14 Chapter 13: Hose Operations and Hose Streams

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Essentials of Firefighting

Fire hose carries water from the hydrant or water source to the pumper/quint and then to the fire. Supply hoses transfer the water from its source to an apparatus fire pump. The pump controls the pressure and forwards the water through attack hoselines to where it is needed. Nozzles create hose streams to apply the water to the fire to accomplish extinguishment.

This chapter describes the background and skill knowledge you will need to learn about:

• Supplying water
• Deploying hose
• Advancing hoselines
• Hose streams and nozzles
• Applying hose streams

Now what?

Let’s get learning!

Lesson 1

Supplying Water

Water is easily stored and can be transferred over large distances in well-designed distribution systems. Familiarize yourself with the types of water supply distribution systems in your community. This section provides the knowledge and skills needed to connect to water supplies: fire hydrants and mobile water supplies. Fire Hydrants Although the initial source of water that firefighters may use is the water tank on their pumper, the most depend-able sources are fire hydrants near the incident. Fire hydrants can provide a consistent volume of water under constant pressure (Figure 13.1). However, hydrants and water supply systems can fail. When hydrants fail to provide sufficient volume or pressure, it is necessary to select an alternative water supply.

Failures or reduction in water supply (volume) or pressure from hydrants can result from:

• Damaged hydrant valves and connections
• Broken water mains
• Greater demand than the system can provide
• Hydrants located on dead-end water mains
• Closed isolation valves
• Restricted mains
• Pipes or hydrants that are frozen

Because hydrants are a basic tool used in fire fighting, you must know hydrant types, markings, use, inspections, and maintenance. Hydrant testing may be performed by firefighters, inspectors, water department personnel, or private contractors.

In general, fire hydrant bonnets, barrels, and foot pieces are made of cast iron. The internal working parts are usually made of bronze; valve facings may be made of rubber, leather, or composite materials. The primary types of fire hydrants used in North America are dry-barrel and wet-barrel. While they serve the same purpose, their designs and operating principles differ considerably.

Regardless of the location, design, or type, hydrant discharge outlets are considered standard if they contain the following two components:

1. At least one large (4 or 41⁄2-inch [100 mm or 115 mm]) outlet often referred to as the pumper outlet nozzle or steamer connection
2. Two hose outlet nozzles for 21⁄2-inch (65 mm) couplings

Hydrant specifications require a 5-inch (125 mm) valve opening for standard three-way hydrants and a 6-inch (150 mm) connection to the water main. The male threads on all hydrant discharge outlets must conform to the female hose couplings that the local fire department uses. NFPA 1963, Standard for Fire Hose Connections, sets regulations for the number of threads per inch and the outside diameter of the male thread.

Dry-Barrel Hydrants

Designed for use in climates with freezing temperatures, the main control valve of the dry-barrel hydrant is located at the base or foot of the hydrant below the frost line, and it has an isolation valve on the distribution line (Figure 13.2). The stem nut used to open and close the control valve is on top of the hydrant. Water is only al-lowed into the hydrant when the stem nut is operated. Any water remaining in a closed dry-barrel hydrant drains through a small drain valve that opens at the bottom of the hydrant when the main valve approaches a closed position. Turning the stem in a counterclockwise direction opens the valve. Turning the stem in a clockwise direction closes the valve.

Wet-Barrel Hydrants

Wet-barrel hydrants have water in the hydrant at all times (Figure 13.3). These hydrants are usually installed in climates without prolonged periods of subfreezing weather. Horizontal compression valves are usually at each outlet, but there may be another control valve in the top of the hydrant to control the water flow to all outlets.

Out-of-Service Hydrants

When a hydrant is taken out-of-service, the water department or fire department should take the following actions:

• Place “out-of-service” tags or devices on the hydrant.
• Notify fire station personnel within the response district the hydrant serves that it is out-of-service and approximately when it will return to service.
• Notify hydrant repair personnel.

If water is seen bubbling up out of the ground at the base of a dry-barrel hydrant when the hydrant is fully open, a broken component in the hydrant barrel is allowing water to get past the drain opening. This hydrant should be reported to the water authority that will mark it out-of-service until it is repaired.

Other reasons for a hydrant to be out-of-service may include:

• Damage to the hydrant, water system piping, or pump that support that location.
• Repairs or upgrades being performed on the water system.
• Obstructions placed within the hydrant.
• A frozen hydrant during extreme cold temperatures.

Fire Hydrant Connection Tools

Firefighters use a variety of tools when making fire hydrant connections, including (Figure 13.4):

• Spanner wrenches
• Hydrant wrenches
• Rubber mallets
• Gate valves
• Hydrant valves

Some of the most common tools used to tighten or loosen hose couplings include the spanner wrench, hydrant wrench, and the rubber mallet. Hydrant wrenches are primarily used to remove discharge caps from fire hydrant outlets and to open fire hydrant valves. The hydrant wrench has a pentagonal opening in its head that fits most standard fire hydrant operating nuts. The lever handle may be threaded into the operating head to make it adjust-able, or the head and handle may be the ratchet type. The head may be equipped with a spanner to help make or break coupling connections. A rubber mallet can be used to tighten or loosen hose couplings. Striking the lugs with a rubber mallet makes it easier for firefighters to achieve an airtight connection.

Fire Hydrant Connections

According to NFPA standards, personnel should operate and inspect fire hydrants at least once a year to verify reliable function and address needed repairs. You must know how to operate fire hydrants in order to:

• Provide water through hoses for fire suppression operations.
• Flow water from hydrant discharge openings to flush sediment.
• Perform periodic inspections.
• Ensure proper operation of valves and caps.
• Assist in flow tests.

Considerations for wet and dry-barrel hydrants

All hydrants must be opened and closed slowly to prevent damage to fire hose, hydrants, and other equipment, or injury to firefighters (Figure 13.6). Opening a hydrant too fast may cause the connected fire hose to flail uncontrollably as water pressure straightens the hose. Closing a hydrant too fast may cause a surge in pressure (water hammer) within the water supply system, which can damage the system piping or appliances attached to the system such as water heaters in adjacent residences. Skill Sheet 13-1 provides the steps for connecting soft-sleeve suction and hard-suction hoses.

Considerations specific to dry-barrel hydrants

To prevent freezing, the dry-barrel hydrant main valve is located underground below the frost line. Normally, the hydrant barrel from the top of the stem down to the main valve is empty. This prevents water in the barrel from freezing during extended periods of subfreezing temperatures. When the stem nut is turned counterclockwise, the main valve moves down and allows water to flow into the hydrant.

As the main valve moves down, a drain valve plate attached to the stem closes a drain hole located near the bottom of the hydrant, but allows water to flow past it into the hydrant barrel. Slowly turning the stem nut clockwise shuts down the hydrant. The main valve rises and shuts off the flow of water into the hydrant barrel. At the same time, the drain valve plate rises, opening the drain hole. The remaining water in the hydrant barrel empties through the drain hole.

Additional precautions should be taken when operating dry-barrel hydrants in areas where subfreezing weather is common. If a dry-barrel hydrant is not opened fully, the drain may be left partially open. The resulting flow through the drain hole can erode the soil around the base of the hydrant. Over time, this erosion can destroy the hydrant’s support and cause it to leak badly. This can put the hydrant out of service and necessitate it being rein-stalled. Therefore, dry-barrel hydrants should be either completely open or completely closed. When a dry-barrel hydrant is shut down, verify that the water in the hydrant barrel is draining out.

