TWO INCH ATTACK HOSE - IT WAS ALWAYS MISUNDERSTOOD!
In the 1970’s the American fire service was looking to up its game especially in the area of
structural fire attack. It was a time when
many fire departments were engaged heavily with daily working fires – and many
large scale fires, too. Fires were attacked aggressively by firefighters
wearing styles of turnout gear not seen today. Tall rubber boots or heavy work
shoes, turnout coats made of cotton or rubber, rubber or canvas gloves that did
not have liner systems and helmets without impact caps or earlaps was usually
worn. Hoods were non-existent.
Liners in turnout coats might have been an old army
field-jacket or something similar. Oh, yes, sometimes firefighters didn’t wear a
turnout coat – only what some felt was comfortable for the job at the time!
Looking back at those times (sometimes referred to as the
“War Years or the “Battle Years”), and comparing the equipment and personal
protection worn by firefighters to gear standards today, firefighters performed
the impossible with what was available.
Fire fighters, through their respective fraternal
organizations ( IE: Int’l Assoc. of Fire Fighters – (IAFF), Int’l Assoc. of Fire
Chiefs (IAFC)) and other agencies were looking for safer and more effective
fire control equipment, procedures and better personal protection. Research and
field-testing of turnout gear and station wear was done by a joint venture of
these two unions along with the NFPA and others. The effort was called “Project FIRES” and the goal was to find
workable ensembles of turnouts and clothing from the study of actual conditions
and physiology – yes, that’s right! It was finding what could protect us and
not hurt us.
Yes, back then you trained with SCBA but they were heavy and
cumbersome. Thankfully our old SCBA became the focus of research which was
looking for better breathing apparatus for firefighters, as part of the ensemble. NASA was involved and helped
with this work. The old devices were bulky and hard to breathe from as they were
“demand” type systems - where you had to
inhale to get any air- meaning they were NOT positive pressure, and the liter
flow was likely very low and not enough to keep you going! It was not uncommon
at a working fire to hear low pressure alarms sporadically ringing short
signals because the users’ demand for air was more than the SCBA regulator
could supply. Firefighters would take them off as soon as they could in many
cases.
Fortunately, many saw the wisdom of better turnout gear and
personal protection for firefighters. Over time the firefighter protective
ensemble or “envelope” has morphed into what it is today. I have said it many
times before in classes and conferences that right now the American fire
fighter is the ‘best protected’ than at
any time in the history of firefighting. In fact, many senior members will say today’s
firefighter is maybe too protected so the wearer cannot recognize the
environment they might be in.
This was also a time when some of the old ‘disciplines’ or ways
of doing the job were taught and expected to be executed on the fire ground –
like truck work and ventilation skills to complement fire attack - as it should still be.
Sadly, some American fire departments began to see
firefighter layoffs, resulting in fire force reductions and other problems. It
was also a time when some of the basics of firefighting started slipping away.
FIRE ATTACK &
EXTINGUISHMENT MECHANISMS
“Put the fire out and
everything gets better!” Andy
Fredericks
While all this and more was taking place in our profession,
fire attack efforts were being looked at for better water delivery. Back then
we knew the fire environment was changing. One of the things looked at was the
growing use of synthetics and other materials that contained hydrocarbons or
similar things. Firefighters were smoke
eaters and the “newer” fires weren’t the same as in the past. Something was
different, and it wasn’t anything friendly. The realization then, was the same
as now – that fires were burning hotter, faster and creating heavier, more
dense toxic smoke than fires that were purely class A – wood, cotton or other
ordinary combustibles.
Yes, it was realized that more water was necessary for aggressive
extinguishment. Along with that came the need for less stress for firefighters
moving hose lines into burning buildings. But also then as now, it was
necessary to understand that each size attack hose line has a point where they
are no longer effective for fire control and a bigger line and a greater flow
is necessary. That point was somewhat lost over time because of people who
thought automatic or other types of nozzles would allow smaller hose lines to
match the flows of larger ones.
In the past, the fire
service focused on three sizes of fire attack hose lines – Booster (3/4 and 1
inch ) 1 ½ inch and 2 ½ inch. Each size has/had its
own capabilities and limitations and for many decades it was the norm to see those
lines on the job. (NOTE: Interestingly, you could go to a major fire somewhere
and maybe see all three sizes stretched
- and maybe abandoned, while the big guns were working. This was
jokingly called “progressive firefighting” as fire departments would sometimes
initially stretch small hose lines that were too small for the initial attack.
