Improving Fireground Water Supply Capability
Gaining Simplicity In Fire-Ground Supply Success.
Water supply sucks, right? Nobody likes to be stuck on the hydrant? There’s nothing glamourous about laying hose, and surely nobody wants to lay hose because it sucks to pick it back up.
Ever hear or see any of these attitudes in action? How about hearing that we are out of water, have no water or don’t have enough water? Sound familiar? It’s a fact that we cannot overlook, that many of our fires are complicated by issues with the water supply. Some of these issues can be resolved with a few changes in philosophy and practice.
If you can stick with me through the first few paragraphs, there are some simple approaches and skills that follow that may make your engine company more capable of being certified badasses in water supply, which will likely pay in dividends at the next significant fire you run.
Water supply seems to be the red headed step child of our business. It is often looked upon as a necessity, but with little interest or effort to make the best of it, and to adapt to challenges we are faced with.
Fire departments are handling routine fires every day without major water supply issues, however, when routine fires escalate or when high volume water supply is required on arrival, companies are often left scrambling for water and there never seems to be enough of it.
With an understanding of local water systems and the proper tools and hose, fire departments can increase their chances for efficiency when fire suppression operations require high volumes of water.
In this article, I will break down some simple steps that can be taken to increase efficiency when a higher volume water supply is required. Please keep in mind that the suggestions provided here are intended to aid in the development of higher than average water flow at fires that will require it.
The “everyday” fire will not require many of these steps, but these runs are great opportunities to practice when possible. This is especially important for companies that are not running high call loads.
In order to achieve success, and before even making the first connection to the hydrant, it is important to understand the capabilities and vintage of the water system where public water is present. In rural areas, accessibility to usable static water sources and water tankers is the go-to requirement.
In either situation, the fire department leaders and apparatus operators must have a working knowledge of the water sources in order to have the best chances for success.
Where public water systems are present, there are many variables that will influence total water flow from one or more hydrants.
The source, and its duration are one of those variables– for some water systems have a small reserve capacity which can be quickly depleted at several thousand gallons per minute.
The distribution system network of piping and the layout also has much to do with its strength. A system with sizable water mains that are well “gridded” will serve your needs much better than a poorly designed or older and poorly maintained system.
Finally, the fire hydrant itself will be the last stop in the process of efficiency before your pump inlet.
The size of the hydrant connection to the water main and the hydrant barrel and outlet sizes will impact its water delivery performance.
Hydrants come in many sizes and shapes, their design will influence flow capability. The size of the barrel and number and size of the outlets will be a significant player in what each hydrant will deliver.
It is the number of variables that exist that make it hard for me or anyone to truly assess the strength of what each water system will provide.
The primary audience for this article is for departments that are operating in areas served by dry barrel hydrants, where there is a single operating valve. In warmer climates served by wet barrel hydrants, the same principles apply, but the hydrants will offer more flexibility without the necessity to use gate valves on additional outlets.
Preplanning your water system can be as simple as paying attention to utility mark outs. This photo tells us the in-service hydrant has a 6” lateral connection to a 12” water main. We can anticipate flows over 2500 GPM from such a configuration in the town where this is located.
This hydrant looks like many where I live and work, but closer inspection shows the barrel is smaller – at 4 1⁄2” vs the standard 5 1⁄4” that we have around here. The permanently affixed 4” storz fitting reduces the 4 1⁄2” steamer outlet to about 3 1⁄2”, decreasing inefficiency. These are things you should know.
In rural communities, static water sources and water tankers/tenders become the necessity for water supply. There are many more variables in these instances that will influence water delivery in large volumes. In this article, the focus is on areas served by public water systems and how we can take advantage of that water supply when possible.
In order to achieve success, you must first believe that you can...
The first step in the process of achieving success in water supply is attitude. A can- do attitude is an absolute requirement. Often, the crutch of operations is in reverting to how things have always been done and nobody has challenged the routine or strived to break any records.
