10 Water Supply. 10 Knowledge Objectives (1 of 3) Describe the mechanics of drafting. Describe how...

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Water Supply

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Knowledge Objectives (1 of 3)

• Describe the mechanics of drafting.

• Describe how to verify the operational readiness of the pump.

• Describe water supply management within the Incident Management System.

• Describe the process for selecting a suitable site for water drafting.

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• Describe how to position a fire pumper for drafting.

• Describe the process for establishing a pumping operation from a draft.

• Describe how to perform drafting operations.

• Describe complications for drafting operations.

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• Describe how to provide an uninterrupted water supply.

• Describe relay pumping operations.

• Describe water shuttle operations.

• Describe dump site operations.

• Describe water shuttle operations in the Incident Management System.

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Skills Objectives

• Perform the vacuum test.

• Position the hard suction hose into the water.

• Draft from a static water source.

• Provide water flow to handlines, master streams, and supply lines.

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Introduction (1 of 2)

• The driver/operator usually pumps water from an onboard tank or pressurized water source. – In rural areas and other emergencies, usual

water supplies are not available or inadequate.

– Drafting water from a static source makes the apparatus a versatile resource.

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Introduction (2 of 2)

• Driver/operator will be successful if:– The apparatus pump is in good condition.– He or she understands and applies drafting

principles.– He or she can deliver water to the incident

from a static source.

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The Mechanics of Drafting (1 of 7)

• Atmospheric pressure – Caused by the weight of the atmosphere– 14.7 psi (101 kPa) at sea level– Increased elevation from sea level decreases

pressure– The atmospheric pressure at the drafting site

is the maximum supply pressure for drafting. – Without atmospheric pressure, drafting is not

possible.

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• The engaging primer starts pumping air out of the fire pump. – Creates a vacuum: any pressure less than the

atmospheric pressure– Vacuum must be contained inside an airtight

vessel or air will rush in to refill the vacuum – As the vacuum increases in the hose, the

atmospheric pressure decreases, resulting in greater pressure outside the hose.

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• The engaging primer (continued)– The pressure difference supports a column of

liquid measured in units of inches or millimeters of Hg.

– Conversion factors used to convert inches (mm) of Hg to feet (cm) of water or psi (kPa) of pressure

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• A fire pumper in good condition should develop a vacuum of 22 in Hg (50.78 cm Hg). – Equal to lifting water 24.8’ (7.59 m) at sea level– It is possible to lift water 20+’ (6.10 m), but the

pump’s discharge capacity is restricted by the vacuum created on the supply side of the pump.

– As water is lifted to a greater height, more atmospheric pressure is required to support the water weight, reducing the available pressure to move it.

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• Pumps on the apparatus have capacity ratings established by pumping from draft. – Class A pumper must lift water 10’ (3.05 m)

through 20’ (6.10 m) of hard-sided supply hose and deliver a rated capacity at 150 psi (1034.2 kPa), as measured at the pump panel.

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Inspections, Routine Maintenance, and Operational Testing (1 of 5)

• Fire departments have a process for inspections, routine maintenance, and operational testing. – Many departments have written a report form.– Some items need special attention to ensure

operational readiness of apparatus for drafting from a static water source.

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• Inspecting the priming system – Priming: the process of removing air from the

fire pump and replacing it with water– When checking the primer oil level in the

reservoir, confirm that the anti-siphon hole is not clogged.

– Check the operation of the primer valve located on the pump panel and labeled “Primer.”

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• Performing a vacuum test– Conducted periodically to assess the

readiness of the priming system– Remove all the discharge caps and drain

booster tank before the vacuum test.

• A fire pump with damaged or leaking valves in discharge or tank lines cannot create a vacuum needed to the lift water from the static source.

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• Finding a vacuum leak– A fire pump that retains the vacuum for 5

minutes should prime and draft water easily. – Close all valves and possible vacuum leak

sources to find the suspected vacuum leak.

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Water Supply Management in ICS (1 of 4)

• Water supply management is a vital part of a fire incident.– Can become a major part of ICS when reliable

public or private water system is not available

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• Water supply officer takes on added responsibilities– Drafting operations– Relay pumping– Water shuttles– Nurse tanker operations

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• Water supply officer reports to operations section chief– Is responsible for ensuring adequate supply of

water available to mitigate the incident– If no operations section chief is designated,

the water supply officer reports to the IC.