After being pushed back by the fire, firefighters would stretch the next size
bigger and repeat the scenario until they ran out of hose options and had to resort
to master stream equipment – or maybe not! A lot of buildings were lost because
of that thinking. Some of those hose line choices no doubt were predicated from
the old belief that a little water goes along way when it turns to steam,
expands and snuffs out the fire!!!
It all sounded good on the drill ground and in the security
of the class room. Of course that type of attack is supposed to be used in a
confined space or hold of a ship! The sales people made fog sound great when
trying to sell you an automatic or other fog nozzle. Just remember, it takes
GPM’s - NOT micro-scopic droplets of
water in small amounts to overpower a fire.
It was also noted in
some circles that the use of fog and its confinement for structural fire attack
set the cause for ventilation back decades in many fire departments.
Today, there are studies and research being conducted and we
see people trying to make a science out of fire fighting. It is not! Perhaps some
people are looking for recognition trying to satisfy their ego and be able to
give the gospel of fire according to themselves. How very wrong because instead
of working to learn / teach principles and practices they are confusing many
and causing unnecessary controversy between what is right and / or wrong about
fire fighting.
THE MOVEMENT BEGINS
Going back into the 1960’s the FDNY started employing RAPID
WATER combined with 1 ¾ inch hose and a 15/16 inch solid tip nozzle. Simply
put, it was system on an engine that employed a device to dispense a friction
reducing agent into pump outlets which allowed greater water flows through
smaller hoses and nozzles. The goal was
to get more water on the fire and minimize weight and hose management stress. Some
departments followed suit and bought into the idea but over time, things like
operational costs, maintenance and reduction in fire activity no longer
warranted the need for it. Many things were researched and tried in the field.
Some lasted some did not. But please never let it be said the fire service is
stagnant and not forward looking.
As different ways of delivering more water were tried, it
paved the way for many different ideas on how we could do it and what tools (
Hose and nozzles ) would be needed. Starting in the 70’s and 80’s many
departments began researching ways to increase their water delivery and some of
the changes were smart and well thought out.
Some departments went for changes in their fire attack
systems and switched hose sizes from “small to big” and “big to small. That may
sound funny or strange but briefly, what happened for example, is some departments moved away from 1 ½ inch
attack hose in favor of 1 ¾ inch attack hose as their primary attack hose
lines, which I think we can agree is a good move in the right direction. One
and three quarter inch hose with a low pressure solid bore or constant
gallonage nozzle makes a great interior attack line with good target flow and
mobility. It is able to handle a good body of fire in a structure when properly
handled. It has excellent use in other firefighting applications such as for
rubbish, vehicles, and other fires and foam hand lines
Interestingly, as this hose was mainly intended for interior
structural operations, it was getting used for vehicles, rubbish and other
fires and then began getting stretched for large structural fires.
It is not and has never been intended to be a heavy hand
line for large scale offensive/defensive fire operations. Its stream does not
have the reach or volume required in those situations. An article written by a
Chicago fire officer noted how the 1 ¾ inch hose line had grown to become the
“booster line” of the 90’s meaning it was used by some departments for
everything and for ridiculous reasons. It is a telling tale when a fire
department uses this size hose line for defensive operations at a major fire.
Another mistake or misunderstanding made by some departments
back then was to keep their old low volume, high pressure nozzles and attach
them to the new hose, which limited the discharge volume!
HERE COMES TWO INCH
HOSE AND MORE MISUNDERSTANDING
Again, the push for more water and easier attack line
management was addressed with two inch hose with 1 ½ inch couplings. I don’t
think anyone could argue the concept. However, it seems some fire service officers/”managers”
were ready to move forward without doing some homework to see how much fire
attack efficiency was to be gained with this size hose.
Tragically, some
departments bought into the thinking that 2 inch hose with an automatic or
other type of high pressure fog nozzle would flow as much water as a 2 ½ inch
attack hose line. They discarded their 2 ½ inch attack hose in favor of two
inch hose. Automatic nozzles (or other regular fog nozzles ) requiring a nozzle pressure of 100 psi at the nozzle
were installed. Coupling nozzle pressure and friction loss in older 2 inch hose
while trying to flow that volume was in some cases dangerous. To flow in the
range of 265/275 gpm’s there was a
friction loss of around 45 psi per 50 foot length. In doing the math, you can
see an average 200 foot layout would require a pump pressure of around 280 psi
to flow that much water through the hose. That’s unmanageable for a firefighter
to safely hold and 30 psi ABOVE annual hose test pressure! In so many instances the 2 inch hose has been
under-pumped all these years to avoid those higher pressures and is probably
flowing what 1 ¾ inch hose can comfortably
flow!
