The rural water supply challenge
Countless rural communities around the globe face an endemic problem, a lack of a pressurized hydrant water infrastructure. Lacking this critical component in emergency response forces these communities to rely on alternative water supplies, including dry hydrants and accessible open water suction points and hauled water tanker shuttles. Even hydrant equipped communities, poor water supply volume or hydrant coverage can wreak havoc on unsuspecting fire departments and communities.
Water Shuttle Operations 101
When does a fire department need to establish a water shuttle operation?
- The Needed Fire Flow (NFF) for a structure cannot be met by water carried on the first due apparatus (engines and water tankers)
- The fire incident is outside the hydrant equipped area or there is a need to supplement a weak or unstable hydrant system
- Fire pumper apparatus relay operation would not be feasible due to distance, time or resource limitations
The equipment needed to facilitate shuttle operations is also of major consideration:
- Fireground: Attack engine(s) fighting structure fire
- Dump Site: Remotely located to fireground to prevent logistic congestion during operations.:
- Usually contains one primary supply engine for relay to fireground (minimum 1500 GPM) drafting from main portable fire tank
- Second transfer engine taking draft from main portable fire tank to supply jet-siphons feeding hard suction hoses to circulate water between supporting adjacent portable tanks to the main portable tank
- Tankers dumping their water into the supporting tanks to keep the operation fully flooded
- Fill Site: Engine operating at draft rated at least 1250 GPM typically outfitted with either 2-½”, 3” or 4” discharge lines with associated field appliances, such as a gated wye with associated tanker drain line valve set up for filling two tankers or other needed manifold appliances.
The water shuttle operation has at least six apparatus (four engines and two tankers) to support the operation, but it is likely more tankers may be needed depending on their assigned filling location, travel time and fireground demand requirements. Gravity tankers may also be supplemented by vacuum tankers, designed specifically for difficult fill sites or to enhance a direct fill tanker operation.
Time and manpower are always major concerns during operation. Portable tank setup is roughly five to seven minutes. Simultaneously, the driver/operator of the drafting engine will deploy suction lines. Complex systems with multiple adjacent tanks, hard suction lines and jet siphons will take roughly 20-30 minutes for appropriate setup. Manpower requirements vary by jurisdiction; however, usually three to four firefighters are running a primary response engine while two are operating a tanker unit or dedicated drafting unit. For the extended water shuttle operation example cited using six apparatus, for every hour of system operation, 16 man-hours are required to operate using four engines (3 firefighters each) and two tankers ( 2 firefighters each). This manpower allocation will likely be difficult to address in all-volunteer fire departments without mutual-aid community-to-community assistance.
Remote Water Alternative
The prototypical water shuttle operation is a necessary tactical response to firefighting in remote properties where no hydrant system exists. Training for such operations may be mixed depending on human resource availability and applied risk assessment methodology. To reduce the manpower and apparatus requirements, floating source pumps (FSP) can fill the need. Hydraulic powered remote floating source pumps are capable of providing full engine flowrates and allow use of difficult access water sources such as rivers, lower elevation ponds, soft-soil approach water sources (the kind that swallows a firetruck) and high obstruction areas with long lay requirements.
Floating source pumps have been available for many decades, such as those products used in mine dewatering. Originally designed to process sludge and solid particulates, these pumps are extremely robust (read: very heavy) that keep deep mines and quarries from flooding. Being in-place for much of the mine’s operation, units are lowered with a crane or other heavy equipment and remain operational for extended periods of time and long duty cycles. The technology has only slowly progressed from this original use, as it is has been difficult to visualize adapting a cumbersome product into rapid response fire fighting needs.
Early 2000’s technology reduced the size of FSPs to rolling cages, manageable with heavy equipment (such as jib cranes and winches). Personal watercraft trailer ramps provide an easier push deployment for these larger FSP units. Typical deployment time for these systems is still in the 20-30 minute range and specifically designed for long duration industrial fire fighting scenarios. However, recent technology improvements in advanced material pump design and controlled power system integration has reduced the size of high-flow units to unprecedented levels. New composite pump casing and impeller materials has reduced the weight of certain FSP designs to sub 75 lbs (34 kg), while still providing flows in excess of 2000 GPM (7500 LPM), essentially making them a “floating hydrant”. These new designs can be carried by firefighters and tossed into the water source, a significant deployment advantage. The entire diesel power system (including the floating source pump) can fit inside a single enclosed skid within the bed of a standard pickup truck.