To test the water level, take the following steps:

1. Turn the stem nut clockwise until resistance is felt to close the main valve, then turn it a quarter-turn counterclockwise.
2. Cap all discharges except one.
3. Place the palm of one hand over the open discharge.

If the hydrant is draining, a slight vacuum should be felt pulling the palm toward the discharge. If this vacuum is not felt, repeat the entire process and try again. If the hydrant still is not draining, the drain hole is probably plugged. Notify the water authority and have them inspect the hydrant. If thisoccurs in winter, the hydrant must be pumped until empty to prevent the water from freezing in the barrel before the hydrant is repaired or replaced. 

Soft Intake Connections

Connecting the pumper to the hydrant with a soft suction hose was described in Chapter 12, Fire Hose. However, not all hydrants have large steamer outlets capable of accepting direct connections from soft intake hose. Operations on hydrants equipped with two 21⁄2-inch (65 mm) outlets require the use of two 21⁄2-or 3-inch (65 mm or 77 mm) hoselines (Figure 13.7, p. 594). These smaller intake hoses can be connected to a siamese at the pump. It is more efficient to connect a 41⁄2-inch (115 mm) or larger intake hose to a hydrant with only 21⁄2-inch (65 mm) outlets. That connection is made by connecting a 41⁄2-inch (115 mm) hose, or whatever size intake hose coupling is used, to a 21⁄2-inch (65 mm) reducer coupling

Hard Intake Connections for Dry-Barrel Hydrants

Connecting a pumper to a fire hydrant using hard intake hose requires coordination and teamwork because more people are needed to connect hard intake hose than are needed to connect soft intake hose. Making hydrant connections with some types of hard intake hose is also considerably more difficult than making connections with a soft intake hose. The first aspect that is important is the positioning of the pumper in relation to the hydrant. No definite rule can be given to determine this distance because not all hydrants are the same distance from the curb or road edge, and the hydrant outlet may not directly face the street or road. While most apparatus have pump intakes on both sides, others may have one at the front or rear. It is considered good policy to stop the apparatus with the intake of choice just in front of the hydrant outlet (Figure 13.8). Depending on local protocols, the hard intake hose may be connected to either the apparatus or the hydrant first when making hydrant connections.

Mobile Water Supply Operations

Many rural areas lack public water distribution systems or they have systems with inadequate volume and pressure for fire fighting operations. In those areas, rural water supply operations must be performed. Two common operations are water shuttle operations and relay pumping. For these operations to succeed, pre-incident planning and frequent practice are required. The following sections briefly explain each of these operations. For additional information on rural water supply operations, see the IFSTA Pumping Apparatus Driver/Operator Handbook and NFPA 1142, Standard on Water Supplies for Suburban and Rural Fire Fighting.

Static Water Sources

Static water supplies or sources are those that may be accessed through drafting.

Static water sources may include (Figure 13.9):

• Lakes
• Ponds
• Rivers
• Swimming pools
• Large above ground animal watering tanks
• Portable water tanks

Vehicle access and drafting capability are critical in using static water sources. If the water source is inaccessible or the ground around the water source will not safely support the pumping apparatus, then it will not work as a static water source. Skill Sheet 13-2 describes the process of connecting and placing a hard-suction hose for drafting from a static water source. Intake Strainers Intake strainers are attached to the drafting end of a hard-suction hose when pumping from a static water source. They are designed to keep debris from entering the apparatus or portable pump. Such debris can either damage the pump or pass through it to clog the nozzle. Intake strainers must not rest on the bottom of a static water source except when the bottom is clean and hard, such as the bottom of a swimming pool. To prevent a strainer from resting on the bottom of a lake or pond, tie one end of a length of rope to the eyelet on the strainer and the other to an apparatus or another anchor point. Floating intake strainers are also available to keep the intake strainer off the bottom of a static water source.

Water Shuttle Operations

Water shuttle operations involve hauling water from a supply source (fill site) to the incident scene. The water is then transferred to an attack pumper’s tank or to portable tanks (dump sites) from which water may be drawn to fight a fire.

There are three key components to water shuttle operations (Figure 13.10):

1. Dump site at the fire
2. Fill site at the water source
3. Mobile water supply apparatus to haul water from the fill site to the dump site

The dump site is generally located near the fire or incident. It usually consists of one or more portable water tanks into which mobile water supply apparatus deposit water before returning to the fill site. Apparatus attacking the fire may draft directly from the portable tanks, or other apparatus may draft from the tanks and supply the attack apparatus (Figure 13.11). Low-level intake devices and floating strainers permit use of most of the water in the portable reservoir. With some special exceptions, there are two One is the collapsible or folding style that uses a square metal frame and a synthetic or canvas duck liner. Another style is a round, self-supporting synthetic tank with a floating collar that rises as the tank is filled (Figure 13.12). These frameless portable tanks are widely used in wildland fire fighting operations.

Before opening a portable tank, a salvage cover or heavy tarp should be spread on the ground to protect the tank’s liner once water is dumped into it. When the situation permits, portable tanks should be as level as possible to ensure maximum capacity. The tank should be positioned in a location that allows easy access from multiple directions but does not inhibit access of other apparatus to the fire scene. The tank discharge outlet should be on the downhill side to allow for easy draining after operations. Portable tanks should be set up so that more than one mobile water supply apparatus can offload at the same time. Ensure that the drain is located on the downhill side of the tank and away from the drafting tank. After use, the tarps, tanks, and siphons will be wet and dirty. They must be cleaned and dried before storage.

Consult Skill Sheet 13-3 for the steps in deploying a portable water tank.

When large quantities of water must be maintained, multiple portable tanks get set up. One portable tank is used for the attack pumper, while the mobile water supply apparatus dump into the other tanks. When two portable tanks are used, they can be interconnected through their drain fittings. If multiple portable tanks are needed, jet siphon devices can be used to transfer water from one tank to another (Figure 13.13). A jet siphon uses a 11⁄2-inch (38 mm) discharge line connected to the siphon. The siphon is then attached to a hard suction hose placed between two tanks.

There are four basic methods to unload mobile water supply apparatus including:

1. Gravity dumping through large (10-or 12-inch [250 mm or 300 mm]) dump valves
2. Jet-assist dumps that increase the flow rate
3. Apparatus-mounted pumps that off-load the water
4. Combination of these methods

To fill mobile water supply apparatus quickly, use the best site or hydrant available, large hoselines, multiple hoselines, and, if necessary, a pumper for adequate flow. Multiple portable pumps may be necessary. Fill sites and dump sites should be arranged so a minimum of backing or maneuvering of apparatus is required.

Deploying Hose

Fire hose carries water from the hydrant or water source to the pumping apparatus. Handlines carry water to points of fire attack at the scene and are deployed from the pumping apparatus. The following sections describe hose deployment tools and deployment methods.

Hose Deployment Tools

Hose deployment tools assist with the movement, handling, protection, and connecting of hose.