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• Water supply officer reports to operations section chief– Water supply officers should be given priority

on any scene.– Dump and fill sites will be incorporated into

the ICS organization.

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Selecting a Drafting Site (1 of 10)

• Ensure the incident has a steady water supply – This is critical to the success and safety of the

incident response. – When drafting water is chosen for the supply,

selecting the appropriate drafting site involves determining the reliability of the static water source.

• Accessibility• Purpose of the site• Positioning of the apparatus

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• Determining the reliability of static water sources– Evaluate the reliability of the static water

source before committing to draft from it. – Factors to consider

• Accessibility• Quantity of water available• Quality of water

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• Estimating the water available– When considering a lake, there is no question

that an adequate supply will be available.

• Calculate the available water in a nonmoving source.– L W D C = Q

• Calculate the available water from a moving source.– W D V C = Q

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• Evaluating the water quality of a static source– Water should be free of aquatic weeds, moss,

algae, and other trash or debris.– Clean water is preferred over muddy or murky

water.– Sand or silt can clog nozzles and cause pump

failure.

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• Accessibility to static water sources– Safely position the apparatus close enough to

the source to completely submerge the strainer of a hard-sided supply hose once connected to the fire pump.

– Check the soil near the source edges to make sure it will support the apparatus, especially for extended wet operations.

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• Accessibility to static water sources (continued)– Once it is determined that the soil will support

the apparatus, identify a level drafting site free of trees, bushes, rocks, fences, and other obstructions limiting access.

– Access to static sources is difficult during winter.

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• Special accessibility considerations– Drafting from a bridge can help

with accessibility problems.• Be sure the bridge is designed to

support the weight of the apparatus.

– Identify drafting sites during preplanning.

– Consider installing dry hydrants where there is difficult access or when the location would be ideal.

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• Special accessibility considerations (continued)– Place portable pumps near static water sources

when accessibility with pumper is not possible.

– Use floating pumps when the water is not deep enough to allow for hard-sided drafting supply lines.

– Placing a dam in the streambed is an option for drafting from shallow flowing water sources.

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• Operational considerations for site selection– The best choice for a drafting site is determined

by the location and the purpose of operation. – As the distance from an incident increases,

water supply options are limited. – If drafting to a supply water shuttle or as source

pumper in relay, considerations apply to the selection.

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Pumping from a Draft (1 of 4)

• After finding a suitable location with an adequate and close water source, set up a pump to draft. – This task requires teamwork; be assisted by

two or more fire fighters. – Hard-sided supply hose is heavy and can be

awkward for fewer than two fire fighters.

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• Making the connection– Decide when to connect the hard suction

hose and pump. – Before connections are made, inspect

gaskets for proper placement, cracks, and debris that might affect the vacuum and draft.

– Once the necessary hose length is determined, put a strainer on the end.

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• Making the connection (continued)– Barrel strainer: used for deep water sources– Low-level strainer: designed for clean, shallow

water sources

Courtesy of Kochek Co., Inc. Courtesy of Kochek Co., Inc.

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• Making the connection (continued)– Floating strainer: operates

below surface scum, and above debris in water source

– Once all connections are made, place a hard suction hose and strainer into the water.

– With connections made and strainer secure, begin drafting.

Courtesy of Kochek Co., Inc.

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Preparing to Operate at Draft by Priming the Pump (1 of 3)

• First step: Prime the pump – Once the suction hose is connected and put

into the source, draw air from the pump using a priming pump.

– Activating the priming pump reduces atmospheric pressure inside the fire pump and hard suction supply hose.

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• Priming the fire pump is similar to testing the priming pump or conducting a vacuum test. – Ensure all drains and valves are closed.– Firmly pull the priming pump handle out until it

stops and hold it out.– Water and air are discharged under the

apparatus.– As handle is held out, the vacuum reading

appears on the supply master gauge, indicating the start of draft.

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• Priming the fire pump (continued)– More water flows out of the priming pump and

is discharged under the apparatus when air is pumped out.

– Do not stop operating the priming pump until pressure is noted on the discharge side.

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Drafting Operations (1 of 3)

• Once the pump is primed, start drafting water and producing discharge pressures. – Before supplying water to handlines, master

streams, or relay pumping operation, you will need to establish a dump line.

