Pumping Apparatus
Driver/Operator — Lesson 12
Pumping Apparatus Driver/Operator
Handbook, 2nd Edition
Chapter 12 — Static Water
Supply Sources
Learning Objectives
1. Match to their definitions terms associated
with static water sources.
2. Select facts about theoretical, maximum,
and dependable lift.
3. State the equation for determining the
maximum lift that a pumper can achieve.
(Continued)
Pumping Apparatus
Driver/Operator
12–1
Learning Objectives
4. Calculate maximum lift.
5. State the equations for determining
pressure correction and net pump
discharge pressure at draft.
6. Calculate net pump discharge pressure at
draft.
(Continued)
Pumping Apparatus
Driver/Operator
12–2
Learning Objectives
7. List types of natural static water supply
sources.
8. State the equation for determining the
adequacy of a natural stream.
9. Calculate natural stream adequacy.
10. Answer questions about the accessibility of
natural static water supply sources.
(Continued)
Pumping Apparatus
Driver/Operator
12–3
Learning Objectives
11. Dam a stream with a ladder and salvage
cover.
12. List common types of man-made static
water supply sources.
13. Select facts about various man-made static
water supply sources.
(Continued)
Pumping Apparatus
Driver/Operator
12–4
Learning Objectives
14. State the equations for determining the
capacity of various kinds of pools.
15. Calculate swimming pool capacities.
Pumping Apparatus
Driver/Operator
12–5
Static Water Source Terms
• Drafting — Raising
water from a static
source to supply a
pumper
• Lift — Elevation
difference between
static water source
and pump intake
(Continued)
Pumping Apparatus
Driver/Operator
12–6
Static Water Source Terms
• Vacuum — The pressure differential between
the inside of the pump and intake hose and
the atmosphere that allows water to be forced
into the hose and pump
• Theoretical lift — Vacuum that would allow
water to be raised by atmospheric pressure to
a height in accordance with this pressure
(Continued)
Pumping Apparatus
Driver/Operator
12–7
Static Water Source Terms
• Maximum lift — The maximum height to
which any amount of water may be raised
through a hard intake hose to the pump
• Dependable lift — The height a column of
water may be lifted in sufficient quantity to
provide a reliable fire flow
Pumping Apparatus
Driver/Operator
12–8
Theoretical Lift
• Customary — At sea level a pump can
theoretically lift water 33.8 feet. For every
1,000 feet of altitude, atmospheric pressure
decreases by about 0.5 psi.
• Metric — At sea level a pump can
theoretically lift water 10 m. For every 100 m
of altitude, atmospheric pressure decreases
by about 1 kPa.
(Continued)
Pumping Apparatus
Driver/Operator
12–9
Theoretical Lift
• Because a total vacuum is not possible in
field conditions, fire department pumpers
cannot be expected to draft water that is
located 33.8 feet (10 m) below the level of the
pump.
Pumping Apparatus
Driver/Operator
12–10
Maximum Lift
• Varies depending on
the atmospheric
pressure and the
condition of the fire
pump and primer
• Is no more than 25
feet (7.5 m) in most
circumstances
Pumping Apparatus
Driver/Operator
12–11
Calculating Maximum Lift
• Customary
L = 1.13 Hg
L = Height of lift in feet
1.13 = A constant
Hg = Inches of mercury
(Continued)
Pumping Apparatus
Driver/Operator
12–12
Calculating Maximum Lift
• Metric
L = (0.013 56)(Hg)
L = Height of lift in meters
0.013 56 = A constant
Hg = mm of mercury
Pumping Apparatus
Driver/Operator
12–13
Dependable Lift
• Every fire pump in good repair should have a
dependable lift of at least 14.7 feet (4.5 m).
• This takes into account:
– Surrounding atmospheric pressure
– Friction loss in the intake hose
(Continued)
Pumping Apparatus
Driver/Operator
12–14
Dependable Lift
• All fire pumps are rated when drafting from a
lift of 10 feet (3 m) through 20 feet (6 m) of
hard intake hose.
• As the lift or length of intake hose is
increased, the capacity of the pump
decreases accordingly.
Pumping Apparatus
Driver/Operator
12–15
Determining Pressure Correction
• Customary
Pressure correction =
Lift + Total intake hose friction loss
2.3
• Metric
Pressure correction =
Lift + Total intake hose friction loss
0.1
Pumping Apparatus
Driver/Operator
12–16
Determining Net Pump
Discharge Pressure at Draft
NPDPDraft = PDP + Intake pressure correction
NPDPDraft = Net pump discharge pressure at draft
PDP = Pump discharge pressure in psi or kPa
Pumping Apparatus
Driver/Operator
12–17
Natural Static Water
Supply Sources
• Lakes
• Ponds
• Rivers
• Oceans
Pumping Apparatus
Driver/Operator
12–18
Adequacy of Natural Static
Water Supply Source
• The adequacy of large sources is generally
not a major issue. However, fire department
personnel must evaluate small streams and
ponds with more caution when determining
their adequacy for fire protection.