Common deployment hose tools include:

• Hose roller
• Hose bridge or ramp

• 

  Chafing block

• Hose strap, hose rope, and hose chain

Hose Rollers

Hose rollers are available in different varieties for different uses as follows:

• Edge protection: These hose rollers protect hose from the damage of dragging hose over sharp corners such as roof edges and windowsills.
  • This device consists of a metal frame with two or more rollers.
  • The notch of the frame is placed over a potentially damaging edge or windowsill, and the frame secured with a rope or clamp.
  • The hose is then pulled across the rollers.

  • 

    The hose roller can also be used to protect rope when hoisting tools over similar edges (Figure 13.14).

• Large-diameter hose (LDH) drainage: These hose rollers are used to quickly drain water from LDH hose before the hose is repacked and stored (Figure 13.15).
• Hose collection: Traditionally, these were limited to hand-cranked spools that allowed fast retrieval of hose.
  • Newer models are walk-behind devices that collect hose after an incident (Figure 13.16).

Hose Bridge

Hose bridges, also known as hose ramps, prevent damage to fire hose when vehicles must drive over it. They should be used wherever a hoseline is laid across an area where it may be driven over (Figure 13.17). Hose ramps can be placed over small spills to keep hoselines from becoming contaminated, and they can be used as chafing blocks.

Chafing Block

Charged hoselines vibrate and rub against other surfaces which can cause abrasions. Chafing blocks protect fire hose from these abrasions. Chafing blocks are particularly useful near pumperswhere intake hose comes in contact with pavement or curbs because vibrations from the pumper may keep the intake hose in constant motion (Figure 13.18). Chafing blocks may be made of wood, leather, or sections of old truck tires.

Hose Strap, Hose Rope, and Hose Chain

Hose straps, ropes, and chains are used to carry, pull, or handle charged hoselines. They provide a more secure means to handle pressurized hose when applying water. They may also be used to secure hose to ladders and other fixed objects (Figure 13.19).

Hose Valves and Appliances

A hose appliance is any hardware used with fire hose to control the flow of water and create pathways for water through hose layouts. Common hose appliances include valves and valve devices, fittings, and intake strainers.

Valves

The following valves are used in hoselines, at hydrants, and at pumpers to control the flow of water:

• Ball valves: Used in pumper discharges and gated wyes. Ball valves are open when the handle is in line with the hose and closed when it is at a right angle to the hose. Ball valves are also used in fire pump piping systems.
• Butterfly valves: Used on large pump intakes and incorporates a flat baffle that turns 90 degrees. Most are operated manually using a quarter-turn handle, but some are operated using an electric motor and can be con-trolled remotely. The baffle is in the centre of the waterway and aligned with the flow when the valve is open.
• Clapper valves: Used in siamese appliances and fire department connections (FDC) to allow water to flow in one direction only. Clapper valves prevent water from flowing out of unused ports when one intake hose is connected and charged before adding more hose. The clapper is a flat disk hinged at the top or one side which swings open and closed like a door.
• Gate Valves: Gate valves are used to control the flow from a hydrant. Gate valves have a baffle that is lowered into the path of the water by turning a screw-type handle.

Valve Devices

Valve devices allow the number of hoselines operating on the fire-ground to be increased or decreased. These devices include wye appliances, siamese appliances, water thief appliances, large-diameter hose appliances, and hydrant valves.

Wye appliances

Wye appliances divide a single hoseline into two or more lines. All wyes have a single female inlet and multiple male outlet connections. Gated wyes have valve-controlled outlets. Ball valves are generally used in gated wyes. One of the most common wyes has a 21⁄2-inch (65 mm) inlet that divides into two 11⁄2-inch (38 mm) 600 outlets, although other combinations are available. For high water volume operations, wyes with a large-diameter hose (LDH) inlet and two 21⁄2-inch (65 mm) outlets are used. Hoselines equipped with wye appliances are typically used in connection with a reverse layout because the wye connection fastens to the 21⁄2-or 3-inch (65 mm or 77 mm) supply hose. One person performing two consecutive operations can unload these hoselines.

Remove the attack lines in hose bundles or disconnect the pre-connected hoselines and place them on the ground behind the apparatus with any necessary nozzles and adapters. Then remove the wye and enough hose to supply the smaller attack lines connected or to be connected to the wye. Kneel on the supply hose to anchor it as the apparatus drives slowly toward the water source.

Siamese appliances

Firefighters sometimes confuse siamese and wye appliances because of their similar appearance. While wyes divide a single hoseline into multiple lines, a siamese combines multiple lines into one line. These appliances permit supply hoselines to be laid parallel to supply a pumper or high-output device. Siamese appliances usually consist of two female inlets, with either a center clapper valve or two clapper valves (one on each side) and a single male outlet.

Some siamese appliances are equipped with three clappered inlets; they are commonly called triamese appliances or manifolds. The clapper valves are used to control the flow of the inlet streams into the single outlet stream. Siamese and triamese appliances are commonly used when LDH is unavail-able to overcome friction loss in exceptionally long hose lays or those that carry a large flow. They are also used when supplying ladder pipes unequipped with a permanent waterway.

Water Thief Appliances

In operation, the water thief resembles a wye appliance; however,

there is an inlet and outlet of matching size combined with smaller outlets that “steal” water from the main line. Larger volume water thief appliances consist of an LDH inlet and outlet and two or more 21⁄2-inch (65 mm) valve-controlled male outlets. Large-diameter hose appliances. Some fire fighting operations require water to be distributed at points along the main supply line. In these cases, an LDH water thief can be used. In other cases, when a large volume of water is needed near the end of the main supply line, an LDH manifold appliance can be used. A typical LDH manifold consists of one LDH inlet and three 21⁄2-inch (65 mm) valve-controlled male outlets.

These devices are sometimes called portable hydrants, phantom pumpers, or large-diameter distributors, depending on the locale and the configuration of the appliance. Gate valves control the flow from a hydrant. Gate valves have a baffle that is lowered into the path of the water by turning a screw-type handle.

Fittings

Fittings connect hoses and outlets of different diameters and thread types. They also protect the couplings on standpipes and on apparatus intakes and outlets. There are two main types of fittings, adapters and reducers. An adapter is a fitting that connects hose couplings with similar threads and the same inside diameter. The double-male and double-female adapters are among the most often-used hose fittings. These adapters allow two male couplings or two female couplings of the same diameter and thread type to connect. Adapters that connect two-way couplings to a threaded outlet on a hydrant are becoming increasingly common.

Reducers are another common type of hose fitting. They are used to connect a smaller-diameter hoseline to the end of a larger one. However, using a reducer limits the larger hose to supplying one smaller line only. Using a wye appliance allows the larger hose to supply two smaller ones. Other common fittings include elbows that support intake or discharge hose at the pumping apparatus. The threads on pump male discharge outlets are protected with hose caps. They are also used on the standpipe outlets in stairway risers to prevent attack line kinks.

Forward Lay

In a forward hose lay, hose is deployed from the water source to the incident. The first coupling to come off the hose bed for a forward lay should be female unless two-way couplings (Storz) are used, in which case either coupling will work. Deploying hose for a forward lay consists of stopping the apparatus at the hydrant and allowing a firefighter to safely leave the apparatus and secure the hose. The firefighter making the hydrant connection must know the proper procedures for securing and connecting to the hydrant and correct operation of the hydrant valve if one is used. When signalled, the apparatus then proceeds to the fire deploying either a single hoseline or parallel hoselines (Figure 13.20).

