Back to Basics, Laying a Large Diameter Hose Supply Line

1You’re probably thinking, what is there to know about laying a large diameter hose supply line? We are already at the mind-set that this big hose is magical. You’ve heard the sayings, “laying a big line is like lying an above the ground water main” or “like taking the hydrant right to the fire”. I hope I will be able to prove to you that there is a little more to this stuff than just laying it out. It must be used properly in conjunction with all other equipment, manpower and the local water system to make it perform to its max.

Well, guess what folks, as simple as it may seem, there are several things that go into the actual supply line evolution in regards to its deployment that makes for a very smooth and efficient operation.

Let’s start off with wrapping the hydrant. There are several techniques that are taught and used throughout the fire service on how to best anchor the supply line to the fire hydrant to allow the engine company to pull away laying the line. For the most part these techniques are geared towards safety. If for some reason the supply line were to get hung up and pull away from the hydrant wrap, it is very important that the fire fighter taking the hydrant stands out of the way. Throughout my years in the fire service, I have always been taught this and told of the consequences if the line were to pull away and a fire fighter were to get struck. I always thought it was one of those accidents that was always talked about but never really happened, and then it did. A firefighter on my department severely injured his leg because the 5” line that he was connecting to the hydrant got snagged in the hose bed and pulled the line out of his hands and away from the hydrant. He required surgery and 6 months of convalescence to get back on the job. A second accident caused by the same type of scenario pulled the wrap off the hydrant and struck a fire fighter in the head with the hydrant adapter on the end of the supply line, fortunately it only hit him in the helmet which protected him from injury.

Folks, these accidents can happen. Let’s not depend on remembering the proper sequence for physically wrapping the hydrant with the supply line. There is a safer method. It involves using a three-piece strap system called the Hydrant Strap. The hydrant strap is made up of a seatbelt that connects to the supply line and a 6 foot looped 1-1/2” strap that also hooks to the supply hose and is used to secure to the fire hydrant while allowing the firefighter to stand clear. Attached to the seatbelt is a tool pouch designed to hold all the tools needed for the hydrant operation. When a line is laid, the fire fighter simply grabs the looped portion of the strap, pulls over to the fire hydrant, places the loop around the fire hydrant, stands back and signals the engine to lay a line.

For best results, 2 ten-foot folds are placed at the end of the supply hose in a bundle with the adapter winding up in the middle. This allows for extra hose at the hydrant to insure that the hose will reach. The seatbelt portion of the strap system is secured just behind the coupling strapping the bundle together. The looped portion of the strap system is passed through the fold at the end of the supply line and secured through itself, thus forming the loop that is used to anchor the hose to the fire hydrant. This system allows for several different types of hose laying evolutions. We’ve already talked about laying the line from the hydrant with one firefighter. What if we wanted to lay a dry line from the hydrant and allow a second incoming unit to hook it up and charge it? Who is best suited to do this job? With just about all fire apparatus having air packs in the jump seats, the firefighters are now packing up and sometimes going on air before they even arrive at the fire, thus allowing for an immediate attack. With this being the case, it is not only safer but also faster for the driver to get out, loop the hydrant with the hydrant strap and get back in the rig to lay the line. He’s not weighted down with an air pack and there’s a good chance that he will not be wearing turnouts.

Another scenario where this strap works well is for the hose lay when a hydrant is not involved, such as a reverse or a rural application where you might be laying down a long road or driveway for an incoming water shuttle operation. The strap can be used to anchor the supply line to a fixed object or even another unit.







Finally, with our fire trucks getting taller and taller every year, it’s getting increasingly difficult to pull hose from the hose bed. The hydrant strap system allows for the loop of the strap to hang over the edge of the rear of the hose bed thus allowing for the fire fighter to pull it from the street without having to climb onto the rig, again making for a safe operation.


