Whats in a Photo?

We know what happened here-but we don't know why, its not our photo.

There are dozens of firefighting web blogs and Facebook pages on the internet, many of them are incredible sources of information, and present diverse and thought provoking topics, photos and questions.  Each sites owner(s) have a style, its what makes them all unique.  This site has a style too, its pretty simple.  Most of our stuff is ours.  We post photos, videos and information that we have personally been involved in.  We like to share photos and videos from other major sites, that might present some interesting perspectives, but the majority of our content comes from our site contributors.

Why does it matter, you may ask?  Take a look at some of the sites out there, the sites that grab one of your photos and ask the world how they would have handled the operation.  How can you moderate the discussion objectively if you cannot speak for the events that took place during that situation which is depicted in the photo?  Its hard to do, everyone should agree on that.  By posting our own photos and videos, its easier to address questions, comments or concerns, when we have access to the people involved, to understand their thought processes in those moments.

the driver of this engine quickly rectified the kinked supply line

So brings the question; is it OK to use other photos and videos as food for a discussion?  I think the answer is a conditional yes.  We have to remember how many variables exist that we cannot fairly identify.  We also need to remember how small of a time window exists when a photo is snapped.  It makes it somewhat of a double edged sword to use any photo as a focal point for discussion, but at the same time, we need to be able to fuel our critical decision making skills and gain insights and feedback from others.

We will always make an effort to post photos tat we can explain and articulate.  In cases where we find a photo or content from other sites that we find interesting and informative, we will share it here and indicate such.  We enjoy the constructive nature of everyone's feedback, its made the site very easy to moderate and administer.  Than you for your continued contributions.

Protect Yourself From Potential Failure of the Devices that are Supposed to Protect You

Large diameter appliances and externally mounted relief valves are found on many rigs.  These devices are critical for safe operation when working with high volume large diameter hose.  An often overlooked issue, is the testing of the relief valves on these appliances.  An improperly adjusted relief valve can lead to a few dangerous issues including but not limited to;

• Burst supply hose due to hose service pressure below the relief valve pressure (Supply grade LDH-200 PSI)
• Failure to open in an overpressure
• Opening at too low of a pressure and dumping critical water, which may be a nuisance, or cause icing.

Some hose testing companies offer appliance testing, but many do not.  For departments that conduct hose testing,  these appliances should be tested along with your hose, at least annually, with the consideration given to more frequently.  Kochek, a large manufacturer, recommends every 6 months.

Here are two links that reinforce the necessity for testing of the appliances;

http://www.state.nj.us/dca/divisions/dfs/reports/hampton_township_ff_Injury_rpt.pdf

http://www.chenangofireems.com/uploads/files/Manifold%20Failure%20Test%20Report.pdf

This is the result of an appliance failure.  Courtesy Lambertville, NJ FD

In both of the previous reports, it was fortunate that there were no fatalities.  Be cautions around these appliances, at all times, not just when testing them.

Testing isn't to be taken lightly.  Any time you are service testing equipment, you should expect it to fail, that is, to take the proper precautions to prevent injury and damage.  Proper head, eye, body and foot protection are a must.  Following appropriate testing standards is another important consideration.

NFPA 1962 recommends testing of appliances to the manufacturers standards.  Kochek happens to offer a guide for doing just such a test.  It can be found here; http://www.kochek.com/docs/PressRelief_Valv_%20TestProc_Web.pdf  Within the 1962 document, there lacks substantial step by step guidance, but rather it has general recommendations.  The document can be viewed at www.nfpa.org

When you raise the throttle, the gauge will "pop" when the relief dump valve on the appliance opens and should not rise above that as the pump pressure continues to rise.

Testing these appliances can be done in house, if you follow the above recommended guidance.  A few points to note are as follows;

• Expect a catastrophic failure of an appliance.  If the appliance has ever been dropped or damaged, and not inspected, it should be removed from service and checked by a qualified professional, to include x-ray inspection of applicable.  Invisible manufacturing flaws may not be evident, use care.
  