The primary advantage of a forward lay is that a pumper can remain at the incident scene so its hose, equipment, and tools are readily available if needed. The pump operator can see the fire suppression operation and better react to changes at the fire scene than if the pumper were at the hydrant.

Making the Hydrant Connection

Local SOPs and resources dictate the method used for connecting the fire hose to the hydrant in a forward hose lay operation. At its simplest, the firefighter takes a hydrant wrench, the finish section of hose, and preferably a radio with him or her when connecting to the hydrant. Departments that use the four-way hydrant valve may have it pre-connected to the hose or in a bag stored near the finish section.

To ensure that water arrives quickly at the pump intake, some form of communication between the driver/ operator and the firefighter at the hydrant is essential. The radio typically provides this link. If radios are not assigned to all personnel, some means of visual or audible signal must be practiced. Horns and sirens can be a problem when other apparatus respond to a scene. At a minimum, the driver/operator and firefighter making the connection should establish a time for opening the hydrant when the connecting firefighter can be sure that water will arrive before the apparatus tank is empty.

The first task when starting a forward lay is for the hydrant catcher to remove enough hose to reach the hydrant and wrap around it. The finish section of hose is usually long enough to accomplish this task. If not, place the fin-ish section, along with the hydrant wrench, on the ground near the tailboard and pull a second section from the hose bed. Next take the end of the finish section and wrap it around the hydrant base. The hydrant catcher can place a foot on the hoseline and against the hydrant to further anchor the hose. Then the firefighter signals the driver/ operator it is safe to proceed to the fire (Figure 13.21).

The procedures for making a hydrant connection from a forward lay are given in Skill Sheet 13-4.

Using Four-Way Hydrant

Valves If a long length of 21⁄2-or 3-inch (65 mm or 77 mm) hose is laid, or if the hydrant has inadequate flow pressure, it may be necessary for a second pumper to position at the hydrant to increase the line pressure. The first pumper in this scenario must have used a four-way hydrant valve if the transition from hydrant pressure to pump pressure is to be made without interrupting the flow of water in the supply hose. Another disadvantage is that one member of the crew is temporarily unavailable for a fire fighting assignment because that person must stay at the hydrant long enough to make the hose connection and open the hydrant. A four-way hydrant valve allows a forward-laid supply line to be immediately charged and allows a later-arriving pumper to connect to the hydrant.

The second pumper can supply additional supply lines and/or increase the pressure to the original line (Figure 13.22). When the four-way hydrant valve is pre-connected to the end of the supply line, the firefighter making the connection can secure the valve and the hose to the hydrant in one action. Reverse Lay When a pumper must go to the fire location before laying a supply line, a reverse hose lay should be deployed from the incident scene to the water source (Figure 13.23). This deployment is also the quickest way to lay hose if the apparatus that lays the hose must stay at the water source, such as when drafting or boosting hydrant pressure to the supply line. Hose beds set up for reverse lays should be loaded so that the first coupling to come off the hose bed is male.

When advancing a charged hoseline up a stairway, excess hose should be deployed on the stairs toward the floor above the fire floor. The weight of the water and gravity will make extending the excess hoseline onto the fire floor easier. If possible, position a firefighter at every turn or point of resistance to aid in advancement of the charged hoseline and at doorways to control the flow path of air.

Advancing a charged hoseline down a stairway can be almost as difficult as advancing one up stairs. Because deploying excess hose down the stairway would obstruct the stairs, excess hose should be stretched outside the stairway, such as in a hallway or room adjacent to the stairway, and firefighters positioned on the stairs to feed the hose down to the nozzle team.

Firefighters must also be positioned at corners and pinch points. You must also have enough hose to reach the fire including the distance in the stairs, around corners, and onto the fire floor. Skill Sheet 13-11 gives steps for advancing a hoseline up and down an interior stairway.

Standpipe Operations

While pre-connected hoselines may be able to access fires on lower floors, fires beyond the reach of these lines require that hose be carried to the standpipe outlet closest to the fire. One approach is to have preassembled hose rolls, bundles, or packs on the apparatus ready to carry upstairs and connect to the building’s standpipe system. How these high-rise packs are constructed is a matter of local preference, but the most common are hose bundles that are easily carried on the shoulder or in specially designed hose packs complete with nozzles, fittings, and tools. Hose must be carried to the fire floor over an aerial ladder or up an interior stairway.

Regardless of how the hose is brought up, fire crews normally stop one floor below the fire floor and connect the attack hoselines to the standpipe (Figure 13.29). If the standpipe connection is in an enclosed stairway, it is accept-able to connect on the fire floor. The standpipe connection is usually in or near the stairway. You can get a general idea of the fire floor layout when you observe the floor below. Be alert for pressure-relief devices and follow your SOPs for removal or connection. If 11⁄2-, 13⁄4-, or 2-inch (38, 45, or 50 mm) hose is used, placing a gated wye on the standpipe outlet will permit the attachment of a second attack hose if needed.

A 21⁄2-inch (65 mm) attack line may be used depending on the size and nature of the fire. While the standpipe connection is being com-pleted, any extra hose should be deployed up the stairs toward the floor above the fire. Skill Sheet 13-12 provides procedures for connecting to a standpipe connection and advancing an attack hoseline onto a floor. When two lines are advanced from the same standpipe connection, deploy one down the lower set of stairs and the other up the stairway to lessen the chances of the two hoselines becoming entangled (Figure 13.30).

When fire extinguishment is complete, the water in the hoselines should be drained down a floor drain, out a window, or down a stairway to prevent unnecessary water damage. When standpipes are not available but stairways are accessible, one of the safest ways to get hose to an upper story is to carry it up the stairs in a bundle and lower the female end over a balcony railing or out a window to connect to a water source. Another method is to hoist the hose and attached nozzle up to a window or landing using a rope. Improvising a Standpipe Most building codes mandate the installation of standpipes in structures three stories and higher.

However, older buildings and those less than three stories may not have standpipes or standpipe connections may be obstructed or out of service as a result of:

• Construction
• Demolition
• Tampering
• Natural disasters like earthquakes

One way to supply water to a building without a standpipe system is to create an improvised standpipe. There are two methods for improvising standpipes:

1. The interior stairway stretch
2. The outside stretch.

The interior stairway stretch is a labor-intensive task used in stairways that have an open shaft or stairwell in the centre. To improvise the standpipe, an uncharged hoseline is suspended in the middle of the stairs rather than laying it on the stairs and around each corner. Hose rolls or bundles can be carried up the stairs, secured to a hand rail and the end lowered to the point where another section is attached to it. Secure the hose to the hand rails for support at appropriate intervals to reduce the tendency of water weight to pull the hose back down once the hose is charged (Figure 13.31). Advancing a dry hoseline during interior stairway stretch should factor in the diameter of the pressurized hose relative to the space between the handrail openings.