Deployment time has also significantly improved. Modern FSP designs should be deployable in less than 5 minutes when on-site, preferably less than 3 minutes if large diameter layflat hose can be managed correctly with appropriate connecting hardware, tools and training. Without the necessity of large lifting equipment or upgraded infrastructure access (i.e. ramps) to open water sources, modern FSP designs can be quickly carried to the water source, connected to its hydraulic power source using quick-connect equipped hydraulic lines and have its main Storz adapter connected to layflat hose. The pump can now be pushed, tossed or kicked into the water. A minimum water depth of only 20” (500 mm) is required to achieve buoyancy and maintain proper operation.
The primary benefit of FSPs is the true access to remote water. With draft pumpers rated to standard 10 foot (3 meter) suction heights and equipped with 20 foot (6 meter) suction lines, either a dry-hydrant system or near direct access to the water is required; otherwise the fire departments must accept large flow de-rates on their pumps. The FSPs are frequently equipped with 75 or more feet (23 m) of hydraulic hose bundle, allowing the power unit to remain on stable ground and remote from the water source. This flexibility allows emergency crews to circumvent restricted access areas, such as flooded subways, providing an additional water transfer benefit to the system. Moreover, FSP systems can be used in conjunction with primary response fire pumper apparatus and even tanker shuttle operations. With a sustainable floating pumping system in the water source, FSPs can provide continuous filling operations to tankers (at a very fast fill rate) and portable tanks alike, while, if located within close proximity of the fireground, provide high-volume water directly to boost engines involved in the firefight.
Manpower allocation is paramount to a successful firefighting operation. In the previous water shuttle operation example, a minimum of 16 man-hours for every hour of operation using four engines and two tankers was required. An FSP needs only a single firefighter for operation. Replacing certain engines with FSP systems shows a tremendous human resource benefit.
- Fireground: Attack engine(s) fighting structure fire
- Dump Site:
- Primary and secondary engine replaced with single FSP for transfer to fireground attack engine(s)
- Tankers dumping their water into the supporting tanks to keep the operation fully flooded.
- Fill Site: Draft engine replaced with FSP filling portable tank and tankers directly. Two tankers still in rotation due to road navigation with hose.
We have reduced our engine load from four units to one and added two FSP systems. At a minimum the operation now needs 9 firefighters. Three firefighters are dedicated to the attacking engine, four to the two tankers and two to the FSP units. This is a reduction from 16 man-hours per hour of operation to 9 man-hours per hour of operation, a 44% improvement. This significantly reduces immediate operational overhead requirements, especially for all-volunteer departments struggling to maintain volunteer hours. Doing more with less, the story of firefighters.
The Economic Impact
Pumpers and tankers have their rightful place in emergency operations. Pumpers, fill multiple roles in carrying equipment and personnel. However, these apparatus also carry a large capital overhead. A typical pumper (1500 GPM with 500 Gallon on-board tank) can average $450,000-550,000 USD, while various options, larger pumps and final destination can push this price much higher. Annual maintenance on a pumper may average $2000-3000 USD (although pricing varies widely), which excludes annual NFPA testing on the pump and hoses. A standard FSP system will average 60-80% less in upfront costs compared to standard pumpers and require only minor maintenance (oil and filters) on the power unit and hydraulic system. Operation is simple for most systems designed, using single button control of flow. Additionally, FSP units are designed for skid loading, trailer attachment and air-lift versions to facilitate rapid deployment in remote locations. For rural communities and underfunded cities alike, floating source pump systems provide a high performing remote water system that addresses water supply shortfalls while clearly demonstrating an economic advantage. Municipalities now have expanded reasonable options to continue performing and providing the community-at-large the emergency response and protection it has come to expect, where the much feared “do more with less” response from municipal officials now has a positive context.
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