Furthermore, another problem that came with 2 inch hose was it
being stretched as an interior second or third line into a bread and butter
type operation when additional lines of 1 ¾ inch hose would have been
sufficient. Because of the close dimensional hose size and same size couplings
it was thought by many to be “about the
same as 1 ¾ inch!” weight-wise and
for handling.
Some officers justified this practice by using the old “back
up” hose line rule where a second line should be at least as big or the next size bigger than the first
line.
Without proper training or educated officers to correct the
problem, it soon became a hose line handled with two or in some cases only one
firefighter inside a building fire. And of course, there is the back pressure
from the higher pressure nozzles. When advancing two inch line up or down
stairways, making turns or bends, it takes two to three firefighters to do it
efficiently. The older jacket and hose liner material needed a bigger bend
radius or it kinked especially in residential or other tight areas. One fifty
foot length of two inch hose holds about 68 lbs. of water where as a one and
three quarter length holds about 52 lbs. of water. Thus it was deemed
unmanageable or unworkable. Minimum fire ground staffing for 1 ¾ and 2 inch
attack lines should always ( yes, always! ) be at least 2 firefighters for each
size line – depending on the situation. More stretching complexities? … then
get additional help on the line.
There were also concerns voiced that replacing 2 ½ inch with
2 inch hose would lead to reduced fire ground staffing. Thus confusion on hose
line selection began! By the way, that same mobility and water weight logic was
used to sell the idea of two inch over two and one half inch hose. Remember
again, each size hose has its limitations.
It took many years of actual flow testing and fire ground
results to realize that the claims of two inch hose were misleading or false. Many
fires were “lost” because of low flows. Two inch hose is an excellent attack
hand line but as mentioned before, it has limitations, and should never have
been thought of as a replacement for 2 ½
hose. Many of those fire departments have since switched back to 2 ½ inch for large hand line operations. Some
departments have retained their 2 inch hose for use as an intermediate size
attack line or for standpipe use. The key to any flow questions is answered
after you put YOUR own equipment and pump pressures to a flow test on YOUR
engines to see just how much water you are really discharging. A fire stream
may look good, but that can be deceiving.
A LITTLE BIT ON NOZZLES
Moving to two inch hose HAS BEEN a good move for the fire
service. Period.
Along with this movement, though came the push to equip
these new hose lines (and one and three quarter inch hose, too) with automatic
type nozzles with variable flow ranges. As automatic fog nozzles were
introduced, they were presented in such a way that misled many firefighters as
to how much water was actually flowing from a nozzle. The stream may look good
but the volume…
The nozzles were said to regulate themselves to pre-set
nozzle pressures – usually around 100 psi. It has been witnessed all over the
country – a 200 ft. stretch of hose with an automatic nozzle at the business
end. Looking at the pump panel outlet pressure gauge and reading a discharge
pressure of around 95 or 100 psi. What about friction loss, you ask?
There were claims and statements floating around, “If you
don’t use these nozzles or embrace this new technology then you’re stuck in
tradition and not progressive !”
What’s wrong with tradition? Isn’t saving lives and property a fire service tradition?
Or another interesting
floater was “ So and so fire department uses these nozzles and they’re
the most progressive department in the world!”
Really? How do you determine that???
Much like we see happening today regarding fire service
politics.
Unfortunately, local homework was not done by many fire
departments and we ended up relying on a sales person or some other uninformed
person who said “Look at that stream!”
“Why, you’re doing 250 gpm’s right now.” Ok, if you say so.
What was not said in many places was “Let’s put this new
stuff on a flow meter and see if it performs like you said it does!”
On the other side of this movement were the departments that
used their old nozzles!
The trend today is to move forward with nozzles that are low
pressure, high volume. Without a doubt, there has and always will be a nozzle
controversy. But the reality is that these nozzles (both solid and fog) will
deliver more water at lower pressures and result in less reaction force.
There will always need to be good strong information and
regular training for any equipment provided to firefighters otherwise they will
teach themselves and create “their own” devices, and draw their own
conclusions.
IT’S A NEW DAY!
Several years ago while still on the job in Cleveland, I was
assigned to conduct an engine company operations class for all engines and all
shifts, including battalion chiefs. In the block of instruction we flowed the
three sizes of attack hand lines ( 1 ¾, 2, 2 ½ inch ) found on engines with a
flow meter, then conducted a simulated offensive fire attack pairing two engine
companies on a 2 ½ hand line.