Now that our line is secured to the hydrant, let’s lay a line. One thing I have noticed in my travels is that a lot of departments tend to baby large diameter hose, especially 5”. For some reason, probably because of the size, they feel it is important to lay this stuff out extremely slow. This hose is pretty tough stuff. Most manufacturers offer a ten-year warranty, what does that tell you? Don’t be afraid that you’ll hurt this stuff. There is nothing wrong with laying a supply line as fast as 15 mph. The hose actually tends to lay onto the ground softer because of the line stretching out from the hose bed tighter based on the higher speed versus the hose and couplings falling straight down from the hose bed due to a slower speed. The key to the fast deployment is having an obstacle free hose bed. If your hose bed has a cross bar going across the top, is it really needed? We don’t ride tailboard anymore. If a grab handle is needed to pull you into the hose bed, look for an alternative place where a side handle can be mounted onto the rig. Let’s clear up the hose bed.

We all know how a supply line can turn into a roadblock once it has been charged. Granted, large diameter hose can be run over by other fire apparatus as a last resort as long as the unit has the clearance, however, it is best not to. If the fire is on the opposite side of the street from the water source, lay the line as far down as you can on the same side as the water source before crossing and blocking the street. This will allow units arriving after the line is laid to get as close as possible to the fire which will eliminate the need for fire fighters to carry equipment long distances.


If an LDH line should become a roadblock, a simple method has been developed to move a charged LDH line by one or two firefighters. This method involves placing a canvas strap around the charged line and simply pulling the line to the desired area.

The strap consists of a canvas piece of material about 3/4″ to 1″ wide and 8′ to 10′ long made into a big loop using a sewing machine.

When placing the strap around the charged line, straddle the line and bend down keeping your back straight. Lift the line just enough to pass the strap under it. The line can be held in the raised position by resting it between the heels of your feet. The hose will be light enough to allow it to be lifted in the above-mentioned manner safely. Next pass the strap under the hose and pull it around the hose and through the other end of the loop until all the slack is gone and the strap is tight against the hose. The line can now be pulled. Although one firefighter can pull the line, it is best to use two whenever possible. A hydrant wrench or some type of bar should be placed in the loop on the free end of the strap to help get a better grip for pulling.

Tests have proven that the line can usually be pulled around 10 feet to the side with no problems. Tests have also proven that it is more difficult to move the line in the area of a sharp bend.

This method for pulling a charged LDH line is not a cure-all but has proven to rather helpful in a lot of situations and it is safe. Give it a try and see if it can be useful for you.






Now let’s talk about making the supply line hookup to the engine. Obviously the first thing to do is pull the amount of hose needed from the hose bed to make the connection to the intake of the pump. Too often I see the firefighter that is pulling the hose to make this hookup stand at the tailboard of the engine pulling the hose straight to the ground forming a big pile of spaghetti. This mess has to be straightened out before the line can be charged for obvious reasons. I have actually seen the hose get pushed underneath the fire truck forming severe kinks totally shutting off the water supply. Don’t count on your memory, especially in the heat of battle, to remember to straighten out the kinks in a supply line after it has been connected. I recommend laying the hose out as kink free as possible when pulling it from the hose bed. It has to be done anyway, so why not do it right away? Simply grab the hose and walk straight back pulling it towards the left or right, depending on which side you’re going to make the hookup, until the appropriate coupling hits the tailboard. Next, disconnect the hose and make the intake hookup. If you do in fact forget to straighten out the supply hose, with this technique there are only two kinks that will have to be dealt with. More times than not the supply line will straighten itself out.





Ideally, supply hose, especially LDH, should be in 50-foot sections. This makes it much easier to pull from the bed making the hookup. Unfortunately, the majority of the large diameter hose out there is in 100-foot sections, making it somewhat more difficult to work with when the last coupling in the hose lay winds up being real close to the tailboard. A lot of departments carry 25 and 50-foot pony sections to complete the supply line hookup at the intake when this situation arises rather than pulling an extra 100 feet of hose from the bed. There are two ways to deal with this problem. One is to mark each length of hose at 25-foot intervals that will give an indication as to how much of the last piece of hose is left in the hose bed. This will in turn indicate whether a 25-foot or 50-foot pony is needed, or if in fact the remaining hose itself can be pulled for the hookup.

My preferred method is to only use the pony sections if less than 25 feet of the last section of hose is on the ground. It is easier and less time consuming to pull the remaining hose from the bed, having only to make one connection rather than having to pull an extra piece of hose from a compartment and having to make two connections.

When making the hookup to the intake valve, make sure that you have a wide bend in the hose to eliminate a possible kink that may not be able to be straightened out.