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• Discharge water from the dump line back into the water source and away from the strainer to avoid introducing air into the hard suction hose.– Air inflow leads to loss of the vacuum, ending

the pump’s draft. – If the dump line cannot be discharged back

into the source, discharge water onto the ground away from the drafting site.

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• Once a water flow is sustained through the dump line, attach the hose lines that will be supplied.– Lines differ depending on the purpose of the

operation. • They can speed up the operation if other crew

members make connections while driver/operator establishes the draft and dump line.

– Once water is flowing from the dump line, increase the amount of water that will flow.

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Producing the Flow of Water (1 of 3)

• Whether supplying attack lines or water for the attack pumper, make sure crews know that water flow is ready before opening the discharge valve. – Notify via radio, face-to-face, or hand signals.

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• Slowly open the corresponding discharge valve for the hose line and begin flowing water. – As with the dump line, opening too fast

causes a loss of vacuum that ends the pump’s draft.

– Increase the engine rpm to maintain draft and provide adequate discharge pressure.

– Keep increasing the throttle until the desired discharge pressure is reached.

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• Once draft is accomplished, do not drop draft until the operation is completed.– The water supply officer or IC gives the order.– Establishing the operation takes time.– Do not leave the incident without the water

supply unless directed by incident command.

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Complications during Drafting Operations (1 of 11)

• Recognize problems that may come up while attempting to draft or during operation itself. – It is the driver/operator’s responsibility to

know what the problem is and how to correct it.

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• Driver/operator must continuously observe the intake pressure while drafting. – If the pressure drops, check the strainer for

debris. – Flowing large volumes of water may draw

debris from areas not visualized when setting up.

– Wipe the strainer clean while it is underwater.– Remove debris from the water source.

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• Continuously observe engine and pump temperature gauges. – Drafting operations require components to

work hard.– Not enough water flows to keep them cool. – If supplying a dump line while waiting to fill a

tanker shuttle operation, flow less than 100 GPM.

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• If not enough water covers the strainer or if it is a strong draft, a whirlpool may form as the vacuum draws in water. – Whirlpool lets the pump suck in air, which

breaks the vacuum and causes a loss of water supply.

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• Cavitation occurs when water flows faster than it is supplied to the pump. – Cavitation during drafting is caused by a

vacuum leak, which introduces air into the intake water supply.

– Air flowing through the pump creates small water hammers along the path to the discharge point.

– Correcting vacuum leak corrects cavitation.

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• Cavitation affects the fire pump’s ability to deliver water.– Can damage the pump– Easy to diagnose because it makes a

significant fluctuation on the discharge pressure reading on the pump panel.

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• If cavitation is suspected during drafting:– Check the water around the intake screen on

the hard supply hose. – Check the vacuum reading on the master

supply gauge. – If the vacuum reading is near-normal, check

for vacuum leaks by confirming the tightness of the supply hose couplings.

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• If cavitation is suspected during drafting (continued):– If the vacuum reading is higher than normal,

check the intake screen.– The second leading cause of cavitation is a

plugged intake screen.

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• A pump’s failure to prime is a common problem that occurs during drafting operations. – Cause is often a driver/operator error– Double-check the steps required for priming

the pump.– A fire pump should prime in 30 seconds or

less.

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• Follow diagnostic steps to identify the problem and find a solution:– Note the vacuum reading on the supply master

gauge after holding the primer valve open for 20–30 seconds.

– If the vacuum reading is less than 12–15 in. Hg (30.48–38.1 cm Hg), verify that all valves on the pump control panel are closed.

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• Follow diagnostic steps to identify the problem and find a solution (continued):– If the vacuum reading is less than 12–15 in.

Hg (30.48–38.1 cm Hg), make sure that the intake screen is clean and water is not being lifted too high.

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Uninterrupted Water Supply

• Establishing an uninterrupted water supply is an important objective for any IC.

• If municipal water supplies are not readily available, the IC has to obtain an uninterrupted water supply from a:– Relay pumping operation– Tanker shuttle– Nurse tanker operation

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Relay Pumping Operations (1 of 2)

• Requires two to four pumpers – Water pumped from a water source through a

hose under pressure to an apparatus engaged in a fire suppression.

