Fire Protection Training: Fire Streams

A fire stream is a stream of water or other extinguishing agent after it leaves a fire hose and nozzle until it reaches the desired point.

Fire streams are intended to reduce high temperatures from a fire and provide protection to firefighters and exposures through the following methods:

* Applying water or foam directly to burning material to reduce its temperature.

* Applying water or foam over an open fire to reduce the temperature, so fire fighters can advance hand line closer to effect extinguishment.

* Reducing high atmospheric temperature.

* Dispersing hot smoke and fire gases from a heated area by using a fire stream.

* Creating a water curtain to protect firefighters and property from heat.

Water has extinguishing properties with its ability to extinguish fire in several ways. The primary way is by cooling, which removes the heat from the fire. Another way is by smothering, which includes water’s ability to absorb large quantities of heat and also to dilute oxygen.

Water when you put water a fire or smoldering object creates steam.

The steam produced by a fire stream can be an aid to a fire extinguishment by smothering, which is accomplished when the expansion of steam reduces oxygen in a confined space.

Several characteristics of water that are extremely valuable for fire extinguishment are as follows:

* Water is readily available and inexpensive.

* Water has a grater heat-absorbing capacity than other common extinguishment agents.

* Water changing into stream requires a relatively large amount of heat.

* The greater the surface area of the water exposed, the more rapidly heat is absorbed.

To produce effective fire streams, it is necessary to know the effects of factors affecting pressure loss and gain. Two important factors that affect pressure loss and gain in a fire stream are friction loss and elevation. Pressure changes possible due to friction loss in a hose and appliances. A loss or gain in pressure may result due to elevation and direction of water flow up hill or down hill.

Friction loss is defined as that part of total pressure that is lost while forcing water through pipe, fittings, fire hose, and adapters.

One point to consider in applying pressure to water in a hose line is that there is a limit to the velocity or speed at which the water can travel. If the velocity is increased beyond the limits, the friction becomes so great that the water in the hose line is agitated by resistance. Certain characteristics of hose layouts such as hose size and length of the lay also affect friction loss.

In order to reduce pressure loss doe to friction, consider the following guidelines.

- Check for rough linings in the hose
- Replace damaged hose couplings
- Eliminate sharp bends in hose when possible
- Use adapters to make hose connections only when necessary
- Keep nozzles and valves fully open when operating hose lines
- Use proper size hose gaskets for the hose selected
- Use short hose lines as much as possible
- Use larger hose (for exp. Increase from booster hose to 1 ¾ hose or from 1 ¾ hose to 2 ½ hose) or multiple lines when floe must be increased Reduce the amount of flow (for exp. Change nozzle tips or reduce flow setting)

Elevation refers to the position of an object above or below sea level. In a fire fighting operation, elevation refers to the position of the nozzle in relation to the pumping apparatus which is at ground level. Elevation pressure refers to a gain or loss in a hose line caused by a change in elevation. When a nozzle is above the pumper there is a pressure loss, when the nozzle is below the pump, there is a pressure gain, these losses and gains occur because of gravity.

When the flow of water through fire hose or pipe is suddenly stopped, a surge is referred to as water hammer. Water hammer can often be herd as a distinct sharp clank, very much like a hammer striking a pipe. This sudden stopping results in a change in the direction of energy. This energy creates excessive pressure that can cause considerable damage to water mains, plumbing, fire hose, hydrants, and fire pumps.

SHUT OFF NOZZLES, HYDRENTS, VALVES, AND HOSE CLAMPS SLOWLEY TO PREVENT WATER HAMMER.

A water fire stream is identified by its size and type. The size refers to the volume of water flowing per min; the type indicates a specific pattern of water. Fire streams a classified in to three different sizes: low-volume streams, hand line streams, and master streams. The rate of discharge of a fire stream is measured in gallons per min(GPM) or liters per min(L/min)

- Low-volume stream-discharges less than 40gpm including those fed by booster hose lines
- Hand line stream-supplied by 1 ½ to 3inch hose which flows from 40 to 350gpm nozzles witch flows in excess of 350gpm are not recommended.
- Master stream- discharges more than 350gpm and is fed by multiple 2 ½ or 3 inch hose lines connected to a master stream nozzle. Master streams are large-volume fire streams.

A solid stream is a fire stream produced from affixed orifice, smoothbore nozzle, it is designed to produce a stream as compact as possible with little shower or spray. It has the ability to reach areas that other streams might not be able to reach, minimize the chance of steam burns to fire fighters and better penetration to the fire It can be affected by gravity, friction of the air, and wind.

When solid stream nozzles are used as hand lines they should be operated at 50psi. Used as a master stream should be operated at 80 psi.

Advantages:

- Solid streams maintain better visibility for firefighters than other types of streams.
- Have grater reach than other types of streams.
- Operate at a reduced nozzle pressure per gallon than other types of streams thus reducing the nozzle reaction.
- Have grater penetration power than other types of streams.
- Less likely to disturb normal thermal layering of heat and gases during interior structural attacks then other types of streams.