Large diameter hose has a tendency to twist around as it’s being charged. For those departments that use Storz couplings this twisting has actually caused the hose to twist off the intake valve when being charged creating an obvious problem. Through their wisdom NFPA recommended that locking devices be placed on all Storz couplings which when working properly does prevent this accident from happening. What the locks don’t prevent is the hose twisting in the tightening direction, which can cause it to twist up like a wet towel, totaling shutting off the water supply. I have personally seen this happen several times. The solution to both of these problems is to install swivels on all intake valve couplings, which will eliminate the twisting in the supply line whether it is in the tightening, or the loosening direction.

In the mid 80’s, my department was experiencing approximately 8 supply line failures a year, mainly in the disconnecting direction. At that time the locks were not available, however, swivel adapters were. My department installed the swivel adapters on all intake valves and eliminated virtually all supply line problems associated with the twisting.


Without the locking device and the swivel on the intake valve, the supply line can twist off.


When large diameter hose is charged from a hydrant, as the water moves through the hose it pushes air. It is very important to bleed the air out before it reaches the pump. Failing to do so will allow the air to go through the pump and into existing handlines, temporarily creating pump cavitation, which in turn will cause handlines to go limp for several seconds. The longer the supply line is, the more air there is. It is a very good idea to make sure that the air bleeder on your intake valve is always open. Don’t let it fool you, as small as it looks, it can expel air fairly quickly. Don’t rely on your memory to open the bleeder valve in the heat of battle. Make it a part of your morning check out to preset the air bleeder in the open mode.


Now that we have our complete supply line evolution laid out and connected into our apparatus; it is time to charge the line. Again, just because this stuff is big, it doesn’t mean that you have to baby it and take forever to charge the line. Your goal should be to charge it as quickly as possible while not allowing the line to violently whip around. Charge it enough to bust kinks loose but not too fast. You’re never going to totally eliminate all twisting of a supply line unless you take extremely too much time.

Remember, this water is precious. We need to get it to the engine as safely and efficiently as possible.

Most departments do not use hose clamps in conjunction with LDH. The firefighter at the hydrant is required to wait for a signal to charge the line. This can eat up valuable time, which could cause a pumper to run out of water if the operation started from the booster tank. Pre-charging the supply line can reduce the time needed to get the supply line into service. As soon as the hydrant hookup is made, the firefighter can slowly start pre-charging the supply line. The line should be charged either to a point just before the line connects to the engine, or to a point where the firefighter at the hydrant cannot visually see the hose any longer.


Through the years, one of the many skills that epitomizes the talented engineer is the ability to properly spot a hydrant with a short soft suction hose (10’ to 15′ long). Several methods have been developed to accomplish this task with some good results. Spotting the steamer connection on the pumper approximately three feet on either side of the port on the hydrant that is going to be used and about a car’s distance away, in most cases, gives a nice “S” shaped lay that will come out kink-free after being charged. The tricky part is placing the pumper in the proper position to make this nice, smooth, kink-free spot and be able to do it from either side of the pumper.

No matter how proficient an engineer become in making this spot, there’s the possibility of some kind of interference that may prevent or at least make the deployment of the soft suction difficult. The hydrant could be recessed from the curb or have a vehicle parked too closely or directly in front of it.


Usually, the first few minutes of a good working fire are the most challenging for the engineer. Crews are pulling attack lines from the pumper and screaming for water, usually as soon as the hose clears the bed. Simultaneously, the engineer is doing everything possible to satisfy the water demands while making the supply line hookup to assure that the water supply is uninterrupted.
Given the above mentioned situation, try to imagine what it would be like if the supply line being used was a short soft suction and the pumper was spotted poorly making the hookup impossible. As we all know, these things do happen on the fireground. There is one way to alleviate this problem, using a pre-connected, 50′ long soft suction line. It accomplishes two objectives:

* Being pre-connected eliminates having to remove the hose from the compartment or hose bed, which in turn, saves in set-up time. Only the hydrant connection needs to be made.

* Using the 50’ long soft suction eliminates having to make a near-perfect apparatus placement at the hydrant. The engineer simply spots the pumper in the general area of the hydrant, pulls the free end of the pre-connected line to the hydrant and makes the hookup.