– Relay can be as simple as one pumper at a pond or lake and another pumper at the scene.

– Can be as complex as multiple pumpers needed to supply water over a long distance

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Relay Pumping Operations (2 of 2)

© Steve Redick

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Components of Relay Pumping Operation (1 of 3)

• Minimum of two fire pumpers, hose lines, and personnel

• Source pumper:– Located at the water source– Supplies water to the incident

• Attack pumper:– First unit on the scene– Supplies hose lines while operating from a

water tank

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• Relay pumpers:– Apparatus placed in the middle of a relay

pumping operation– Obtain water from the source pumper and

increase the pressure to the next pumper in the relay

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Equipment for Relay Pumping Operations (1 of 2)

• Fire hose– Primary path to get water from one pumper to

another in relay– Can be a single LDH 4” (102 mm) or 5” (127 mm)

in diameter or multiple medium-size hoses 2½” (64 mm) or 3” (76 mm) in diameter

– Single lines of LDH have a low friction loss variable.

– Overcome higher friction loss with medium-size hose lines by using two hoses for water supply

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Equipment for Relay Pumping Operations (2 of 2)

• Relay operations may require other equipment.

• No matter which hose supplies water from the source pumper, each pumper in relay and attack pumper must be equipped with an intake relief valve. – Most modern pumpers are equipped with

valves, but older pumpers may need to be retrofitted.

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Personnel for Relay Pumping Operations

• Safe relay operation requires adequate personnel.

• At least two crew members should be assigned to each fire pumper.– Driver/operator’s responsibility is to operate

the pump and manage intake and discharge pressures.

– Second fire fighter is responsible for managing the area around the apparatus to ensure safety.

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Preparing for Relay Pumping Operation (1 of 2)

• Length of relay operation is determined by the distance from the water source to the incident

• Amount of water required by the attack pumper and the size of the supply line affect if and how many relay pumpers are required.

• Supply hose is critical for successful relay operation.

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Preparing for Relay Pumping Operation (2 of 2)

• Once the hose is in place for a relay, determine whether the relay pumper is needed.– Calculate the amount of friction loss for the

length of hose lay

• Adapters, reducers, manifolds, and appliances are used in a relay pumping operation.

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Types of Relay Pumping Operations

• Calculated flow relay: – Requires the source pumper driver/operator

to obtain the required GPM from the attack pumper

• Constant pressure relay: – Source and relay pumpers supply a constant

pressure and flow for the operation regardless of the flow discharged by the attack pumper.

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Operating the Source Pumper (1 of 2)

• Relay pumping operation starts at the source pumper, so it should be the largest fire pump.

• When setting up the source pumper at a static source, consider the maximum water available for the operation.

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Operating the Source Pumper (2 of 2)

• Whether supplying the next pumper or attack pumper, the same steps apply:– Open the discharge valve.

– Slowly flow the water while advancing the throttle

– When desired pressure is reached, set the pressure relief valve to prevent pump damage.

• Establishing the relay pumping operation from the hydrant is the same as using the hydrant as a supply source.

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Operating the Attack Pumper

• Getting water from the source pumper is critical to continued operations and fire fighter safety.

• Slowly open the intake valve while backing down the throttle until the valve for the supply line fully open.

• Advise the source pumper of water needed and indicate whether incoming pressure is sufficient to maintain 20+ psi (138+ kPa) of residual pressure.

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Operating the Relay Pumper (1 of 2)

• Lay out the hose between yourself and the next pumper and supply the required pressure and volume to the next pumper or attack pumper.

• The relay pumper is ready when the supply hose to the pumper and the discharge hose to the next pumper are connected.

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Operating the Relay Pumper (2 of 2)

• A relay pumper driver/operator monitors the incoming residual pressure from the source or other relay pumper.

• Once flow is stabilized, set the pressure relief valve or governor to prevent damage to the fire pump.

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Water Relay Delivery Options

• The last pumper in the relay operation may supply two attack pumpers.

• To use a manifold in a relay operation, the last relay pumper provides a supply line to the manifold via LDH from the discharge port.

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Joining an Existing Relay Pumping Operation (1 of 2)

• Most relay operations are set up all at once from the beginning of an incident.

