turn will help decide what size line can be used. The other thing the in-line pressure gauge can do is help to dial in the required pressures for the handline. For example let’s say you’re using Combat Ready 1-3/4” hose and the required pressure for that line to flow 185 GPM with the 15/16 smoothbore is 105 psi. This can be noted with a label on the side of the gauge body so if an adjustment is needed at the standpipe a firefighter simply adjusts the standpipe outlet valve to the required pressure. The same can be done for the 2 ½ “ line.

 

Maximizing the Water Supply on a Large Flow Fire With Supplemental Pump Operations

 

 streams

Obtaining a water supply on the fireground is one of those “gotta haves” for a successful outcome in combating a fire. For the simple low flow fireground operation this task is fairly easy. When fire hydrants are available usually a single line from the hydrant will do the trick. Well what about the more complex large flow fires that require large volumes of water to support master streams and big handlines to get the job done? This is where water supply operations can get quite difficult. There are a lot of things that can dictate how well a water supply operation works. Issues such as fire hydrant performance, fire hydrant availability, supply hose, available units, topography of the fireground, and management of water supply, just to name a few.

 

In this article in going to discuss three different types of supplemental water supply operations for large flow water delivery involving multiple units.  A supplemental water supply is defined by IFSTA as a method of operation for bringing in additional water to a pumper that is already connected to a water supply and needing more water.

 

 

Relay Pumping.

A relay pump operation is used when there is not enough pressure at the water source to move the water through the supply hose to the pumping apparatus on the fireground. It involves placing a pumper at the water source to increase the pressure in the supply hose. A relay pump operation is the back bone of big water operations simply because the additional water needed to support the fire ground operations will more than likely be coming from distant hydrants. The longer the supply line is the more pressure loss will be because of the friction loss in the hose.

 

It’s been an accepted practice to allow the shorter LDH supply lines to be supplied solely from hydrant pressure. Remember the old saying “laying an LDH supply line is like taking the hydrant to the fire, or like laying and above the ground water main.” In other words, LDH laid from a hydrant, especially on the shorter lays, is going to bring in maximum flow. It is this type of thinking that can get us in trouble. LDH is great, but can still have its restrictions. LDH must be used in conjunction with everything else on the fireground to its best capability in order to reap its benefits.

DSC00026

Looped Supply Line Operation

The first supplemental water supply operation we will be discussing is what I like to call a looped supply line operation. A looped supply line operation is a combination of supply line hose evolutions set up to work as one. Large flow operations most always require multiple supply lines from various locations all working towards the goal of providing an overall water supply for the incident. These operations can be quite complex and taxing because the overall goal is to provide the required flow to multiple units without interruption. Notice I said goal. It can be extremely hard to implement a water supply operation and accomplish it without issues.

 

The looped supply line operation is designed to deliver a supplemental water supply to as many pumpers as possible based on the placement of the apparatus on the fire. Think of this as a fire hydrant water main system. A single supply line connected to a pumper is like a fire hydrant connected to a dead end main only getting water from one supply, the main that is feeding it. The hydrant that is connected in the looped grid system is actually receiving additional water from another point in the grid system itself thus the term supplemental. Well if it works with underground water mains it should work above ground with supply hose as well.

 

The technique or operation that is a key factor in building a looped supply line operation is a pump operation called dual pumping. Dual pumping is a water sharing evolution designed to share water between pumpers. This has actually been done throughout the years by one pumper discharge pumping into another. This works and can usually move slightly more water than a dual pump operation. So why don’t we just use this operation? When you discharge the pump through a hose line the water only goes in one direction, from discharge to intake. This can hinder a true looped operation. Dual pumping, believe it or not, is an operation that connects two or more pumpers together through the unused intakes of the pumps involved to share the water. Yes I said intake to intake. Because there is no actual discharge pumping in the dual pump operation the water can flow in either direction. The water will flow in the direction of the pumper that has the lowest residual pressure. Here’s how it works. Let’s say a pumper lays in a 5 inch supply line and goes to work. The supply line has the capability of moving 1500 GPM and the pumper that laid the line is going to flow 500 GPM. After flowing 500 GPM the intake gauge of the pumper reads 60 psi. The 60 psi is a residual pressure of the water supply left over after the 500 GPM is flowing. The 60 psi represents water under pressure from the hydrant that is available within the supply line and the intake side of the pump. Now let’s say this first in pumper wants to share some of its water with another pumper. A line is connected from its unused intake to the intake of the pumper it is going share water with. When the command is given to share the water the first pumper opens its intake valve that is connected to the dual pump line and the water will start to move through the supply hose to the next pumper under the 60 psi residual pressure. You can really just think of this as being connected to a hydrant because the 60 psi residual pressure is actually coming from the hydrant. It’s before the impeller of the first pumpers pump therefore does not have anything to do with the pumping capabilities of the first pumper. When the water is received by the second pumper the pump operator simply opens up the intake valve and gets the shared water from the first pumper. One of the unique things about this operation is that the pumper that is sharing the water with the next pumper can never be robbed of water it is discharging. Due to the pumps design all available water that comes into the initial pumper will always be available for that unit. Let’s go back to the initial part of this example. After the first pumper is flowing 500 GPM and sharing water through a dual pump operation to the next pumper the first pumper has to increase its flow by another 500 GPM. The only thing the pump operator will have to do is open the proper discharge lines and throttle up to the proper pressure to flow that extra 500 GPM. The water will basically be taken back from the dual pump operation to the next pumper. Again the initial pumper receiving water from the water supply will always have priority.

 

There are a couple things that need to be monitored during a dual pump operation by both pump operators. Once the initial pumper shares the remaining water supply it will lose some residual pressure because the residual pressure is being used to move the water to the next pumper. So the pump operator on the initial pumper might have to apply more throttle to increase the pressure back to whatever is required pressure was. If the pump is equipped with an electronic governor it will automatically adjust the RPMs to the new residual pressure. Again the initial pumper is not losing any water only residual pressure. If the initial pumper needs to take back some water, the pump operator should communicate with the pumper that is receiving the extra water that he will be taking water back which will in turn drop the intake pressure of the receiving pumper. The pump operator on the second pumper should try to maintain the engine pressure that was required for its flow and may have to throttle up because of a drop in intake pressure. Below is an illustration of a basic dual pump operation.

DSC00008

Dual pumping.

