This is a short video that was done to give an idea as to what a wildland apparatus engineer should be able to do and be trained to do. We do not employ the level of Engineer that is so desperately needed in our environment. In this video I place an emphasis on the aspect of multiple helicopters. I would rather deal with 15 engines than 3 helicopters because helicopters have a very HIGH flow demand in their Equivalent Gallon Per Minute ratings.

As an example, the simple thing we often use to determine what our Head pressure is going to be and what is taught in the Engine Academies is to take the elevation gain and divide by 2. But why?

Because 1 cubic foot of water will produce on a gauge (if it were sensitive enough and scaled small enough) a pressure of .434 pounds. But how do we know this to be fact?

A engineer would be able to explain it to you so that it made sense. And that explanation might be something like this.

Water weighs in at 62.4 pounds per cubic foot. There are 1,728 cubic inches to the cubic foot. 62.4lbs / 1,728in^3 = .036 psi per cubic inch. If you multiply the .036 times 12 inches of height you get .036 x 12 = .433 psi. Then we say round this .434 to .5 to = 1 foot.

The sharp tack in the room might say, wait a minute, how do we get square inches from cubic inches? Good question. If you had this 12 inches of vertical column and laid this column over on its side, it would only be 1 inch in height now. At this point You’d only have .036 pounds of pressure in a “Vertical” weight component regardless if the entirety of the 12 inch column was full of water or just the 1 inch, it is still only 1 inch in height! Thus the horizontal is not counted. Only the vertical component is and thus this becomes the square component rather than the cubic.

This is why we say (in the academy) it is irrelevant of the size and shape of the column of water. This is also why a 1.5” hose and a 6” hose of equal length and equal vertical elevation will produce the same pressure on a gauge.

The NON engineer will not be able to explain this.

How much excellence do you wish to achieve? Demand better training.

Engineers Make it Happen!