Pumping Apparatus
Driver/Operator
12–19
Calculating Natural
Stream Adequacy
• Customary
Q = A x V x 7.5
Q = Flow in gpm
A = Area in ft2 (width x depth)
V = Velocity in ft/min
7.5 = A constant (the number of gallons
per ft3)
(Continued)
Pumping Apparatus
Driver/Operator
12–20
Calculating Natural
Stream Adequacy
• Metric
Q = A x V x 1 000
Q = Flow in L/min
A = Area in m2 (width x depth)
V = Velocity in m/min
1 000= A constant (the number of liters
per m3)
(Continued)
Pumping Apparatus
Driver/Operator
12–21
Calculating Natural
Stream Adequacy
• The rule of thumb for evaluating pond and
small lake capacity is that every 1 foot (0.3 m)
of depth of an area of 1 acre (0.4 ha)
(approximately the size of a football field)
provides 1,000 gpm (4 000 L/min) for 5 hours.
Pumping Apparatus
Driver/Operator
12–22
Accessibility of Natural Static
Water Supply Sources
• Common problems include:
– Inability to reach the water with a pumper
– Wet or soft ground approaches
– Inadequate depth for drafting
– Silt and debris
– Freezing weather
Pumping Apparatus
Driver/Operator
12–23
Inability to Reach the
Water with a Pumper
• Bridges too high above the water’s surface
• Bridges that will not support the weight of the
fire apparatus
• Extremely high banks
• Terrain that will not allow the apparatus close
enough to reach the water with intake hoses
(Continued)
Pumping Apparatus
Driver/Operator
12–24
Inability to Reach the
Water with a Pumper
• Problems can be avoided by:
– Using public boat launching facilities
– Constructing gravel drives
– Installing dry hydrants
– Clearing brush to drafting points with a
high potential for use
– Noting appropriate drafting sites in preincident plans
Pumping Apparatus
Driver/Operator
12–25
Wet or Soft Ground Approaches
• Soggy approaches may not support the
weight of fire department apparatus.
• Grass and vegetation can obscure holes and
soft spots.
• Settling may occur after a vehicle stops for a
period of time.
(Continued)
Pumping Apparatus
Driver/Operator
12–26
Wet or Soft Ground Approaches
• Frozen ground that allows the apparatus to
be safely driven across at first may later thaw
out and cause the apparatus to sink in place.
• Very marshy land or land with a high sand
content may be too soft to support the weight
of the apparatus.
Pumping Apparatus
Driver/Operator
12–27
Inadequate Depth for Drafting
• A depth of 2 feet (0.6 m) of water is
suggested above and below a barrel-type
strainer.
• Floating strainers may be used if water is not
deep enough for barrel-type strainers. These
strainers allow safe drafting from water as
shallow as 1 foot (0.3 m) deep.
(Continued)
Pumping Apparatus
Driver/Operator
12–28
Inadequate Depth for Drafting
• Low-level strainers can draft from portable
water tanks and can draw water down to a 1to 2-inch (25 mm to 50 mm) depth.
• In small, fast streams with inadequate draft
depth, a ladder and salvage cover can be
used to dam the stream and raise the water
level to permit drafting.
Pumping Apparatus
Driver/Operator
12–29
Silt and Debris
• May clog the strainer, resulting in reduced
water intake
• May cause seizing-up or damage to fire
pumps
• May clog fog stream nozzles
(Continued)
Pumping Apparatus
Driver/Operator
12–30
Silt and Debris
• All hard intake lines should have strainers
attached when drafting from a natural source.
• The intake hose should be located and
supported so that the strainer does not rest
on or near the bottom to avoid getting dirt and
debris into the strainer.
(Continued)
Pumping Apparatus
Driver/Operator
12–31
Silt and Debris
• Either a single ladder or a roof ladder can be
used to keep the strainer off the bottom.
(Continued)
Pumping Apparatus
Driver/Operator
12–32
Silt and Debris
• Can be avoided by the installation of a dry
hydrant
– Allows access to natural sources without
the set-up time required for a regular
drafting operation
– Avoids the wet ground approach problem
and can circumvent the problem of silt and
debris when installed properly
Pumping Apparatus
Driver/Operator
12–33
Aiding Access to
Frozen Ponds and Lakes
• Barrels filled with antifreeze solution are
floated on the water’s surface before the
water freezes. If the need to draft arises, the
top and the bottom of the barrel may be
knocked out to provide an access hole for the
intake hose and strainer.
(Continued)
Pumping Apparatus
Driver/Operator
12–34
Aiding Access to
Frozen Ponds and Lakes
• Wooden plugs or plastic garbage cans are
stabilized at a location so that they may be
driven through the ice if the need to draft
arises.
• It may be necessary to cut a hole through the
ice using an axe, chain saw, or power auger.
(Continued)
Pumping Apparatus
Driver/Operator
12–35
Aiding Access to
Frozen Ponds and Lakes
CAUTION! Extreme caution should be taken
when operating on the ice. Provisions for
making an ice rescue should be on scene
before firefighters begin working on the ice.
All firefighters working in close proximity to
bodies of water must wear personal flotation
devices (PFDs).