BASIC DUAL PUMPINGPage-1

Summary of Dual Pump Operations

  1. Dual pumping moves water from one pumper to another with supply hose connected intake to intake.
  2. The water is moved by the residual pressure of the first pump.
  3. Dual pumping works real good for low flow operations such as handlines when the water source to the initial pumper is coming directly from a hydrant with hydrant pressure only.
  4. If a dual pump operation is going to be used to share big water, the water source to the initial pump needs to be boosted from the hydrant with a relay pump operation.
  5. The distance a dual pump operation is based on the flow requirements and the available residual pressure.
  6. The opening of the intake valves should be done slowly until the line is charged to avoid cavitation.
  7. 7.      Since dual pumping shares residual pressure, pump operators need to monitor the pump discharge pressures in case there is a drop in residual pressure.

Most firefighters have never heard of dual pumping before so what I would like to suggest is before integrating it into a looped supply line multi-company operation, go out and train with it to get comfortable with its operations to see what it can really do for you.

 

The next illustration I’d like to show you is the beginning of a multi-company large flow operation. The illustration shows three pumpers connected to their initial water sources.

 

PROACTIVE SUPPLYLINEPage-1

This is basically the first alarm assignment. These units are in the big water mode so they are really starting to tax the main that is connected to the three hydrants. Grabbing the closest hydrants by first in companies is a realistic scenario and there is the possibility of some if not all hydrants being on the same main. Now is when these first-in units start running low on water. Just running low on water in itself isn’t the risk as long as the engines will not be trying to deliver more water than their current discharge evolutions. However, often times especially with the first alarm assignment, the units are usually in a good spot to deploy multiple streams. With this being the case there is a good chance the first alarm assignment will need more water.

 

The next illustration will show supplemental pumping by use of the looped supply line operation which involves relay pump operations and looping or connecting the receiving pumpers together to share a common water supply. Remember these units already have water coming into them from their initial supply lines, they just need to freshen up their water supplies. In some cases they won’t need that much more water while in others they may need to double their current flow. As mentioned earlier when units are connected in a dual pump operation the water will automatically flow in the direction of the pump that has the lowest residual pressure.

 

 second alarmPage-1

 

 

 

 

I’m a big fan of preparing for worst-case scenarios. In regards to this operation it’s best if the pumpers are equipped with at least three large intakes, the two steamers coming off the pump and either a front or rear suction. There are manufacturers that actually make valves that can be connected to the main steamer that will allow two supply lines to be connected. The illustration shows two dual pump operations using pumpers with two intakes and pumpers with three intakes. Both will work however the pumper with three intakes allows for more options.

 

Manifold Operations

 

The second method for supplementing a water supply at a large flow operation is to use large diameter hose manifolds in conjunction with a relay pump operation. Remember in a supplemental operation we are giving additional water to units that already have their own supply lines but are running low on water and need more. There are two types of large diameter hose manifolds that are available. One has a large diameter hose inlet and outlet as well as multiple 2 ½ inch outlets. This style is designed more for handline operations supported by a large diameter hose line. In our situation where we are attempting to move large volumes of water only, the 2 ½ inch discharge ports on the manifold will be very restricting and therefore should not be used for this type of operation.

 

The other manifold that I do recommend has a large diameter hose inlet and two large diameter hose outlets. The body of these manifolds is large and have unrestricted waterways and are very efficient for moving big water. These manifolds work best in conjunction with a relay pump operation. The manifold should be placed on the fireground close to the units that it will be supplying and can be fed by a single large diameter hose relay line.

 

Although this is an efficient operation it’s important to remember that the water is being discharged through the entire hose evolution and therefore will only flow the water in one direction. Therefore it cannot be used in a looped system.

LV Training Center 03-07-09 035 - Copy

2-1/2” outlets on the large diameter hose manifold are for 2-1/2” or smaller hose. This would be very restrictive for supplying large volumes of water.

P9210863

Large diameter hose can be connected to the 2-1/2” ports on the manifold however the

2 ½ inch waterway is very restrictive.

100_0127

Large diameter hose manifold with large diameter inlet and outlet’s is very efficient.

second alarm WITH TRIPLE MANIFOLDPage-1

 

 

A Pumper Supplying Multiple Large Diameter Supply Lines

The third method for supplying a supplemental water supply to units on the fireground is by simply pumping multiple large diameter hose discharge lines to the individual units. This can be done either from the hydrant or at the end of a relay on the fireground. Most units only have one large diameter discharge however the 2-1/2” discharge adapted to a large diameter hose line can move 1000 GPM fairly efficiently.

DSC00039

This pumper is at the receiving end of a relay on the fire ground supporting two 5 inch supply lines to units on the fireground. One 4” discharge and one 2 ½ inch discharge are being used.

DSC00026

This pumper is set up at the hydrant discharging two 5 inch supply lines in a relay directly to units on fire ground.

 

 

In summary

There are several ways to support units with an adequate water supply on the fireground. This article has talked about three different evolutions. The key to a successful operation such as this is to be proactive with the water supply and develop an evolution that works best for your agency based primarily on safety and efficiency.

Big Streams Requires a Proactive Water Supply

DSC00043Big Streams Requires A Proactive Water Supply

Fire departments all across the country have the responsibility for protecting their communities from the ravages of fire both big and small. It would be ideal if all fire stayed in the small range requiring only one or two hand lines to extinguish. There are some communities that pretty much fall into this category but even they have the potential for a large fire. It is the small fires that we tend to have the most experience in either by working a lot of them or from simply just training or both. Think about it, when it comes to water delivery on a small fire it’s very basic. Fire attack is started from the onboard booster tank from the first-in engine and if a sustained water supply is needed a supply line is laid from the hydrant. If I had to put a number on it I would say just about all small fires can be handled with 500 GPM or less.

 

So what happens when we do get the large fires? When it comes to water delivery this is where a lot of fire departments tend to struggle to develop the required flow. The problem isn’t coming up with the required streams in regards to deploying the actual lines and appliances. Actually it’s pretty basic. On large flowing fires it’s the master streams and large hand lines that usually get put into play. Whether its smoothbore tips or combination nozzles being used, the goal is to put the big ones into service. This is half the battle but now we have to get the required flow delivered from the water supplies to support the big streams.