Unlike the short soft suctions, if a spot is made too close to the hydrant causing a kink after it is charged, the hose can easily be straightened out. This is possible because the longer line has more room to expand or grow under pressure. More times than not, the kink will be removed on it’s own after the line is fully charged.

The key to avoiding kinks in a long soft suction line is to make wide bends whenever slack in the hose needs to be taken up.

The pre-connected long soft suction line is the answer to the troublesome hydrant spotting and is one more way of making the firefighter’s job a little easier.

The soft suction can either be stored in a flat load or a donut roll. Both loads can be pulled easily however the donut roll allows more hose to be stored in a smaller space as long as there are no high clearance problems.


A 5” soft suction 50’ long stored in a flat load.


A 5” soft suction 50’ long stored in a donut roll.



This hydrant spot was made too close to the hydrant. To avoid kinks, the hose was flaked out in front of the pumper in a wide bend thus eliminating the possibility of any kinks.


This is a normal spot using a 50’ soft suction. The pumper simply spots in the general area of the hydrant.


With a 50-foot soft suction simply pull up in the area of the water source and make the first connection,


and then the second connection, end result a perfect spot.


Recently I taught a large diameter hose basics class to a group of small fire departments that had made a combined first time purchase of 5” hose. Their plan was to get the new stuff loaded on their engines just prior to the day I was to teach so all units would be ready. Well wouldn’t you know it, two days before the scheduled class they got the big one and because the 5″ was on the engines, it was used. It worked out really good because the supply line that was needed was 1300’ long. These guys were able to move water like they have never done before. The down side of the new and exciting experience was that they now had to pick up the 1300 feet of 5” not realizing that it would be a lot different than what they were used to with their 3” hose.

The first thing that they realized was that the hose was heavier (110 lbs per section dry). After disconnecting each section of hose and draining the water, they thought that the hose could be loaded back on the engine just like the 3”. WRONG!! They soon found out that there was a little more to it than that. You see, this big stuff really can retain a lot of air. In fact they were not able to get the last 300’ of hose back into the hosebed. When I showed up the guys had this very frustrated look about them. They were wondering if they had made the correct decision with their new hose purchase. I assured them that once they learned how to work with this stuff that it would be easier to pick up than the 3”.

Picking up large diameter hose (LDH) is based on a vacuum principle, which allows water to be drained out of the hose while at the same time not allowing any air to be pulled back in. This process in turn draws the hose down completely flat and makes it very easy to reload.

The first step in this process after the hydrant has been shut down is to disconnect both sides of the line, at the pumper and at the water source. Ideally you should not have to disconnect any of the couplings in between.

After both ends have been disconnected, seal off the end of the hose that the water is going to be drained away from. This can be done by either connecting a blind cap to the coupling or by re-coupling the end of the hose back into the remaining hose in the hosebed. This should be done as soon as possible so air does not get drawn back into the hose.

After the hose has been sealed off, it can be drained by walking the water away from the sealed end. This can be accomplished by the use of either a hose rolling tool or some type of bar. Either method will require a minimum of three firefighters to accomplish. Two firefighters will do the actual drain process getting on each side of the tool. A third firefighter will stay behind keeping the hose taut thus allowing the water to drain freely. As the water drains out a vacuum is created in the hose because of the seal not allowing air to enter in from behind which in turn draws the hose down flat. As soon as the draining process reaches a point about 10′ from the end of the line, stop, leaving the remaining water in the hose. The hose should now be folded over a couple of times at that point so air cannot enter in. The small amount of water left in the hose will help seal the hose at the fold.

At this point, if the cap has been used, the hose can now be loaded back into the hosebed. Before removing the cap from the hose place a fold several feet back from the end of the hose so when the cap is removed air will not enter back into the hose. If the line as been sealed off by re-coupling it back into the remaining hose in the hosebed the above-mentioned step will not be needed.

When picking up the hose, the pumper can either back into it, straddle it going forward, or run parallel to it going forward. Some water can accumulate in the hose every so often especially on the longer lays. If this should happen, simply open the line at the next coupling allowing water to drain out. Then reconnect the remaining hose and continue the process.


An end cap can be used to seal off the end of the hose.


An alternative to the end cap is to recouple the hose into the remaining hose in the hosebed.


The backup method for loading the hose


The straddle method for loading the hose


The parallel method for loading the hose