• It is a good idea to attach the appliance being tested to a section of hose to move it away from the rig and personnel prior to testing.  CAUTION:  Check the service pressure of the hose you are using, and do not exceed it.  This means that standard supply grade LDH (single jacket rubber type) will not be sufficient for testing over 200 PSI.
  
• Inspect the devices for any obvious corrosion or deficiencies prior to testing.
• ALWAYS consult the manufacturer for their recommended testing and the rating of the appliance being tested.
• Air trapped in appliances represents greater stored energy potential, and if not bled can cause a more catastrophic failure if such were to occur.

Bleed the air from each discharge at idle before pressurizing the valve.  With the pump discharge barely opened, a small stream of water is all that should be exiting when you crack the valves.  Once you close the valves on the appliance, the water pressure inside the appliance will increase slowly as the low volume of water from the discharge comes up to pressure.

The relief dump valve has opened properly here.  Take note that on manifolds such as this, the relief valve only protects the appliance with the valves in the closed position when it is used as a DISCHARGE manifold (Supplied from the single inlet side), not in reverse, being fed by several lines.  Also, note the allen wrench in the relief valve set screw used to adjust through its range.

Test the air bleeder on intake valves.  Bleed the air out at idle before pressurizing the valve.

If you test the appliance connected to the rig, do not connect it to the same side as the operators panel where you will be standing.

Many newer apparatus have intake relief valves which must be periodically tested/adjusted as well.  In this photo, the relief valve is to the right, attached to the bronze port on the butterfly valve body.  The relief dump opening is seen underneath it, as a threaded port facing downward.

Built in intake valves often have their own individual relieve valves.  Hale Master Intake and Waterous Monarch, to name two, will likely have these.  They must be tested according to the manufacturers specifications, which will require water being pumped to the intakes from another rig or a testing pump.  In addition, many pumps will have an additional relief valve attached to the suction/intake side of the pump. which needs to be tested.

Whether you test these valves in house, or have a vendor perform the testing, it is critical to have it done at the manufacturer recommended intervals and to follow their procedures.

Do You REALLY Want Them to Learn Something...?

An instructor or company officer has a duty to the student/firefighter in training to assure that the concept being taught is understood.  How do you accomplish this?  In the world of engine company operations, consider that the use of gauges and flow meters may have a MUCH greater impact on learning than trying to sit in a classroom and crunching numbers on notepads.  Check out some of these photos to see how this concept is applied in training evolutions.

The most important thing you must do before you use the equipment is connect with the students/members; a little tailgate talk assures that everyone is on the same page.

A handheld pitot tube is a must have for engine company training

A properly calibrated portable flowmeter goes a long way proving and disproving hydraulic concepts

Want to teach the principle of elevation loss....take a pitot tube into the air and have the operator raise and lower the ladder to show the change in readings

Aerial inlet gauges compared to a pitot or gauge reading at the tip will help show pressure loss in the piping and elevation loss

Using a handheld Pitot to verify wagon pipe flows

A nozzle test rack is a great tool.  To check flows of combination nozzles, inline gauges at the inlet compared to the pump panel gauge will illustrate pressure loss in the hose.  The proof is in seeing it!

A Flow test tube (Fixed Pitot) is a great way to show the performance/limitations of a relay pumping operation

Make idle time a learning time, attaching a gauge to the hydrant will show the water system pressure at different stages of the operation. 

Foam systems with flowmeters are a valuable teaching tool if they are calibrated and understood.  This test was utilizing the front suction, flowing 1035 GPM.

Don't forget the trusty gauge.  See the differences between the main pump gauge and the line gauge.  50 PSI Vs. 120 PSI.  This shows a 70 PSI loss in the rigs piping,  This is flowing to a rear step discharge.

Properly anchored, unmanned deluge sets are one of the safest ways to provide flows and test them during pump operator training.  This reduces the chances of personal injury that are greater when manned hoselines are used.