 

The introduction of large diameter hose many years ago seems to most like this would be the solution to the water supply problem. In fact fire departments did see a dramatic increase in water delivery when they switched to large diameter hose. So why is it when we get fires that require large flow water delivery and we use large diameter hose for our supply lines that we still run out of water? For those of us that were around before large diameter hose, especially the pump operators, you know that they really had to work to deliver the required flow on large fires. Relay pump operations were the norm supplying multiple 2 ½ and 3 inch supply lines to the fire. Fire departments knew what they had to do to move water through their small supply lines. Then came large diameter hose and all the fancy pump operations fell to the wayside. The true fact is that we still need special pump operations even with large diameter hose to move the water from the water supply to the fire ground.

 

The real problem when you analyze water delivery operations from fire hydrants isn’t usually a lack of water at the source. The water in a stored capacity in the water mains is almost always available.  It is the hydrant system pressure, or should I say residual pressure, that is usually lacking to move the required flow for the required distance. In order to get the job done it may take using multiple hydrants as well as hydrants on other grids further away in conjunction with specific pump operations. But for the most part as long as the manpower, equipment, and the will to get the job done are all available the required flow can usually be produced.

 

As I’m sure you know the overall fire ground operation consists of several companies working in a coordinated effort under the direction of an overall supervisor to execute a fire attack as safely and efficiently as possible. All phases of the operation need to be conducted at the proper time, again to make the final outcome of the operation successful. This is where obtaining and successfully delivering the required flow from a water supply becomes crucial.

 

Oftentimes the request for more water is put out when the existing water supply becomes depleted. Keep in mind that on a large scale fire there’s a good possibility that multiple supply lines from the closest hydrants are already in place. Bringing in additional supply lines from new water sources will more than likely require long hose evolution’s preferably set up in the relay pump operation to get maximum flow. From the time the request comes in for additional water until the time the operation is set up and ready to deliver can easily take 10 to 15 minutes. If the current water supply is already depleted and frantic requests are coming in for more water, 10 to 15 minutes is too long to wait.

DSC00027

Multiple large streams usually can’t be supplied from the initial hydrant. A secondary supply line needs to be brought in.

 DSC00022

DSC00008

Getting a relay operation ready for service takes longer than you can afford to wait when you are out of water. You have to be proactive

The best way to implement the request for additional water is to be proactive. Don’t wait until the operation needs more water, have it ready for them before the request is made. Setting up additional water supplies during the initial phases of a large flow operation will allow the overall water supply situation a better chance for success in fulfilling the required demands for the fire streams without interruption.

Here are two suggestions on how to proactively deliver additional water to the fire ground. When command is established on a fire that has the potential to become a large flow operation, if possible one engine company from the first alarm assignment should be given the task to establish a supplemental water supply. The engine should start its evolution from the fire ground at a strategic location where the additional water may be needed. If the line is not ready to be connected to an engine simply have a firefighter anchor the line. The engine should try to lay to a hydrant that is on a grid separate from the current hydrants already being used. The engine should also set up at the hydrant for relay pump operation. After making the hookups to the hydrant the operator should charge the lines however unless the water supply is already needed at the fire do not charge the supply line itself. The reason for doing this is that if the line turns out not to be needed it will be a lot easier to pick up dry versus having to drain a charged line. The trade-off for this is very minor. Charging a supply line should only take a couple of minutes.

 

Another thing to consider in proactively seeking additional water is to make special requests in the dispatch assignment for units that will be totally dedicated to bringing in additional water through supply line evolutions. Let’s say for example a particular fire requires a three alarm assignment to meet the challenge of the fire attack. Consider making a call for a fourth alarm with the additional alarm being assigned to water supply. I understand that not all agencies have these kind of resources. However having some type of plan for additional water will make for a better chance for a successful outcome on the fire ground.

 

The following two illustrations show a first alarm and section alarm assignment. Note that the first alarm shows an engine that laid a proactive supply line set up for a relay. The receiving end of the line is not connected to an engine basically because at the time it was deployed there was no need for the extra water. The second alarm shows the proactive relay connected to an engine to supplement the depleted water supply. There is also an additional relay set up with the second alarm assignment.

 

 

FIRST ALARM ASSIGNMENT

PROACTIVE SUPPLYLINEPage-1

SECOND ALARM ASSIGNMENT

second alarmPage-1

The following illustration shows how just three engines can deliver 5000 GPM.

5000 theoretical drillPage-1

 

Summary

Timing is crucial when implementing the various assignments involved with maintaining a positive water supply on a large flow operation. It can be intense, time-consuming, and resource consuming. Taking a proactive approach in dealing with the water supply is extremely important simply because the fire itself does not wait for the required water supplied to be delivered. Just a few minutes can make a huge difference on the outcome of a large flow fire.

Developing Pump Discharge Pressures

Developing Pump

Discharge Pressures

Henderson Training Center 03-20-10 014

 

 

Pump operators have one of the most critical jobs within the fire company. They must be able to deliver the troops in a timely and safe manner and provide them with an adequate water flow to suppress the fire as fast as possible. This involves securing a water supply sufficient enough to produce the required fire streams to get the job done, and to develop the required streams by means of a combination of hose evolutions and proper pump operations.

 

A pump operator should understand the operation and capabilities of all appliances that have anything to do with the movement of water, such as:

1 – Type of nozzles (smooth bore, automatic, selectable gallonage, fixed gallonage, etc.)

       2 – The flow range of the nozzles

3 – Flow range, requirements, and capabilities of master stream appliances

       4 – Hose capabilities, supply and discharge

 

There are things that a pump operator needs to know in regards to physics when it comes to delivering water on the fire ground.  Here is a list of things to know about moving water that will help the pump operator to have a better understanding of what is required of him.

*The understanding of friction loss in both hose and plumbing.

*GPM

*Elevation gain or loss (head pressure)

*Properly reading gauges

*Nozzle exit or base pressure

*Nozzle friction loss

 

Besides all of the above-mentioned items, the pump operator needs to develop the proper discharge pressure to provide the energy to move the water through the hose evolution and discharge it onto the fire.

 

There are several things in a hose evolution that require pressure to move the proper amount of water. Back in the olden days when buckets were used, the only energy required to move the water was in the form of human power in bucket brigades. In today’s water delivery system, pressurized water is used to overcome things such as friction loss in fire hose, plumbing, and appliances, head pressure loss from elevation and an exit pressure from the stream producing fire nozzle (also known as nozzle pressure).

 

There have been several methods used over the years to calculate the required discharge pressure, some worked well and others not so well. There is a standing joke in the fire service that says “throttle up until the firefighter and nozzle come off the ground, then back her off a couple of pounds”. I wonder how many people practice that these days. How about this one, “pump 150”, whether it is for a handline of any size (diameter and length), for master streams, relays, or for building fire protection systems? If water comes out the other end, the correct discharge pressure is being developed. I think you know these methods leave a lot to be desired.

