The US Navy has been using seawater to extinguish fires for over 200 years. There are many classes of fire. Class C fire is an electrical fire, but it will no longer be a class C fire once you turn off the space’s electricity. It will be a class A fire which is insulation. Using high-pressure fog, instead of a solid stream, we can move the oil in a safe direction and cool it enough to stop the class B fire (flammable). Foam is better, but water is better than nothing.
For class A fires, a solid stream is good for breaking-up the fuel into smaller pieces once the fire is out. Those things are dredged out of my ancient memory, and things may have changed over the last 50 years. We use modern technology to extinguish fire rapidly. But what if we use seawater or saltwater to put out massive fires? Let’s see!
Why can’t we use ocean water to put out fires?
Seawater can be used to extinguish the fire, but it’s best to know the fuel is involved. There are a few difficulties with saltwater because it has some critical characteristics and external elements.
Corrosiveness: Seawater has salt and ions like chloride ion (Cl−), sodium ion (Na+), sulfate (SO24−), magnesium (Mg2+), calcium (Ca2+), and potassium (K+). After flushing the burning equipment with saltwater, it affects the equipment quality. It is because the ions and metal of the water will damage the equipment by rust and corroding. So, seawater is corrosive and prolonged, damaging the pump’s internal parts.
Water pumping: Sea has some of the highest tides in the world. That can be as much as a 20-25 foot difference between high and low tide. So we can’t pump ocean water into the water mains. We are also limited by the amount of large diameter supply lines.
We can move seawater almost 950 meters using modern technology, but that ties up all the hoses and pumpers of three fire departments. We need continuous water flow to extinguish the fire, but we can not do it frequently.
Soil quality: A large amount of ocean water on small areas as dropping from an aircraft will leave salt in the soil. It will damage the soil quality, and many native species may die. Also, it will cause barren areas where the watershed is lost, and erosion will destroy the topsoil. Spreading the salt downhill causes more damage.
Expense: The logistics of moving much water more than a very short distance inland would severely complicate operations and be expensive. Also, it consumes more time, and the process will be very long. But we need emergency water to put off the fire immediately. So it is one of the significant problems of carrying seawater from one place to another. But we can manage it for the ship as the primary firefighting medium.
So there are many limitations to using ocean water to put off the fire. Our high technology or AI will reduce this limitation in the future, and we can use this method easily. Let’s wait and see!
Read more similar topics:
“Sodium Chloride MSDS.” Sigma Aldrich.
Lide, D. R.. CRC Handbook of Chemistry and Physics (86th ed.).
“Solubility.” University of Wisconsin Fundamentals of Chemistry.
Thermophysical properties of seawater: a review of existing correlations.