A deluge set adapted to receive 2 1/2" or 1 3/4" hose is used to teach handline pump pressures.  This eliminates the need for members to man hoselines and be exposed to the potential for injury.  The operators practice pump pressures for either diameter of hose, not both.  The results are checked with a pitot tube, inline gauge or flowmeter.

Evolution and Technology Change the Rules for Length of Foam Lines

I was asked, the other day, whats the longest hose lay you can use when operating with a foam injection system.  This question is born from the use of truck mounted bypass eductor systems, where there was a maximum efficient hose lay to allow the eductor to properly pick up the foam concentrate.  The bypass eductor systems required that the correct nozzle be used and that it be open fully, the correct size/length of hose and maximum elevation limitations to properly function.  It could become quite the balancing act. 

The answer to the question of how long of a hose lay you can have with an injected foam system is pretty much unlimited, with the parameters of the system maximum capacities.

Foam Injection Systems

Hale 3.3 System Capacities

Let's use Hale's Foamlogix as an example.  The system uses a foam pump to inject concentrate into a water/foam manifold, where it then provides that foam solution to the discharges that are supplied by that manifold.  The foam capable discharges will be marked as such on the pump panel.  Its also important to remember that the foam system capacity is cumulative for all of the foam capable discharges.  Before we proceed, lets take a look at the maximum capacities of a 3.3 Foamlogix system.

By the data supplied on this plate, we can deduct two important things that relate to total water flow (with foam) capability.  The maximum working pressure of 400 PSI and maximum water flow of 1250 GPM are the two major factors that lead us to the answer of how far we can pump the foam. FoamPro lists similar capacities below.

FoamPro Specs-Courtesy FoamPro

Courtesy of Hale

The other information we need to know is what is the maximum water/foam flow at each percentage.  because the foam pump can only supply 3.3 GPM of concentrate, there are limitations on the total flow it can produce.  For this 3.3 model system, the chart to the right shows the maximum water flow for the chosen foam percentage.  To accomplish this, the system meters water flow and communicates with the foam pump to meter the appropriate amount of concentrate to maintain the foam percentage.  As a sidebar, the best way to take advantage of the capabilities and limitations of a foam injection system when using class B foam is to use lower percentage foam (higher concentration).  1% or 1%/3% foam provides the capability for higher total water flow.  Compare the differences between the 3.3 and 5.0 systems.  The 5.0 system uses a 5 GPM foam pump.

A Bit About Eductors

A simple 125 GPM inline eductor.

 Anyone who's used a truck mounted bypass eductor system will remember the rule of no more than 150ft of hose, or in some cases 200'.  These distances also apply when using portable foam eductors.  Many departments also used red hose on that foam crosslay/preconnect, to make it more apparent that it was the foam line.  Lets take a step back and see where the old distance rules came from.

Most eductors require 200 PSI at the inlet in order to properly create the foam.  The flow of water through a small orafice in the eductor into a larger chamber within it results in a low pressure zone, which draws foam concentrate up the pickup tube and mixes it into the water stream.  The proper pickup of foam concentrate is also influenced by backpressure on the eductor.

Backpressure can be caused by;

• Pressure (friction) loss in the hose.  The distance you can pump beyond the eductor is based largely on the water flow.  This is where basic hydraulics comes back into play.
• The nozzle.  The nozzle creates backpressure by design, this is how we create a useful fire stream.  A nozzle, not opened all the way will create too much backpressure, reducing the efficiency of the foam operation
• Elevation.  Head pressure will create backpressure that will deteriorate the foam operation.

Eductors can use about 65 percent of the inlet pressure on the outlet side.  What this translates to is a maximum discharge pressure of 130 PSI  on the outlet of the eductor before the foam concentrate flow is compromised.  Using an inline gauge on the outlet of the eductor can monitor this, but the information is easy to figure out beforehand.  If you consider the maximum outlet pressure from the eductor is like a maximum pump pressure, then the following chart illustrates the maximum hose lays when using eductors.

Courtesy Akron Brass Corp.

You may note the 150' and 200' hose lays in the first column, when used with 3%/6% concentrate, as it was one of the most common types of ATC/AR foam types used.  Confusing, maybe a little, but planning ahead of time and marking the pump panel can eliminate any confusion.