 

Probably one of the most common methods used for calculating the right discharge pressure is the use of fireground hydraulics. This is a mathematical formula that is based on the size and length of the hose line, the amount of water being delivered (GPM), appliance friction loss, elevation gain or loss, building plumbing loss, and nozzle pressure. The old formula 2Q squared plus Q was designed for 2-1/2” hose calculations and it is my understanding that the numbers were based on 2-1/2” pipe, not fire hose. In other words dimensions. A coefficient could then be used in the formula to apply it to other hose diameters. I know this formula works on paper with the help of a calculator, but is it practical and accurate? No and no.

Kent, WA June 2002-15

 

Looks like spaghetti, how do you figure this one out?

 

First off, hose has different characteristics than pipe. It curves and sometimes kinks and it’s even been known to expand when it’s charged in some cases. Pipe doesn’t do that. It is a proven fact that the same size hose at a given flow can have different friction loss characteristics from different manufacturers. The following statistics show just that.

 

To mix it up even more, you know as well as I do, that there are occasions that the length, diameter, flow, and other key components of a hose evolution may not be known, now what? The formula can’t be used if you can’t supply all of the numbers. For those that can work the formula at the fire, my hat goes off to you, it’s pretty tough.

 

In recent years IFSTA has streamlined the formula to make it more accurate but in my opinion it’s not the best method to use. If there is a good characteristic about the fireground hydraulics it is that they usually calculate a higher than reality pressure.

 

Flow meters have seen their way into the apparatus industry utilizing an electronic readout of the amount of water flowing. Although these instruments can be accurate, most require calibration to remain in good operating service. From what I have seen, most departments do not calibrate their flow meters. If a flow meter is to be used I recommend the type that also has a pressure gauge. This makes for a reliable backup.

 

Pump Charts

 

A pump chart is a reference chart for all discharge evolutions that assists the pump operator in developing pump discharge pressures for any hose evolution a department may encounter. Pump charts should be designed to be as easy as possible to read. Make sure the letters and numbers are as large as possible and keep it in a place that is easy to access and has a light for night time use. A pre-determined pressure should be calculated for all pre-connected evolutions, such as pre-connected handlines, fixed master stream appliances, and any evolution that will always be the same. The numbers calculated from the flow test should reflect the discharge gauges that are being used by the apparatus. Most discharge pressure gauges read in 10 psi increments. Pressures should be rounded off to the nearest increment on the gauge to make it more practical to read. I would recommend rounding off to the next highest increment.

100_1390

Pre-connected lines remain the same thus allowing for a pre-determined discharge pressure.

 

 

 

Let’s take a look at a method that allows for developing pump discharge pressures that work every time. This is mainly for pre-connected lines or lines that are the same length and flow every time as well as fixed master streams and quints. The method involves conducting flow tests through the use of flow meters and pitot gauges. These tests are not done at the fire, they are used to develop pump charts that should be placed on the fire apparatus and used as a reference guide by the pump operator. The flow meter should be calibrated before the test begins to guarantee accuracy. This is done by first using a smooth bore nozzle to measure a flow with a certified pitot gauge, which measures the nozzle pressure. The flow meter can then be calibrated to the flow that is measured through the smooth bore. I like placing the flow meter on the supply line at the intake of the pump. This allows the discharge evolution to be exactly like it would be in a real operation without the insertion of the flow meter tube. Most manufacturers of flowmeters require a certain amount of straight water travel through the hose or plumbing about 10 feet before and after the flow meter tube for best results.

P1000578

Flow meters should be used whenever possible for determining accurate discharge pressures.

 

anchor-and-hold-12

Handheld pitot gauge is used to measure the exit pressure of a water delivery appliance.

 

Besides having predetermined pump discharge pressures, there is also a need to have a friction loss chart for the various sizes of hose that are used. The reason for this is simple. There are times that lines have to be made up at the fire which could involve various lengths of hose. By having a friction loss chart the pump operator can add up the amount of hose that is being used on a specific line cross-referenced to the friction loss chart to come up with the required pump discharge pressure.

3

Storage hose beds can also be used to develop operations, which can result in an undetermined amount of hose.

 

You still need to set up a discharge line and determine the required flow you are testing through the methods just explained to you in the last paragraph. There also needs to be two in line pressure gauges connected into the discharge line 100 feet apart to measure the friction loss. These gauges also need to have 10 feet of straight hose entering into them for best results. The friction loss is determined by subtracting the lower pressure from the higher pressure on the two gauges.

 

Finally, it’s important to flow test all pumping apparatus in the fleet because their designs in regards to plumbing design and gauge placement could be different from one another thus having different pump discharge pressures. Every unit should have its own pump chart developed from itself

 

 

 

 Handlines.

him

 

The handline evolution is the most basic discharge evolution used by firefighters in regards to its simplicity. There are two basic parts, the hose and the nozzle. The most common form of this evolution is the pre-connected handline.

 

Preconnects

 

The method used for calculating the correct pump discharge pressure for the pre-connected handline is the basic flow tests previously mentioned. For combination nozzles a flow meter is used and for smoothbore nozzles either a flow meter or handheld pitot gauge can be used. It’s important to flow the lines from the actual pre-connected discharge because they are usually smaller in diameter than the 2 ½ discharges and can have numerous bends in the plumbing design that could affect the required pressure. Additionally the discharge gauge may be located further away from the end of the discharge plumbing than a standard 2-1/2” discharge gauge. Here is an example of what would be on the pump chart

 

1-3/4” 150 GPM Handline X 200’ With A TFT Automatic 100 psi Nozzle

150 psi PDP

2-1/2” 325 GPM Handline X 200’ with a 1-1/4” Smooth bore 50 psi Nozzle

100 psi PDP

 

Handline Assembled At The Fire.

If the handline is developed or assembled at the fire scene and has a different length than the pre-connected lines the final calculation is done by using the friction loss section of the chart. First the length of the handline needs to be determined. Next the friction loss chart needs to be referenced to the correct size of hose and GPM. The Friction loss numbers are listed for 100 foot sections so simply divide the length of the hose by 100 and multiply the answer by the actual friction loss listed on the chart to come up with the friction loss for the entire line. It should be noted that the friction loss can be calculated for 50 foot sections if so desired. Finally add the nozzle pressure based on the actual nozzle that is to be used.