When it came to the two inch hose, it was generally found
that flows were way under what was expected. Most two inch hose at that time
was between 10 and fifteen years old. Higher pressure automatic nozzles were
assigned to the two inch hose. The nozzles were old and not well maintained. ( NOTE: If your department uses automatic
or other fog nozzles a regular nozzle maintenance program is absolutely
necessary. Low pressure fog and/or solid bore nozzles are worth investing in.)
Using the CFD SOP mandated set pump pressure of 125 , some
older two inch hose flowed in the neighborhood of 135 gpm’s. This flow is
easily beaten with 1 ¾ inch hose which has less hose & water weight to deal
with.
Since those “early times” hose and nozzle research has taken
place and has given the fire service more information, resulting in better
qualities for each. Standards that mandate certain items or functions,
materials and manufacturing, testing, etc. for nozzles and hose is allowing for
greater flows and manageability.
This photo illustrates some of the 2 inch hose and nozzles
tested. A couple of points of consideration for hose was bend radius and
resistance to kink along with potential for nozzle whip. A well-matched attack
hose system needs a good, high volume nozzle valve and tip size (or high volume
– low pressure fog tip).
RECENT FLOWS AND
FINDINGS
There is no perfect size or weight of fire attack hose line
for all fires – there isn’t! There is no
“One size fits all” hose line, either. Otherwise we would have found it by now.
However, if we did, someone somewhere would have found something to complain
about and probably would possess a degree and would have conducted a study to down
play all the previous facts, figures and work accomplished.
A couple of years ago, Jerry Herbst of Elkhart Brass Co. was
introducing a newer solid bore tip size
aimed at better flows for 2 inch hose for the fire service. It is the
one and one sixteenth inch tip. This tip size beats down the old hydraulic
rules of solid tip sizes and hose diameters. Since working with it back then, I
have been a proponent of it. I have presented it in training and conference
venues, and I tell people this is some of that “old style stuff” with the new
modern approach. The bottom line is it gives greater flows with lesser
resistance pressures, especially when matched with good quality
hose.
Recently, I have been doing some research with a small group
of firefighters from local fire departments in my area. Jeff Diederich, a
lieutenant with the Bedford, Ohio fire department brought the group together,
and expressed concerns of his department’s initial operations from standpipes
in taller buildings with low initial staffing.
Another of his concerns is standardization and minimum attack flows for
his department and the other fire departments they work with. Understandably, his
issues and others are echoed by many departments across the country.
In this picture good
nozzle mechanics are demonstrated with this 2 inch line. The nozzle tips used
were San Francisco style long barrels. Stream quality is very good and volume
is approximately 280 gpm. As mentioned earlier, at the minimum, a second firefighter
should always be with the nozzle man to provide support on the line.
During the times we flowed, a plan was devised to get good
data on hose, nozzles and flows so an informed decision could/can be made
regarding which hose performed best with flows and manageability of two inch
hose.
A flow meter was attached to a side discharge of a pump.
Right after the flow meter tube an inline psi gauge was also installed.
An inline gauge was installed behind an Elkhart 1 3/8 split
ball valve shut off. The nozzle was pressurized to 50 psi and then we pito’ed
the stream to verify the inline gauge accuracy. +/- 2psi.
Below are our observations.
2” Ponn
Conquest, 100ft, in 1.5 couplings.
Here are some of the
results of that testing:
Tip Size 15/16th 1-1/16 1-1/8
Outlet PSI 66 85 95
Nozzle psi 50 50 50
GPM 220
280 320
Est FL/50ft 8 17 (+ / - 2psi) 23
A discussion regarding the Fl properties of 2” hose, and
specifically why it can NOT replace the 2.5 hose for longer lays was had. To
prove our point we used the Bedford Niedner 2” as an example - 2” Niedner xl-800, 200ft, in 1.5 couplings
Tip Size 1-1/16 1-1/8
Outlet PSI 144 170
Nozzle PSI 50 50
GPM 270 300
Est FL/50ft 24 30
In June of this year I presented at the Boise Fire
Symposium. FIRENUGGETS.com and the Boise Fire department, as you would expect,
put together a great conference as was evidenced by the number of students and
where they came from. ( I urge all of you to stay up on this conference and
attend this school sometime in the future!)