• Many departments that use relay operations because of limited water supply use relay valves in long hose lays.– Relay valve lets the apparatus hook into the

relay without shutting down the operation

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Joining an Existing Relay Pumping Operation (2 of 2)

• If a relay valve is not in use, hooking into an existing relay operation is more complex.

• Contact the source pumper that the apparatus is ready for water.

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Pressure Fluctuations

• Needs and capacity of the attack pumper affect all others in the relay operation.

• Sometimes the driver/operator must manually adjust the pump pressures.– Pressure is not a concern unless it is greater

than 200 psi (1379 kPa).

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Shutting Down a Relay Pumping Operation

• Terminate a relay operation ordered by the IC or water supply officer after careful consideration.

• When shutting down, the attack pumper acts first.

• The source pumper closes the hydrant to stop water flow into the pump.

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Safety (1 of 2)

• Safety cannot be overlooked when conducting relay pumping operations.

• Incident safety improves when crew members have appropriate training and knowledge of equipment, and practice using it.

• Address communication as part of the relay operation.

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Safety (2 of 2)

• Causes of safety concern:– Fire hoses– Personnel working around the relay pumping

operation– Use of PPE

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Water Shuttle (1 of 5)

• In rural and remote areas, water must be carried to the scene in a water shuttle. – Tanker or tender used for operation

• A water shuttle includes tankers, fill sites, and dump sites. – Fill site: where tankers get water tanks filled– Dump site: where tanker offloads water– Water shuttles can be large and complex

operations.

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• Establish a fill site using a hydrant.– Can be simple if the hydrant has a flow

pressure of at least 50 psi (345 kPa)

• Establish a fill site at a static water source.

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• Fill sites in inaccessible areas– May not be able to get close to a static water

source because the area is blocked– Consider using portable pumps to get water to

the tankers.– Once the area is ready, connect the hard-

sided suction lines to the pump and place the strainer on the intake end of the hose.

– Portable floating pumps are popular.

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• Filling tankers– Whether the fill site is supplied by a hydrant or

pumper, the same procedure is used. – Fill one at a time when using medium-size

hose lines.– Having two hose lines with control valves and

personnel at either ends ready to connect to the tankers increases operation speed and reduces turnaround times.

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• Filling tankers (continued)– Once the tank is full on the tanker, close the

control point valve before closing the tank fill valve on the tanker.

– This sequence allows for the disconnection of the hose from the tanker since there is less pressure.

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Safety for Water Shuttle Operations (1 of 2)

• Water shuttle operations present the same risks encountered in relay operations.

• Steps to improve incident safety:– Preplan locations for obtaining water.– Be trained in use and operation of equipment.– Know which equipment to use.

• Communication between tankers and fill sites may require a separate radio frequency.

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Safety for Water Shuttle Operations(2 of 2)

• Personnel at fill sites need the same level of PPE as during relay operation to protect from:– Falling equipment– Catastrophic equipment failures– Traffic

• Extreme caution must be emphasized while driving tankers because they handle differently from standard pumpers.

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Establishing Dump Site Operations (1 of 3)

• Establishing a dump site location takes practice and forethought. – Site should be on firm, level ground and not

susceptible to significant changes from apparatus movement or getting wet from water.

– Location must be large and strong enough to support the weight of the water and incoming tankers.

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• Establishing dump site location (continued)– Location should provide enough room for the

movement of tankers in and out. – Large parking lots and fields that are flat and

smooth make excellent dump sites.

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• In cases with no intersections or large parking lots, do not obstruct the flow of additional responding apparatus or tanker shuttle by placing portable tanks in the road. – Give thought to which way the tanker will

offload.– Once a good site is determined, set up

portable tanks and create a static source for the source pumper.

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Using Portable Tanks

• Portable tanks should hold as much water as the capacity of the tanker allows.

• Before deploying the portable tank, cover the ground where the tank will be with a salvage cover or tarp to prevent damage to the tank.

• The tank is filled by a tanker before entering the water shuttle operation.

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Offloading Tankers (1 of 3)

• Driver/operator reviews the dump site characteristics on arrival to ensure that the tanker can access the location. – The driver/operator should know the vehicle

better than anyone.

• Once the tanker is positioned at the dump site, it is easy to unload through the dump valve.

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• In older tankers, water is released manually by personnel at the dump tank.

• Some tankers are equipped with a jet dump to offload water.