 

It’s important to understand that a handline like this as compared to the same length line on a preconnect can vary a little. Remember you are working with two different types of discharges and the pump discharge pressure for the assembled line is developed from numbers on the chart versus using a flow meter for the pre-connect line. Here is an example of what would be on the pump chart.


 

Friction loss for 100‘ sections of hose

 

1-3/4” @ 150 GPM     25 psi

2-1/2” @ 250 GPM     15 psi

2-1/2” @ 300 GPM     20 psi

2-1/2” @ 328 GPM     25 psi

5”      @ 1000 GPM    5 psi

 

   GPM   100’     200’    300’      400’         500’

2-1/2”  328    25 psi   50 psi   75 psi   100 psi     125 psi

Plus 50 psi for the nozzle pressure for the 1-1/4” tip

 

Stacked Smoothbore Tips

A common smooth bore nozzle used on a 2-1/2” handline is the triple stack tips. It has three actual tip sizes in a stack just like a master stream. The sizes are 1”, 1-1/8” and 1-1/4”. The easiest way to list the pump discharge pressure for a line using this nozzle is to calculate the line using the highest flow tip which is the 1-1/4”. No matter which tip is being used always calculate for the 1-1/4” tip. There is a good chance that the pump operator will not know which tip is being used any way. If a lower tip size is used the flow and nozzle pressure will only increase slightly and still fall within the guidelines for the nozzles capabilities.  Listed below is a chart that reflects this.

 

 

1-1/4” tip  328 GPM

1-1/8” tip  295 GPM

1”tip        260 GPM   

 

Gated Wye Evolutions

 

Using a gated wye on a handline evolution is accomplished the same way as the handline that is put together on the fire scene with a couple of little differences. The friction loss in the feeder line going to the wye is going to be calculated for the total water that is delivered through all the handlines that are connected to the gated wye. For example, let’s say there are two

1-3/4” lines connected to the gated wye with each of them flowing 150 GPM. That means that a total of 300 GPM is going through the feeder line that goes from the engine to the gated wye. Therefore the friction loss calculation will be for 300 GPM. As far as calculating for the small handlines connected to the gated wye, basically the calculation is made for a single line even though there are two or more connected. This holds true whether all the small handlines connected to the wye are equal or not. If they are not equal calculate for the highest pressure line. Here’s an example of what would be on the pump chart.

 

100_0424

Friction Loss For 100‘ Sections Of Hose

 

1-3/4” @ 150 GPM     25 psi

2-1/2” @ 250 GPM     15 psi

2-1/2” @ 300 GPM     20 psi

2-1/2” @ 325 GPM     25 psi

5”     @ 1000 GPM    5 psi

    GPM  100’     200’    300’      400’     500’

2-1/2”   300   20 psi   40 psi   60 psi   80 psi          100 psi

Plus the required pressure for the 1-3/4” hose and the nozzle pressure.

 

Master Stream Operations

 Img_4779FIRERESCUERS

 

First I would like to talk about master stream basics to establish a base of information to so that the method for determining pump discharge pressures can be better understood. 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.

Smooth Bore Tips

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 flowing 2000 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.

 

Now that you have read this information I would like you to keep an open mind about the following information on smooth bore tip operations. At no time does any of the operations in this document break the rules that the manufacturers of all equipment involved have set.

 

One Pump Discharge Pressure With Smooth Bore Tips In Conjunction With Master Streams

 

Master stream operations using smooth bore tips 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 pump discharge pressure for the maximum flow operation with the most common flow being 1000 GPM with a 2” tip at 80 psi NP. With portable and elevated operations this holds true for the supporting discharge evolutions needed to deliver the water to the appliance. 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.

 

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

 

                     1-3/8″ 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        

 

Here is an example of what would be on the pump chart.

 

Portable Master Stream

This Chart Is For All Tip Sizes

GPM          100’   200’          300’    400’     500’

5”   1000 5 psi  10 psi  15 psi  20 psi  25 psi

Plus 80 psi nozzle pressure and 15 psi appliance friction loss

 

High Pressure Smooth Bore Tip Operations

DSC00015

The following operations can be used with fixed, elevated, and portable master stream operations.

 

High pressure smooth bore tip operations have been around for decades however most firefighters have either never heard about it or have been told that it is a counter productive and dangerous operation.

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 firefighting stream itself while still maintaining efficient stream performance.

The maximum allowed nozzle pressure for this type of operation in a fixed, portable or elevated master stream 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.

 

Task Force Tips 200 PSI inlet pressure

Akron Brass 200 PSI inlet pressure

Elkhart Brass 200 PSI inlet pressure

 

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.

1250 GPM  631 lbs. NR

1500 GPM  758 lbs. NR

2000 GPM  1010lbs. NR

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 the elevated and portable mode.

 

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. A high percentage of the time tips up to 1-½” can be pumped up to 200 psi pump discharge pressure

 

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 and the incident.

 

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.


 

1250 GPM Appliance

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

2” tip @ 100 PSI NP = 1189 GPM 628 NR

 

 

2000 GPM Appliance

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 has 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

 2-37

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

180 PSI NP.

 

100_0391 

 

 


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

165 NP     1527 GPM         220′ REACH       1005 NR

  

 

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.


Here is an example of what would be on the pump chart

 

Fixed Master Stream With Smooth Bore Tips

1-3/8”, 1-1/2”, and 1-3/4” tips    200 psi PDP

2” tip                                   140 psi PDP

 

Combination Nozzles

 

The same concept described with the smoothbore tips in regards to pumping the highest flow also applies to combination nozzles as well.

Selectable Gallonage Nozzle

The pump discharge pressure should be established for the highest flow in the flow range of the nozzle. If for whatever reason a lower flow in the flow ranges selected there will only be a slightly elevated nozzle pressure, nozzle reaction, and flow which will be well within the guidelines for the operations.

Fixed Gallonage Nozzle

The pump discharge pressure should be established for the rated flow of the nozzle. If for whatever reason the flow should be less than what the nozzle is rated at the reach of the fire stream will decline. Whether or not the reach will be good enough is based on the actual fire ground scenario.

Automatic Nozzle

For a large flow operation the pump discharge pressure should be established for the highest rated flow. If the flow rate is not achievable the automatic nozzle will adjust its pressure to whatever flow is being delivered while maintaining optimum stream performance.