Disadvantages:

- Do not allow for different stream patterns.
- Can not be used for foam applications.
- Provide less heat absorption per gallon delivered than other types of streams.

CAUTION: Do not use solid streams on energized electrical equipment. Use fog patterns with at least 100psi nozzle pressure. Do not use wand applicators because they can be conductors.

A fog stream is a fire stream composed of very fine water droplets. The design of the fog tip is to produce different stream patterns from the nozzle. The idea of the fog nozzle is to expose the maximum water surface for heat absorption. Fog nozzles permit settings of straight stream, narrow-angle fog, and wide-angle fog. REMBER LEFT FOR LIFE RIGHT FOR FIGHT.

There are five factors that affect the reach of a fog nozzle:

- Gravity
- Water velocity
- Fire stream pattern selection
- Water droplet friction with air
- Wind

Fore water flow adjustment, it is often desirable to control the rate of water flow through a fog nozzle such as when the water supply is limited. Two types of nozzles provided this capability: manually adjusting and automatic nozzles.

Manual adjusting nozzles: you can adjust the nozzle flow by turning the dial on the nozzle

Automatic nozzles: you can adjust the nozzle flow by opening and closing the valve.

CAUTION: Water flow adjustments in manual and automatic for nozzles require close coordination between the nozzle person, the company officer, and the pump operator.

Advantages:

- The discharge pattern of fog streams may be adjusted to suit the situation
- Some fog nozzles have adjustable settings to control the amount of water being used
- Fog streams dissipate heat by exposing the maximum water surface for heat absorption

Disadvantages:

- Fog streams do not have the reach or penetration power of solid streams.
- Fog streams are more susceptible to wind currents.
- Fog streams may contribute to fire spread create heat inversion, and cause steam burns to firefighters when improperly used during interior attacks.

Maintenance of nozzles:

- Check the swivel gasket for damage or wear replace worn or missing gaskets.
- Look for external damage to the nozzle.
- Look for internal damage and debris. When necessary, thoroughly clean nozzles with soap and water using soft bristle brush.
- Check for ease of operation by physically operating the nozzle parts. Clean and lubricate and moving parts that appeared to be sticking according to manufacture’s recommendations.
- Check to make sure that the pistol grip is secured to the nozzle.

(The usual disclaimers: I am not a journalist; This is a blog that expresses an outlook and is not conclusive in any shape or manner.)

Fire Protection Training: Hose Loads

Picture this scenario, we have a fire, a fire truck, and water. We need a way to get the water from the fire truck to the fire. The best method found is by using a flexible tube we refer to as fire hose. Fire hose has been one of the most important tools for firefighters for many of years. It replaced the aging bucket brigades and aided the firefighters in a rapid method of getting the water to where it needs to be, “on the fire.”

Fire hoses are a type of flexible tube used by firefighters to carry water under pressure from the source of supply to a point where it is discharged. A fire hose is the most used item in the fire service.

Fire hoses are manufactured in different configurations such as: Single jacket, Double jacket, Rubber single jacket, or Hard rubber non-collapsing types. There are various “Fire Hose Sizes.” Each hose is designed for a specific purpose. Diameter of fire hose refers to the dimensions of the inside of the hose. Fire hose is most commonly cut and coupled into lengths of 50 or 100 feet. Intake hose is used to connect a fire department pumper or a portable pump to a near-by water source. There are also two groups of intake hose: Soft Sleeve – transfer water from a pressurized source, and Hard Suction – used primarily to draft water from an open water source.

There are many causes and prevention of fire hose damage. The fire hose is a tool that is subjected to many sources of damage. The most important factor is the care that is given after fires, in storage, and on the apparatus. A fire hose can not endure: mechanical injury, heat, mildew, mold, or chemical contacts to list a few.

There are some general hose loading guidelines related the fire hoses. These guidelines should be followed regardless of the type of hose load being used.

Check gaskets and swivel before connecting any coupling. Keep flat sides of the hose in the same plane when two sections of hose are connected. Tighten the couplings hand tight when two sections of hose are connected. Never use wrenches or undue force. Remove wrinkles from fire hose when it must be bent to form a loop in the hose bed by pressing with the fingers so the inside of the bend is smoothly folded.

Make a short fold (Dutchman) in the hose during the loading process so that couplings do not have to be turned around to be pulled out of the bed.

The loading of large diameter hoses (3 ½ inch or larger), all couplings need to be placed at the front of the bed. This procedure saves space and allows the hose to lie flat. Couplings should be laid in a manner that does not require them to turn over when the hose pays out of the bed. Do not pack hose to tight because this puts excess pressure on the folds of the hose, and causes couplings to snag when hose pays out of the bed. General rule is to allow enough room for the hand to be easily inserted between the folds.

On a fire truck there can be different types of loads and setups depending what is best for your department:

“The Accordion Hose Load,” derives its name from the appearance after loading. The first coupling is placed in the bed located to the rear of the bed. Simple design it requires only two or three people to load the hose on to the vehicle. When deployed an accordion load, you can pick up a number of folds and placing them on the shoulder.

