Pumping Apparatus Driver Operator (1st Edition)
Chapter 14 - Water Shuttle Operations
"By the Numbers"
NOTICE: Equations and examples from this chapter are not covered on this study page.
- Water shuttles require at least 2 pumpers to be successful.
- Fill site pumpers should have a minimum pump capacity of 1,000 gpm.
- NFPA 1901 requires that tenders be filled at a rate of 1,000 gpm.
- Tenders that use MDH supply lines for filling their tank must have at least 2 external fill connections piped directly into the tank.
- Fill site pumpers in jurisdictions that frequently use water shuttles may have capacities up to 1,600 gpm at a maximum of 80 psi with irrigation or trash pumps that discharge through LDH.
- Per NFPA 1901, tenders are apparatus that carry at least 1,000 gallons of water.
- The majority of water tenders in use today carry from 1,500 to 3,000 gallons of water.
- Vehicle weight restrictions generally limit single, rear axle trucks to a maximum tank capacity of 1,500 gallons.
- When tanks of over 1,500 gallons are used, trucks must have tandem rear axles, tri-axles, or semi-trailer construction.
- Tenders with water tanks less than 2,500 gallons and with quick unloading times are the most efficient tenders for water shuttles.
- Tenders that have water tanks in excess of 2,500 gallons are best suited for stationary water supply operations.
- Pumps on tenders range from small PTO-driven pumps capable of flowing only 250 gpm up to standard midship transfer-driven pumps that can flow 2,000 gpm.
- Tenders with 750 gpm or larger pumps are generally called pumper-tenders or pumper-tankers.
- Tenders equipped with a fire pump must have a tank-to-pump line (at least 2" in diameter) capable of supplying the pump with 500 gpm until at least 80% of the water in the tank is emptied.
- Tenders must be equipped with at least 1 external fill connection, consisting of a valve, strainer, and 30 degree elbow, that allows the tank to be filled at a minimum rate of 1,000 gpm.
- Valves on external fill connections that are larger than 3" must be of the slow-closing type.
- Tenders must have a least 1 large tank discharge ("dump line") capable of discharging 90% of the tank volume at an average rate of 1,000 gpm, however, at least 3 discharges are recommended.
- Because most tender water tanks are less than 6 feet tall, the backpressure created by a nearly full tank on a bottom fill inlet is less than 3 psi.
- Front dump valves are difficult to design into most tenders because of the 1,000 gpm flow requirement.
- Gravity dumps usually consist of 8" or larger round or square piping with a valve that extends to the exterior of the apparatus.
- Fill sites selected should be able to supply at least 1,000 gpm.
- With particularly strong hydrants, MDH lines can be connected between the 2 1/2" hydrant outlets and the auxiliary intakes in addition to the LDH connection.
- When using MDH to fill a tender, use 3" line if available to provide quicker fill times.
- If a fill site pumper cannot access the source of water, 2 or more high-volume portable pumps may be used to relay water to the fill site pumper if it is less than 100 feet away from the portable pumps.
- If a large in-line LDH gate valve is not available when LDH is used as fill lines for water shuttle operations, an LDH manifold may be placed between the last 2 sections of hose to act as a gate valve.
- In-line jets should be pumped at 150 psi, which allows them to provide 700 to 800 gpm through 4" pipe.
- A single portable tank works on fires that require flow rates less than 300 gpm.
- Portable water tanks should have a capacity of at least 500 gallons larger than the capacity of the water tank on the apparatus carrying it.
- Low-level strainers allow drafting down to about 2 inches.
- When multiple portable tanks are used at a dump site, the number of tanks is usually 2 to 5.
- If only 2 or 3 portable tanks are used and portable tanks are filled using a jet-siphon, the dump site pumper can usually supply the jet-siphon.
- Incidents that require flow rates of more than 300 gpm are best served by a multiple portable tank dump site operation.
- Jet siphons have inlet connections for 1 1/2" or larger hose.
- Average speed between fill and dump site is assumed to be 35 mph.