Building Fire Protection Systems

highrise

A building fire protection system is a plumbing system within a structure designed to deliver water to be used for fire suppression within its confines.

The water supply is provided either by the system water supply, which is plumbed into a municipal water source, or by FD pumping apparatus connected to a water source. The final discharging of the water is accomplished through strategically installed sprinkler heads and/or fire department attack lines via standpipe hose connections.

 

The following information is the basic codes set forth by

N.F.P.A. 14 2010 Edition  outlining pressure limitations for building fire protection systems that have a direct effect on how the fire department delivers water within the structure.

 

 

System hydrostatically tested at no less than 200 psi.

 

For a system pressure of 150 psi or higher the hydrostatic test will be no less than 50 psi higher than the system pressure.

 

The maximum allowed system pressure is no higher than 350 psi.

Express standpipes can exceed 350 psi.

Buildings with a single pump as well as express standpipes for multiple pumps can exceed 350 psi to meet the standards on tall buildings.

 

There are two basic sets of standards that have been put out by NFPA that effect water delivery. The first standard was in place until 1993 and the second standard which is still in place started at 1993. Please note that structures with the Pre 93 standards were not required to upgrade to the Post 93 standards.

PRE 1993 The minimum requirement for water delivery is 500 GPM at 65 psi standpipe residual pressure at the highest standpipe outlet in the system. The pressure restricting device has a minimum allowed residual pressure at the standpipe outlet at of 100 psi. The pressure reducing valve has a maximum static pressure of 175 psi at the standpipe outlet.

POST 1993 The current code requires the same 500 GPM flow but the minimum residual pressure was increased to 100 psi. The pressure restricting device pressure setting of 100 psi is not required and the pressure reducing valve static pressure setting remains at 175 psi.

 

Sprinkler Systems

 

Pump operations for building sprinkler systems are basic. The system itself is rated at 200 psi and the pump discharge pressure for the operation is 150 psi. It is important to remember that the 150 psi needs to be maintained. With the possibility of additional heads activating after the 150 pressure is established, the RPM’s may need to be increased via the throttle to maintain the pressure. Here is an example of what would be on the pump chart.

Sprinkler Systems

Maintain 150 psi.

 

Multi Story Building Fire Protection System With No Building Pump

 

Lowrise building standpipe systems without a system pump, whether they are standpipes only or combination systems, can be found in lowrise structures. These systems can be either wet or dry. If the system is wet it is supplied from municipal water which does not nessacerily provide enough pressure to support handlines. And of course if it is dry the FD pumping apparatus needs to provide all the pressure. It is the responsibility of the FD pumping apparatus to increase the system pressure to the required pressure to support the handlines deployed by the firefighters.

Throughout the years the pump discharge pressure for a system like this was always calculated using fireground hydraulics. Let’s see what the requirements were.

25 psi for the standpipe

 

5 psi for each floor

 

Pressure requirements for the handline which includes friction loss for the hose and the nozzle pressure

 

Friction loss in the lines supplying the FDC from the pumper

 

The following questions must be answered for the formula to work.

 

Does the pump operator know what floor the handline or handlines are connected on?

 

Does the pump operator know how many handlines are being used?

 

Does the pump operator know the makeup of the handline (length, diameter, nozzle pressure, and GPM)?

 

In the real world of firefighting there is a good chance that the poor pump operator will not have all the answers. Additionally, formulas can create answers that will be hard to find on a standard pumper 10 psi increment discharge gauge.

 

The alternative is to pump a maximum pressure, 200 psi.

Here’s why. The 200 psi number is based on the maximum allowed system pressure There is no guessing, the 200 psi gives the firefighters maximum pressure which in turn will provide maximum flow. If the pressure/flow is excessive the firefighter can control it by gating the standpipe outlet valve.

 

There is a good chance that the PDP developed from the hydraulic formula will be close to 200 psi anyway

 

Example

                           EVOLUTION

Three story building with fire on the third floor

150’ of 1-3/4” hose with a 100 psi automatic nozzle  flowing 150 GPM

CALCULATIONS

10 psi for elevation

150 psi for the 1-3/4” handline

25 psi for the standpipe

Negligible for the lines supplying the FDC

Total 185 psi

 

Here is an example of what would be on the pump chart.

 

Standpipe System With No Building Pump

Maintain 200 psi

Multi Story Building fire protection system with a building pump

If the fire department needs to pump the system in a high-rise building, it will have to match the building pump pressure and possibly exceed it.

Explanation: there are one-way check valves located where the FDC enters into the system and after the building pump on the discharge pipe both on the discharge side of the building pump. Because of these one-way check valves, if the pump is running but not doing the job (producing the pressure or GPM) the only way the fire department can enter into the system to take over is to exceed the building pump pressure. Either the building system pressure does the job, or the fire department pumper. As a rule they do not work together. If the building pump is not running there will still be system head pressure up against the check valve that will have to be overcome by the engine companies.

If the building pump should fail to provide the required pressure for whatever reason, the fire department pumper will still have to pump the system as though the fire problem is on the roof Yes, the highest pressure. The reason for this is simple. A building fire pump does not have the capability of controlling its engine pressure over a wide pressure range as would be needed to provide the proper pressure to all the floors in a multi-story building. Therefore, the building pump is designed to pump to the highest point in the building. Because of the potential of high pump pressures in the system, there needs to be a way to reduce the pressure at the lower floors to provide the proper pressure to the handlines. This is done through a different types of pressure regulating devices. The PRV is designed to reduce the building pressure to the proper pressure on the floor it is in service on.

Two Pump Discharge Pressures

After all lines are connected, the system pressure should be determined and the engine pressure of the pumper supplying the system should be set at 50 psi below the system pressure. Setting the FD pumper engine pressure 50 psi below the building system pressure will allow the building pump to stay running and do the job as long as it can. A pressure drop in the system of more than 50 psi is a good indication of a substantial amount of water flowing which in turn is a good indication of a drop in residual pressure that could affect the flow to the handlines. It might also be an indication of pump failure. It’s at this point the FD pumpers should take over the building system.

Once the fire department pumper is set up and pumping its required engine pressure, it should be determined whether or not the pumper is flowing water into the system. At any time the pumper should start flowing water, whether it be initially after the pumper goes into operation or at any time during the incident, or if the firefighters inside request more pressure, immediately PUMP THE SYSTEM PRESSURE.

Below is an example of a supplemental chart listing all building system pressures.