Usually, there is room to improve, but without the willingness to attempt, nothing can be gained. In the town where I live, we have flowed well over 20000 GPM from hydrants in several areas of town.
When speaking to firemen from other companies, they are often amazed that this was even possible, because their operations are scaled to what they’ve always done, and they aren’t taking any steps to maximize the efficiency of the water supply system. Having a minimalistic or closed-minded attitude is a certain recipe for failure.
We put a lot of emphasis on the proper flow and line selection from the engine to the fire, but why so little on the choices made between the water supply and the engine(s)?
There are some common failure points that starve engine companies of higher volumes of water when required. To address them, there are some relatively simple strategies and tactics that can be employed.
In the following paragraphs, it is assumed the water system can support flows of 1500 GPM or better. That has to be the case for most of these suggestions to work, and if it isn’t, you need to accept that much of this information will not help you.
Where the water system isn’t capable of such flows, alternative methods are required which I won’t discuss in this article. There isn’t a one size fits all approach, but there are some steps that will work universally from department to department.
It is a no brainer that if we don’t simplify things, there will be immediate push-back and resistance. When a solution seems complicated and much thought is involved, you will immediately lose support.
In the world of hydraulics, there is a lot of science and math involved, but we don’t need to bring that to the streets with us, at least not all of it. We can employ simple approaches that will give us the best result for the given conditions.
Without quantifiable flow testing and detailed analysis, there is no way to measure what kind of flows you’ll get from your water systems, but by considering the following simple principles, it will put you ahead of the curve and whatever water you have is more likely to end up on the fire instead of trapped in the water system.
6 Simple Principles to Gain Water Supply Success
1. Know Your Flow. Recognize the average flow from each fire stream that is deployed.
2.Establish an effective initial water supply. Lay supply hose early and do it quickly and efficiently. Supply hose for anticipated higher flows must be a minimum of dual 3” hose lay. If you don’t lay supply line early, what are the chances you will have the opportunity to do it later when things are spiraling downhill?
3. Always put a pump on the hydrant. Use a 4-way hydrant valve such as a Humat or Hydrassist valve if your first engine routinely forward lays and the second engine is not ALWAYS arriving before the hydrant is charged. NEVER simply connect a supply hose lay directly to the hydrant when it is longer than 100 feet.
4.Tap those outlets. Attach at least one 2 1⁄2” gate valve to the smaller “hose outlets” on the hydrant. This will aid in augmenting water supply later on if necessary.
5.Use Large diameter (4” or greater) supply hose to make connections to the pumper that is positioned at the hydrant – even if you are laying 3” as the primary diameter supply hose.
6. Use the Heavy Water Hookup. Connect the pumper that is on the hydrant to at least two hydrant outlets with large diameter hose – using adapters as necessary.
In the following sections, I’d like to expand upon each of the previous points in some detail.
#1. Know Your Flow.
Before laying hose, officers and pump operators need to know how much water is flowing to assure the water supply
will support those streams. There are a wide range of nozzles and fireground flows but here is a simplified approach to determining fireground flow.
• 1 3⁄4” Attack Line: 150 GPM
• 2 1⁄2” Attack Line: 250 GPM
• Portable Monitor: 500 GPM
• Engine mounted master stream: 500- 1000 GPM
• Ladder pipe (Tower or aerial Ladder) 500- 1000 GPM
Without understanding the amount of water being used on the fireground, it is hard to manage water supply. Company drills can include flow testing your hose and nozzle configurations using flow meters and gauges.
As the first in engine company driver, I hand stretched 4” LDH supply hose for this small fire in a dwelling. The supply line is attached to a Humat valve, which allows for water supply flexibility, should an increase in flow be required.
#2. Establish an effective initial water supply.
It is critical that in instances where a consistent volume of water will or may be required that the initial arriving engine(s) establish a supply hose lay.
There are several options that include forward, reverse and split laying hose to complete the initial supply hose lay. However you do it, it is imperative that each arriving engine understands what is happening so they can position properly.
