Fire Department Connections: Should I use Large Diameter Hose?

From my Tumblr Account: battalionbean

I recently was working on a new General Order and the title question was raised and sparked a lot of dinner table conversation. I found a great article about FDC Operations by my good friends at Fire Engineering.http://www.fireengineering.com/articles/print/volume-164/issue-3/features/fire-department-connections-start-to-finish.html. 

I have cut and pasted the relevant part. I did remove the pictures as they would copy correctly. Enjoy the discussion and answer. 

Chief Bean

In recent years, the fire service has seen the introduction of sexless or quick-connect type fittings on system FDCs typically with four- or five-inch hose. The local fire authority would make the selection, since compatibility with hose fittings is required. There are, however, some things that need to be considered when using these fittings and large-diameter hose (LDH) for supplying system FDCs. These considerations should be part of any discussion on changing over to LDH connections for existing systems or using them for new system installations.

LDH was introduced to the fire service as a means to provide large volumes of water over long distances with reduced friction loss compared with traditional 2½- or three-inch supply lines. This advantage of large volume and reduced friction loss did not contemplate appreciable pressure loss caused by elevation, such as in standpipes for high-rise buildings. LDH supplies volume to pumper apparatus, which then produce the necessary operating pressures for firefighting operations. Fire sprinkler and standpipe systems rely on specific pressures at certain volumes to achieve effective sprinkler coverage or hose stream reach and penetration. Successful usage of LDH to move large volumes of water is also dependent on the pumping apparatus’ design and piping. The installation of an adapter to convert an existing 2½-inch discharge into a five-inch discharge creates a chokepoint at the pump discharge where water velocity will be greatly increased and result in additional friction loss as flow volume increases.

You must also consider the hose. Since LDH is generally classified as supply hose, its service pressure is 200 psi, whereas three-inch hose is available with service pressure listings from 300 to 600 psi. When looking at the requirements for properly supplying standpipe systems in vertical buildings, particularly multizone systems, you will encounter minimum pressures well beyond 200 psi. Although the friction loss in the 100 feet of hose between the pumper apparatus and the FDC will be less in the LDH, do not overlook the fact that pumping 175 psi through the LDH and supplying upward of 1,000 gpm is wholly inadequate for the companies operating off the standpipe system if it will take 250 psi and 750 gpm to actually reach them and support their hose streams. The use of three or more three-inch hoselines into the FDC will easily deliver beyond that 750 gpm; more importantly, it will deliver it with the necessary pressure to overcome the elevation loss (gravity) in reaching those crews. Large-demand sprinkler systems or standpipes that require flows of more than 750 gpm are still better served by multiple (three or more) hoselines through a three- or four-way FDC.

When you consider the needs to properly supply a multizone building (discussed below), very few pumping apparatus are equipped to properly support two or more LDH discharges. The most basic engine apparatus will have at least six discharges for 2½-inch hose couplings, which can feed three lines into each FDC on two different zones. With this popularization of LDH, many agencies began to remove three-inch hose from their apparatus and use LDH for their supply lines. This is not a question of using LDH as a supply between hydrants and apparatus; it’s about recognizing that while you may be “supplying” the FDC, you are actually on the discharge side of the pump and you should be using “attack”-rated hose to connect to the FDC. Although it is not necessary in these cases to carry 1,000 feet of three-inch hose, consider your response area and its building makeup. Fire departments still must maintain some complement of three-inch hose on their attack apparatus to properly provide for the vital function of supporting an FDC.

At the height of a firefight in a standpiped building, the interior crews are relying on the water supply through the FDC for their protection and safety. In a building equipped with a single large-diameter FDC, there is one and only one hoseline between the fire pumping apparatus and the building. If the hoseline is damaged by falling debris, driven over by an errant vehicle, or ruptured by pressurization, that singular hoseline becomes lost and instantly endangers the interior crews. Several minutes would be needed to stretch and reconnect a new hoseline while interior crews scramble for cover and safety in deteriorating conditions. When multiple hoselines, even two, are in place and are supporting the FDC, it provides a safety factor if one of the hoselines is lost or damaged. Interior crews should use the water remaining in the additional FDC lines to retreat to a protected stairwell with hoseline protection.

The codes have traditionally required that FDCs be positioned between 18 and 42 inches above the adjacent grade level. The lower measurement takes into consideration accessibility during snowfalls and snow drifting; the upper measurement considers ease of reach and connection but also the weight of water-filled hoselines pulling at their fittings and kinking. The impact of water weight and pull on couplings is dramatically compounded in LDH, as a single foot of five-inch hose weighs approximately 34½ pounds when filled with water. The higher an FDC is mounted, the more hose length that must be supported by the fitting before the hose makes ground contact—at 42 inches high, about 121 pounds of water would be hanging on the connection (photo 11).