BUILDING FIRE PROTECTION SYSTEM PRESSURES

BUILDING – (ENGINES)

SYSTEM PRESSURE

STARTING ENGINE PRESSURE

 

Allure Condos (3)

330 psi

320 psi

 

Atrium Building (2)

135 psi

85 psi

 

 

Relay Pump Operations

DSC00025

 

Relay pumping is a pump operation that has been with the fire service for years. A relay pump operation is a supply line evolution that is required when there is not enough pressure from the water source to move the required volume of water to the fire through the supply hose. This operation requires a pumper to be connected into the supply line evolution at the water source to boost the pressure in the supply line high enough to move the water to the pumper at the fire. This holds true for long and short distance operations.

 

Developing the required pump discharge pressure is simple. When the units are hooked up and ready to flow water the line is charged under low pressure. Basically treat it like you would charging a supply line from a hydrant. Once the line is charged the pumper at the water source throttles up to an initial pressure to give the receiving pumper enough water to get started. I like starting at about 120 psi. Once the pump operator at the receiving end starts flowing he can communicate to the pump operator at the water source and advise him if more pressure is needed. Here is an example of what the pump chart should look like.

Relay Pump Operation.

Start at 120 psi.

 

The following chart shows how far a single pumper can move specific amounts of water. Based on these statistics a decision can be made on how many pumpers will be needed in a relay. This can also be placed on a pump chart.

4”

  500’                     1400 GPM

1000’              950 GPM

1500’              750 GPM

2000’              650 GPM

2500’              600 GPM

3000’              500 GPM

 

Pump Chart

Friction Loss For 100‘ Sections Of Hose

 

1-3/4” @ 150 GPM     25 psi

2-1/2” @ 250 GPM     15 psi

2-1/2” @ 300 GPM     20 psi

2-1/2” @ 328 GPM     25 psi

5”      @ 1000 GPM    5 psi

 

1-3/4” Preconnect

1-3/4” 150 GPM Handline X 200’ With A TFT Automatic 100 psi Nozzle

150 psi PDP

 

2-1/2” Preconnect

2-1/2” 328 GPM Handline X 200’ with a 1-1/4” Smooth bore 50 psi Nozzle

100 psi PDP

 

Gated Wye

    GPM  100’     200’    300’      400’     500’

2-1/2”   300   20 psi   40 psi   60 psi   80 psi          100 psi

Plus the required pressure for the 1-3/4” hose and the nozzle pressure.

 

2-1/2” Handline Made Up

   GPM   100’     200’    300’      400’         500’

2-1/2”  328    25 psi   50 psi   75 psi   100 psi     125 psi

Plus 50 psi for the nozzle pressure for the 1-1/4” tip

 

Relay Pump Operation.

Start at 120 psi.

Pumper Placement For A Relay Pump Operation

4”

 500’               1400 GPM

1000’              950 GPM

1500’              750 GPM

2000’              650 GPM

2500’              600 GPM

3000’              500 GPM

 

Portable Master Stream

This Chart Is For All Tip Sizes

GPM          100’   200’         300’    400’     500’

5”    1000 5 psi  10 psi  15 psi  20 psi  25 psi

Plus 80 psi nozzle pressure and 15 psi appliance friction loss

 

Automatic Nozzle @ 1000 GPM

140 psi

 

Elevated Stream (Quint)

200 psi

 

 Fixed Master Stream

1-3/8”, 1-1/2”, and 1-3/4” tips    200 psi PDP

2” tip                                   140 psi PDP

 

Sprinkler System

Maintain 150 psi

 

Standpipe System With No Building Pump

Maintain 200 psi

 

Standpipe System With A Building Pump

 

BUILDING FIRE PROTECTION SYSTEM PRESSURES

BUILDING –

SYSTEM PRESSURE

STARTING ENGINE PRESSURE

 

Allure Condos

330 psi

320 psi

 

 

Large Diameter Hose Manifold

Large Diameter

Hose Manifold

100_0043

 

 

Fireground hose evolutions can take many forms, from the very basic LDH supply line with 1-3/4″ attack lines to the extremely complex multi apparatus combination master stream and handline operation. No matter what type of evolution is going to be in operation the goal should be to provide the required flow as safely and efficiently as possible.

 

There are various types of appliances and adapters that are used to put together these evolutions. One appliance in particular that is very useful is the large gated manifold. The large gated manifold is an appliance that distributes water from one LDH supply line on the inlet side to multiple gated outlets on the discharge side.

Manifold designs

Let’s talk about the design of the manifold. Most manifolds are equipped with a pressure dump valve (PDV). Its main purpose is to guard against pressure surges in the system. The PDV valve is connected to the manifold body and expells excess pressure that may be created from a shutdown of a line or overpressurization from the pump. Another function of the PDV allows it to be preset to the potential pressure setting of the discharge lines which in turn helps to come up with an accurate pump discharge pressure(PDP). The PDV is adjusted by actually pumping the required pressure to the PDV/manifold and turning the adjusting bolt on it either clockwise or counter clockwise until just a trickle of water is discharging from the PDV port.

 

There are three basic types of large manifolds.One type has an LDH inlet and wyes off to multiple 2-1/2″ gated discharge ports with the most common being three ports. This manifold is used at the end of the feeder line and supplies multiple discharge lines. The second type of manifold also has an LDH inlet but also has an LDH gated outlet which allows the manifold to be placed inline in an LDH system which in turn allows water to be distributed through its discharge outlets and then sent down the line to another delivery system such as another manifold or engine. It can also be used as a wye and dead ended. The most common manifold of this type has four 2-1/2″ gated outlets. Finally the third type has a large diameter intake and two large diameter gated discharge ports.

Gated Wye Operation

The key to a sucessful gated wye operation with the manifold is two fold. First, it is important not to commit more discharge lines to the manifold than the water supply will allow. For the most part this is not an issue if small attack lines are used. However when you start getting into the higher flows that a 2-1/2″ attack line or other high demanding lines might create, just make sure that the water supply will support it. Because of the multiple outlets on manifolds there is a tendancy to over extend the discharge capabilities. It’s really simple, water in equals water out.

 

Developing The Correct Pump Discharge Pressure

Now let’s talk about a really important issue with the manifold , that is developing the correct PDP for the discharge lines connected to it. When discharge lines are extended from an engine, it is easy to control the pressure on the lines because of the individual valves and gauges that are able to be used. However when these lines are extended hundreds of feet from the engine and supplied from one discharge through one supply line there is only one gauge that can be monitored. This can present a real problem when multiple lines are placed in service. Because of this issue, dialing in multiple lines is more difficult and cannot be expected to be as accurate as it would be if directly connected to an engine. The goal should be to provide as close to the required flow as possible and in a safe manner.