An outside stretch can be used for lower floors of high-rise buildings. Supply hose can be hoisted up the exterior of the building to the desired floor using a rope. Because the weight of the water in the charged line can cause the hose to fall back down the building, some of the hoseline can be extended into windows and secured to available anchor points inside the building at an interval of about once every three stories (Figure 13.32).

Advancing Hose Up a Ladder If standpipes are not available, stairways are not accessible, or there is no other viable option, it may be necessary to advance the hose up a ground ladder or aerial device. Advancing fire hose up a ladder is easier and safer with an uncharged line. In most cases, the firefighter heeling the ground ladder can help feed the hose to those on the ladder (Figure 13.33). If the hose is already charged with water, it may help to drain the hose before advancing it up the ladder. The best way to advance an uncharged hoseline up a ground ladder or aerial ladder is described in Skill Sheet 13-13. To avoid overloading the ladder, only one person is allowed on each section of the ladder. Rope hose tools or utility straps can be used for this advancement. The hose can be charged once it has reached the point from which the fire at-tack will be made. When it is absolutely necessary to advance a charged line up a ladder, firefighters should follow the steps described in Skill Sheet 13-14.

Sometimes, firefighters need to operate a hoseline from a ground ladder or supported aerial ladder (the tip of the aerial ladder must be in contact with the windowsill). In these situations, firefighters should follow the steps described in Skill Sheet 13-15. Aerial platforms can be used as portable standpipes for advancing a hoseline onto a floor. A high-rise pack is placed on the platform along with the attack line crew. When the platform arrives at the desired floor and the window is opened, the hose is attached to the discharge outlet on the platform. The crew advances the hoseline onto the floor and the hose is charged.

Lesson 3

Hose Streams and Nozzles

Hose streams could simply be the direct flow of water from the water supply through the nozzle to the fire. Hose streams may also include additives such as fire fighting foam.

The following factors affect a hose stream:

• Velocity of the water/extinguishing agent
• Flow rate of the water/extinguishing agent
• Gravity
• Wind direction and velocity
• Air friction
• Operating pressure
• Nozzle design and adjustment
• Condition of the nozzle opening

Hose streams are used for the following:

• Applying water or foam directly onto burning material to reduce its temperature (Figure 13.34)
• Applying water or foam into open flames to reduce the temperature so that firefighters can advance handlines
  

  

• Reducing the temperature of the upper gas layers
• Dispersing hot smoke and fire gases from a heated area
• Creating a water curtain to protect firefighters and property from heat
• Creating a barrier between a fuel and a fire
• Performing hydraulic ventilation

Hose streams can be best described in terms of the following information:

• Patterns they form
• Nozzles that create those patterns
• Types of control valves that permit the flow of water through the nozzle
• Factors that limit a hose stream

The size of the nozzle opening or orifice and nozzle pressure determines the quantity of water flowing from the nozzle. The size of the opening also influences the reach or distance of the stream. Finally, the type of nozzle determines the shape of the hose stream. A smooth bore nozzle produces a tightly-packed solid stream of water. An adjustable pattern spray nozzle, usually referred to as a fog nozzle, produces a fog or straight stream (Figure 13.35). The sections that follow provide more detail about hose streams.

Extinguishing Properties of Water

Water is extremely valuable for fire extinguishment because:

• It is readily available.
• It is relatively inexpensive.
• It has a greater heat-absorbing capacity than most other common extinguishing agents.
• When it changes into steam, it absorbs a large amount of heat.
• It can be applied in a variety of ways.

Water extinguishes fire because water absorbs heat. When water absorbs enough heat to reach its boiling point, the water converts into water vapour or steam in a process called vaporization. At 212o F (100oC) water expands to approximately 1,700 times its original volume as it turns to steam (Figure 13.36). As the temperature increases, steam (like any gas) continues to expand. The volume of steam produced depends on the amount of water applied. The effects of this steam on conditions inside a compartment depend on where the steam is produced. In order for complete vaporization to occur, boiling temperatures must be maintained long enough for all the water to be vaporized. A solid stream of water has a smaller surface area and absorbs heat less efficiently.

When the water is broken into small particles or droplets, such as a fog pattern or broken stream, it absorbs heat and converts into steam more rapidly because more of the water’s surface is exposed to the heat. For example, 1 cubic inch (1 638.7 mm3 because a surface area of only 6 square inches (387 mm2 divided into 1/8-cubic inch (204.8 mm3 ) of ice dropped into a glass of water takes time to absorb its capacity of heat. This is ) of the ice is exposed to the water. If that cube of ice is ) cubes and dropped into the water, a surface area of 48 square inches (3 096 mm2) of is now exposed to the water. The finely divided particles of ice absorb heat more rapidly. This same principle applies to water in the liquid state.

Hose Stream Nozzles

For this manual, straight tip nozzles will be referred to as smooth bore nozzles and spray nozzles will be referred to as fog nozzles. Smooth bore and fog nozzles are used on handlines and on master stream appliances such as fixed apparatus-mounted monitors, portable monitors, and elevated monitors mounted on aerial devices. Delivery devices for broken hose streams, which the standard does not include, can be used to apply water in confined spaces that attack hoselines cannot reach.

Both categories of nozzles as well as the broken-stream delivery devices perform three main functions:

• Controlling water flow
• Creating reach
• Shaping the hose stream

Smooth Bore Nozzles

Smooth bore nozzles have a straight, smooth tip and produce a solid hose stream. They are designed so that the shape of the water in the nozzle is gradually reduced until it reaches a point a short distance from the orifice. At this point, the nozzle becomes a cylinder with a length of 1 to 11⁄2 times its inside diameter. The short, cylindrical section gives the water its round shape before discharge.

Characteristics of smooth bore nozzles:

• Operate at low nozzle pressures
• Are less prone to clogging with debris
• Can be used to apply compressed-air foam
• May allow hoselines to kink due to less pressure
• Do not allow for selection of different stream patterns

The velocity of the stream is a result of the nozzle pressure. This pressure and the size of the discharge opening determine the flow from a smooth bore nozzle. When smooth bore nozzles are used on handlines, they are usually operated at 50 psi (350 kPa) nozzle pressure. Most smooth bore master stream appliances are operated at 80 psi (560 kPa).

Some smooth bore nozzles are equipped with a single-size tip for a single flow rate and others have stacked tips to provide varied flows (Figure 13.37). When using nozzles equipped with a stacked tip, remove low-flow tips before placing the nozzle in operation if higher flows are required. Table 13.1 shows the flow rates available through various size tips at a constant pressure.

Fog Nozzles

Fog nozzles can create straight stream, narrow-angle fog, and wide-angle fog patterns. A fog nozzle’s discharge rate may be either automatic or manual. Automatic fog nozzles maintain a near constant pressure regardless of the pattern setting. Manual fog nozzles allow the nozzle operator to adjust the discharge rate at the nozzle.

Characteristics of fog nozzles are:

• Feature adjustable discharge patterns.
• Can provide protection to firefighters with a wide fog pattern.
• Can be used for a variety of applications.
• Offer a variety of nozzle choices and manufacturing options.
• Can be used to apply certain types of foam.