“The Horseshoe Load,” is named for the way it appears after loading. The fire hose is laid on the edge around the perimeter of the hose bed in a U-shape. The last length is in the center of the horseshoe. The primary advantage in using this hose load is fewer sharp bends. Disadvantage is, the hose sometimes comes out in a wavy, or snakelike, lay in the street, and horseshoe loads don’t work for large diameter hose. When loading the horseshoe load in a single bed the first length may be started on either side. In a split bed, first length is started against the partition.

“The Flat Hose Load,” is the easiest to load and is suitable for any size of hose. The best way to load large diameter hose is have it laid so the folds are flat. Disadvantage to this type of hose load are folds contain sharp bends at both ends. In a singe hose bed, may be started on either side. In a split bed, lay the first length against the partition with the coupling hanging an appropriate distance below the hose bed. The flat load can be adapted for loading large diameter hose. Flat loads can also be loaded directly from the street or ground by straddling the hose with the pumper and driving slowly backward. A hose wringer or roller can be used to expel the air and water from the hose as its being placed in the hose bed. To keep the couplings from turning over, make a short fold or reverse bend (Dutchman) in the hose.

The Dutchman serves two purposes, it changes the direction of the coupling and it changes the location of the coupling.

When using the different types of hose loads for the fire truck’s supply hose lays remember to keep threaded coupling supply hose, usually arranged in the hose bed, so when hose is laid off the fire truck, the end with the female is toward the water source and the male end is toward the fire.

Several hose lays options are available, the basic hose lays for supply hose are the Forward lay (straight lay), Reverse lay, and Split lay (combination lay).

Regardless of the method chosen, the following basic guidelines should be followed when laying hose, do not ride in a standing position anytime the apparatus is moving. Drive the fire truck at a speed no greater than that which allows the couplings to clear the tailboard as the hose leaves the bed – generally between 5 and 10 miles an hour.

Once hoselines have been laid out and connected for firefighting, they must be advanced into final position on the fire ground. Advancing hoselines into a structure general safety guidelines should be observed. Place the firefighter on the nozzle and back-up firefighter(s) on the same side of the line. Check the door for heat before entering. Release (bleed) air from hoseline once it is charged and before entering the building or fire area. Stay low and avoid blocking ventilation openings such as doorways or windows. When advancing hose up a stairway the shoulder carry is adaptable to stairway advancement. Lay the hose on the outside wall of the stairs to avoid sharp kinks and bends. Excess hose should be flaked up the stairs toward the floor above the fire floor. Firefighters should be positioned at every turn or areas of resistance to ensure swift efficient deployment of the hoseline. When advancing hose down a stairway an uncharged hoseline is easier than advancing a charge hoseline and this is recommended ONLY when there is no fire present or it is very minor. Firefighters must be stationed at critical points to help feed the hoseline.

When advancing hose up a ladder this can best achieved with a uncharged line. If already charged, it is safer, quicker, and easier to drain before advancement is made. Have one firefighter at the base of the ladder to help feed the hose. Have one firefighter at the base to heel the ladder during advancement. Have the lead firefighter drape the nozzle or end coupling over the shoulder from the front on the side being carried. This firefighter advances up the ladder to the first fly section. The second firefighter drapes a large loop of hose over the shoulder and starts up. If there is a three section ladder, a third firefighter will be required. To avoid overloading the ladder, only one person should be allowed on each section of the ladder. Rope hose tools or utility straps can also be used for this advancement. If charged and necessary to advance up the ladder. Firefighters should position themselves on the ladder within reach of each other. Each firefighter should be locked in via a leg lock or ladder belt. The hose is pushed up from firefighter to firefighter. The firefighter on the nozzle takes the line into the window, and other firefighters continue to hoist additional as necessary.

Warning: caution must be exercised to ensure that the rated capacity of the ladder is not exceeded. If the hose cannot be passed up the ladder without exceeding the load limit, another method of advancement should be used.

When operating a charged line from the ladder The hoseline should be secured to the latter with a hose strap at a point several rungs below the one the nozzle person is standing. All firefighters must use a leg lock or ladder belt to secure themselves to the ladder. The firefighter on the nozzle projects the nozzle through the ladder and holds it with a rope hose tool or similar aid. When the line and firefighters are secured, the nozzle can be opened.

There may be times on the fire ground to extending a section of hose on the fire ground after being deployed. Occasionally it becomes necessary to extend a length of hose with the same size or perhaps even smaller hose. This situation is very dangerous. Start with closing a valve at the pump or hydrant to turn off the water is the safest way to control. A hose clamp may be used at a stationary point. It is possible to kink the hose at a point away from the break.

The fire hose is the most common and most used tool we have in the fire service. Each firefighter must understand the mechanics of its use and the appliances as well as tools needed to make your job more efficient and easier. Fore more information concerning fire hoses refer to the IFSTA Essentials of Fire Fighting on Fire Streams.

(The usual disclaimers: I am not a journalist; This is a blog that expresses an outlook and is not conclusive in any shape or manner.)