Tying it Together

Does it seem like we went way off tangent? Perhaps, but it provides the basis from which we got the old rule of thumb for the maximum hose lay with foam systems.  Now that we are seeing more foam injection systems, this hose lay rule doesn't apply the same way, because the required balance of hose length, nozzle, elevation isn't at all similar.  We previously mentioned the maximum capabilities of a Hale system.  Lets see how that translates to real world terms.

If the maximum pressure of the system is 400 PSI, and we are operating a 100 PSI nozzle, we can use the remaining 300 PSI to account for pressure loss in the hose and any elevation loss.  Keep in mind, 400 PSI is an extreme pump pressure, and it might be more realistic to shoot for a maximum pressure lower than this.  Factoring your maximum hose length is probably better done at a maximum of 250 PSI, as any pressure in a hoseline greater than that will be arguably dangerous and difficult to manage (very rigid) when the water is not flowing.  The point here, is to illustrate how to deduct the maximum working length of a hose line when using an injected foam system.  Using the maximum capacity of the system (400 PSI) we can determine the following;

• A 95 GPM foam line can be run about 2100 feet, using a 100 PSI nozzle.  The system capacities will limit the maximum foam percentage to 3% at 110 GPM, so for round numbers (since 95 and 110 are pretty close) your 3% foam can be pumped about 2100 feet in 1 3/4" Hose.  If we switched to 2" hose, the distance increases to 4200 feet.  Using 1 1/2" hose, the maximum distance is 1350 feet.  If your nozzle is a low pressure fog or smooth bore (50 or 75 PSI tip pressure, the distance will be greater).

To arrive at the answer to this question, when using a foam injection system, consider this simple formula;

MD=MSP-NP-FL-EL

MD is Maximum distance

MSP is Maximum System Pressure (Replace with 250 PSI for more realistic flows)

NP is nozzle pressure

FL is fricton loss (for the flow you have chosen)

EL is elevation loss

To truly know the maximum distance, you should consider the maximum flow you will use at each percentage of foam (typically .5, 1, 3 and 6%) and find the friction loss value on a chart to insert that number into the equation.  Because most nozzles are set to predetermined flows (except for automatic nozzles), using predetermined friction loss values for flows such as  95, 125, 150, 180, 200 GPM makes that part of the equation easy to determine.  You will just need to verify your desired flow is within the range of the foam system.

The short and scientific answer here is....

You can go WAY FURTHER than 150 or 200 feet from the rig when using an injected foam system!

Apparatus mounted bypass eductor systems are still an option today, but they limit your foam flow to one discharge and also have top end flow restrictions that are lower than larger injection pump systems.  Understanding the system you have is critical, before you can determine how to best utilize it.

Read the owners manual for your foam system to learn its capabilities.  Links to major manufacturers are below.

Akron: www.akronbrass.com

Hale: www.haleproducts.com

FoamPro: www.foampro.com

Waterous: www.waterousco.com

Pierce: www.pierceparts.com or www.piercemfg.com

Managing the Transition...

Making the transition from operating off the booster tank on your rig to receiving a supply from a pressurized source; such as a hydrant or nurse tanker, can be a careful balancing act. Preventing over pressure to the attack lines is possible with proper technique and equipment, but there is one situation where pressure relief protection will not work.

The two primary means to control the desired discharge pressure during the transition are the discharge relief valve and the electronic pressure governor.

A Hale TPM Model Discharge Relief Valve Control

Discharge relief valves monitor pressure on the discharge side of the pump by use of a pilot valve/sensing chamber. When the hand wheel or crank is set, any spike in pressure causes the actual valve to open, resulting in the flow of water back to the intake manifold in the pump or dumping it to the ground. This is how the system attempts to relieve the over pressure condition. Discharge relief valves require a differential between intake and discharge pressures. This differential can be from about 25-50 PSI. At high flows, it is possible to overtake the relief capacity of a discharge relief valve.