There are four types of fog nozzles that the fire service commonly uses (Figure 13.38):

• Basic fog nozzle: An adjustable-pattern fog nozzle in which the rated discharge is delivered at a designated nozzle pressure and nozzle setting
• Constant gallonage fog nozzle: An adjustable-pattern fog nozzle that discharges at a constant discharge rate throughout the range of patterns from a straight stream to a wide fog at a designed nozzle pressure
• Constant pressure (automatic) fog nozzle: An adjustable-pattern fog nozzle in which the pressure remains relatively constant through a range of discharge rates
• Constant/select gallonage fog nozzle: A constant discharge rate fog nozzle with a feature that allows manual adjustment of the orifice to effect a predetermined discharge rate while the nozzle is flowing

The rate of discharge from a manually adjustable fog nozzle can be changed by rotating the selector ring — usually located directly behind the nozzle tip — to a specific gpm (L/min) setting. Each setting provides a constant rate of flow as long as there is adequate nozzle pressure. The nozzle operator has the choice of making flow rate adjustments either before opening the nozzle or while water is flowing. Depending upon the size of the nozzle, the operator may adjust flow rates from 10 gpm to 250 gpm (40 L/min to 1 000 L/min) for handlines and from 350 gpm to 2,500 gpm (1 200 L/min to 10 000 L/min) for master streams. Most of these nozzles also have a flush setting to rinse debris from the nozzle. Adjust the rate of flow in small increments. Major adjustments can cause abrupt changes in the reaction forces of the hoseline that may throw firefighters off balance.

Fog nozzles are designed to operate at a variety of nozzle pressures. The designed operating pressure for most fog nozzles is 100 psi (700 kPa). Nozzles with a designed operating pressure of 75, 50, or even 45 psi (525, 350, or 315 kPa) are also available. Although these nozzles have less nozzle reaction compared to nozzles designed to operate at 100 psi (700 kPa), droplet size is much greater, fog pattern density is lower, and the hose stream has less velocity.

Broken-Stream Delivery Devices

A broken stream can be used to extinguish fires in concealed spaces in basements, chimneys, attics, or other types of concealed spaces. The nozzles that are designed to produce a broken stream include piercing nozzles, Bresnan distributors, and Rockwood cellar pipes.

Piercing Nozzle: A piercing nozzle can be used to pierce material such as stucco, block, wood, and lightweight steel in order to access fires in concealed spaces. The nozzle consists of a piercing tip, shaft, hose connection, and striking plate at the end. A control valve can be attached between its hose connection and the supply hose. The nozzle is usually driven into place with a mallet, sledgehammer, or flathead axe (Figure 13.39).

Cellar Nozzles: A cellar nozzle consists of a rotating head with outlets that distribute water in a circular pat-tern. The nozzle and hose get lowered into the cellar, attic, cockloft, or confined space through a hole cut in the overhead surface. Two commonly used cellar nozzles are the Bresnan distributor and the Rockwood cellar pipe (Figure 13.40).

Maintenance

Nozzles should be inspected after each use, and at least annually, to ensure that they work properly. Basic maintenance, care, and cleaning should be performed in accordance with the manufacturer’s recommendations. Only qualified technicians should perform technical maintenance.

Inspections include the following actions:

• Inspect the swivel gasket for damage or wear.
• Replace worn or missing gaskets.
• Look for external damage to the nozzle body, coupling, and tip.
• Look for internal damage and debris.
• Check for ease of operation of the nozzle parts.
• Ensure that the pistol grip (if applicable) is secured to the nozzle.
• Ensure that all parts are in place and in good condition.

General nozzle care includes:

• Thoroughly cleaning nozzles after each use with soap and water using a soft bristle brush.
• Following manufacturer’s recommendations for cleaning and lubricating any moving parts that are sticking.
• Storing nozzle with the control valve bale in the closed position.
• Never dropping or dragging nozzles.
• Using the flush setting on fog nozzles to remove any internal debris.
• Shutting off the water supply, removing the nozzle, and physically removing any remaining debris.

Nozzle Control Valves

Nozzle control or shutoff valves enable the operator to start, stop, increase, or decrease the flow of water while controlling the nozzle. These valves allow the operator to open the nozzle slowly, control increases to nozzle reaction, and close it slowly to prevent water hammer. There are three main types of nozzle control valves found on smooth bore, fog nozzles, and broken-stream delivery devices: ball, slide, and rotary control.

Ball Valve

Ball valves provide effective nozzle control with little effort. A smooth waterway perforates the ball. It is suspended from both sides of the nozzle body and sealed against a seat. Moving the valve handle or bale backward to open it and forward to close it can rotate the ball up to 90 degrees (Figure 13.41). With the valve in the closed position, the waterway is perpendicular to the nozzle body, blocking the flow of water through the nozzle. With the valve in the open position, the waterway is in line with the axis of the nozzle, allowing water to flow through it. Although the nozzle will operate in any position between fully closed and fully open, operating it with the valve in the fully open position gives maximum flow and performance. When a ball valve is used with a smooth bore nozzle, the turbulence caused by a partially open valve may affect the quality of the solid stream.

Slide Valve

The cylindrical slide valve control seats a movable cylinder against a shaped cone to turn off the flow of water. When the shutoff handle is in the forward position, the cylinder closes to prevent water flow past the shaped cone. As the handle is pulled back, the cylinder slides open permitting water to flow through the nozzle. Slide valves have one particular advantage: the nozzle operator controls the operating flow and resulting nozzle reaction. As a result, slide valves do not cause turbulence (Figure 13.42).

Rotary Control Valve

Rotary control valves are found only on rotary control fog nozzles. They consist of an exterior barrel guided by a screw that moves the barrel forward or backward, rotating around an interior barrel.

Rotary control valves also control the discharge pattern of the stream (Figure 13.43). This type of nozzle is commonly found in standpipe cabinets attached to occupant-use hoselines. Hose Stream Patterns Hose stream patterns are described according to size and type. Size refers to the volume or quantity of water flow-ing from the nozzle per minute. Type indicates the specific pattern or shape of the water after it leaves the nozzle. Stream Flow Rates Hose streams are classified based upon flow rate: low-volume streams, handline streams, and master streams (Figure 13.44).

The rate of discharge of a hose stream is measured in gallons per minute (gpm) or litres per min-ute (L/min) as follows:

• Low-volume stream: Discharges less than 40 gpm (160 L/min). Supplied by 3⁄4-inch (20 mm), 1-inch (25 mm), or 11⁄2-inch (38 mm) hoselines.
• Handline stream: Supplied by 11⁄2-to 3-inch (38 to 77 mm) hose, with flows from 40 to 350 gpm (160 to 1 400 L/min). Nozzles with flows in excess of 350 gpm (1 400 L/min) are not recommended for handlines. This includes initial attack lines and backup lines.
• Master stream: Discharges more than 350 gpm (1 400 L/min) and is fed by one or more 21⁄2-or 3-inch (65 or 77 mm) hoselines or large-diameter hoselines connected to a master stream nozzle. Nozzle pressures of 80 to 100 psi (560 to 700 kPa) are common with master stream devices. Master streams are large-volume hose streams created by appliances such as apparatus-mounted deck guns and ladder pipes.