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Use of Multiple Portable Tanks

• Standard practice in rural firefighting

• Tanks are positioned at a high point of ground, sloping downward.– Many tanks are equipped with two drains so

they can be hooked together.– Jet siphon adaptors use a hard suction hose

as a pathway for flowing water forced through the hose by Venturi forces.

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Source Pumper Considerations

• Main objective in moving water from one tank to another when using multiple tanks:– Keep main portable tank full.

• After the source pumper establishes draft from a static water supply, prevent air from being introduced into the pump.

• Main tank should not run low on water during the operation if the tanker shuttle is working as designed.

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Traffic Flow (1 of 2)

• Movement of tankers into and out of the dump site can cause congestion.

• Most tankers can offload from the sides and rear, giving the driver/operator more freedom in deciding a travel direction into the dump site and how to approach the portable tank.

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Traffic Flow (2 of 2)

• Once tanker offloading is known, determine the best direction of approach to the portable tanks.– Place portable tanks in as open an area as

possible to allow easy maneuverability around the site.

• All tankers should travel the same path to enter and exit the dump site.– Communicate the traffic plan to all tanker

driver/operators.

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Nurse Tanker Operations (1 of 5)

• Offloading a tanker into another tanker or pumper as a water source – Operation eliminates portable tanks; the attack

pumper is supplied directly by the nurse tanker. – Nurse tanker operation is set up when there is no

room to establish a dump site, relay operation, or both.

– Performed at the start of an incident to provide water to the attack pumper while relay or fill-and-dump operation is established

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• Ideal nurse tanker is the largest tanker available because it serves as the primary water source for fire attack. – Tractor-trailer tankers are good choices

because they can be supplied by smaller tankers through a second nurse tank operation.

– Nurse tanker must have a fire pump to supply water to the attack pumper.

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• Most tractor-trailer tankers have a small pump on the trailer to assist with offloading. – Larger pump on the tanker means more water

can be supplied with greater pressure. – Nurse tanker can function like a combination

of a contained portable tank and source pumper if positioned near the attack pumper.

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• Other tankers can supply a new “source.”

• When filling the nurse tanker, do not fill too fast. – Avoid or limit air in the water. – Use two medium-size hose lines at 50 psi

(345 kPa) to fill the nurse tanker.

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• Communication for tanker operations– Communication is vital on the fire ground.– Tanker driver/operator must communicate

locations within shuttle flow and indicate whether he or she is filling or returning to a dump site.

– Staying in communication maintains accountability for each tanker and personnel.

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Water Shuttle Operations in ICS (1 of 3)

• A sustainable water supply is a vital part of the fire incident scene. – Water supply officers are given top priority at

the scene.– Once the water shuttle operation is

established, the water supply officer should be established as part of ICS.

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• The dump site officer is responsible for establishing the dump site, creating traffic patterns, and ensuring the source pumper at the site has a sustained supply. – For a complex incident with multiple dump

sites, officers may be responsible for all of them and have to coordinate larger flow between the fill site and each dump site depending on demands.

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• The fill site officer is responsible for establishing fill site location(s), ensuring a water source for filling tankers will meet demand, and creating traffic patterns in and out of the fill site. – Filling two tankers at once requires a strong

source. – Ultimate goal: to provide an uninterrupted

water supply to the fire incident

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Summary (1 of 3)

• The ability to draft water from a static source makes the apparatus a versatile resource.

• Fire departments have a process for performing inspections, routine maintenance, and operational testing of supply apparatus and mechanisms.

• Water supply management is a vital part of the fire incident and can be a major part of ICS if reliable public or private water is not available.

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Summary (2 of 3)

• Drafting operations, relay pumping, water shuttles, and nurse tanker operations become the responsibility of the water supply officer.

• Driver/operator should be assisted by two or more fire fighters.

• Driver/operator must identify problems with the drafting operation and know how to correct them.

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Summary (3 of 3)

• In a relay operation, water is pumped from a source through a hose under pressure to the apparatus engaged in fire suppression efforts.

• Establishing a dump site location to create a static source for a firefighting operation takes practice and forethought.

• Having a sustainable water supply is a vital part of a fire incident scene.

10 Water Supply. 10 Knowledge Objectives (1 of 3) Describe the mechanics of drafting. Describe how...

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