Relay in the Urban Setting Making Water Supply Work for You!
Does the City of Henderson Have an Adequate Water Supply System to Fight Large, Defensive Fires? Parowan Fire Parowan Fire Crystal Creek Fire Crystal Creek Fire Pallet Yard Fire Pallet Yard Fire Quail Run Fire Quail Run Fire
Case Study : Quail Run Fire January 15, 2011 (approx. 10am) January 15, 2011 (approx. 10am) Large custom home in District 94 Large custom home in District 94 E94 hooks closest hydrant (100) for offensive attack, uses 2 1/2 valve w/3 line for additional supply E94 hooks closest hydrant (100) for offensive attack, uses 2 1/2 valve w/3 line for additional supply T82 sets up behind E94 for Roof Div. assignment T82 sets up behind E94 for Roof Div. assignment Fire transitions to defensive, truck uses aerial streams Fire transitions to defensive, truck uses aerial streams E98 who is staged at hydrant (500), forwards in and supplies truck E98 who is staged at hydrant (500), forwards in and supplies truck Aerial, A Div., B Div., and D Div. play musical master streams due to inadequate water supply Aerial, A Div., B Div., and D Div. play musical master streams due to inadequate water supply
E98 Supplies T82 on Quail Run Fire
E98 is Approx. 20 uphill from House with White Tile Roof
Hydrant is Located 500 away, 20 downhill
Water Supply Facts 100 of 5 hose = 5psi FL per 1000gpm flowing 100 of 5 hose = 5psi FL per 1000gpm flowing 20 of elevation gain = 10 psi FL 20 of elevation gain = 10 psi FL 2nd principle of fluid pressure states fluid at rest (static) is of the same intensity (pressure) in all directions 2nd principle of fluid pressure states fluid at rest (static) is of the same intensity (pressure) in all directions 6 th principle of fluid pressure states the pressure of a fluid on the bottom of a container is independent of the shape of the container 6 th principle of fluid pressure states the pressure of a fluid on the bottom of a container is independent of the shape of the container
Water Facts Cont… A 70-psi hydrant static pressure (SP) will read 70 psi no matter the length of 5 we attach, because we are simply changing the shape of the container A 70-psi hydrant static pressure (SP) will read 70 psi no matter the length of 5 we attach, because we are simply changing the shape of the container Once water is flowing FL occurs Once water is flowing FL occurs A 70-psi hydrant would lose 25 psi on the supply side once water is flowing by the time it reaches the pumpers inlet with 500 of 5 on the ground without factoring in any potential elevation gain A 70-psi hydrant would lose 25 psi on the supply side once water is flowing by the time it reaches the pumpers inlet with 500 of 5 on the ground without factoring in any potential elevation gain
Furthermore… 35 psi FL (500 of 5 & 20 elevation) is about a 50% drop on most hydrants 35 psi FL (500 of 5 & 20 elevation) is about a 50% drop on most hydrants 16-25% drop is the highest for flowing 1 like-line 16-25% drop is the highest for flowing 1 like-line If we have a 1500gpm hydrant how much less water we will be available after a percentage drop twice that? If we have a 1500gpm hydrant how much less water we will be available after a percentage drop twice that? Regardless of the flow available in any given hydrant, we are not using its full potential by forwarding large distances from a secondary hydrant on potential defensive fires! Regardless of the flow available in any given hydrant, we are not using its full potential by forwarding large distances from a secondary hydrant on potential defensive fires!
Water Supply Test on Station 82 Drill Grounds on 1/31/11 Lay 40 bypass to engine, record flow Lay 40 bypass to engine, record flow Lay 600 of 5 to engine, record flow Lay 600 of 5 to engine, record flow Place supply pumper at hydrant, lay 600 of 5 to attack pumper, record flow Place supply pumper at hydrant, lay 600 of 5 to attack pumper, record flow Results Results
5 Bypass to Attack Engine Static Pressure = 55 psi Static Pressure = 55 psi Volume of Flow = 1350 gpm Volume of Flow = 1350 gpm Residual Pressure = 20psi Residual Pressure = 20psi
5 & 3 Bypass to Attack Engine Static Pressure = 55 psi Static Pressure = 55 psi Volume of Flow = 1700 gpm Volume of Flow = 1700 gpm Residual Pressure = 20psi Residual Pressure = 20psi
600-Foot Forward to Attack Engine Static Pressure = 55 psi Static Pressure = 55 psi Volume of Flow = 750 gpm Volume of Flow = 750 gpm Residual Pressure = 20psi Residual Pressure = 20psi
600-Foot Relay to Attack Engine Static Pressure = 55 psi Static Pressure = 55 psi Volume of Flow = 1300 gpm w/ only 5 Volume of Flow = 1300 gpm w/ only 5 Residual Pressure = 20psi 20psi Residual Pressure = 20psi 20psi
600-Foot Relay to Attack Engine Static Pressure = 55 psi Static Pressure = 55 psi Volume of Flow = 1680 gpm w/ 3 added Volume of Flow = 1680 gpm w/ 3 added Residual Pressure = 20psi 20psi Residual Pressure = 20psi 20psi
Results Showed hydrant had at least 1700 gpm available with shortest lay possible Showed hydrant had at least 1700 gpm available with shortest lay possible Showed as we laid 600 away, on flat ground, we lost more than ½ of available water Showed as we laid 600 away, on flat ground, we lost more than ½ of available water Showed static pressure reading tricks us into believing we have same water regardless of 5 length Showed static pressure reading tricks us into believing we have same water regardless of 5 length Showed adding a source pumper enabled us to maximize hydrants available water Showed adding a source pumper enabled us to maximize hydrants available water Adding source pumper enables us to use additional 3 to our advantage Adding source pumper enables us to use additional 3 to our advantage