This also increases kinking of the hoseline, which in turn reduces and may eliminate the hydraulic efficiency of a LDH. A charged three-inch line has enough rigidity so that it would be relatively self-supporting at even 42 inches above-grade, but a charged five-inch hoseline has no self-supporting characteristics and will immediately create a kink and pull at the coupling-to-FDC. Some agencies have been stipulating the installation of a pipe elbow to alleviate this condition (photo 12), but we must still remember that height is working to our disadvantage here and the codes have not contemplated the use of LDH for FDCs. A similar effect can occur on FDCs that are low to the ground (photo 13). When you include the size of the hose coupling, you force a kink to occur under the connection that, once again, robs hydraulic throughput and defeats any advantage of LDH.

Early LDH couplings lacked a physical means for retaining their connection, and they were just friction twisted together with as little as a ¼- to ½-turn action. Today, we have large-diameter connections with a ¼-turn twist action and a safety latch to physically hold them connected. There is no question about the value of or need for this safety latch, and we can regularly inspect and maintain our hose. When using these connections on an FDC, we have much less control over the care and maintenance of this safety latch; if it becomes broken or damaged, we have no reliable means to restore it in an emergency. This increases the possibility that the hose connection will fail or separate under pressure and deprive interior crews of water. When using traditional hose sizes, we rely on hose threads that make up their connection over several turns vs. a fractional turn. If a threaded hose connection is found damaged, responding personnel have several options for making a rapid field repair and achieving a timely hose connection to allow for support through the FDC. A failed or damaged large-diameter connection effectively renders it useless for the duration of the fire emergency and must be repaired by a service contractor.

If you think this post is about you...it is!

Sorry to offend you, but you've lost your dinosaur.

Span of Control: What do you know?

I hope to have some input by comments on this posting.

Most everyone of you have heard the term "Span of Control".

My question to you is:
1) What does it mean?
2)What number is your "Span"
3) Extra Credit: Where did this number come from?

I'll chime in if I get any reposts as comments. I'll give you a clue, the extra credit is a "Magical Number".

Stay safe, and don't do anything stupid!
Chief Bean

Fear the Uninformed but Influential

The other day I was riding home listening to the locally produced political radio talk show. The normal host was out that day and the show featured two local conservative politicians (one as has-been, the other and never-was). Both guest hosts had experience in the fire department. The has-been’s father was a paid and volunteer firefighter IN THE 1970’S, and the never-was served grits at the local Sunday breakfast. Therefore, they were both well versed in the ways of the fire service. They were speaking out against the spending of the local (not Howard) county regarding how officers made too much overtime. They discussed both administrative and field personnel should not get overtime because they were managers.

There is a clear line between management and supervision that they didn’t understand. Managers have the ability and authority to hire, fire, and discipline personnel. Having been through my share of each of these situations, I can assure you that I do not have that ability or authority.

Additionally, there are legal definitions that make clear distinctions between salaried and hourly wage personnel. Clearly they didn’t have any clue about these two key issues.

But then again most politicians look for the easy answer that supports their platform. They certainly don’t let the law or facts get in the way of them getting their point across.

Decision Making: 101

When I started my fire service career, I began a collection. Lots of firefighters have collections. Some collect fire figurines, for others its patches, I even know a few guys that collect full-sized retired engines and trucks. Some of the things I collect came easy; others I had to dig for. By now you’re getting ready to log off, so I’ll spill what it is that I collect. I collect memories.

If you’re a fan of Harry Potter, you’ll probably remember the Pensieve in Dumbledore’s office. If you’re not a fan, it was a bird-bath type of contraption that the most wise and powerful wizard used to store memories. He could look into his memories and bring them back in full detail. If someone else looked into his memories, they could observe Dumbledore’s memories as if they had been there too. Dumbledore used this bit of wizardry to carefully review long-past memories seeking out minute details, while trying to solve mysteries. Even the most wise and powerful wizard admitted that he couldn’t recall every detail regarding all his memories. Dumbledore shared some of his memories with Harry in order to “teach” him things about his enemy, Voldemort.

How unfortunate it is that we don’t have Pensieve’s in the fire service. Imagine being able to see, through the eyes of each the officers you’ve been assigned to; all the fires they have fought and learn the lessons they have learned. (I’m sure Vincent Dunn would have a mess of memories available on DVD’s).