Many new rigs come with electronic pressure governors, which work well when functioning within their design parameters. These devices use a pressure sensor ( transducer) on the discharge side of the main pump to adjust engine throttle, thereby maintaining the desired pump pressure. This is accomplished in the "PSI" or "pressure" mode. When the sensor detects the increasing pressure as you open the intake, it will progressively ramp the engine down until it reaches idle. Herein lies the problem.



Fire Research Electronic Pressure Governor



Many departments run smooth bore or low pressure nozzles. These nozzles, coupled with high performance attack hose can result in pump pressures below 100 psi. For example, a 200' 2" preconnect with a 15/16" tip will have a pump pressure of approx 90 PSI. If the incoming pressure is over 90 PSI, the governor cannot lower the engine RPM enough to alleviate the pressure surge. Correspondingly, there fails to exist enough differential between pressures for a standard discharge relief valve to work. In fact, since the discharge pressure is lower than the intake pressure, neither pressure protection device will work, and the line(s) will be over pressurized, unless you anticipate and take additional action.

In the example we just reviewed, you must prepare to gate back the discharge(s) as you make the transition. With a situation where incoming pressure is higher than outgoing pressure, there is no other way to deal with the over pressure to the line(s).

You have little control over this when operating from hydrants, but you do if operating from tanker nurse. The best option is to have the tanker driver start pumping to you at 50 PSI when being nurse fed.

As you can see, having an extra hand can be necessary. You must prepare to gate back the discharges when making the transition in the event the pressure protection devices cannot work as intended. As a final note, always make the transition SLOWLY!

Stay Sharp on the Highways

Complacency on the highways is commonplace, watch these videos for some refreshers on the dangers and how to protect yourselves

Electrical Safety-Videos

take a look at the following videos for some insight on fireground electrical safety. 

We deal with electrical issues on a routine basis, stay aware and be safe

Fire Sprinkler Systems-Overview

Here is a short video that reviews the basic principles of wet and dry fire sprinkler systems.  While somewhat dry, understanding these systems is critical.

How many runs do you go on that involve automatic alarms and sprinklers?

Stay tuned for additional articles and videos discussing suppression systems.

Communications Drill-With Video

If you ever need to do a drill that doesn't require alot of preparation and is simple to conduct, can be done indoors and has a positive impact on your members, this might be a concept to consider.

The drill can be conducted using a number of principles.  We chose to do C.A.N. reports, MAYDAY messages and L.U.N.A.R. Reports, with the emphasis strictly on clear and effective communications.  To add realism and reinforce the need for brief and clear messages, we will create realistic background noises and distractions.  Some ideas for these distractions include, but are not limited to;

• Smoke alarm activating
• Low air alarm sounding
• Power saw operating
• Member striking Halligan with sledge or axe (simulate forcible entry)
• Water flowing from nozzle and striking walls and ceilings or ground nearby
• Vent Fan blowing air
• PASS Alarm activated
• Recorded fireground audio clips played at heightened volume (YouTube)
• Pump engaged at high RPM

The noises are intended to be characteristic of actual fireground chaos and sounds.  However you accomplish this isn't as relevant as the idea that you need to create something legitimate and effective.


Two to four members will go during each evolution.  One member will act as the "officer/IC" while one will operate as the firefighter or officer issuing the radio report(s).  An additional firefighter or two may need to assist with creating the background distractions.  Members who will be issuing the report need fire gloves, a radio (worn in whatever manner they will wear it during firefighting operations) and an SCBA with mask.

