Portable Fire Extinguishers: Learn what types of portable extinguishers are used on board ships


For any type of fire on ship, the first line of action that is always undertaken is the usage of portable fire extinguishers. According to SOLAS regulations, all areas of ship should have sufficient number of fire extinguishers, irrespective of the probability of fire occurrence. Every type of fire has its own specific type of fire extinguisher which produces the best results in the fire extinguishing process. For understanding the types of fire extinguishers dedicated to their specific fire type, a general idea of the different types of fire is imperative. Lack of knowledge regarding the types of fires might lead to reverse effect, increasing the intensity of the fire.

In order to avoid any mishaps due to deficit of knowledge, the article will first describe the type of fire and its causes.

Types Of Fires

Type 1 – This type of fire occurs in solid materials such as wood and soft furniture. Fires of this type may be extinguished by quenching or cold water.

Type 2 – Cause of this type of fire are fluid sources such as gasoline, lubricating oil and other dangerous inflammable fluids. An attempt to extinguish this type of fire with water lead to devastating results , increasing the intensity of fire. Oil with lesser density will stay on top,erupting into steam so rapidly that it will be thrown in all directions. The only way of extinguishing these fires is by smothering.

Type 3 -This type of fire is caused due to fires in electrical equipments. Fire extinguishers for this type of fire must be non-conductive.

Types of Fire Extinguishers

According to types of fires, different types of fire extinguishers are made. The most commonly used types of fires are :

  • Soda Acid Extinguisher
  • Foam Extinguisher
  • Dry-powder type
  • Carbon dioxide Extinguisher
  • Halon type

Soda Acid Extinguisher

This is a typical type-A fire extinguisher. A 9 liter cylindrical shaped Soda extinguisher is shown in the figure.The outer shell of the cylindrical shape body is made of steel. The end of the shells are flattened, dished and then welded or riveted to a wrapper plate.

The shell of these type of extinguishers are capable of withstanding pressures upto14 bars even if there is a resistance in the discharge nozzle.


Near the neck of the extinguisher is a small glass phial which contains sulphuric acid. The outer container contains alkaline sodium bicarbonate solution. The rest of the body is filled with water. The shell and the casings are hydraulically tested before the installation. It is to be noted that the extinguished is to be operated only in the upright position.


In order to operate the extinguisher, the pin at the top of the extinguisher which is attached to the sulphuric acid glass phial inside the extinguisher, is pushed. This breaks the glass phial, which results in the mixture of sulphuric acid and sodium bicarbonate. The chemical reaction between the acid and the alkali, leads to the formation of the carbon dioxide. This highly pressurized carbon dioxide pushes the water out of the discharge. The discharged water contains residue of chemical reaction.


Refilling of extinguisher is done once in an year, if it is not used. Chemicals (or chemical kits) are available in sealed bottles for recharging. A small screwed brass cap is examined in order to check the cap seal and the small holes in the sides. The holes are used to release any internal pressure before the cap is removed. The ball valve fitted below the plunger is checked in order to prevent the liquid rising into the internal pipe.

soda acid extinguisher


Marine Auxiliary Machinery, 7th Edition, 1995 by McGeorge

Image Credits

Marine Auxiliary Machinery, 7th Edition, 1995 by McGeorge

This post is part of the series: Portable Fire Extinguishers

This series deals with the different types of portable fire extinguishers used on ships. It also contains their construction and working, including the reason why a particular type of extinguisher should be used for a specific type of fire.
  1. Portable Fire Fighting Equipments
  2. Portable Fire Extinguishers Types
  3. DP, Halon, Co2 & Mechanical Fire Extinguishers