The nozzle’s design and the water pressure at the nozzle determine the flow rate of discharged water. To be effective, a hose stream must deliver enough water to absorb heat faster than the fire generates it. If the heat-absorbing capability of a hose stream does not exceed the heat output from the fire, extinguishing the fire using water alone becomes impossible. The type of hose stream indicates a specific pattern or shape of the stream as it leaves the nozzle. Effective hose streams must meet or exceed the critical flow rate (Figure 13.45). They must also have sufficient reach to put water where it is needed. The major types of hose stream patterns include solid, fog, straight, and broken (Figure 13.46). The hose stream pattern may be any one of these in any size classification.

To produce an effective hose stream, regardless of type and size, several things are needed. All hose streams must have an agent (water), a pressurizing device (pump), a means for the agent to reach the discharge device (hoseline), and a discharge device (nozzle) (Figure 13.47). The following sections more closely examine the characteristics of different types of hose streams.

Solid Streams

A solid stream is a hose stream produced from a fixed orifice, smooth bore nozzle. Smooth bore nozzles produce a stream as compact as possible with little shower or spray. A solid stream can reach areas that other streams might not. It can also penetrate and saturate burning materials or debris. The reach of a solid stream can be affected by gravity, friction with air, and wind. Solid streams provide large amounts of water quickly. When a solid streams breaks up when contacting a wall or ceiling, the now-broken stream provides greater surface area to absorb heat and can be used to cool a compartment.

It is difficult to say just exactly where the stream ceases to be effective.

Observations and tests covering the effective range of hose streams classify effective streams as:

• A stream that does not lose its continuity until it reaches the point where it loses its forward velocity (break-over) and falls into showers of spray that are easily blown away (Figure 13.48).
• A stream that is cohesive enough to maintain its original shape and attain the required height even in a light, gentle wind (breeze).

The performance of a solid stream depends on the velocity of the stream resulting from the pump pressure and the size of the nozzle orifice. A nozzle pressure (NP) of 50 psi (350 kPa) will produce hose streams from smooth bore nozzles with good reach and volume. If greater reach and volume are needed, the nozzle pressure may be in-creased to 65 psi (450 kPa). Above this pressure, the nozzle and hoseline require more personnel to handle safely.

Fog Streams

A fog stream is a fine spray composed of tiny water droplets. Water droplets, in a shower or spray, form to expose the maximum water surface for heat absorption. The amount of heat that a fog stream absorbs and the rate that the water is converted into steam or vapour characterizes the desired fog steam performance.

Fog streams have the following characteristics:

• Can be adjusted to suit the situation.
• Can be used for hydraulic ventilation.
• Can be used for vapour dispersion.
• Can be used for crew protection.
• Expose the maximum water surface for heat absorption.
• May be used to cool the hot fire gas layer as well as hot surfaces.
• Have shorter reach or penetration than solid or straight hose streams (Figure 13.49). 
• Can be more affected by wind than are solid or straight hose streams.
• May disturb thermal layering in a room or compartment if applied incorrectly.
• May intensify the fire by pushing fresh air into the fire area if used incorrectly.

The angle of fog streams range from narrow to wide. A narrow-angle fog pattern has the highest forward velocity, and its reach varies in proportion to the pressure applied. A wide-angle fog pattern has less forward velocity and a shorter reach than other fog settings. See Skill Sheet 13-16 for procedures for operating a smooth bore or fog nozzle.

Straight Streams

A straight stream pattern is a semi-solid stream produced by a fog nozzle. Characteristics of straight stream patterns are similar to those of the solid stream (Figure 13.50).

Broken Streams

A broken stream is a hose stream that has been broken into coarsely divided water droplets. Specialized nozzles such as cellar nozzles, piercing (penetrating) nozzles, and chimney nozzles are designed to create broken streams. While a solid stream may become a broken stream past the break over point, a true broken stream takes that form as it leaves the discharge device (Figure 13.51). Firefighters can deflect solid or straight streams off of walls or ceilings to create a broken stream. The solid or straight stream breaks up as it is deflected, cooling hot gases above the fire. This stream is used to extinguish fires in attics, cocklofts, basements, and other confined spaces.

Hose Stream Limiting Factors

Four factors limit the reach of a hose stream:

• Gravity: Gravity not only limits the vertical and horizontal distance the hose stream will travel, it also causes solid streams to separate and lose their compact shapes.
• Velocity loss: Water loses velocity as it travels, so if there is insufficient starting pressure, the reach of the hose stream will be limited.
• Water droplet friction with air (drag): Air friction affects the water droplets in a fog stream more than it does the outer surfaces of a compact solid stream. As a result, for nozzles with the same psi and flow rate, solid streams have the longest reach.
• Wind: Wind direction and speed can considerably shorten the reach and deteriorate the shape of the hose stream. The negative effect increases on fog streams.

Lesson 4

Applying Hose Streams

Firefighters operate hoselines and nozzles to apply hose streams to control and extinguish fires.

The following sections describe:

1. Operating small hoselines
2. Operating nozzles
3. Operating large hoselines
4. Staffing master stream devices

Operating Small Hoselines

One or two firefighters can operate small hoselines, such as booster lines and 11⁄2-, 13⁄4-, and 2-inch (38, 45, and 50 mm) hoselines. Small hoselines can require additional firefighters when the hose is charged and there are obstruc-tions to negotiate.

One-Firefighter Method for Small Hoseline Operations

Skill Sheet 13-17 illustrates the one-firefighter method for operating a small hoseline.

Assigning one firefighter to operate an attack hoseline only occurs when combating a:

• Small ground cover fire
• Rubbish or trash fire
• Vehicle fire
• Rekindle during overhaul operations

Two-Firefighter Method for Small Hoseline Operations 

Two firefighters are the minimum number required for handling any attack line during interior structural operations. The nozzle operator holds the nozzle with one hand and holds the hose just behind the nozzle with the other hand. The hoseline then rests against the waist and across the hip. Holding nozzles equipped with a pistol grip is slightly different – hold the pistol grip in one hand while holding the operating bale in the other.

The backup firefighter takes a position on the same side of the hose about 3 feet (1 m) behind the nozzle operator. The second firefighter holds the hose with both hands and rests it against the waist and across the hip or braces it with the leg. The backup firefighter must keep the hose straight behind the nozzle operator. During extended operations, one or both firefighters may apply a hose strap or rope hose tool to reduce the effects of nozzle reaction.

Operating Large Attack Hoselines

Once a large attack hoseline has been advanced to the fire, it must be placed into operation. The methods described in the following sections can be used with 21⁄2-and 3-inch (65 and 77 mm) or larger attack hoselines.

One-Firefighter Method for Large Hoseline Operations

During exposure protection or overhaul operations, one firefighter may be assigned to operate a large hoseline if a master stream device is not available (Figure 13.52). To reduce fatigue during extended operations, the nozzle operator can use a hose strap or rope hose tool looped over the shoulder or reduce the nozzle flow if conditions allow. Except for limited lateral (side-to-side) motion, this method does not permit very much maneuvering of the nozzle. Skill Sheet 13-18 describes the method for one firefighter operating a large hoseline for exposure protection.

Two-Firefighter Method for Large Hoseline Operations

When two firefighters are assigned to handle a large hoseline, they may need a way to anchor the hoseline to offset nozzle reaction. Skill Sheet 13-19 illustrates the steps for handling a large hoseline with two firefighters. Another two-firefighter method uses hose straps or rope hose tools to assist in anchoring the hose. The nozzle operator loops a hose strap or rope hose tool around the hose a short distance from the nozzle placing the large loop across the back and over the outside shoulder. The operator then holds the nozzle with one hand and the hose just behind the nozzle with the other hand.