Preparation for the drill is fairly simple and includes the following;

• Create "Scenario Cards" which will give the member issuing the report some basic information on the situation they are in.  Make sure the info is brief but includes anything that would be pertinent to the type of report they are going to give.  The cards are not intended to be read, but rather to create a mental image.  You may opt to include a photo as well, of an actual incident/situation.
• Set up the area where the report will be issued from.  Whatever you intend to use to create the different noises must be set up in this location.  Based on the variety of options, the location you choose may be anything from an office with a computer you can play audio footage to the outside wall of the firehouse where you might opt to spray a hose stream to make noise.
• Have the member giving the report don the SCBA and Mask and report to the location
• Provide the "officer" that will receive the report with a notepad and pen along with a radio.
• Assure the radio is operating on a private/non-emergency channel.  If any doubt exists, notify your communications center at the start and end of the drill that you are doing training and advise what channel is being used.
• Initiate the exercise, and if possible, record the radio traffic to replay for both members to listen to and confer about afterwards.
• After the "IC/Officer" indicates that the report is understood and has verified it with the other member, terminate the evolution and bring everyone in to discuss the exchange.  Play the audio back first, before any discussion.  Discuss the length of time it takes for the report(s).

The scenario cards are intended to give a brief, bullet point overview.  Not to be read over the radio

Acronym cheat sheets are good for the first few runs, but take them away later in the drill

The drill will conclude when the two members participating feel that the report is understood between themselves.  The end goal is a very brief transaction.  Expect there to be hiccups and speed bumps in the beginning.  Practice the scenarios over and over. Discuss the elements of the different reports you are covering.  Assure that everyone understands the intent of each evolution.  Members may find that they need to adjust how they carry their radios, how they talk (volume, rate) or how they try to explain it.

This is just another company drill idea, it has a lot of flexibility and allows you to craft scenarios that are based on situations your company would encounter.  It fosters radio confidence, strengthens communications skills and gives the participants the opportunity to experience the situation being simulated in a controlled but fairly realistic environment.

Stay safe and train often and realistically!

TFT Nozzle Test

Video from a nozzle test we did today

Isn't Your Life Worth More Than a Stupid Candy Bar Wrapper?

When you choose a nozzle, many factors go into this critical decision, or at least they should.

One major manufacturer of nozzles offers an option to prevent debris from fouling their automatic nozzle tips.  The screen that they offer, is typically found at the nozzle inlet, behind the bale.  In the break-apart models it is located at the inlet of the fog tip, ahead of the bale.  the screen prevents larger debris that cannot be passed through the nozzle on the flush setting from fouling the nozzle.  Theres a catch though....we have vandals on the prowl....



this kid has too much free time, so he thinks it would be funny to stick a candy bar wrapper in the standpipe outlet.  Here, we use the gated wye attached to a flow tube, it serves the purpose just as well.



The water flows, at 162 GPM.  A nice stream forms at the nozzle, if you bleed your nozzle too quick, you'll never know whats about to happen as you step over the threshold of the door to the fire floor.

...and then, boom, catastrophic failure of the stream.  This is from, a stupid candy bar wrapper....that's it.

The nozzleman is armed with a breakapart automatic nozzle, the smooth bore slug tip is 15/16"  He is quick to see the potential issue and you see the result above.

Is this possibility realistic?  You tell me?

Another test shows that trying the flush doesn't have any effect.

Don't die for a candy bar wrapper, buy the right equipment and know how the equipment you have works.  This nozzle works very well, if you use it properly in the right applications.

Thanks to the Richmond, Virginia Fire Department for planting the seed that led to this experiment.  Oddly, our nozzleman just happens to be wearing one of their hats!

Standpipes and Gated Wyes

Today, we conducted a brief experiment to determine the pressure loss in a 2 1/2" x 1 1/2" gated wye when the use of 2 1/2" hose is desired. A 20' section of 2 1/2" hose was attached to the flow tube on the fire hydrant. We used adapters in place of a bushing on the outlet of the wye with the following results;

With gated wye. 1 1/8" tip, 250 GPM. The flow was verified with a flow meter and handheld pitot gauge. Pressure at hydrant was 83 PSI. Tip pressure 50 PSI. Pressure loss was 33 PSI

Without gated wye. Same tip, same flow. Pressure at hydrant was between 48 and 50 PSI with corresponding tip pressure readings, meaning the pressure loss was negligible without the wye.

Assume a loss of 25 to 30 PSI through the valve with a setup like this. As you can see, the old 10 PSI loss is a big underestimate here.