“Hydraulics” is the science and engineering that deals with fluids at rest and in motion in the modern world.  The word “hydraulics” originates from the Greek word ὑδραυλικός (hydraulikos) which in turn originates from ὕδωρ (hydor, Greek for water) and αὐλός (aulos, meaning pipe).

The Most effective and practical method to extinguish a fire is to cool it below its ignition temperature so that combustion will cease. How much water is required is something that a good “Engineer” will have an idea of because of his ability know how much heat water can absorb based upon the temperature of the water in his tank and most importantly, he will know how to calculate it. There are other methods for extinguishing a fire, however, It is requested of the student to force himself to think ONLY in terms of water and hydraulics as this is the topic of this unit. One should therefor always play a mental game with him or herself to constantly challenge their own wit as to how to move water over vast distances and be effective and efficient. The more important he takes his craft, the more important he becomes over all other figures on the fire apparatus.  

Hydraulics knowledge also means that one should be familiar with the properties of water and principles of Friction loss and pump impellers in order to take full advantage of all of these elements when the need arises.  It also means that he will have an ability rapidly estimate the needed fire flows and number of Rapid Deployment Tanks (RDT’s) necessary in order to provide the proper infrastructure required to efficiently handle all operations water!

In the wildland fire service, this means flowing the right amount of water in the right form through the right size “pipe” or hose. It DOES NOT MEAN we say to ourselves, “this is wildland and we don’t flow big water”! Such is a myth and simply NOT TRUE.  This statement should be equated as saying, less water bigger fire.  The Erickson Air Crane houses a 2650 gallon pod. If it makes 8 trips an hour it just hauled 21,200 gallons. If a type 1 airship works a typical 8 hour shift. It will have flown 169,600.00 gallons of water. This equates to an effective flow of 353.33 Gallons per minute.  There are times when 2 and 3 type 1 ships have been on fires. If they all worked the same number of trips and hours. They would have moved  508,800 gallons of water. This not counting type 2 and 3 ships.  That is an adjusted Effective Fire Flow of over 1000GPM.  Putting this into perspective, a rural towns typical water supply tank is approximately 25 Feet in radius. And 15 feet high. This tank would hold 220,304.18 Gallons of water. So essentially 3 Type 1 SkyCranes have the ability to move enough water to fill a rural towns water storage tank in about 2.3hrs! Yes we do move big water and this should tell you why we spend so much time relying on Helicopters. The engines we have are ineffective at producing the needed fire flows for the heat being generated, but, we can still use them effectively in other ways if we know how!   

As an Engine Operator (ENOP), you will have the title of ENGINEER. Let us first define what an engineer is. An Engineer is a practitioner of engineering, concerned with applying scientific knowledge, mathematics, and ingenuity to develop solutions for technical, societal and commercial problems. Engineers design materials, structures, and “systems” while considering the limitations imposed by practicality, regulation, safety, and cost. The word engineer is derived from the Latin words ingeniare (“to contrive, devise”) and ingenium (“cleverness”).