In the 1980’s, the military wanted to learn the decision making process of highly effective combat officers. What they found was a process called Recognition Primed Decision Making (RPDM). They found that effective fire officers too used RPDM when confronted with on-scene situations. To view a very informative report on this process go to:

http://www.standto.com/rpdm.html

In short, both military combat officers and effective fire officers have a “slide-show” in their brain. When confronted with a situation, in a nano-second, the officer views their slide-show to try to best match the current situation with one that they have seen in the past. Sometimes there isn’t an exact match, but usually if you’re an experienced officer you’ve seen something similar…enough.

So now that you have a better idea about what RPDM is, what can you do with this information? As I said earlier in this posting, some of my collection came easy like learning not to touch the steel doors of the burn building without your gloves on no matter how long the fire has been out (wow, that hurt!). Other memories I had to dig for. Back when I was riding the ambulance (yes, I did!), if we had a call where the paramedic did some critical interventions, I would bug them on the way home to explain to me, what was physically happening with the patient, what intervention they did, and it changed the physiological status (or was supposed to) of the patient. I was lucky I worked with a lot of good paramedics back-in-the-day. To this day, current paramedics sometimes call me a “closet-medic”. I usually have a pretty good idea what is going on with the patient and how to alter the course though interventions.

Here is where you come in. If you’re a seasoned officer, you must share your on-scene observations and how it affected your decision making process with those with whom you work. If you’re a young-buck, ask questions without out being a pest. If an officer knows you are seeking guidance to fill your “slide-show”, they will most likely share their experiences (often in the form of war-stories) with you. There is a lot to learn.

In closing, I would like to acknowledge one of those great fire officers, and who turned my on to the concept of RPDM many, many years ago. Chief George Morgan (there is a Pensieve I’d like to glare into…or maybe not! ;-)) was always a wealth of knowledge. It was years later that I further explored the concept that I formally knew what he was talking about.

Communications 101

Question: Do you know what the term Collyer’s Mansion means? Three…Two…One: Time

I have heard a number of very knowledgeable officers use this term, and had to do a little time with Uncle Google to find out what Collyer’s Mansion means. Collyer’s Manson syndrome is another term for the disorder commonly called being a hoarder. Most of us have been exposed to a hoarder sometime in our fire service career; if not it’s only a matter of time.

The point of this posting is to reinforce the use of common language to identify common problems. On the radio this morning I heard an unit officer ask our dispatch center to make a note in our dispatch notes for this address that indicated that the house was a Collyers Mansion situation. That would be acceptable if that officer is the only person that responds, but what about the newly promoted officer, or the firefighter acting above class? Will they know what that means?

We all pretty much know what a hoarder is, if not watch the high-numbered channels on basic cable.

Pyramid

I have to apologize for my lack of contributions lately; I was pretty busy with college and preparing for the promotional process.

Recently, a good friend and I were talking about worker safety. He attended a seminar in which the presentation included a section that discussed a “Risk Triangle” shown below. If you start at the bottom of the triangle it lists unsafe practices and associates a number of those unsafe practices. The next step up the triangle shows us near misses. Up one more is minor injuries. Then it shows life threatening injuries and finally a single fatality. You may be asking what this has to do with the fire service. What the triangle shows is the progression and escalation of dangerous actions.

Look we’ve all done things on the fireground that are unsafe practices, more than a few of us have had near misses; a few have received minor injuries. Thankfully life threatening injuries are few and in the modern era, our department has never had a on the job death. I pray it stays this way.

What is often forgotten is the other basic building block listed unsafe conditions. These can be operational based unsafe conditions, but it can also be unsafe conditions in the stations, during training, or just driving to and from miscellaneous details. This could provide a significant number of “events” that contribute to our overall exposure to injury liability.

So what do you do? The pyramid is built on a wide base and each of the other levels is derived from the corresponding number below (e.g. 5,000-10,000 near misses are 10% of the 50,000-100,000 unsafe conditions/practices). What you can do is reduce the number at the base, and thereby reduce the probability of the climbing to the next level. If it takes a single employee 50 years to accumulate 50,000 unsafe practices/conditions, the employee will most likely retire before he encounters a fatal event. A different employee may reach the 50,000 unsafe practices/conditions in 5 years. If so, the second employee will most likely enjoy any retirement. The way to reduce your pyramid is to whittle away at the base. As you decrease your number of unsafe practices/conditions, your career survivability skyrockets.

Each year hundreds of thousands of tourists visit Egypt and Latin America to climb to the top of the pyramids. Let’s hope that we never see the top of ours.

Authors Note #1: The graphic represents a different industry. I believe the fire service numbers to be much lower

Authors Note #2: This logic is not an exact science, as employees could have fatal accidents long before accumulating 50,000 unsafe practices. The numeric representation is a representation meant for job/industry wide occurrence..