Solid SOPs and consistent routine approaches will make these decisions less likely to get messed up. Consider laying hose on the street for reported or confirmed fires when you have a good address.
Some departments utilize booster tank water from the first two engines. This tactic should still include a plan to get supply line laid out in preparation for the fire escalating or if the fire is advanced on arrival.
Fire attack using the booster tank is often limited to flows of around 500 GPM, and the water will be quickly depleted at flows over the average 1 3⁄4” attack line, leaving little time to play catch up to securing a sustained water supply. In summary, you need a plan that works, and that has been practiced for worst case situations.
#3. Always Put A Pump On The Hydrant
This practice will assure that if the fire requires higher volumes of water that the pumper at the hydrant can be used to augment the pressure available from the hydrant alone, virtually assuring you will gain the maximum flow when your supply hose lay and other factors support it.
If your department practice is for the initial and even subsequent arriving engines to forward lay, it is worth considering that a 4-way hydrant valve such as a Humat or Hydrassist style is used.
This is especially critical in departments where the second arriving engine cannot be guaranteed to arrive by the time the booster tank on the first engine is exhausted.
The 4-way valve will allow the first engine to establish flow from the hydrant off system pressure and then it can be boosted later by another pump if necessary, often offering double or better the original flow.
The second or subsequent arriving pumper can position and connect to the initial supply line and increase pressure with no interruption in flow when a 4-way valve is used on the hydrant by the initial arriving engine.
Don’t simply connect the supply line to the hydrant, even if you are using large diameter hose. On hose lays beyond 100 feet, connecting directly to the hydrant without a 4-way valve is an assurance that you will not achieve the hydrant capacity if needed.
#4. Tap Those Outlets
Attach at least one 2 1⁄2” gate valve to the smaller “hose outlets” on the hydrant. These smaller outlets may seem insignificant, but they can offer several hundred gallons per minute more water in times of critical need.
These 2 1/2” gate style valves will afford the best flow and control for the smaller outlets on the hydrant, especially when coupled with “rigid thread” 5” storz adapters.
In testing, I’ve seen as much as 750 additional GPM obtained using only one of these smaller 2 1⁄2” outlets.
Gate style valves are superior to commonly used quarter turn ball valves, as they are lower profile, often have a larger waterway and they are safer to use due to the slow opening/closing principle of design.
Older quarter turn ball valves sometimes will vibrate closed under high flows, resulting in water hammer. They are also not compatible with adapters required to increase the 2 1⁄2” thread up to LDH thread/ fittings.
You can see the notable size difference in the waterway of the ball valve on the right compared to the gate valve on the left.
This ball style valve needed its plastic knob on the handle removed to open it fully with the LDH adapter attached.
#5. Use The Right Hose
Use Large diameter (4” or greater) supply hose to make connections to the pumper that is positioned at the hydrant.
This is important even if you are laying 3” as supply hose your engines should be carrying several lengths of LDH supply hose for direct connection from the hydrant to the pump.
Common lengths of 20, 25, 35 and 50 feet are best. Engines should be carrying at least two short and one longer length of LDH supply hose.
If space allows, I prefer two 50 foot lengths and two 25 to 35 foot long sections. It is ideal to have not less than one 50-foot section of LDH and one 25-35 foot spare lengths in addition to preconnected “soft sleeve” on engines with preconnected intake hose for either front, side or rear intakes.
Carrying two shorter and two longer lengths assures that no matter how the engine is positioned at the hydrant, there will be at least two lengths of LDH to connect to the hydrant. If the engine is connecting to a 4-way valve, you’ll often use a 25 and a 50 foot length to make the connections, so it is prudent to carry another length at a minimum for a second connection from the hydrant to the pump.
When there is no access to the steamer (main) hydrant connection due to it either being blocked, rusted cap or if the hydrant does not have a steamer connection, using large diameter hose will often yield better results.
Many times, using medium diameter supply hose such as 3” is the chosen method to fully dress the hydrant. This doesn’t always yield the full potential of the hydrant.
