Why Does It Always Have to be Done That Way?
Myth 2: Laying a large diameter hose supply line is like taking the hydrant to the fire or like laying an above the ground water main.
Reality: It is this type of thinking that has gotten LDH users in trouble many times at large flow operations. Think about what that statement is saying. Basically it tells you that there is nothing that needs to be done in conjunction with the hose evolution, just lay it and it will deliver all the water that is available. This could not be further from the truth. As good as LDH is, it still needs to be used in conjunction with fire pumping apparatus, water systems and various hose evolutions.
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Example, a flow test was done using 500 feet of 5” hose supplied directly from the hydrant and its system pressure. A flow of 1150 GPM was obtained. We next put a pump at the hydrant to pump the water in a relay pump operation to the receiving pumper and were able to almost double the flow. We were able to produce 2100 GPM. Most departments, especially the ones using 5”, would not consider setting up a relay at just 500 feet away. They would instead just settle for what they got from the hydrant.
A simple LDH supply line evolution flow can be doubled with the use of various pump operations