Fighting Fire With Chemicals
In the mid 1870’s, fighting major fires with the use of chemicals began to be popular. It is said that once established in the USA alone, over 80 percent of all fires were put out using chemicals and their specialized equipment.
The primary use of chemicals lasted for about 50 years — well into the 20th century — even though they were eventually found to be not as effective as they were originally claimed to be!
Sulphuric acid, when combined with bicarbonate of soda forms a chemical reaction which produces carbon dioxide. When mixed, the pressure created forces the mixture out of the chemical tank and propels it onto the fire. This is the basic function of most hand-held fire extinguishers. However, fighting a major fire required much larger, specialized apparatus like the “chemical engines” that came into use.
Though widely touted as being a more effective way to put out a fire — up to 40 times more efficient — the fact is they were found to be no more effective than using plain water. Their advantage was, that being self contained, requiring no hookup to a water source, they were ready to go at a fire scene allowing firefighters to get extinguishing chemicals on a fire faster than ever before.
Chemical equipped fire engines, first steam-powered, later gasoline powered, quickly became the equipment of choice with fire companies in cities and towns of all sizes — in some places they were used right into the 1930’s. Even after motorization, chemical tanks were still a common accessory on fire trucks. Chemical tanks were gradually replaced with “booster” tanks which were found to be easier and less expensive to use. These used a booster pump to propel water from a tank onto the flames and variations of this are used to present day. The last chemical engine was produced in 1934.
Many large houses and estates included brightly painted “chemical carts” as fire protection.
Portable chemical fire extinguishers were produced in many types and styles. More information on these can be found here.
The Museum has many examples of hand-drawn and motorized vehicles utilizing chemical tanks.
An early Babcock Chemical Engine, circa 1872, proudly presented by a fire crew.
On to the next gallery (Canadian Firefighters overseas WWII)