Using only two LDH connections, the engine can achieve a flow higher than the previous photo, which requires three connections and uses 3” hose on the 2 1⁄2” hydrant outlets. This pumper is flowing 2540 GPM with 25 feet of 5” to the front intake and 50 feet of 5” to the officer’s side main pump inlet.
Using two LDH lines on the hydrant can yield nearly its full capacity when the steamer connection is blocked, absent or otherwise unable to be used. It is possible to achieve flows in excess of 2000 GPM using such a configuration
#6. Use the Heavy Water Hookup.
The heavy water hookup is a term that refers to connecting the pumper at the hydrant with at least two LDH supply lines to gain maximum available water flow from the hydrant.
Where LDH is not available, using a soft sleeve and two 3” lines will yield reasonable results as well. The goal is to connect a hose from each hydrant outlet to the pump intakes.
Connect the pumper that is on the hydrant to at least two hydrant outlets with large diameter hose – using adapters as necessary.
If your engine company “has their own hydrant” then you’ll make your own connections to directly support your fire streams. If your engine company is being supplied through a hose lay, it will be the responsibility of the supply pumper to perform this hookup.
The best and simplest approach is to tap all of the available hydrant connections. While some tests have shown the third supply line having negligible increases, it is still truly the simplest way to assure you’ve gotten the full potential from the hydrant without having to do any sort of calculation. Simplicity is key.
Don’t fall into the crutch of being “out of water” if you’ve only made a single supply connection to the hydrant. It is very possible to take the water supply to near vacuum with one connection but to be able to restore residual intake pressure (get more water) with subsequent connections to the hydrant.
Truly being “out of water” requires that you’ve tapped the hydrant to its full potential and that you’ve taken your intake pressure as low as you are comfortable going, which should be at least 20 PSI of residual intake pressure but can acceptably be 10 PSI or less with due regard.
To summarize, there are many variables that will influence water supply. The underlying purpose of my article is to get you thinking how to achieve success in water supply with some simple steps. Employing even just one of these suggestions can potentially lend your operations to improvement in operations.
The heavy water hookup performed by a supply pumper supporting another pumper that has forward laid supply hose with a 4-way valve. This configuration allows the supply pumper to achieve the maximum possible flow that the hydrant can offer.
This 1500 GPM pumper was able to supply well over 2000 GPM using three 5” hose connections on this hydrant, which is on a 16” water main. Carrying the proper adapters and “pony” lengths of large diameter supply hose is critical for success.
One area that I did not discuss here was the rigs themselves. There is such a drastic variation in how apparatus are designed that it would take another whole article and then some to address the issues that you may find.
The best advice I can give is to go out and try various hookups and flow water. You can simplify the process of assessing maximum hydrant flows if you lack access to test gauges and flow meters by flowing water to any combination of streams to achieve your desired flows.
By taking this simple approach, you can experiment with various supply hookups to see where you meet your water supply capability from a single hydrant.
I live and work in central New Jersey. The water systems where I am are substantial and easily capable of producing flows in the 2000+ GPM range, even on mains as small as 6-8”. The static pressures we see are in the 50-100 PSI range.
I am aware that some communities have higher pressure systems, and this could certainly provide greater performance. Much of what we do is relative to the regions you work in, and that message is one I cannot stress enough.
Each department needs to do their research and figure out what the water system in their response areas can provide, before the fire happens.
One final thought that I want to leave you with is the value of time, and how important each second of every minute is. Initial water supply decisions are the foundation for the rest of the fire.
If your initial strategy and tactics for water supply are scaled for what you are dealing with at the moment you make the decisions, and fails to consider the potential for escalating fire conditions, it is likely that you will be struggling to catch up.
I’m not advocating laying out a water supply system that can fight a fire the size of a city block upon arrival, but it is prudent to have a plan to adapt the initial water supply to scale it up if necessary, and that plan shouldn’t be complicated or time consuming to execute.
Thanks for taking the time to read and good luck. Now get out there and send the water!