Fire safety is a broad topic that encompasses everything from correct welding procedures to verifying the correct function of installed and portable firefighting systems and extinguishers. During my time in the military I served as a Fire Marshal of multiple ships and held the highest firefighting certifications the Navy offers. What I learned from this is being prepared for fires and complying with OSHA regulations minimizes damage and prevents unnecessary injuries and deaths.
Fires can be broken down into four categories each requiring their own individual precautions, plans, and reactions.
Class A- Burning solid material that leaves ash examples include burning wood, paper, or cloth. Prevention is most commonly accomplished through good housekeeping procedures. These include storing materials away from heat sources, disposing of scrap correctly, and maintaining cleanliness. Believe it or not dust and particulates such as saw dust or grain chaff are incredibly flammable. Planning for these fires involves having the correct fire extinguishers located at the correct intervals. Smaller fires can be extinguished with water or a portable extinguisher but plans should also provide for adequate escape routes and an evacuation plan.
USS Bonhomme-Richard LHD 6 underway returning to San Diego from Sasebo Japan to undergo overhaul availability.
USS Bonhomme-Richard LHD 6 fully engulfed after crew incorrectly stowed cardboard and other flammable materials near heat source
The USS Bonhomme-Richard is a prime example of not only a Class A fire but what the result of poor planning, complacency, and OSHA violations result in. As a crewmember stationed aboard USS Bonhomme-Richard from 2002-2005 I was horrified to watch as an out of control Class A fire burned for 4 days in 2020. The lack of planning executed by leadership and flagrant OSHA violations resulted in a total loss of the ship costing $3.2 billion.
Aerial photo of USS Bonhomme-Richard after structural failure from melting steel.
Class B- Burning liquids such as gasoline or cooking oil. Prevention is ensuring flammable liquids are stored and used correctly. Planning for these fires involves having the correct fire extinguishers located in areas where flammable liquids are used. Ideally these areas would contain an installed firefighting system as well. Correct extinguishers utilize CO2, powdered agent, or Aqueous Film Forming Foam (AFFF). Never use water to extinguish a Class B fire as the flammable liquid will be redistributed, and the fire will spread. Plans most commonly involve evacuation as the source of flammable liquids can explode. The link below shows videos of cooking oil being displaced on to flames and the result.
Class C- Electrical fires such as circuit breaker fires, wiring shorts, and incorrectly used electrical plugs. Planning for these fires is crucial since the most effective extinguisher is shutting off the power. Never use water to extinguish a Class C fire due to the risk of electrical shock.
Scorched life ring caused by an electrical short in an unattended welding cable on board USS Fort Worth LCS 3. Crewmember seriously injured by UV light from arc flash.
Class D- most often caused by magnesium shavings or pyrotechnic phosphorus. These fires burn so hot that if introduced to water it will break the molecular bond of H2O into hydrogen and oxygen. Minimal storage amounts and good housekeeping are the best prevention methods. Planning for evacuation and OSHA compliance are crucial. I have fought one of these fires on overheating magnesium jet brakes. Our final solution was to push the entire jet off the ship into the ocean. The link below shows the effects of water on a Class D fire