 

The first thing that needs to be done to establish the PDP is to come up with the dimensions of the line that the PDP will be calculated from. This can obviously be different from incident to incident. Establish a common line that will most likely be used a high percentage of the time for the purpose of creating a starting point for the pump operator to get water flowing. I like to use a 200′ line simply because in most cases it will be long enough to reach the fire. The next step is to preset the PDV on the manifold to the pressure. Since there is the chance of having 1-3/4″ and 2-1/2″ handlines from one manifold as well as other types of discharge lines, the goal is to come up with one pressure that will safely flow all types of lines. More than likely the individual lines will not be 100% accurate. We are looking for ballpark flows that will provide a required flow safely.

 

Here is an example of three types of discharge lines that could be on one manifold. First, a 150 GPM combination nozzle and 15/16″ smooth bore tip combined into a break apart nozzle with a nozzle pressure of 50 psi and a friction loss of 35 psi per 100′ of 1-3/4″ hose. Second, a 250 GPM combination nozzle with a nozzle pressure of 50 psi and a 1-1/8″ smooth bore tip both used on 2-1/2″ hose with a nozzle pressure of 50 psi with a friction loss of 15 psi per 100′ of hose. Finally, a Mercury portable master stream flowing 500 GPM using 3″ hose with a 1-1/2″ tip at 55 psi nozzle pressure with a friction loss of 20 per 100′ of 3″ hose. In this case the target pressure on the PDV should be set at 120 psi. Here’s the reasoning behind this pressure. The 1-3/4″ hose at 200′ actually calculates out to 120 psi. This is probably the most important line to keep to the flow and pressure requirements. With the 2-1/2″ handline calculating out to 80 psi and the Mercury master stream calculating out to 90 psi based on the 120 psi pressure setting ,they will be over pumped creating a higher flow and nozzle pressure. Flow tests can evaluate whether or not this is an issue but in this particular situation I think you will find that it will not be a problem. It’s one pressure does all.

 

The purpose for setting it at the required pressure for the handlines is to be an indicator to the firefighters from its activation that the correct pressure at the manifold has been obtained.

 

With the PDV being preset, the pump operator simply throttles up to the set pressure on the manifold and through communication with the firefighters at the valve slowly continue increasing the pressure until the PDV starts to activate.

Now let’s say that the lines attached to the manifold are going to be longer than 200′. A simple friction loss chart can indicate what the new PDV setting should be allowing the PDP and PDV to be readjusted accordingly.

 

LV Training Center 03-07-09 035 - Copy 2-34

Supplying multiple handlines

 

Inline operations

When the manifold is used in an inline operation to support discharge lines as well as sending the remaining water on through the hose evolution, the PDV concept of calculating the PDP will not work.The reason for this is that the PDP has to be able to provide the required flow for the entire operation which could include a number of different operations through multiple manifolds and/or engines being used. There is only one accurate way to establish the PDP for the discharge lines. An inline pressure gauge can be placed between the discharge port of the manifold and the discharge line to read the required pressure for the line. This will allow the valve controlling the line to be gated down accordingly. This requires adding additional gauges to the manifold since they are not provided from the manufacturer. The other option is to gate the line down by the feel of the nozzle reaction on the handline itself. An experienced firefighter should have a feel of what a particular line should feel like at the required flow.This would be able to create a safe operating situation and although it might not be 100% accurate it should be close enough.

 

S4300015

Used in an inline operation

 

 

A common water supply problem that can develop happens when a large flow multi company operation is created. What usually happens is the first few units placed in service grab the closest hydrants for their water supply.

There is a real good chance that some if not all of these hydrants could be on the same main thus drawing down the available water from each other. Oftentimes these units are in place to attack the fire and have the available hose, appliances, and personnel to get the job done. The initial attack gets started but eventually gets stifled due to a dwindling water supply.These units are already flowing water and in most cases only need a little bit more to accomplish their goal. This is where a relay pump operation comes into play.

 

A traditional relay pump operation only delivers water to one pumper. There is a good possibility that the receiving pumper will have water left over from the relay, especially if it already has its own supply line,.and will not be able to share it. This is when a relay/manifold operation can be put into place to supplement units on scene. The manifold allows for multiple supply lines to be connected supplementing units hopefully with the balance of water that they need.

 

Don’t be fooled by the 2-1/2″ outlets on the manifold thinking that it will restrict the water delivery capabilities. Yes, the 2-1/2″ is more restrictive than a larger 5″ outlet but it is possible to move enough water through the 2-1/2″port to make it work. The key to this operation is to use the same diameter hose to supply the engines. The reason for this is that water follows the path of least resistance. So if you have a large diameter hose and a small diameter hose, more water is going to move through the larger making for an unbalanced delivery.

 

When the pumper suppling the relay makes its hookup at the hydrant a minimum of two LDH lines should be used to get maximum flow. The pumper should plan on throttling up to the maximum allowed pressure if possible.

 

After the relay/manifold operation is set up the PDV can be readjusted to the proper setting which is indicated when just a trickle of water is coming from the PDV port.

100_0128

 

Suppling water to multiple engines using the same diameter supply lines

 

The large manifold is a tool that will probably not be used that much. However, if the situation should arise, and it will at some point, the manifold will prove itself as a water distribution appliance worth its weight in gold.

Deploying the Blitz Attack From Tank Water

Deploying the Blitz Attack From Tank Water

FirehoseFinal_edited

          This article 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.

The most common initial hose evolution that most departments use when they are facing a threatening fire on tank water is to pull a small handline, 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 the scientific statistics about 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 what needs to be done? 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 or at least diminish the fire problem as quick as possible.

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.. 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.

Blitz Attack4 Blitz Attack Blitz Attack3 Blitz Attack7

 

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 cavitating 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. The 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 handlines. More than likely if a high flow handline 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.

13 100_0065

 

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.

Blitz Fire

500 GPM delivered from the Minis

 

In closing, moving quick to stop a fire is the name of the game. The data offered in this article illustrates a quick attack method that has been proven time and time again. A tank water blitz attack involves strict coordination between the crew members as well as other units involved with the operation, and if done correctly can stop fire progression dead in its tracks. It is very important that crews train in this type of operation to insure that its implementation is successful.