In our area of Engine
Operations – Fire Attack training, there were three sections and one dealt
with flows of different sizes of attack
hand lines using low pressure nozzles. When the two inch was being
demonstrated, the results were very much consistent as back in Ohio. (Before
the conference I had the same 2 inch hose shipped to Boise and the same
nozzles.) The intent was to check quality of pumps and flows of the same hose
and nozzles. Here were the results:
100 feet ( 2- 50
ft. lengths) 2 inch hose. Couplings were 1 ½ inch thread size.
Nozzles were
controlled with an Elkhart split ball valve. 1 3/8 inch waterway.
Tips sizes were :
Solid Bore - 1 “; 1- 1/16”; 1- 1/8”
Pump Discharge
Pressure : Approximately 90 – 95 psi. ( 50 psi NP plus 20 psi FL/ 50 ft.
length of hose)
Flow results: 1” – 260 gpm; 1- 1/16” – 280 gpm; 1 1/8” -
297 gpm.
Each student rotated through, holding each size nozzle at
each of the different flows. This was to have them experience the actual force
and how to counter it with good nozzle mechanics. Of course working as a team
with a back - up firefighter. Coincidentally,
after I demonstrated the hose line flowing around 300 gpm’s, a student asked me
how the back pressure felt. I said,
“Look, I’m 63 years old and I just held this BY MYSELF!” You however, should have someone to back you
up on this line and all hose lines; if they do their job, you won’t have any
problem with this line – or any other one for that matter! I believe every one came away with a little
more understanding about the newer hoses along with nozzles, pressures and
mechanics.
WHY IS THIS HAPPENING?
As I mentioned earlier, the newer standards that apply to
the materials, manufacture, testing, etc. of our hoses and nozzles are mostly
what is allowing for better flows and manageability. In the far distant past
when many of the old mathematical formulas were developed, there was one kind
of material for hose lining – rubber! Hose jackets were cotton or Dacron. So,
the formulas were based on those materials.
Today, we have several different types of hose linings and a
few of those allow greater flows because of low friction loss. Other factors
are the hoses’ ability to expand and carry more water. Couplings, nozzle
valves, and nozzle tips have all been re-worked for better flows.
In any event, if your department wants to conduct
testing/research for hoses and nozzles then you should do it AFTER you have
developed a plan to find what you are looking for. For example, do you need to
consider greater flows and mobility? Personnel
availability and initial stretching considerations? A quick, blitz line with
move-in capabilities?
A WORD ABOUT TWO INCH
ATTACK LINES
This is an intermediate size line and should not be considered as a replacement for 2 ½ inch
attack lines.
The two inch hose is an excellent size attack line for
immediate large flow from an engine water/booster tank or perhaps a
tanker-pumper. It can provide for heavy knock-down and then advancement into a
structure if that’s what conditions call for. Just remember, it can take a tank
down quickly.
It is also a hose line
where its use in standpipe operations is being realized or considered more and
more, either as an entire 2 inch attack line or as the “lead length” for 2 ½
inch line.
The flows we attained were under training and controlled
conditions. Like any attack hose line, there needs to be set “target flows”
that give a particular size line its identification and capabilities. Even
though we have consistently flowed over 260 gpm’s with this size line, it seems
two inch hose should have a target flow of approximately 230 gpms. This figure
is what our group agreed upon considering flowing pressures, manageability and
looking at the 1.75 and 2.5 inch target flows. In any event, each fire
department should test and flow their own equipment as results will vary from
department to department.
DON’T EXPECT to see absolute accurate numbers! In the past,
some old “Drillmasters” would pull out an old hydraulic formula and quiz you on
it to see if you knew exactly what you were pumping! That was pre-flow meter era and, what we in the
job now realize is that we are looking at approximates - “target flows” which are the minimum gpm’s that a particular hose line should be
flowing, however we work to beat that!
By the way – this proves that fire fighting is not a science
– it never has been, and never will be. Unfortunately, those who do not
understand principles and practices will try to change the job for themselves.
Low pressure, high volume nozzles are being looked at and
are winning favor in fire departments across the country. They work well with
all size hose lines. They are a must for two inch hose.
Old rules of hydraulics stated that a solid bore tip should
not exceed 50% of the hose diameter. That is not true any more. We have
successfully shown that bigger tips are applicable. Interestingly, I ask
firefighters to look at the waterways of 1 ½ inch hose couplings and nozzle
valves – they are 1 3/8 inches. I then ask them to consider a deck gun with 1
3/8 inch tip @ 80 psi and to consider its volume – which is around 500 gpms’s.
We’re not looking for anything near that amount but it shows that this line can
provide a high flow for us. All we have to do is our homework!