The hoseline rests against the body. Leaning slightly forward helps control the nozzle reaction. The backup firefighter again serves as an anchor about 3 feet (1 m) back. The backup firefighter also has a hose strap or rope hose tool around the hose and leans his or her shoulder forward to absorb some of the nozzle reaction (Figure 13.53).

Operating Nozzles

Because of the differing designs of handline nozzles, each one handles somewhat differently when operated at the recommended pressure. Variable pattern nozzles may handle differently at different settings. The nozzle’s water pattern may affect the ease with which a nozzle is operated. At or above standard operating pressures, handline nozzles can be difficult to control.

When water flows from a nozzle, it creates force in the direction of the stream and equal force in the opposite direction. The force in the opposite direction pushes back on the nozzle operator. The velocity and flow rate cause this nozzle reaction. The reaction acts against both the nozzle and the curves in the hoseline, sometimes making the nozzle difficult to handle. Increasing the nozzle discharge pressure and flow rate increases nozzle reaction.

The nozzle reaction that a fog nozzle causes will vary depending on its setting. When the fog nozzle is set on straight stream or narrow stream pattern, the reaction resembles that of a smooth bore nozzle. As the fog pattern widens, the reaction decreases, making the nozzle easier to handle.

During interior operation, the nozzle can be operated while the operator is on one knee. One person can usu-ally operate a nozzle on a 11⁄2-inch (38 mm) or smaller hoseline. A 13⁄4 inch (45 mm) or larger hoseline requires additional personnel to overcome the reaction and maneuver the hoseline. Handling the fog nozzle is the same as that of the smooth bore nozzle (Figure 13.54). Information on operating hoselines during fire attack is included in Chapter 14, Fire Suppression.

Friction Loss

Friction loss is that part of total water pressure that is lost while forcing water through:

• Pipes
• Fittings
• Fire hose
• Adapters

When water flows through these items, the water molecules rub against the insides, producing friction. The friction slows the water flow and reduces its pressure at the nozzle. The loss of pressure in a hoseline between a pumper and the nozzle (excluding pressure changes due to elevation) is the most common example of friction loss (Figure 13.55). Certain characteristics of hose layouts, such as hose size and length of the hose lay, also affect friction loss. The smaller the hose diameter and the longer the hose lay, the higher the friction loss at a given pressure and flow rate.

Friction loss in fire hose is increased by the following conditions:

• Rough linings in fire hose
• Sharp bends in hose
• Length of hose lay
• Increasing pump pressure
• Hose diameter

Friction loss is overcome or reduced in the following ways:

• Increasing the hose size
• Adding parallel hoselines
• Removing kinks or sharp bends from the hoseline

The difference in elevation between the nozzle and the pumping apparatus causes elevation pressure. When a nozzle is above the fire pump, there is a pressure loss. When the nozzle is below the pump, there is a pressure gain (Figure 13.56). Adjusting the pressure at the pump compensates for the changes in pressure due to gravity.

Water Hammer

When the nozzle is closed suddenly, a shock wave is produced when the moving water reaches the closed nozzle and stops with great force. The resulting pressure surge is referred to as water hammer (Figure 13.57).

This sudden change in the direction creates excessive pressures that can cause considerable damage to:

• Water mains
• Fire hose
• Plumbing
• Hydrants
• Fire pumps

At low-flow rates, water hammer is minimal. At higher flow rates, the effects of water hammer increase significantly. To prevent water hammer, slowly close nozzles, hydrants, control valves, and hose clamps.

Operating Master Stream Devices

Master streams are usually deployed when the fire is beyond the effectiveness of handlines or there is a need for hose streams in areas that are unsafe for firefighters. Proper placement of the master stream device is extremely important. Master stream devices must be properly positioned to apply an effective stream on a fire, particularly when using a fog nozzle because fog streams do not have the stream reach and penetration of solid streams. While a master stream nozzle can be adjusted up and down and right and left, it must be shut down before it can be relocated.

Moving a master stream device can be a time-consuming and labour-intensive process, causing the device to be out of operation for some time. Another consideration for master stream placement is the angle at which the stream enters the structure. Firefighters should aim the stream so that it enters the structure at an upward angle causing it to deflect off the ceiling or other overhead objects. This angle makes the stream diffuse into smaller droplets that rain down on the fire, providing maximum extinguishing effectiveness (Figure 13.58). Streams that enter the opening at a horizontal (or less) angle are not as effective.

Finally, place the master stream device where it allows the stream to cover the most surface area of the building, especially where there is a large volume of fire and a limited number of masterstream devices (Figure 13.59). Doing so allows firefighters to change the direction of the stream and to direct it into more than one opening. See Skill Sheet 13-20 for information on deploying and operating a portable master stream device.

A master stream device can provide effective exposure protection to other structures. The most effective approach is to direct the stream at the surface of the structure facing the fire. The stream should strike the surface and run down. If the surface is wide, multiple devices can be used, or one unit can sweep the face and keep it wet.

Master stream devices flow a minimum of 350 gpm (1 400 L/min), which can mean high friction loss in sup-ply hose. Therefore, it is not practical to supply master stream appliances with anything less than two 21⁄2-inch (65 mm) hoselines, except for small quick-attack devices designed to operate from a single 21⁄2-inch (65 mm) line. Conventional master stream devices may be temporarily supplied by one 21⁄2-inch (65 mm) line while adding additional hoselines.

When greater quantities of water are required, a third 21⁄2-inch (65 mm) or large-diameter supply line will be required (Figure 13.60). Some master stream devices are equipped to handle one large-diameter (4-inch [100 mm] or larger) supply line. The operation of master stream devices consumes large amounts of water that accumulate inside structures when master streams are directed into buildings. This water accumulates on floors, and the building contents may also absorb some of this water. Both accumulation and absorption of water add weight that affects structural integrity and increases the potential for structural collapse during overhaul and fire investigation activities.

Except for apparatus-mounted deck guns, deploying a master stream device and the necessary water supply hoselines will usually require a minimum of two firefighters, although more firefighters can accomplish it faster. Once a device is in place, one firefighter can operate it. When water is flowing, at least one firefighter should be stationed at the master stream device unless the device is being used in a hazardous position (close to a fire-weakened wall or near an LPG tank). The firefighter tending the device can change the direction of the stream when required and prevent pressure in hoselines from moving the device.

If the situation is too dangerous to have firefighters stationed at the device, it can be securely anchored in position. Once the device is deployed, hoselines attached and charged and the desired stream developed, personnel can be withdrawn to a safe distance. If the device starts to move, the pump operator can decrease the pressure at the apparatus to stop any movement.

Elevated master stream devices apply water to the upper stories of buildings, either as a direct fire attack or as a water supply for handlines. They can also provide exposure protection to endangered structures. Different types of aerial apparatus can deliver elevated master streams, most commonly quints, aerial ladders, and aerial platforms. Under a variety of circumstances, you may be assigned to operate an elevated master stream device or to support such an operation.

Chapter Review