Pumping Apparatus
Driver/Operator
12–36
Swift Water
• The current may make it difficult to keep the
strainer submerged below the surface of the
water.
• All firefighters working near the water’s edge
must wear a PFD.
Pumping Apparatus
Driver/Operator
12–37
Man-Made Water Supply Sources
• Cisterns
• Private water storage tanks
• Ground reservoirs
• Swimming pools
• Agricultural irrigation systems
Pumping Apparatus
Driver/Operator
12–38
Cisterns
• Underground water
storage receptacles
found in areas not
serviced by a
hydrant system
• Receive water from
wells or rainwater
runoff
(Continued)
Pumping Apparatus
Driver/Operator
12–39
Cisterns
• Are usually for domestic or agricultural use
• Some are placed for fire department use as a
backup if the water supply system fails
• Sizes from 10,000 to 100,000 gallons (40 000
L to 400 000 L) are common
(Continued)
Pumping Apparatus
Driver/Operator
12–40
Cisterns
• May be accessed by:
– A manhole-type cover that is removed to
provide access for intake hose and strainer
– Attached dry hydrant arrangement that
allows for quick connection by a fire
department pumper
• May be susceptible to freezing if not below
the frost line
Pumping Apparatus
Driver/Operator
12–41
Private Water Storage Tanks
• Are commonly found on large residential,
industrial, and agricultural properties
• Range in size from several hundred to many
thousands of gallons (liters)
• May be at ground level or elevated
(Continued)
Pumping Apparatus
Driver/Operator
12–42
Private Water Storage Tanks
• May not be reliable,
depending on:
– Size,
– Amount of water inside
at time of fire, and
– Appropriate
connections for fire
apparatus
Pumping Apparatus
Driver/Operator
12–43
Ground Reservoirs
• Man-made
impoundments that have
same characteristics as
a pond or small lake
• Are commonly found on
commercial or industrial
properties and at
municipal water
treatment facilities
Pumping Apparatus
Driver/Operator
12–44
(Continued)
Ground Reservoirs
• Typically contain many millions of gallons
(liters) of water
• Are typically more accessible than regular
ponds or lakes
• May include dry hydrants to speed their use
Pumping Apparatus
Driver/Operator
12–45
Swimming Pools
• May be difficult to access due to security
measures (fences)
• The pump should be flushed with clear water
after drafting from a swimming pool to
remove any access chlorine from the pump
and piping.
Pumping Apparatus
Driver/Operator
12–46
Calculating Swimming Pool
Capacities (Square/Rectangular)
• Customary
Capacity in gallons = L x W x D x 7.5
L = Length in feet
W = Width in feet
D = Average depth in feet
7.5 = Number of gallons per cubic foot
(Continued)
Pumping Apparatus
Driver/Operator
12–47
Calculating Swimming Pool
Capacities (Square/Rectangular)
• Metric
Capacity in liters = L x W x D x 1 000
L = Length in meters
W = Width in meters
D = Average depth in meters
1 000 = Number of liters per cubic meter
Pumping Apparatus
Driver/Operator
12–48
Calculating Swimming
Pool Capacities (Round)
• Customary
Capacity in gallons =  x r2 x D x 7.5
 (Pi) = 3.14
r = Radius or ½ the diameter in feet
D = Average depth in feet
7.5 = Number of gallons per cubic foot
(Continued)
Pumping Apparatus
Driver/Operator
12–49
Calculating Swimming
Pool Capacities (Round)
• Metric
Capacity in liters =  x r2 x D x 1 000
 (Pi) = 3.14
r = Radius or ½ the diameter in meters
D = Average depth in meters
7.5 = Number of liters per cubic meter
Pumping Apparatus
Driver/Operator
12–50
Agricultural Irrigation Systems
• May flow in excess of 1,000 gpm (4 000
L/min)
• Usually transport water one of two ways:
– Open canals
– Portable pipes
Pumping Apparatus
Driver/Operator
12–51
Summary
• Although many cities and towns have
pressurized water systems that supply fire
hydrants throughout the jurisdiction, other
entities do not have these vital fire fighting
facilities. In these cases, fire departments
must rely on water tenders or static water
sources in fixed locations.
(Continued)
Pumping Apparatus
Driver/Operator
12–52
Summary
• Regardless of what static sources may be
available, departments who depend on these
sources for fire fighting water must know
where the sources are located, the
approximate capacity of these sources, and
what impediments may exist that could
prevent the department from using the water
contained in them.
Pumping Apparatus
Driver/Operator
12–53
Discussion Questions
1. What is the equation for determining
maximum lift?
2. What is the equation for determining
pressure correction?
3. What is the equation for determining net
pump discharge pressure?
4. Name types of natural static water supply
sources.
(Continued)
Pumping Apparatus
Driver/Operator
12–54
Discussion Questions
5. What is the equation for determining the
adequacy of a natural stream?
6. Name some common types of man-made
static water supply sources.
7. What is the equation for determining the
capacity of a square/rectangular swimming
pool?
8. What is the equation for determining the
capacity of a round swimming pool?
Pumping Apparatus
Driver/Operator
12–55