BY PAUL SHAPIRO

Part 1 (May 2018) discussed how options exist for fire departments to get big flows with existing pumpers in their fleets—specifically out of pumpers with 1,250- or 1,500-gallon-per-minute (gpm) pumps.

It also described quick-attack units with large-flow monitors. Part 2 describes the steps involved with supplying the large flows to a super pumper or quick-attack unit.

SETTING UP THE PUMPER

I believe there is a place for this type of unit for a city department with some modifications in the unit itself as well as the water delivery operations required to support it. Let’s take a look at how this can be done.

I would make this unit capable of running as a regular engine company assigned to its own station and district with the few modifications previously mentioned to make it a high-flow pumper. The super pumper should have at least a 1,250- to 1,500-gpm pump.

Both sizes of hose will work in a 3,000-gpm evolution; however, with four-inch hose, you basically have to work twice as hard. Two four-inch lines equal approximately one five-inch line hydraulically. Other than that, the unit can be designed and equipped as a standard engine company to run the standard calls.

If there is a big fire that requires this unit to go into the high-volume mode, it can be special called for the incident if not already assigned. As mentioned above, the unit would need multiple supply lines to develop a 3,000-gpm stream. If five-inch hose is used, I recommend a minimum of three supply line evolutions from three separate hydrants set up in a relay pump operation no matter how close or far away the hydrant may be from the super pumper. We attempted four flow tests using two hydrants, five-inch hose, and two pumpers. Basically, we could not get enough water from the hydrants and we ran out of throttle. The third pumper with a third hydrant made a difference. The extra pump reduced the overall revolutions per minute (rpm) for the other two engines, making the operation more efficient and doable.

If the hose being used is five-inch, most likely three hydrants would also be needed, with two of them set up in a dual four-inch relay line and one in a single relay operation. If single supply lines are used instead of duals, plan on using up to five hydrants because of the extra friction loss in the supply hose. The super pumper operation itself would probably qualify for an extra alarm just to set it up, so it may need to be put in as a special callout procedure if the super pumper is needed. The pumpers hooking up to the hydrants for the relay operation should hook up a minimum of two soft suctions to get maximum flow from the hydrant, and both of them should be large-diameter hose (LDH). The 2½-inch port on the hydrant can be adapted to LDH to connect to the intake of the engine. In fact, if you think the hydrant is strong enough, I would go ahead and make a three-line hookup to the hydrant for maximum flow if the unit is equipped for three lines.

It’s very important to know your hydrant systems and what they are capable of. This should include the grid system and the size of the mains for the hydrant you might choose. A water main map is a must for this type of operation.

Finally, when using a master stream, the stream itself needs to be moving to cover the entire fire area it is responsible for. Just setting up a master stream and leaving it in one position does nothing m